Mitsubishi Motors (Japan)

Polymer electrolyte membrane (PEM) fuel cells are electrochemical devices that directly convert the chemical energy stored in fuel into electrical energy with a practical conversion efficiency as high as 65%. In the past years, significant progress has been made in PEM fuel cell commercialization. By 2019, there were over 19,000 fuel cell electric vehicles (FCEV) and 340 hydrogen refueling stations (HRF) in the U.S. (~8,000 and 44, respectively), Japan (~3,600 and 112, respectively), South Korea (~5,000 and 34, respectively), Europe (~2,500 and 140, respectively), and China (~110 and 12, respectively). Japan, South Korea, and China plan to build approximately 3,000 HRF stations by 2030. In 2019, Hyundai Nexo and Toyota Mirai accounted for approximately 63% and 32% of the total sales, with a driving range of 380 and 312 miles and a mile per gallon (MPGe) of 65 and 67, respectively. Fundamentals of PEM fuel cells play a crucial role in the technological advancement to improve fuel cell performance/durability and reduce cost. Several key aspects for fuel cell design, operational control, and material development, such as durability, electrocatalyst materials, water and thermal management, dynamic operation, and cold start, are briefly explained in this work. Machine learning and artificial intelligence (AI) have received increasing attention in material/energy development. This review also discusses their applications and potential in the development of fundamental knowledge and correlations, material selection and improvement, cell design and optimization, system control, power management, and monitoring of operation health for PEM fuel cells, along with main physics in PEM fuel cells for physics-informed machine learning. The objective of this review is three fold: (1) to present the most recent status of PEM fuel cell applications in the portable, stationary, and transportation sectors; (2) to describe the important fundamentals for the further advancement of fuel cell technology in terms of design and control optimization, cost reduction, and durability improvement; and (3) to explain machine learning, physics-informed deep learning, and AI methods and describe their significant potentials in PEM fuel cell research and development (R&D).

Vying for newer sodium-ion chemistry for rechargeable batteries, Na2FeP2O7 pyrophosphate has been recently unveiled as a 3 V high-rate cathode. In addition to its low cost and promising electrochemical performance, here we demonstrate Na2FeP2O7 as a safe cathode with high thermal stability. Chemical/electrochemical desodiation of this insertion compound has led to the discovery of a new polymorph of NaFeP2O7. High-temperature analyses of the desodiated state NaFeP2O7 show an irreversible phase transition from triclinic (P1̅) to the ground state monoclinic (P21/c) polymorph above 560 °C. It demonstrates high thermal stability, with no thermal decomposition and/or oxygen evolution until 600 °C, the upper limit of the present investigation. This high operational stability is rooted in the stable pyrophosphate (P2O7)4– anion, which offers better safety than other phosphate-based cathodes. It establishes Na2FeP2O7 as a safe cathode candidate for large-scale economic sodium-ion battery applications.

<div class="htmlview paragraph">The major problems of the various mixture formation concepts for direct injection gasoline engines that have been proposed up to the present were caused by the difficulties of preparing the mixture with adequate strength at spark plug in wide range of engine operating conditions. Novel combustion control technologies proposed by Mitsubishi is one of the solution for these problems. By adopting upright straight intake ports to generate air tumble, an electromagnetic swirl injector to realize optimized spray dispersion and atomization and a compact piston cavity to maintain charge stratification, it has become possible to achieve super-lean stratified combustion for higher thermal efficiency under partial loads as well as homogeneous combustion to realize higher performance at full loads.</div> <div class="htmlview paragraph">GDI™ (Gasoline Direct Injection) engine adopting these technologies is developed. At partial loads, fuel economy improvement exceeding 30 % is realized. At higher loads, since air cooling by the latent heat of vaporization increases volumetric efficiency and reduces the octane number requirement, a high compression ratio of 12 to 1 can be adopted. As a result, 10% increase in performance is realized. NOx emission had been considered as one of the most significant issues of lean burn engines. This problem is solved by using the inherent characteristics of stratified combustion of high EGR tolerance and by the newly developed lean-NOx catalyst.</div>

