Helen Hayes Hospital

The Clinician's Guide to Prevention and Treatment of Osteoporosis was developed by an expert committee of the National Osteoporosis Foundation (NOF) in collaboration with a multispecialty council of medical experts in the field of bone health convened by NOF. Readers are urged to consult current prescribing information on any drug, device, or procedure discussed in this publication.

A simple external marker system and algorithms for computing lower extremity joint angle motion during level walking were developed and implemented on a computer-aided video motion analysis system (VICON). The concept of embedded axes and Euler rotation angles was used to define the three-dimensional joint angle motion based on a set of body surface markers. Gait analysis was performed on 40 normal young adults three times on three different test days at least 1 week apart using the marker system. Angular motion of the hip, knee, and ankle joints and of the pelvis were obtained throughout a gait cycle utilizing the three-dimensional trajectories of markers. The effect of uncertainties in defining the embedded axis on joint angles was demonstrated using sensitivity analysis. The errors in the estimation of joint angle motion were quantified with respect to the degree of error in the construction of embedded axes. The limitations of the model and the marker system in evaluating pathologic gait are discussed. The relatively small number of body surface markers used in the system render it easy to implement for use in routine clinical gait evaluations. Additionally, data presented in this paper should be a useful reference for describing and comparing pathologic gait patterns.

BACKGROUND: A single infusion of intravenous zoledronic acid decreases bone turnover and improves bone density at 12 months in postmenopausal women with osteoporosis. We assessed the effects of annual infusions of zoledronic acid on fracture risk during a 3-year period. METHODS: In this double-blind, placebo-controlled trial, 3889 patients (mean age, 73 years) were randomly assigned to receive a single 15-minute infusion of zoledronic acid (5 mg) and 3876 were assigned to receive placebo at baseline, at 12 months, and at 24 months; the patients were followed until 36 months. Primary end points were new vertebral fracture (in patients not taking concomitant osteoporosis medications) and hip fracture (in all patients). Secondary end points included bone mineral density, bone turnover markers, and safety outcomes. RESULTS: Treatment with zoledronic acid reduced the risk of morphometric vertebral fracture by 70% during a 3-year period, as compared with placebo (3.3% in the zoledronic-acid group vs. 10.9% in the placebo group; relative risk, 0.30; 95% confidence interval [CI], 0.24 to 0.38) and reduced the risk of hip fracture by 41% (1.4% in the zoledronic-acid group vs. 2.5% in the placebo group; hazard ratio, 0.59; 95% CI, 0.42 to 0.83). Nonvertebral fractures, clinical fractures, and clinical vertebral fractures were reduced by 25%, 33%, and 77%, respectively (P<0.001 for all comparisons). Zoledronic acid was also associated with a significant improvement in bone mineral density and bone metabolism markers. Adverse events, including change in renal function, were similar in the two study groups. However, serious atrial fibrillation occurred more frequently in the zoledronic acid group (in 50 vs. 20 patients, P<0.001). CONCLUSIONS: A once-yearly infusion of zoledronic acid during a 3-year period significantly reduced the risk of vertebral, hip, and other fractures. (ClinicalTrials.gov number, NCT00049829.)

