The Association Between Adult Height and Stroke Incidence in Japanese Men and Women: A Population-based Case-Control Study.

BACKGROUND: No studies have examined the associations between adult height and ischemic stroke subtypes. METHODS: We conducted a population-based case-control study that included 2,451 thrombotic and 687 embolic stroke cases, as well as 1,623 intracerebral and 768 subarachnoid hemorrhage cases without history of stroke aged 40-79 years, and the same number of sex- and age-matched controls. Cases and controls were grouped according to the quintile cut-off values of height in controls, and the third quintile, which was approximately the average height group, was used as the reference group. Height divided by one standard deviation of height in controls was also examined as a continuous variable. The analyses were carried out separately for participants aged 40-59 years and 60-79 years. RESULTS: In both younger and older men, height was linearly inversely associated with total and thrombotic strokes, and the shortest quintile compared to the reference group was associated with increased risks of these strokes. Although height was linearly inversely associated with embolic stroke and intracerebral hemorrhage in younger men, the shortest quintile did not show increased risks of these strokes. Height did not seem to be associated with total stroke and any stroke subtypes in younger women. In contrast, the tallest quintile was significantly associated with increased risks of total stroke and intracerebral hemorrhage, and height tended to be positively associated with these strokes in older women. CONCLUSION: We reported the associations between adult height and ischemic stroke subtypes for the first time, which differed according to sex and age group.

The association between objective measures of residence and worksite neighborhood environment, and self-reported leisure-time physical activities: The Aichi Workers' Cohort Study.

The possible effects of a neighborhood's built environment on physical activity have not been studied in Asian countries as much as in Western countries. The present study cross-sectionally examined the relationship between geographic information system (GIS) measured residence and worksite neighborhood walkability, and the number of parks/green spaces and sports facilities within a 1 km radius of home and workplace, with self-reported leisure-time habitual (3-4 times per week or more) walking and moderate-to-vigorous intensity habitual exercise among local government workers aged 18 to 64 years living in an urban-suburban area of Aichi, Japan in 2013. A single-level binomial regression model was used to estimate the multivariable odds ratios (ORs) and 95% confidence intervals (95% CIs). Of the 1959 male and 884 female participants, 288 (15%) and 141 (16%) reported habitual walking, respectively, and 18% and 17% reported habitual exercise, respectively. Compared with women who resided in neighborhood with a walkability index of 4-30, those living in an area with that of 35-40 were significantly more likely to engage in leisure-time habitual exercise (multivariable OR: 1.70, 95% CI: 1.08-2.68). Marginally significant positive associations were found between leisure-time habitual exercise and the residential neighborhood's number of parks/green spaces among women, as well as the number of sports facilities among men. In conclusion, a residential neighborhood environment characterized by higher walkability may contribute to the initiation or maintenance of moderate-to-vigorous intensity leisure-time exercise among working women living in an urban-suburban area of Japan.

A Point System for Predicting 10-Year Risk of Developing Type 2 Diabetes Mellitus in Japanese Men: Aichi Workers' Cohort Study.

BACKGROUND: Relatively little evidence exists for type 2 diabetes mellitus (T2DM) prediction models from long-term follow-up studies in East Asians. This study aims to develop a point-based prediction model for 10-year risk of developing T2DM in middle-aged Japanese men. METHODS: We followed 3,540 male participants of Aichi Workers' Cohort Study, who were aged 35-64 years and were free of diabetes in 2002, until March 31, 2015. Baseline age, body mass index (BMI), smoking status, alcohol consumption, regular exercise, medication for dyslipidemia, diabetes family history, and blood levels of triglycerides (TG), high density lipoprotein cholesterol (HDLC) and fasting blood glucose (FBG) were examined using Cox proportional hazard model. Variables significantly associated with T2DM in univariable models were simultaneously entered in a multivariable model for determination of the final model using backward variable selection. Performance of an existing T2DM model when applied to the current dataset was compared to that obtained in the present study's model. RESULTS: During the median follow-up of 12.2 years, 342 incident T2DM cases were documented. The prediction system using points assigned to age, BMI, smoking status, diabetes family history, and TG and FBG showed reasonable discrimination (c-index: 0.77) and goodness-of-fit (Hosmer-Lemeshow test, P = 0.22). The present model outperformed the previous one in the present subjects. CONCLUSION: The point system, once validated in the other populations, could be applied to middle-aged Japanese male workers to identify those at high risk of developing T2DM. In addition, further investigation is also required to examine whether the use of this system will reduce incidence.