<div class="htmlview paragraph">Novel combustion control technologies for the direct injection SI engine have been developed. By adopting up-right straight intake ports to generate air tumble, an electro-magnetic swirl injector to realize optimized spray dispersion and atomization and a compact piston cavity to maintain charge stratification, it has become possible to achieve super-lean stratified combustion for higher thermal efficiency under partial loads as well as homogeneous combustion to realize higher performance at full loads. At partial loads, fuel is injected into the piston cavity during the later stage of the compression stroke. Any fuel spray impinging on the cavity wall is directed to the spark plug. Tumbling air flow in the cavity also assists the conservation of the rich mixture zone around the spark plug. Stable combustion can be realized under a air fuel ratio exceeding 40. At higher loads, fuel is injected during the early stage of the intake stroke. Since air cooling by the latent heat of vaporization increases volumetric efficiency and reduces the octane number requirement, a high compression ratio of 12 to 1 can be adopted. As a result, engines utilizing these types of control technologies show a 10% increase in improved performance over conventional port injection engines.</div>

<div class="htmlview paragraph">A premixed compression-ignited (PCI) combustion system, which realizes lean combustion with high efficiency and low emissions, was investigated and its effects and problems were ascertained. With PCI combustion, fuel was injected early on the compression stroke and a premixed lean mixture was formed over a long mixing period. The test engine was operated with self-ignition of this premixed lean mixture. From the results of combustion observation and numerical simulation, a need to prevent the fuel spray from adhering to the cylinder liner and combustion-chamber wall was identified. Consequently, an impinged-spray nozzle with low penetration was made and tested. As a result, an extremely low nitrogen-oxide (NOx) emission level was realized but fuel efficiency was detracted slightly. Also, the engine operating range possible with PCI combustion was found to be limited to partial-load conditions and PCI combustion was found to cause an increase in hydrocarbon (HC) emission. Since it offers ideal combustion characteristics with a high degree of constant volume of heat release, however, PCI combustion potentially represents a more efficient, cleaner combustion (ultra-low NOx and low smoke) than those of conventional diesel engines.</div>

The development of high-performance Na-ion intercalation electrodes has been required recently because Na-ion batteries hold much promise for inexpensive and efficient energy storage, which can be deployed in a power grid. For both optimization and better understanding of the electrode materials, it is indispensable to clarify the relationship between the electronic state and electrochemical properties systematically. In this work, we studied the electrochemical properties of P2–Na2/3MnyCo1–yO2 in detail. A series of the P2 phases was successfully synthesized by the conventional solid-state reaction. The solid solution P2 compounds showed that the redox potential of Co4+/Co3+ and Mn4+/Mn3+ shifts systematically by the transition-metal substitution. The charge–discharge cycle tests revealed that with increasing y the initial specific capacity increases while the cycle stability degrades. The origin for the cycle degradation was analyzed by the electrochemical impedance spectroscopy, which evidenced that the substitution of Co for Mn accelerates the formation of the passivating layer at the electrode surface.

Anisotropic and controllable silver shell formation on gold nanorods was realized in a micellar solution of hexadecytrimethylammonium chloride. Uniformity of the anisotropic Au-Ag core-shell particles contributes separation of four extinction bands. The ability to manipulate the shapes and sizes of these nanoparticles offers a wide-range control of the surface extinction from the visible to the near infrared regions (450-800 nm).

The magnetic structure and properties of polycrystalline NaFePO4 polymorphs, maricite and triphylite, both derived from the olivine structure type, have been investigated using magnetic susceptibility, heat capacity, and low-temperature neutron powder diffraction. These NaFePO4 polymorphs assume orthorhombic frameworks (space group No. 62, Pnma), built from FeO6 octahedral and PO4 tetrahedral units having corner-sharing and edge-sharing arrangements. Both polymorphs demonstrate antiferromagnetic ordering below 13 K for maricite and 50 K for triphylite. The magnetic structure and properties are discussed considering super- and supersuperexchange interactions in comparison to those of triphylite-LiFePO4.