Before publication of the original version of this report in 1987, practitioners of bone histomorphometry communicated with each other in a variety of arcane languages, which in general were unintelligible to those outside the field. The need for standardization of nomenclature had been recognized for many years,1 during which there had been much talk but no action. To satisfy this need, B Lawrence Riggs (ASBMR President, 1985 to 1986) asked A Michael Parfitt to convene an ASBMR committee to develop a new and unified system of terminology, suitable for adoption by the Journal of Bone and Mineral Research (JBMR) as part of its Instructions to Authors. The resulting recommendations were published in 19872 and were quickly adopted not only by JBMR but also by all respected journals in the bone field. The recommendations improved markedly the ability of histomorphometrists to communicate with each other and with nonhistomorphometrists, leading to a broader understanding and appreciation of histomorphometric data. In 2012, 25 years after the development of the standardized nomenclature system, Thomas L Clemens (Editor in Chief of JBMR) felt that it was time to revise and update the recommendations. The original committee was reconvened by David W Dempster, who appointed one new member, Juliet E Compston. The original document was circulated to the committee members and was extensively revised according to their current recommendations. The key revisions include omission of terminology used before 1987, recommendations regarding the parameters and technical information that should be included in all histomorphometry articles, recommendations on how to handle dynamic parameters of bone formation in settings of low bone turnover, and updating of references. It is generally agreed that a bone is an individual organ of the skeletal system, but the term “bone” has at least three meanings. The first is mineralized bone matrix excluding osteoid; this usage conforms rigorously to the definition of bone as a hard tissue. Osteoid is bone matrix that will be (but is not yet) mineralized, and is sometimes referred to as pre-bone. The second meaning of “bone,” and the one we have adopted, is bone matrix, whether mineralized or not, ie, including both mineralized bone and osteoid. The third meaning of “bone” is a tissue including bone marrow and other soft tissue, as well as bone as just defined. We refer to the combination of bone and associated soft tissue or marrow as “bone tissue.” “Tissue” is defined3 as “an aggregation of similarly specialized cells united in the performance of a particular function.” In this sense, bone, bone marrow, and the contents of osteonal canals are certainly not the same tissue, but in a more general sense, most textbooks of histology recognize only four fundamental tissues—epithelium, nerve, muscle, and connective tissue4—of which the last-named includes bone and all its accompanying nonmineralized tissue. In current clinical and radiologic parlance, “trabecular” and “cortical” refer to contrasting structural types of bone. But “trabecular” does not appear in any standard textbook of anatomy or histology as a name for a type of bone; rather, “spongy” or “cancellous” is used. “Spongiosa” (primary or secondary) is best restricted to the stages of endochondral ossification; “cancellous” is most commonly used in textbooks4, 5 and is the term we have chosen. We retain the noun “trabecula” and its associated adjective “trabecular” to refer to an individual structural element of cancellous bone, in accordance with current practice in histology,4 pathology,6 and biomechanics.7 Etymologically, a trabecula is a beam or rod, and in young people plates rather than rods are the predominant structural elements, both in the spine8 and in the ilium,9 but no convenient alternative is available. The size, shape, and orientation of trabeculae (as just defined) vary considerably between different types of cancellous bone.9, 10 “Density” is a frequent source of confusion in discussions about bone. We propose that the term should be restricted as far as possible to its primary meaning in physics of mass per unit volume,11, 12 with a subsidiary meaning analogous to population density, which is applied mainly to cells. This precludes the use of “density” in its stereologic sense, as will be to the the to which mass is referred be of mineralized bone, bone, bone tissue or or a bone. bone is than bone density, which the of and This is and generally be but is to Bone the of osteoid; bone matrix excluding and has been referred to as bone Bone tissue the of soft tissue, or bone density, referred to as bone density, the of bone tissue, cancellous bone tissue, and marrow a bone, the organ of which is by is in the clinical and In most bone are or formation and all cells on the are or but in the most bone are with to bone We refer to the cells that bone as cells and the term to cells that are bone matrix or with only rather than including all cells that are not cells are of and are to have The term is restricted to cells and are have only one or no for of and whether or should be or A of types of primary be on of a or between or between and histomorphometrists report all only in the for to three be to and the of the or the of an are not this is a but bone be in In other of that as an the is to by the of which is the We that this also should be the of bone are for between between and between different types of bone, for element of bone for of and for many of bone as the of and the of individual But as a it is to on adoption of a stereologic that be and a only in bone the is to the bone its before In the the use of a in the was a convenient of of but this for at an the of the of to most stereologic also that the be meaning that a to any element of has an of in any in not for all cancellous bone, in the there is only and stereologic be used with 25 But it is more to the of a is which is with the use of a but there is no other of canals generally not the by more than stereologic in bone are but of the stereologic to bone has not been we that histomorphometric should one of all and in the and or (as by the only the the and with the an is for each type of of how it was the primary as A of and should not be used in the same The only is the type of primary for which there is no convenient of to three the of the of in three is possible the same be in of and but this has not been applied to bone. as also be The original committee not to the terminology of the of as was at the on Bone use the term “density” in a general to any referred to that is and per unit is the of terminology is in the the of “density” in different the all to at the of bone histomorphometry will need to be with the of many to bone are published in the Journal of which is the of the of of and are of the of tissue and be between only to a which will be or the and in have no and in three but it is convenient to refer to as and to as the is the of and of individual have meaning in and are the only type that not a different and to different that use of is and it is to between used include tissue bone bone and and their or of the the use of as a term The of the is not commonly used as a at but is for with of bone for the of and cancellous bone of or for the of different types of bone and different to as of and of and for in the between and of bone of the as a the possible an to the in of to bone as an be as of the the of the to the mainly on the of the bone at the of be with a the but the of and cancellous tissue in the bone be with type of the be by the of and cancellous bone tissue in the The same be applied to and to bone by the by the as the The individual are in in of their or general are in a the is to be rather than the use of is mainly to time or there is a more for as for other their use in other but confusion is with that be with is not to or the use of and but to that the same are used by To this we have the to and the of new with different meanings. We have included in bone their and commonly used in and as well as for all the structural of bone and of and for of bone with are and in to their one the and in of only is it is and used and a suitable The most commonly used are a have an in many to the second or and the second of the by the are used for that are in to for the primary of and and for in its used in should be by a in the of each is to be as an individual In this any combination of be to which are included in the Bone histomorphometry be applied to many types of but the most are of of bone and of we first the terminology for to the the between and is it is to the of the bone at the for the the term is more is and cancellous for on the their are but it is possible to of their and In this the are generally by their of the and that one be in by or at the time of the but this is The generally has more and tissue than the The other of the is referred to as only the of the have the same as the the more term is the of the is to the of the its are It is convenient to as and of for and cancellous for are by the between and in the to of bone different on on by and with of of of on on cancellous to cancellous the and not and their is used for for the the by the and are the be used to and the of bone bone is similarly and cancellous for or marrow for The between and bone and cancellous or marrow on the of the be at in to the in both and bone it is for to recognize a between and cancellous bone tissue and in and This is not in or of its are not A has been used to this in This be to bone but this has not been all all in with bone marrow are referred to as and are cancellous bone and the is the of the between is to in accordance with and will also on whether the is not in with bone marrow are generally referred to as with as the also be referred to as the or osteonal of the of a bone; is on the and is on the the cancellous bone of the is not bone cancellous marrow The standard and for all should be that the of to as well as to the and are used only as and are used only as to the on which the was whether this was a particular or a particular type of tissue. of the commonly used have been many are by the are restricted to of a as the of a or the of cancellous the same be but the should be in the of on the the source is as it will not be to the source each time a particular is referred only one source is used in an it need only be are their be used as for of in or and in most will need to be only are that confusion between is as only one source is possible and its is The three and the are the key to one to is to in stereologic terminology, and and are to in stereologic are the and by which is for or by which has been for cancellous The with that the be and and to in stereologic terminology and are with the and a of the bone is as a and are to and it be to to the mineralized as an alternative to the more bone and of bone formation be to the or to the of as well as to or bone it be to use the between mineralized bone and or bone as a for the of or of the is are In many as only one is used for each the need only be and not each time the is more than one is with the same be to are with in both and in have been but need is used for of mineralized bone and is by Osteoid need to be as or as the in the between which to a and which to a for all are with the is a general term to all tissue that is not and includes marrow in cancellous bone and and canals in bone. both types of tissue, with on individual as cells or The be as an of tissue, by use of the is the of all referred to the of tissue and in The also be as individual by of a is the of individual confusion is the term be as or in be to in the are in be used to but it is to this as Osteoid not that should be for of We the formation and the of current be and for the same we the is with or and the and the individual also be as or cells and are for and the cells on the or cells. is with or the term that will at The of connective tissue the cells on should not be referred to as It is possible that by cells should be as rather than as In all be in by at or by of and The is more and a and a standard as well as a but that be The is and to The is used for between and and and the is used for and are used for and The is for the the between individual at particular and at particular during the The by in an individual be the in a of is the the to the between bone and It is used in and in different types of and different stages of in the should be to the between and is on an individual it has been used in the for of the of and in as an of in is the between on of a as for the is an of bone the but is of the of bone to the most of the but that are the of be restricted to the of the of are but to and need for a be In most the will be an or but of also be per is the of per to bone in cancellous bone tissue, a that with as and as are are and are in a that has been to of its The of to in a is an of be structural or of the are on that are but not rigorously and individual to use or of the that we have is with and time are L and but have other in the according to the as which is to of for cancellous the alternative is with by To between the alternative this is to the with It should be that there is in the term which has been a different by the ASBMR with with the it as the between rather than between is according to the as or as This by is an of the marrow to the and a is by but be in any to the of the marrow as the between is by and also be The of in at a particular time is by the of the resulting at that The of the of is to the of the first and second the of the of are available. of the term or a between the of the the second it is in time to the the only one was in of the or after the the and of the and of the of are the of the and should be be in to a variety of is to the of during which It should be that of individual on the Parfitt and that were than of the in which were This should be in the of and and it is to a is used to in bone formation in a Mineral is the between the or between the of by the time between the of the the of for and the of the vary with the of the which be and We the and to confusion between and and are used in to refer to the bone formation is no convenient of between the and by different that the is it is that the be used is as and the or the bone formation the It is analogous to the and is with formation and “bone formation but of alternative is The is in a and in the of the is the best a of the of the of formation of mineralized bone and of bone matrix, the including of and are their are of and the term be used. 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CONTEXT: Vertebral fractures significantly increase lifetime risk of future fractures, but risk of further vertebral fractures in the period immediately following a vertebral fracture has not been evaluated. OBJECTIVE: To determine the incidence of further vertebral fracture in the year following a vertebral fracture. DESIGN AND SETTING: Analysis of data from 4 large 3-year osteoporosis treatment trials conducted at 373 study centers in North America, Europe, Australia, and New Zealand from November 1993 to April 1998. SUBJECTS: Postmenopausal women who had been randomized to a placebo group and for whom vertebral fracture status was known at entry (n = 2725). MAIN OUTCOME MEASURE: Occurrence of radiographically identified vertebral fracture during the year following an incident vertebral fracture. RESULTS: Subjects were a mean age of 74 years and had a mean of 28 years since menopause. The cumulative incidence of new vertebral fractures in the first year was 6.6%. Presence of 1 or more vertebral fractures at baseline increased risk of sustaining a vertebral fracture by 5-fold during the initial year of the study compared with the incidence in subjects without prevalent vertebral fractures at baseline (relative risk [RR], 5.1; 95% confidence interval [CI], 3.1-8.4; P<.001). Among the 381 participants who developed an incident vertebral fracture, the incidence of a new vertebral fracture in the subsequent year was 19.2% (95% CI, 13.6%-24.8%). This risk was also increased in the presence of prevalent vertebral fractures (RR, 9.3; 95% CI, 1.2-71.6; P =.03). CONCLUSION: Our data indicate that women who develop a vertebral fracture are at substantial risk for additional fracture within the next year.

