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Aims/Introduction: Changes in histologically quantified β‐ and α‐cell mass during the development of glucose intolerance have not been fully elucidated. The aim of the present study was to explore differences in β‐ and α‐cell mass according to the glucose tolerance status. Materials and Methods: Autopsy samples from a total of 103 individuals (40 with normal glucose tolerance, 31 with prediabetes and 32 with type 2 diabetes mellitus) who underwent a 75‐g oral glucose tolerance test within 5 years before death were selected from 643 community‐based autopsy samples collected from 2002 to 2016. Fractional β‐cell area (BCA) and α‐cell area were quantified with Image Pro Plus software. Associations of BCA and α‐cell area with glucose tolerance status were assessed using a linear regression analysis, and Spearman's correlation coefficients between glycemic markers and β‐cell function were estimated. Results: The mean values of BCA decreased significantly with worsening glucose tolerance status (mean ± standard error 1.85 ± 0.10% in normal glucose tolerance, 1.59 ± 0.11% in prediabetes and 1.17 ± 0.11% in type 2 diabetes mellitus, P for trend < 0.001), whereas there was no significant association between α‐cell area and glucose tolerance status. BCA was inversely correlated with fasting and 2‐h plasma glucose levels during oral glucose tolerance test and glycated hemoglobin measurement, and positively correlated with disposition index (all P < 0.01). Conclusions: β‐Cell mass decreased significantly with worsening glucose tolerance, from the stage of prediabetes, in the Japanese population. Prevention of declining β‐cell mass before the onset of glucose intolerance is important to reduce the burden of type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]

Purpose: In assisted reproductive technology, normal zygotes are bipronuclear (2PN) during fertilization confirmation; however, sometimes, nonpronuclear zygotes (0PN) and monopronuclear zygotes (1PN) are found during routine observations. Methods: To elucidate the clinical usefulness of in vitro‐fertilized embryos, we investigated the rates of clinical pregnancy, live birth, miscarriage, and congenital abnormality after transfer of frozen‐thawed 1PN‐ and 0PN‐derived single blastocysts at Denentoshi Ladies Clinic, Kanagawa, Japan. Results: The rates of pregnancy and live birth for 1PN‐derived blastocysts obtained by conventional in vitro fertilization were 37.5% and 27.1%, respectively, which was not significantly different from those for 2PN‐derived blastocysts; however, the rates for 0PN‐derived blastocysts were significantly lower. The pregnancy and live birth rates for 0PN‐derived embryos obtained by intracytoplasmic sperm injection (ICSI) were 45.7% and 34.8%, respectively, which was not significantly different from those for 2PN‐derived blastocysts; however, the rates for 1PN‐derived blastocysts were significantly lower (4.0% for both) than those for 2PN‐ and 0PN‐derived blastocysts. No congenital abnormalities were found in infants resulting from transfer of 0PN‐ or 1PN‐derived blastocysts. Conclusions: Both 1PN‐ and 0PN‐derived blastocysts can be used for embryo transfer; however, care should be taken in making decisions about 1PN‐derived blastocysts, especially if they are obtained by ICSI. [ABSTRACT FROM AUTHOR]

Aims/Introduction: The present study aimed to examine cross‐sectional associations between objectively measured sedentary time and the prevalence of diabetes mellitus in a general Japanese population, and to elucidate possible mediating roles of diet, obesity and insulin resistance in this relationship. Materials and Methods: A total of 1,758 community‐dwelling individuals aged 40–79 years wore an accelerometer for ≥7 days and underwent a comprehensive health examination in 2012. Diabetes mellitus was diagnosed by a 75‐g oral glucose tolerance test. The associations of sedentary time with the presence of diabetes mellitus and the levels of the homeostasis model assessment of insulin resistance were estimated by logistic and linear regression models. Results: After adjustment for demographic and lifestyle factors including moderate‐to‐vigorous physical activity, participants who spent ≥10 h in sedentary time had a significantly higher odds ratio of the presence of diabetes than those who spent <6 h in sedentary time (odds ratio 1.84, 95% confidence interval 1.02–3.31). This significant association remained after adjusting for overall and central obesity (as measured by body mass index and waist circumference), but weakened after adjusting for dietary energy intake or homeostasis model assessment of insulin resistance. Sedentary time was positively associated with homeostasis model assessment of insulin resistance levels among non‐diabetic participants after adjusted for obesity or energy intake (P for trend <0.01). Conclusions: Longer sedentary time was associated with a higher prevalence of diabetes mellitus in a general Japanese population. Insulin resistance appeared to be mainly involved in this association. These results highlight the importance of public health strategies targeting reductions in sedentary time for the primary prevention of diabetes mellitus. [ABSTRACT FROM AUTHOR]