OBJECTIVE: We aimed to estimate the proportion of postmigration HIV acquisition among HIV-positive migrants in Europe. DESIGN: To reach HIV-positive migrants, we designed a cross-sectional study performed in HIV clinics. METHODS: The study was conducted from July 2013 to July 2015 in 57 clinics (nine European countries), targeting individuals over 18 years diagnosed in the preceding 5 years and born abroad. Electronic questionnaires supplemented with clinical data were completed in any of 15 languages. Postmigration HIV acquisition was estimated through Bayesian approaches combining extensive information on migration and patients' characteristics. CD4 cell counts and HIV-RNA trajectories from seroconversion were estimated by bivariate linear mixed models fitted to natural history data. Postmigration acquisition risk factors were investigated with weighted logistic regression. RESULTS: Of 2009 participants, 46% were MSM and a third originated from sub-Saharan Africa and Latin America & Caribbean, respectively. Median time in host countries was 8 years. Postmigration HIV acquisition was 63% (95% confidence interval: 57-67%); 72% among MSM, 58 and 51% in heterosexual men and women, respectively. Postmigration HIV acquisition was 71% for Latin America and Caribbean migrants and 45% for people from sub-Saharan Africa. Factors associated with postmigration HIV acquisition among heterosexual women and MSM were age at migration, length of stay in host country and HIV diagnosis year and among heterosexual men, length of stay in host country and HIV diagnosis year. CONCLUSION: A substantial proportion of HIV-positive migrants living in Europe acquired HIV postmigration. This has important implications for European public health policies.

<div class="htmlview paragraph">Spray motion visualization, mixture strength measurement, flame spectral analyses and flame behavior observation were performed in order to elucidate the mixture preparation and the combustion processes in Mitsubishi GDI engine. The effects of in-cylinder flow called reverse tumble on the charge stratification were clarified. It preserves the mixture inside the spherical piston cavity, and extends the optimum injection timing range. Mixture strength at the spark plug and at the spark timing can be controlled by changing the injection timing. It was concluded that reverse tumble plays a significant role for extending the freedom of mixing.</div> <div class="htmlview paragraph">The characteristics of the stratified charge combustion were clarified through the flame radiation analyses. A first flame front with UV luminescence propagates rapidly and covers all over the combustion chamber at the early stage of combustion. Then, the combustion of rich mixture proceeds in the reaction zone behind a second flame front with thermal radiation. The second flame front propagates into the post flame zone of the first flame front filled with the products of first flame such as radicals and CO. Soot generated in the rich mixture zone is burned-up in this radical rich zone.</div> <div class="htmlview paragraph">Based on this finding, a new mixing control strategy for knock suppression named “two-stage mixing” was proposed. A first injection is performed during the early stage of the intake stroke to prepare the very lean premixed mixture and a second injection is performed during the later stage of the compression stroke to prepare the distinctively stratified mixture. The premixed mixture is too lean to induce knock and the stratified mixture does not have the enough time for the incubation reaction of knock to proceed. What is interesting is that soot generated in the rich mixture zone is not emitted at all. In the case of the conventional stratified charge rich combustion, soot behind the flame front propagates to the air zone and is cooled to generate cold soot that will not be reburned. In case of the two-stage mixing, soot in the rich mixture zone propagates to the lean premixed mixture zone, where soot plays a role of the ignition site and ignites the lean mixture. Soot in the lean mixture zone is burned-up efficiently utilizing the air, radicals and heat generated by the combustion of the lean mixture.</div>