The dentate granule cell layer of the rodent hippocampal formation has the distinctive property of ongoing neurogenesis that continues throughout adult life. In both human temporal lobe epilepsy and rodent models of limbic epilepsy, this same neuronal population undergoes extensive remodeling, including reorganization of mossy fibers, dispersion of the granule cell layer, and the appearance of granule cells in ectopic locations within the dentate gyrus. The mechanistic basis of these abnormalities, as well as their potential relationship to dentate granule cell neurogenesis, is unknown. We used a systemic chemoconvulsant model of temporal lobe epilepsy and bromodeoxyuridine (BrdU) labeling to investigate the effects of prolonged seizures on dentate granule cell neurogenesis in adult rats, and to examine the contribution of newly differentiated dentate granule cells to the network changes seen in this model. Pilocarpine-induced status epilepticus caused a dramatic and prolonged increase in cell proliferation in the dentate subgranular proliferative zone (SGZ), an area known to contain neuronal precursor cells. Colocalization of BrdU-immunolabeled cells with the neuron-specific markers turned on after division, 64 kDa, class III beta-tubulin, or microtubule-associated protein-2 showed that the vast majority of these mitotically active cells differentiated into neurons in the granule cell layer. Newly generated dentate granule cells also appeared in ectopic locations in the hilus and inner molecular layer of the dentate gyrus. Furthermore, developing granule cells projected axons aberrantly to both the CA3 pyramidal cell region and the dentate inner molecular layer. Induction of hippocampal seizure activity by perforant path stimulation resulted in an increase in SGZ mitotic activity similar to that seen with pilocarpine administration. These observations indicate that prolonged seizure discharges stimulate dentate granule cell neurogenesis, and that hippocampal network plasticity associated with epileptogenesis may arise from aberrant connections formed by newly born dentate granule cells.