Blood pressure, heart rate, and double product in a pooled cohort: the Japan Arteriosclerosis Longitudinal Study.

OBJECTIVE: To identify the characteristics of blood pressure (BP), heart rate (HR), and double product in a Japanese population sample. METHODS: We pooled individual records from 1999 to 2005 for 111 007 participants in 25 community-based cohorts and seven worksite-based cohorts. The data were analyzed to provide information on BP, HR, and double product according to age-sex groups and use of antihypertensive medication. RESULTS: Average BP was 130/77 mmHg among men and women combined. Among untreated individuals, SBP increased with age, whereas DBP reached a ceiling around the age of 60 years. The average SBP of treated participants was around 140 mmHg, irrespective of age, whereas DBP decreased linearly with age, and 56.4% of treated participants had a BP of 140/90 mmHg or over. HR did not differ across age groups or treatment status. The double product, also called the rate-pressure product, calculated by multiplying the SBP and the HR, increased with age among untreated individuals, whereas it first decreased and then increased with age among treated individuals. CONCLUSION: Based on these collaborative data, insufficient BP control in Japan, where the average life expectancy is the longest in the world, was seen.

Association between parental history of diabetes and the incidence of type 2 diabetes mellitus differs according to the sex of the parent and offspring's body weight: A finding from a Japanese worksite-based cohort study.

OBJECTIVE: To investigate differences in the association of parental history of diabetes with the risk of type 2 diabetes mellitus (T2DM) in the offspring according to the sex of the parent and the offspring's body weight. METHODS: A prospective cohort study of 4446 middle-aged non-diabetic Japanese men and women were followed in Aichi Prefecture, central Japan, from 2002 to 2011. Subjects were categorized by their self-reported parental history of diabetes ("no parental history," "father only," "mother only," and "both"). The association of parental history of diabetes and incidence in the offspring was examined according to overweight status adjusted for age, sex, birth weight, smoking, alcohol consumption, physical activity, total energy intake, body mass index, and number of metabolic syndrome components. RESULTS: During follow-up (median 8.9 years), 277 subjects developed T2DM. Parental history of diabetes was positively associated with T2DM incidence. However, stratified analysis by overweight status revealed that only maternal history was associated with increased T2DM incidence in non-overweight subjects (hazard ratio=2.35, 95% confidence interval: 1.41-3.91). While in overweight subjects, paternal history was significantly associated with higher T2DM incidence (hazard ratio=1.98, 95% confidence interval: 1.19-3.28). CONCLUSIONS: Our results suggest that parental history of diabetes mellitus is associated with the incidence of T2DM in offspring differently according to the sex of the affected parent and the offspring's body weight.

Breakfast Skipping is Positively Associated With Incidence of Type 2 Diabetes Mellitus: Evidence From the Aichi Workers' Cohort Study.