We focus on Pt degradation occurring during fuel cell vehicle (FCV) combined drive cycles involving load and open circuit voltage (OCV) just after startup and during idling. Load cycle durability is evaluated as a function of OCV/load holding time, load rate and relative humidity (RH) with a graphitized carbon black-supported platinum catalyst (Pt/GCB) in the cathode. The degradation of Pt/GCB is suppressed for shorter OCV holding times, lower load rates and lower RH. Scanning ion microscopy (SIM) images of membrane cross-sections indicate that the amount of Pt deposited in the membrane decreases during drive cycles involving load with short OCV holding times. Investigations of the Pt distribution in the cathode catalyst layer (CL) by using scanning TEM-EDX show that the dissolution of Pt is suppressed on the membrane side in the CL. The Pt dissolution is accelerated by the high Pt oxidation due to the long OCV holding time. A load cycle with both long OCV holding time and low load inhibits the Pt2+ migration into the membrane but accelerates the Pt particle growth due to electrochemical Ostwald ripening; meanwhile, a load cycle with long OCV holding time at lower RH prevents both the Pt dissolution and particle growth.

<div class="htmlview paragraph">The effect of the use of the EGR system on the lubrication of a passenger car diesel engine was investigated. The higher the EGR rate, the more soot in the oil. And the most detrimental effect was found in valve train wear. Some engine tests, including motoring tests, were carried out to investigate the contribution of soot to valve train wear. The mechanism of cam and rocker arm wear in used oils was studied by analyzing for elements on the lubricated metal surface and subsequently the mechanism was more thoroughly studied using the four-ball test. Soot seems to act as an abrasive on the anti-wear solid film formed by the oil on the metal surface and this film contains Ca, O, P and S. Some hardware modifications and oil formulations to reduce valve train wear are also discussed.</div>

<div class="htmlview paragraph">A novel leanburn concept, ‘Barrel-Stratification’ is proposed. Fuel is introduced into the cylinder through one of the intake ports of a dual-intake-valve engine of which the tumbling air motion is intensified by the sophisticated intake port design. Because the velocity component in the direction parallel to the axis of tumble is small, charge stratification realized during the intake stroke is maintained until the end of the compression stroke. By the effects of charge stratification and the turbulence enhancement by tumble, stable combustion is realized even at extremely lean conditions.</div> <div class="htmlview paragraph">The concept was verified by flow field analysis applying a multi-color laser sheet technique and the flame structure analysis employing the blue-end image intensification realized by the interference mirror and the short delay phosphor.</div> <div class="htmlview paragraph">The combustion process in a spark ignition engine is generally characterized as a combination of the air entrainment process, in which the flame front propagates at a speed determined by the turbulence intensity, and an eddy burning process in which the burning rate is determined by the laminar burning velocity and the turbulence length scale.</div> <div class="htmlview paragraph">For the enhancement of air entrainment, an increase of turbulence intensity is required, while for the increase of the eddy burning rate, a reduction of turbulence scale is required.</div> <div class="htmlview paragraph">Small scale turbulence is subject to dissipation. Therefore, to conserve the intense turbulence with a small scale until the combustion process, it is necessary to increase the kinetic energy introduced into the cylinder during the intake process, thereby conserving the kinetic energy by maintaining a large scale vortices and convert it into turbulence immediately before the combustion.</div> <div class="htmlview paragraph">As the large scale vortex employed for this purpose, swirl, that is, the horizontally rotating air motion has been adopted. Recently it has been reported that tumble, a large scale vertical rotational air motion around the axis perpendicular to the cylinder axis, may be adopted as an alternative of the conventional swirl <sup>(<span class="xref">1</span>, <span class="xref">2</span>, <span class="xref">3</span>, <span class="xref">4</span>, <span class="xref">5</span>, <span class="xref">6</span>, <span class="xref">7</span>, <span class="xref">8</span>, <span class="xref">9</span>, <span class="xref">10</span>, <span class="xref">11</span>, <span class="xref">12</span>, <span class="xref">13</span>, <span class="xref">14</span>, <span class="xref">15</span>, <span class="xref">16</span>, <span class="xref">17</span>, <span class="xref">18</span>, <span class="xref">19</span>, <span class="xref">20</span> and <span class="xref">21</span>)</sup>.</div> <div class="htmlview paragraph">Tumble is an air motion suitable for two-intake-valve engines with a pentroof-type combustion chamber. The authors have performed studies on the generation and distortion processes of tumble and its effects on combustion <sup>(<span class="xref">22</span>,<span class="xref">23</span>)</sup>. During the study, it was found that when the charge is stratified during the intake process by introducing the fuel from only one of the dual intake ports of a two-intake-valve engine, charge stratification is maintained during the compression process because the velocity component in the direction parallel to the axis of tumbling vortex is small.</div> <div class="htmlview paragraph">By using the effects of turbulence enhancement and the charge stratification realized by tumble, it was found, significant combustion enhancement could be realized in the extremely lean conditions such as the air fuel ratio of 30.</div> <div class="htmlview paragraph">Mitsubishi Motors Corporation named this lean combustion concept as the ‘Barrel-Stratification Method’, and developed a new engine, MVV (Mitsubishi Vertical Vortex) engine employing this concept. The authors consider that the potentiality of this method is remarkably high, because it realizes stratified charge lean combustion by efficiently using the fuel-air introduction property and in-cylinder flow characteristics inherent to the two-intake-valve engines with no additional devices such as a swirl control valve or a valve deactivation mechanism.</div> <div class="htmlview paragraph">Comprehensive studies on this system have been performed in the authors' laboratory. Results have been reported in several papers. Effects of intake port design on tumble intensity are described in <span class="xref">Reference (25)</span>. Characteristics of turbulence generated by tumble and its effects on combustion are reported in <span class="xref">References (22</span>,<span class="xref">23)</span>. Effects of tumble and charge stratification on flame structure are described in <span class="xref">Reference (29)</span>. Structure of the flow field after the distortion of tumble is clarified in <span class="xref">References (27</span>,<span class="xref">28)</span>. Strategies for the control of mixing are proposed in <span class="xref">Reference (30)</span>. Detailed configuration and the control strategies of the developed engine will be described in <span class="xref">References (31</span>,<span class="xref">32)</span>.</div> <div class="htmlview paragraph">In this paper, the concept of the proposed combustion system will be described using the selected experimental results. For the details, please refer to these papers.</div>