Summary: The aim of the present study was to examine the prevalence and causes of adult epilepsy in a general Japanese population. We examined a total of 3333 Japanese residents in the town of Hisayama aged ≥40 years in 2012‐2013. The examination was performed mainly at the municipal center for health promotion, but some subjects were examined in their homes, hospitals, or nursing homes. Twenty‐three subjects had a diagnosis of epilepsy. The prevalence (95% confidence interval [CI]) of epilepsy per 1000 was 6.9 (4.1‐9.7) in total, 4.9 (1.3‐8.5) in men, and 8.4 (4.3‐12.5) in women (P = 0.23 between sexes). The prevalence of epilepsy was significantly higher in the elderly (aged ≥65 years; 10.3 per 1000 [95% CI 5.4‐15.1]) than in the middle‐aged (aged 40‐64 years; 3.6 per 1000 [95% CI 0.7‐6.4]; P = 0.02). The major cause of epilepsy was cerebrovascular diseases (n = 11; 48% of the epilepsy patients). More than half of the epilepsy patients experienced the first episode of seizure in older age (≥65 years; n = 13; 57%). The findings of this study suggest the clinical importance of the prevention of cerebrovascular diseases to reduce the burden of epilepsy in the future. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the association between daily sleep duration and risk of dementia and death in a Japanese elderly population. Design: Prospective cohort study. Setting: The Hisayama Study, Japan. Participants: Community‐dwelling Japanese individuals aged 60 and older without dementia. Measurements: Self‐reported daily sleep duration was grouped into 5 categories (<5.0, 5.0–6.9, 7.0–7.9, 8.0–9.9, ≥10.0 hours). The association between daily sleep duration and risk of dementia and death was determined using a Cox proportional hazards models. Results: During follow‐up, 294 participants developed dementia, and 282 died. Age‐ and sex‐adjusted incidence rates of dementia and all‐cause mortality were significantly greater in subjects with daily sleep duration of less than 5.0 hours and 10.0 hours and more than in those with daily sleep duration of 5.0 to 6.9 hours. These associations remained unchanged after adjustment for potential confounding factors (<5.0 hours: hazard ratio (HR)=2.64, 95% confidence interval (CI)=1.38–5.05 for dementia; HR=2.29, 95% CI=1.15–4.56 for death; ≥10.0 hours: HR=2.23, 95% CI=1.42–3.49 for dementia; HR=1.67, 95% CI=1.07–2.60 for death). Similar U‐shaped associations were observed for Alzheimer's disease and vascular dementia. With regard to the influence of hypnotic use on risk of dementia and death, subjects who used hypnotics and had any sleep duration had a risk of dementia that was 1.66 times as great and a risk of death that was 1.83 times as great as those who did not use hypnotics and had a daily sleep duration of 5.0 to 6.9 hours. Conclusion: Short and long daily sleep duration and hypnotic use are risk factors for dementia and death in Japanese elderly adults. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To clarify the association between midlife and late-life smoking and risk of dementia. DESIGN: Prospective cohort study. SETTING: The Hisayama Study, Japan. PARTICIPANTS: Japanese community-dwellers without dementia aged 65 to 84 (mean age 72) followed for 17 years (1988-2005) (N = 754), 619 of whom had participated in a health examination conducted in 1973-74 (mean age, 57) and were included in the midlife analysis. MEASUREMENTS: The risk estimates of smoking status on the development of dementia were computed using a Cox proportional hazards model. RESULTS: During follow-up, 252 subjects developed all-cause dementia; 143 had Alzheimer's disease (AD), and 76 had vascular dementia (VaD). In late life, the multi-variable-adjusted risk of all-cause dementia was significantly greater in current smokers than in never smokers; similar associations were seen for all-cause dementia, AD, and VaD in midlife current smokers. Meanwhile, no significant association was observed between past smoking and risk of any type of dementia in late or midlife. Multivariable analysis showed that smokers in midlife and late life had significantly greater risks than lifelong nonsmokers of all-cause dementia (adjusted hazard ratio (aHR) = 2.28, 95% confidence interval (CI) = 1.49-3.49), AD (aHR = 1.98, 95% CI = 1.09-3.61), and VaD (aHR = 2.88, 95% CI = 1.34-6.20). Such associations were not observed for midlife smokers who quit smoking in late life. CONCLUSION: Persistent smoking from mid- to late life is a significant risk factor for dementia and its subtypes in the general Japanese population. [ABSTRACT FROM AUTHOR]