BACKGROUND: Romosozumab, a monoclonal antibody that binds sclerostin, increases bone formation and decreases bone resorption. METHODS: We enrolled 7180 postmenopausal women who had a T score of -2.5 to -3.5 at the total hip or femoral neck. Patients were randomly assigned to receive subcutaneous injections of romosozumab (at a dose of 210 mg) or placebo monthly for 12 months; thereafter, patients in each group received denosumab for 12 months, at a dose of 60 mg, administered subcutaneously every 6 months. The coprimary end points were the cumulative incidences of new vertebral fractures at 12 months and 24 months. Secondary end points included clinical (a composite of nonvertebral and symptomatic vertebral) and nonvertebral fractures. RESULTS: At 12 months, new vertebral fractures had occurred in 16 of 3321 patients (0.5%) in the romosozumab group, as compared with 59 of 3322 (1.8%) in the placebo group (representing a 73% lower risk with romosozumab; P<0.001). Clinical fractures had occurred in 58 of 3589 patients (1.6%) in the romosozumab group, as compared with 90 of 3591 (2.5%) in the placebo group (a 36% lower risk with romosozumab; P=0.008). Nonvertebral fractures had occurred in 56 of 3589 patients (1.6%) in the romosozumab group and in 75 of 3591 (2.1%) in the placebo group (P=0.10). At 24 months, the rates of vertebral fractures were significantly lower in the romosozumab group than in the placebo group after each group made the transition to denosumab (0.6% [21 of 3325 patients] in the romosozumab group vs. 2.5% [84 of 3327] in the placebo group, a 75% lower risk with romosozumab; P<0.001). Adverse events, including instances of hyperostosis, cardiovascular events, osteoarthritis, and cancer, appeared to be balanced between the groups. One atypical femoral fracture and two cases of osteonecrosis of the jaw were observed in the romosozumab group. CONCLUSIONS: In postmenopausal women with osteoporosis, romosozumab was associated with a lower risk of vertebral fracture than placebo at 12 months and, after the transition to denosumab, at 24 months. The lower risk of clinical fracture that was seen with romosozumab was evident at 1 year. (Funded by Amgen and UCB Pharma; FRAME ClinicalTrials.gov number, NCT01575834 .).

The repeatability of gait variables is an important consideration in the clinical use of results of quantitative gait analysis. Statistical measures were used to evaluate repeatability of kinematic, kinetic, and electromyographic data waveforms and spatiotemporal parameters of 40 normal subjects. Subjects were evaluated three times on each test day and on three different test days while walking at their preferred or natural speed. Intrasubject repeatability was excellent for kinematic data in the sagittal plane both within a test day as well as between test days. For joint angle motion in the frontal and transverse planes, the repeatability was good within a test day and poor between test days. Poor between-day repeatability of joint angle motion in the frontal and transverse planes was noted to be partly due to variabilities in the alignment of markers. Vertical reaction and fore-aft shear forces were more repeatable than the mediolateral shear force. Sagittal plane joint moments were more repeatable than frontal or transverse plane moments. For electromyographic data, repeatability within a day was slightly better than between test days. In general, the results demonstrate that with the subjects walking at their natural or preferred speed, the gait variables are quite repeatable. These observations suggest that it may be reasonable to base significant clinical decisions on the results of a single gait evaluation.

Since the purification of BDNF in 1982, a great deal of evidence has mounted for its central roles in brain development, physiology, and pathology. Aside from its importance in neural development and cell survival, BDNF appears essential to molecular mechanisms of synaptic plasticity. Basic activity-related changes in the central nervous system are thought to depend on BDNF modification of synaptic transmission, especially in the hippocampus and neocortex. Pathologic levels of BDNF-dependent synaptic plasticity may contribute to conditions such as epilepsy and chronic pain sensitization, whereas application of the trophic properties of BDNF may lead to novel therapeutic options in neurodegenerative diseases and perhaps even in neuropsychiatric disorders.