INTRODUCTION: We aimed to determine the prospective association of smoking status, smoking intensity, and smoking cessation with the risk of hearing loss in a large Japanese cohort. METHODS: The cohort study included 50195 employees, who were aged 20-64 years and free of hearing loss at baseline. Participants were followed up for a maximum of 8 years. Pure-tone audiometric testing was performed annually to identify hearing loss at 1 and 4 kHz. Cox proportional hazards regression models were used to investigate the association between smoking and hearing loss. RESULTS: During follow-up, 3532 individuals developed high-frequency hearing loss, and 1575 developed low-frequency hearing loss. The hazard ratio (HR) associated with current smokers was 1.6 (95% confidence interval [CI] = 1.5 to 1.7) and 1.2 (95% CI = 1.1 to 1.4) for high- and low-frequency hearing loss, respectively, as compared with never smokers. The risk of high- and low-frequency hearing loss increased with the number of cigarettes smoked per day (both p for trend <.001). The HR associated with former smokers was 1.2 (95% CI = 1.1 to 1.3) and 0.9 (95% CI = 0.8 to 1.1) for high- and low-frequency hearing loss, respectively. The analysis by quitting years showed a decline in risk of hearing loss after quitting smoking, even among those who quitted less than 5 years before baseline. CONCLUSIONS: Smoking is associated with increased risk of hearing loss, especially at the high frequency, in a dose-response manner. The excess risk of hearing loss associated with smoking disappears in a relatively short period after quitting. IMPLICATIONS: The prospective association between smoking and hearing loss has not been well studied. To the best of our knowledge, our study is the largest to date investigating the association between smoking and incident hearing loss. Our results indicate that smoking is associated with increased risk of hearing loss in a dose-response manner. Quitting smoking virtually eliminates the excess risk of hearing loss, even among quitters with short duration of cessation. These results suggest that smoking may be a causal factor for hearing loss, although further research would be required to confirm this. If so, this would emphasize the need for tobacco control to prevent or delay the development of hearing loss.