Objectives To determine the effect of milk and dairy intake on the development of all-cause dementia and its subtypes in an elderly Japanese population. Design Prospective cohort study. Setting The Hisayama Study, Japan. Participants Individuals aged 60 and older without dementia (N = 1,081). Measurements Milk and dairy intake was estimated using a 70-item semiquantitative food frequency questionnaire grouped into quartiles. The risk estimates of milk and dairy intake on the development of all-cause dementia, Alzheimer's disease ( AD), and vascular dementia (VaD) were computed using a Cox proportional hazards model. Results Over 17 years of follow-up, 303 subjects developed all-cause dementia; 166 had AD, and 98 had VaD. The age- and sex-adjusted incidence of all-cause dementia, AD, and VaD significantly decreased as milk and dairy intake level increased ( P for trend = .03 for all-cause dementia, .04 for AD, .01 for VaD). After adjusting for potential confounders, the linear relationship between milk and dairy intake and development of AD remained significant ( P for trend = .03), whereas the relationships with all-cause dementia and VaD were not significant. The risk of AD was significantly lower in the second, third, and fourth quartiles of milk and dairy intake than in the first quartile. Conclusion Greater milk and dairy intake reduced the risk of dementia, especially AD, in the general Japanese population. [ABSTRACT FROM AUTHOR]

Aims/Introduction We examined secular trends in the prevalence of type 2 diabetes and prediabetes in community-dwelling Japanese subjects. Materials and Methods A total of 2,490 subjects in 1988 and 2,852 subjects in 2002 aged 40-79 years underwent a 75-g oral glucose tolerance test, and their glucose tolerance status was defined by the 1998 World Health Organization criteria. Results The age-adjusted prevalence of type 2 diabetes increased significantly from 1988 to 2002 in men (14.6% in 1988 to 20.8% in 2002, P < 0.001) and women (9.1% in 1988 to 11.2% in 2002, P = 0.002). A significant rise in the age-adjusted prevalence of prediabetes was also observed in both sexes (26.2% in 1988 to 35.3% in 2002, P < 0.001 for men; 22.5% in 1988 to 25.1% in 2002, P = 0.04 for women). In age-stratified analysis, the prevalence of type 2 diabetes increased markedly over time in men aged 60-69 and 70-79 years (both P < 0.001) and women aged 70-79 years ( P = 0.02). The prevalence of overall and central obesity increased significantly in men aged 60-69 and 70-79 years, and women aged 70-79 years from 1988 to 2002, whereas the frequency of regular exercise decreased significantly in men aged 70-79 years between the surveys. Conclusions Our findings suggest that the prevalence of type 2 diabetes and prediabetes increased significantly in both sexes from the 1980s to the 2000s in a general Japanese population, and that the increasing prevalence of obesity and the decline in physical activity exerted an influence on this rising trend. [ABSTRACT FROM AUTHOR]

Aims Periodontal disease and metabolic syndrome ( MS) are more prevalent in males than in females. However, whether there is a gender difference in the association between these health conditions has not yet been investigated. This study examined the gender difference in this association, considering the definition of periodontal disease. Materials and Methods We recruited 1040 males and 1330 females, aged ≥40 years, with at least ten teeth from subjects of the 2007 Hisayama health examination. We performed a logistic regression analysis with various definitions of periodontal disease the dependent variable and MS as the independent variable. Following the analysis, the data were reanalysed with the structural equations model. Results The logistic regression analysis suggested a stronger association between periodontal disease and MS in females than that in males when periodontal disease was more severely defined. When we constructed the structural equations model in each gender, the model showed a good fit to the data of females, suggesting the association between periodontal disease and MS in females, but not in males. Conclusions Gender differences seem to exist in the association between periodontal disease and MS; MS might show a stronger association with periodontal disease in females than in males. [ABSTRACT FROM AUTHOR]