Data on the number of U.S. women with low femoral bone mineral density (BMD) are currently available only from indirect estimates. We used dual-energy X-ray absorptiometry (DXA) measurements of femoral BMD from phase 1 of the third National Health and Nutrition Examination Survey (NHANES III, 1988-1991) to estimate prevalences of low femoral BMD in women ages 50 years and older using an approach proposed recently by an expert panel of the World Health Organization (WHO). Cutpoints for low BMD were derived from BMD data of 194 non-Hispanic white (NHW) women aged 20-29 years from the NHANES III dataset. The prevalence of older U.S. women with femoral osteopenia (BMD between 1 standard deviation [SD] and 2.5 SD below the mean of young NHW women) ranged from 34-50% in four different femur regions, which corresponds to approximately 12-17 million women. The prevalence with osteoporosis (BMD > 2.5 SD below the mean of young NHW women) ranged from 17-20%, or approximately 6-7 million women. Prevalences were 1.3-2.4 times higher in NHW women than non-Hispanic black women (NHB), and 0.8-1.2 times higher in NHW versus Mexican American (MA) women. The estimated numbers of NHW, NHB, and MA women with osteopenia were 10-15 million, 800,000-1.2 million, and 300,000-400,000, respectively; corresponding figures for osteoporosis were 5-6 million, 200,000-300,000, and 100,000 respectively. Thus, the first data on BMD from a nationally representative sample of older women show a substantial number with low femoral BMD.(ABSTRACT TRUNCATED AT 250 WORDS)

The occurrence of seizure activity in human temporal lobe epilepsy or status epilepticus is often associated with a characteristic pattern of cell loss in the hippocampus. An experimental model that replicates this pattern of damage in normal animals by electrical stimulation of the afferent pathway to the hippocampus was developed to study changes in structure and function that occur as a result of repetitive seizures. Hippocampal granule cell seizure activity caused a persistent loss of recurrent inhibition and irreversibly damaged adjacent interneurons. Immunocytochemical staining revealed unexpectedly that gamma-aminobutyric acid (GABA)-containing neurons, thought to mediate inhibition in this region and predicted to be damaged by seizures, had survived. In contrast, there was a nearly complete loss of adjacent somatostatin-containing interneurons and mossy cells that may normally activate inhibitory neurons. These results suggest that the seizure-induced loss of a basket cell-activating system, rather than a loss of inhibitory basket cells themselves, may cause disinhibition and thereby play a role in the pathophysiology and pathology of the epileptic state.

Abstract Most estimates of osteoporosis in older U.S. adults have been based on its occurrence in white women, even though it is known to affect men and minority women. In the present study, we used dual-energy X-ray absorptiometry measurements of femoral bone mineral density (BMD) from the third National Health and Nutrition Examination Survey (NHANES III, 1988–1994) to estimate the overall scope of the disease in the older U.S. population. Specifically, we estimate prevalences of low femoral BMD in women 50 years and older and explore different approaches for defining low BMD in older men in that age range. Low BMD levels were defined in accordance with an approach proposed by an expert panel of the World Health Organization and used BMD data from 382 non-Hispanic white (NHW) men or 409 NHW women ages 20–29 years from the NHANES III dataset. For women, estimates indicate 13–18%, or 4–6 million, have osteoporosis (i.e., BMD &amp;gt;2.5 standard deviations [SD] below the mean of young NHW women) and 37–50%, or 13–17 million, have osteopenia (BMD between 1 and 2.5 SD below the mean of young NHW women). For men, these numbers depend on the gender of the reference group used to define cutoff values. When based on male cutoffs, 3–6% (1–2 million) of men have osteoporosis and 28–47% (8–13 million) have osteopenia; when based on female cutoffs, 1–4% (280,000–1 million) have osteoporosis and 15–33% (4–9 million) have osteopenia. Most of the older U.S. adults with low femur BMD are women, but, regardless of which cutoffs are used, the number of men is substantial.

IMPORTANCE: Additional therapies are needed for prevention of osteoporotic fractures. Abaloparatide is a selective activator of the parathyroid hormone type 1 receptor. OBJECTIVE: To determine the efficacy and safety of abaloparatide, 80 μg, vs placebo for prevention of new vertebral fracture in postmenopausal women at risk of osteoporotic fracture. DESIGN, SETTING, AND PARTICIPANTS: The Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) was a phase 3, double-blind, RCT (March 2011-October 2014) at 28 sites in 10 countries. Postmenopausal women with bone mineral density (BMD) T score ≤-2.5 and >-5.0 at the lumbar spine or femoral neck and radiological evidence ≥2 mild or ≥1 moderate lumbar or thoracic vertebral fracture or history of low-trauma nonvertebral fracture within the past 5 years were eligible. Postmenopausal women (>65 y) with fracture criteria and a T score ≤-2.0 and >-5.0 or without fracture criteria and a T score ≤-3.0 and >-5.0 could enroll. INTERVENTIONS: Blinded, daily subcutaneous injections of placebo (n = 821); abaloparatide, 80 μg (n = 824); or open-label teriparatide, 20 μg (n = 818) for 18 months. MAIN OUTCOMES AND MEASURES: Primary end point was percentage of participants with new vertebral fracture in the abaloparatide vs placebo groups. Sample size was set to detect a 4% difference (57% risk reduction) between treatment groups. Secondary end points included change in BMD at total hip, femoral neck, and lumbar spine in abaloparatide-treated vs placebo participants and time to first incident nonvertebral fracture. Hypercalcemia was a prespecified safety end point in abaloparatide-treated vs teriparatide participants. RESULTS: Among 2463 women (mean age, 69 years [range, 49-86]), 1901 completed the study. New morphometric vertebral fractures occurred less frequently in the active treatment groups vs placebo. The Kaplan-Meier estimated event rate for nonvertebral fracture was lower with abaloparatide vs placebo. BMD increases were greater with abaloparatide than placebo (all P < .001). Incidence of hypercalcemia was lower with abaloparatide (3.4%) vs teriparatide (6.4%) (risk difference [RD], −2.96 [95%CI, −5.12 to −0.87]; P = .006). [table: see text]. CONCLUSIONS AND RELEVANCE: Among postmenopausal women with osteoporosis, the use of subcutaneous abaloparatide, compared with placebo, reduced the risk of new vertebral and nonvertebral fractures over 18 months. Further research is needed to understand the clinical importance of RD, the risks and benefits of abaloparatide treatment, and the efficacy of abaloparatide vs other osteoporosis treatments. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01343004.