&lt;div class="htmlview paragraph"&gt;Crankshaft torque fluctuation has been theoretically analyzed and possible sources of error have been reviewed in the cases of determining the indicated mean effective pressure (P&lt;sub&gt;mi&lt;/sub&gt;) from measurement of the flywheel angular-speed fluctuation.&lt;/div&gt; &lt;div class="htmlview paragraph"&gt;The specific objective of this study was to develop a new approach to determine P&lt;sub&gt;mi&lt;/sub&gt; from the crankshaft torque of a SI engine, and it has successfully proven that using an appropriate data processing for the angular-speed fluctuation, P&lt;sub&gt;mi&lt;/sub&gt; in low- to medium-speed ranges can be estimated with very high accuracy in terms of 99% or higher coefficient of correlation to the in-cylinder pressure sensor.&lt;/div&gt;

OBJECTIVE: Risk models and scores have been developed to predict incidence of type 2 diabetes in Western populations, but their performance may differ when applied to non-Western populations. We developed and validated a risk score for predicting 3-year incidence of type 2 diabetes in a Japanese population. METHODS: Participants were 37,416 men and women, aged 30 or older, who received periodic health checkup in 2008-2009 in eight companies. Diabetes was defined as fasting plasma glucose (FPG) ≥ 126 mg/dl, random plasma glucose ≥ 200 mg/dl, glycated hemoglobin (HbA1c) ≥ 6.5%, or receiving medical treatment for diabetes. Risk scores on non-invasive and invasive models including FPG and HbA1c were developed using logistic regression in a derivation cohort and validated in the remaining cohort. RESULTS: The area under the curve (AUC) for the non-invasive model including age, sex, body mass index, waist circumference, hypertension, and smoking status was 0.717 (95% CI, 0.703-0.731). In the invasive model in which both FPG and HbA1c were added to the non-invasive model, AUC was increased to 0.893 (95% CI, 0.883-0.902). When the risk scores were applied to the validation cohort, AUCs (95% CI) for the non-invasive and invasive model were 0.734 (0.715-0.753) and 0.882 (0.868-0.895), respectively. Participants with a non-invasive score of ≥ 15 and invasive score of ≥ 19 were projected to have >20% and >50% risk, respectively, of developing type 2 diabetes within 3 years. CONCLUSIONS: The simple risk score of the non-invasive model might be useful for predicting incident type 2 diabetes, and its predictive performance may be markedly improved by incorporating FPG and HbA1c.

By exploring the pyrophosphate chemistry for rechargeable Li-ion batteries, we report the synthesis and electrochemical characterization of a Li2MnP2O7 cathode. Easily prepared by conventional solid-state synthesis (at 600 °C), the Li2MnP2O7 displays an Mn3+/Mn2+ redox potential centered at 4.45 V versus lithium. It has registered the highest voltage ever obtained for the Mn3+/Mn2+ redox couple in any Mn-based cathode material. Following the pristine and partially (Mn) substituted Li2FeP2O7 (3.5–3.9 V vs. Li) and Li2CoP2O7 (4.9 V vs. Li), which show the highest Fe3+/Fe2+ and Co3+/Co2+ redox potentials among the known cathode compounds, the highest Mn3+/Mn2+ redox voltage (ca. 4.45 V) in Li2MnP2O7 establishes ‘pyrophosphates’ as a novel family displaying the highest M3+/M2+ redox potentials among all polyanionic compounds. Fundamental study of these pyrophosphates can provide useful insights into design of high-voltage cathode materials.