BACKGROUND: Small increases in bone mass are commonly seen with existing treatments for osteoporosis, which reduce bone remodelling and primarily prevent bone loss. Since these drugs reduce but do not eliminate risk of fractures, an anabolic agent that would increase bone mass and potentially cure the underlying skeletal problem is needed. METHODS: We did a 3-year randomised controlled trial to find out the effects of 1-34 human parathyroid hormone (hPTH [1-34], 400 U/25 micrograms daily subcutaneously) in postmenopausal women with osteoporosis taking hormone-replacement therapy (n = 17). The controls were women taking hormone-replacement therapy only (n = 17). The primary outcome was bone-mineral density of the lumbar vertebrae, with bone-mineral density at other sites and vertebral fractures as secondary endpoints. FINDINGS: Patients taking hormone-replacement therapy and PTH (1-34) had continuous increase in vertebral bone-mineral density during the 3 years, whereas there was no significant change in the control group. The total increase in vertebral bone-mineral density was 13.0% (p < 0.001); 2.7% at the hip (p = 0.05); and 8.0% in total-body bone mineral (p = 0.002). No loss of bone mass was found at any skeletal site. Increased bone mass was associated with a reduction in the rate of vertebral fractures, which was significant when fractures were taken as a 15% reduction in vertebral height (p = 0.04). During the first 6 months of treatment, serum osteocalcin concentration, which reflects bone formation, increased by more than 55%, whereas excretion of crosslinked n-telopeptide, which reflects bone resorption, increased by only 20%, which suggests some uncoupling of bone formation and resorption. By 6 months, there were similar increases in both markers, which gradually returned towards baseline as the study progressed. Vertebral bone-mineral density increased most during the first year of PTH treatment. INTERPRETATION: We found that PTH has a pronouned anabolic effect on the central skeleton in patients on hormone-replacement therapy. PTH also increases total-body bone mineral, with no detrimental effects at any skeletal site. The increased vertebral mass was associated with a reduced rate of vertebral fracture, despite increased bone turnover. Bone-mass changes may be consistent with a reduction in all osteoporotic fractures. If confirmed in larger studies, these data have important implications for the treatment of postmenopausal osteoporosis.

PHYSICIANS have traditionally considered PTH to be an agent that is catabolic to the skeleton. However, as early as 60 yr ago, Albright and his colleagues (1) and later Selye (2) noted that the peptide extract could also be anabolic to the skeleton, producing increases in bone tissue in animals. The potential for an agent that can increase bone mass and hence reverse the skeletal defect in patients with osteoporosis is great, particularly if in doing so it also repairs microarchitectural damage. The agents currently available in the United States for treatment of osteoporosis, estrogens and salmon calcitonin, primarily stabilize bone mass and prevent further loss of bone, although a transient small increment in mass is often reported, particularly in patients with elevated levels of bone remodeling. This increase is not a true anabolic effect but is related to the temporal effects on turnover in which resorption declines initially followed by a reduction in formation that may take several months. Fluoride, in contrast, does increase bone mass by a true anabolic action, but there is controversy about the quality of the bone formed. Two recent controlled studies failed to find a reduction in fracture recurrence (3, 4), although the dose may have been excessive, and consequently, fluoride is currently not approved for treatment of osteoporosis in the United States. Thus, if PTH is capable of improving bone mass and quality, the peptide will have a potential therapeutic role in osteoporosis. This review summarizes the data available to date, starting at the cellular level.

All therapies currently recommended for the management of osteoporosis act mainly to inhibit bone resorption and reduce bone remodeling. PTH and its analog, teriparatide [recombinant human PTH(1-34)], represent a new class of anabolic therapies for the treatment of severe osteoporosis, having the potential to improve skeletal microarchitecture. Significant reductions in both vertebral and appendicular fracture rates have been demonstrated in the phase III trial of teriparatide, involving elderly women with at least one prevalent vertebral fracture before the onset of therapy. However, there is as yet no evidence that the antifracture efficacy of PTH will be superior to the bisphosphonates, whereas cost-utility estimates suggest that teriparatide is significantly more expensive. Teriparatide should be considered as treatment for postmenopausal women and men with severe osteoporosis, as well as for patients with established glucocorticoid-induced osteoporosis who require long-term steroid treatment. Teriparatide should also be considered for the management of individuals at particularly high risk for fractures, including subjects who are younger than age 65 and who have particularly low bone mineral density measurements (T scores < or = 3.5). Teriparatide therapy is not recommended for more than 2 yr, based, in part, on the induction of osteosarcoma in a rat model of carcinogenicity. Total daily calcium intake from both supplements and dietary sources should be limited to 1500 mg together with adequate vitamin D intake (< or =1000 U/d). Monitoring of serum calcium may be safely limited to measurement after 1 month of treatment; mild hypercalcemia may be treated by withdrawing dietary calcium supplements, reducing the dosing frequency of PTH, or both. At present, concurrent therapy with antiresorptive therapy, particularly bisphosphonates, should be avoided, although sequential therapy with such agents may consolidate the beneficial effects upon the skeleton after PTH is discontinued.

The relationship between an episode of status epilepticus, the resulting hippocampal pathology, and the subsequent development of pathophysiological changes possibly relevant to human epilepsy was explored using the experimental epilepsy model of perforant path stimulation in the rat. Granule cell hyperexcitability and decreased feedforward and feedback inhibition were evident immediately after 24 hours of intermittent perforant path stimulation and persisted relatively unchanged for more than 1 year. All of the pathophysiological changes induced by perforant path stimulation were replicated in normal animals by a subconvulsive dose of bicuculline, suggesting that the permanent "epileptiform" abnormalities produced by sustained perforant path stimulation may be due to decreased GABA-mediated inhibition. Granule cell pathophysiology was seen only in animals that exhibited a loss of adjacent dentate hilar mossy cells and hilar somatostatin/neuropeptide Y-immunoreactive neurons. GABA-immunoreactive dentate basket cells survived despite the extensive loss of adjacent hilar neurons. However, parvalbumin immunoreactivity, present normally in a subpopulation of GABA-immunoreactive dentate basket cells, was absent on the stimulated side. Whether this represents decreased parvalbumin synthesis in surviving basket cells or a loss of a specific subset of inhibitory cells is unclear. Hyperexcitability and decreased paired-pulse inhibition in response to ipsilateral perforant path stimulation were also present in the CA1 pyramidal cell layer on the previously stimulated side, despite minimal damage to CA1 pyramidal cells or interneurons. The possibility that CA1 inhibitory neurons were hypofunctional or "dormant" due to a loss of excitatory input to inhibitory cells from damaged CA3 pyramidal cells was tested by stimulating the contralateral perforant path in order to activate the same CA1 basket cells via different inputs. Contralateral stimulation evoked CA1 pyramidal cell paired-pulse inhibition immediately in the previously stimulated hippocampus. Thus, we propose the "dormant basket cell" hypothesis, which implies that despite malfunction, inhibitory systems remain intact in "epileptic" tissue and are capable of functioning if appropriately activated.

Zoledronic acid 5 mg (ZOL) annually for 3 years reduces fracture risk in postmenopausal women with osteoporosis. To investigate long-term effects of ZOL on bone mineral density (BMD) and fracture risk, the Health Outcomes and Reduced Incidence with Zoledronic acid Once Yearly-Pivotal Fracture Trial (HORIZON-PFT) was extended to 6 years. In this international, multicenter, double-blind, placebo-controlled extension trial, 1233 postmenopausal women who received ZOL for 3 years in the core study were randomized to 3 additional years of ZOL (Z6, n = 616) or placebo (Z3P3, n = 617). The primary endpoint was femoral neck (FN) BMD percentage change from year 3 to 6 in the intent-to-treat (ITT) population. Secondary endpoints included other BMD sites, fractures, biochemical bone turnover markers, and safety. In years 3 to 6, FN-BMD remained constant in Z6 and dropped slightly in Z3P3 (between-treatment difference = 1.04%; 95% confidence interval 0.4 to 1.7; p = 0.0009) but remained above pretreatment levels. Other BMD sites showed similar differences. Biochemical markers remained constant in Z6 but rose slightly in Z3P3, remaining well below pretreatment levels in both. New morphometric vertebral fractures were lower in the Z6 (n = 14) versus Z3P3 (n = 30) group (odds ratio = 0.51; p = 0.035), whereas other fractures were not different. Significantly more Z6 patients had a transient increase in serum creatinine >0.5 mg/dL (0.65% versus 2.94% in Z3P3). Nonsignificant increases in Z6 of atrial fibrillation serious adverse events (2.0% versus 1.1% in Z3P3; p = 0.26) and stroke (3.1% versus 1.5% in Z3P3; p = 0.06) were seen. Postdose symptoms were similar in both groups. Reports of hypertension were significantly lower in Z6 versus Z3P3 (7.8% versus 15.1%, p < 0.001). Small differences in bone density and markers in those who continued versus those who stopped treatment suggest residual effects, and therefore, after 3 years of annual ZOL, many patients may discontinue therapy up to 3 years. However, vertebral fracture reductions suggest that those at high fracture risk, particularly vertebral fracture, may benefit by continued treatment.