&lt;div class="htmlview paragraph"&gt;The 4-stroke SI engine offers better performance if its valve events can be varied depending on the operating conditions. Some engines in production are therefore incorporated with variable valve timing (VVT) mechanisms. All of such mechanisms available today however are for two-mode change-over between low-and high-speed operations.&lt;/div&gt; &lt;div class="htmlview paragraph"&gt;To achieve even better output and fuel economy, a new multi-mode VVT mechanism has been developed, featured by a unique hydraulic device for three-mode change-over as follows:&lt;/div&gt; &lt;div class="htmlview paragraph"&gt; &lt;ul class="list disc"&gt; &lt;li class="list-item"&gt;&lt;div class="htmlview paragraph"&gt;Deactivate both intake and exhaust valves&lt;/div&gt; &lt;/li&gt; &lt;li class="list-item"&gt;&lt;div class="htmlview paragraph"&gt;Select low-speed cam with moderate lifts and short durations&lt;/div&gt; &lt;/li&gt; &lt;li class="list-item"&gt;&lt;div class="htmlview paragraph"&gt;Select high-speed cam with high lifts and long durations&lt;/div&gt; &lt;/li&gt; &lt;/ul&gt; &lt;/div&gt; &lt;div class="htmlview paragraph"&gt;This mechanism enables shutting off unnecessary cylinders during low-speed cruise, or select optimum valve events during WOT acceleration over the entire engine speed range. The engine with this VVT demonstrates a fuel economy improvement up 16% during the Japanese test driving cycle and a power increase by 20% from its predecessor.&lt;/div&gt;

&lt;div class="htmlview paragraph"&gt;Flow and flame structure visualization and modeling were performed to clarify the characteristics of bulk flow, turbulence and mixing in a four-valve engine to adopt the lean combustion concept named “Barrel-Stratification” to the larger displacement center-spark four-valve engine. It was found that the partitions provided in the intake port and the tumble-control piston with a curved-top configuration were effective to enhance the lean combustion of such an engine. By these methods, the fuel distribution in the intake port and the in-cylinder bulk flow structure are optimized, so that the relatively rich mixture zone is arranged around the spark plug. The tumble-control piston also contributes to optimize the flow field structure after the distortion of tumble and to enable stable lean combustion.&lt;/div&gt;

AIMS: The control of blood glucose levels, blood pressure (BP), and low-density lipoprotein cholesterol (LDL-C) levels reduces the risk of diabetes complications; however, data are scarce on control status of these factors among workers with diabetes. The present study aimed to estimate the prevalence of participants with diabetes who meet glycated hemoglobin (HbA1c), BP, and LDL-C recommendations, and to investigate correlates of poor glycemic control in a large working population in Japan. METHODS: The Japan Epidemiology Collaboration on Occupational Health (J-ECOH) Study is an ongoing cohort investigation, consisting mainly of employees in large manufacturing companies. We conducted a cross-sectional analysis of 3,070 employees with diabetes (2,854 men and 216 women) aged 20-69 years who attended periodic health examinations. BP was measured and recorded using different company protocols. Risk factor targets were defined using both American Diabetes Association (ADA) guidelines (HbA1c < 7.0%, BP < 140/90 mmHg, and LDL-C < 100 mg/dL) and Japan Diabetes Society (JDS) guidelines (HbA1c < 7.0%, BP < 130/80 mmHg, and LDL-C < 120 mg/dL). Logistic regression models were used to explore correlates of poor glycemic control (defined as HbA1c ≥ 8.0%). RESULTS: The percentages of participants who met ADA (and JDS) targets were 44.9% (44.9%) for HbA1c, 76.6% (36.3%) for BP, 27.1% (56.2%) for LDL-C, and 11.2% (10.8%) for simultaneous control of all three risk factors. Younger age, obesity, smoking, and uncontrolled dyslipidemia were associated with poor glycemic control. The adjusted odds ratio of poor glycemic control was 0.58 (95% confidence interval, 0.46-0.73) for participants with treated but uncontrolled hypertension, and 0.47 (0.33-0.66) for participants with treated and controlled hypertension, as compared with participants without hypertension. There was no significant difference in HbA1c levels between participants with treated but uncontrolled hypertension and those with treated and controlled hypertension. CONCLUSION: Data from a large working population, predominantly composed of men, suggest that achievement of HbA1c, BP, and LDL-C targets was less than optimal, especially in younger participants. Uncontrolled dyslipidemia was associated with poor glycemic control. Participants not receiving antihypertensive treatment had higher HbA1c levels.