Abstract Two neuronal calcium‐binding proteins, calbindin‐D 28k (CaBP) and parvalbumin (PV), were localized in the normal rat hippocampus by using immunocytochemical methods to determine (1) their location and (2) whether a correlation exists between the presence of these two calcium‐binding proteins and the selective vulnerability of different hippocampal neuronal populations to experimental seizure activity. CaBP‐like immunoreactivity (CaBP‐LI) is present in all dentate granule cells and some, but not all, CA1 and CA2 pyramidal cells. Some CA1 pyramidal cells lack CaBP‐LI, and those that do are lightly stained compared to the dentate granule cells. CA3 pyramidal cells appear to contain neither CaBP‐ nor PV‐LI, and no granule or pyramidal cells exhibit PV‐LI. CaBP‐LI is present in distinct populations of dentate and hippocampal interneurons but absent from others. In area dentata, CaBP‐LI is present in a small number of interneurons of the molecular and granule cell layers and in a small population of presumed basket cells in or below the granule cell layer. Conversely, more presumed dentate basket cells exhibit PV‐LI than CaBP‐LI. In the hilus of area dentata, few cells are CaBP‐ or PV‐immunoreactive. The hilar somatostatin/neuropeptide Y (NPY)‐immunoreactive cells and hilar mossy cells, two distinct and large populations, lack CaBP‐ and PV‐LI. In the CA3 region, CaBP‐LI is present in a relatively small number of interneurons in each stratum. PV‐immunoreactive interneurons in area CA3 are more numerous. In area CA1, CaBP‐LI is present in many interneurons in strata radiatum and lacunosum‐moleculare. Some, but relatively fewer, CaBP‐positive interneurons are present in strata pyramidale and oriens. Conversely, PV‐immunoreactive interneurons are numerous in strata pyramidale and oriens but rare in strata radiatum and lacunosummoleculare. Staining with the particulate chromagen benzidine hydrochloride revealed a previously undescribed dense band of CaBP‐LI in the inner dentate molecular layer, a lamina enriched with kainate‐displaceable glutamate‐binding sites and innervated by the apparently excitatory ipsilateral associational/commissural (IAC) pathway that originates in the CaBP‐negative hilar mossy cells. Bilateral electrical stimulation of the perforant path was performed in order to destroy the hilar mossy cells and to determine if this band of CaBP‐LI is normally present within the mossy cell terminals. Perforant path stimulation that destroyed hilar mossy cells throughout the dorsal portions of both hippocampi did not abolish the dense CaBP‐like immunoreactivity in the inner molecular layer. In summary, the cell populations visualized by immunocytochemical staining for CaBP‐ or PV‐LI are clearly distinct. All of the relatively seizure‐resistant dentate granule cells and many basket cells and hippocampal CA2 pyramidal cells are darkly stained for either CABP‐ or PV‐LI. The seizuresensitive dentate hilar somatostatin/NPY‐positive cells, hilar mossy cells, and hippocampal CA3 pyramidal cells appear devoid of both CaBP‐ and PV‐LI. The seizure sensitive CA1 pyramidal cells are devoid of PV‐LI and exhibit less CaBP‐LI than the seizure‐resistant granule cells. Therefore, a positive correlation exists between the presence of at least one of these calcium‐binding proteins in hippocampal neurons and their relative resistance to seizure‐induced neuronal damage. These data suggest that the relative vulnerability of different cell populations may be related to differences in the concentration of cytoplasmic proteins capable of sequestering free intracellular calcium.

UNLABELLED: Osteoporosis causes an elevated fracture risk. We propose the continued use of T-scores as one means for diagnosis but recommend that, alternatively, hip fracture; osteopenia-associated vertebral, proximal humerus, pelvis, or some wrist fractures; or FRAX scores with ≥3% (hip) or 20% (major) 10-year fracture risk also confer an osteoporosis diagnosis. INTRODUCTION: Osteoporosis is a common disorder of reduced bone strength that predisposes to an increased risk for fractures in older individuals. In the USA, the standard criterion for the diagnosis of osteoporosis in postmenopausal women and older men is a T-score of ≤ -2.5 at the lumbar spine, femur neck, or total hip by bone mineral density testing. METHODS: Under the direction of the National Bone Health Alliance, 17 clinicians and clinical scientists were appointed to a working group charged to determine the appropriate expansion of the criteria by which osteoporosis can be diagnosed. RESULTS: The group recommends that postmenopausal women and men aged 50 years should be diagnosed with osteoporosis if they have a demonstrable elevated risk for future fractures. This includes having a T-score of less than or equal to -2.5 at the spine or hip as one method for diagnosis but also permits a diagnosis for individuals in this population who have experienced a hip fracture with or without bone mineral density (BMD) testing and for those who have osteopenia by BMD who sustain a vertebral, proximal humeral, pelvic, or, in some cases, distal forearm fracture. Finally, the term osteoporosis should be used to diagnose individuals with an elevated fracture risk based on the World Health Organization Fracture Risk Algorithm, FRAX. CONCLUSIONS: As new ICD-10 codes become available, it is our hope that this new understanding of what osteoporosis represents will allow for an appropriate diagnosis when older individuals are recognized as being at an elevated risk for fracture.