BACKGROUND: Skipping breakfast has been suspected as a risk factor for type 2 diabetes (T2DM), but the associations are not entirely consistent across ethnicities or sexes, and the issue has not been adequately addressed in the Japanese population. METHODS: We followed 4631 participants (3600 men and 1031 women) in a work-site cohort of participants aged 35-66 years in 2002 through 2011 for T2DM development. Frequency of eating breakfast was self-reported and was subsequently dichotomized to breakfast skippers, who eat breakfast 3-5 times/week or less, and to eaters. Cox proportional hazards models were used to adjust for potential confounding factors, including dietary factors, smoking and other lifestyles, body mass index (BMI), and fasting blood glucose (FBG) at baseline. RESULTS: During 8.9 years of follow-up, 285 T2DM cases (231 men and 54 women) developed. Compared to participants who reported eating breakfast every day, maximally-adjusted hazard ratios and 95% confidence intervals (CI) of those with the frequency of almost every day and 3-5, 1-2, and 0 days/week were: 1.06 (95% CI, 0.73-1.53), 2.07 (95% CI, 1.20-3.56), 1.37 (95% CI, 0.82-2.29), and 2.12 (95% CI, 1.19-3.76), respectively. In a dichotomized analysis, breakfast skipping was positively associated with T2DM incidence (maximally-adjusted hazard ratio 1.73; 95% CI, 1.24-2.42). The positive associations were found in both men and women, current and non-current smokers, normal weight and overweight (BMI ≥ 25 kg/m(2)), and normal glycemic status and impaired fasting glycemic status (FBG 110 to <126 mg/dL) individuals at baseline (Ps for interaction all >0.05). CONCLUSIONS: The present study in middle-aged Japanese men and women suggests that skipping breakfast may increase the risk of T2DM independent of lifestyles and baseline levels of BMI and FBG.

Smoking and diabetes: is the association mediated by adiponectin, leptin, or C-reactive protein?

BACKGROUND: Although the association between cigarette smoking and risk of type 2 diabetes is well established, its mechanisms are yet to be clarified. This study examined the possible mediating effects of adiponectin, leptin, and C-reactive protein (CRP) concentrations on the smoking-diabetes association. METHODS: Between 2002 and 2011, we followed 3338 Japanese workers, aged 35-66 years, who were enrolled in the second Aichi workers' cohort study. We used multivariable-adjusted Cox regression models to determine the hazard ratios and respective 95% confidence intervals (CIs) of the association between smoking status and risk of diabetes. A multiple mediation model with bootstrapping was used to estimate the magnitude and the respective bias-corrected (BC) 95% CIs of the indirect effects of smoking on diabetes through the three biomarkers. RESULTS: Relative to never smokers, the risk of diabetes was significantly elevated in current (hazard ratio 1.75, 95% CI 1.25-2.46) and ex-smokers (hazard ratio 1.54, 95% CI 1.07-2.22). The indirect effects of smoking on diabetes through adiponectin levels were statistically significant among light (point estimate 0.033, BC 95% CI 0.005-0.082), moderate (point estimate 0.044, BC 95% CI 0.010-0.094), and heavy smokers (point estimate 0.054, BC 95% CI 0.013-0.113). In contrast, neither the indirect effects of smoking on diabetes through leptin nor CRP levels were significant, as the corresponding BC 95% CIs included zero. CONCLUSIONS: In our analysis, adiponectin concentration appeared to partially mediate the effect of smoking on diabetes, while leptin and CRP levels did not.

Independent association of liver fat accumulation with insulin resistance.

BACKGROUND: To examine the association of intrahepatic fat with homeostasis model assessment-insulin resistance (HOMA-IR), a marker of insulin resistance, in Japanese adults, and whether intrahepatic fat is associated with insulin resistance independent of waist circumference and other measures of obesity. METHODS: Fifty-three individuals aged 37-69 were studied. Spectrum obtained using a 3-T magnetic resonance imager was analysed with LCModel to quantify intrahepatic fat. Blood levels of insulin, glucose and other biochemical markers were obtained after 8h or more fasting. Percent body fat was estimated by a bioelectrical impedance analyzer. HOMA-IR and intrahepatic fat content were log-transformed in the analysis. RESULTS: We found a positive correlation between intrahepatic fat and HOMA-IR, which was independent of the anthropometric measures of obesity. In contrast, significant and positive correlations of body mass index, percent body fat, and waist circumference with HOMA-IR were largely explained by their associations with intrahepatic fat. Intrahepatic fat was positively associated with alanine transaminase and triglycerides even after adjustment for HOMA-IR. CONCLUSION: Intrahepatic fat was associated with insulin resistance independent of age, sex, and measures of obesity in Japanese adults. Hypertriglyceridemia and liver injury may directly occur subsequent to intrahepatic fat accumulation.

Body mass index-modified relationship of chronic mental stress with resting blood pressure during 5 years in Japanese middle-aged male workers.

BACKGROUND: Chronic mental stress has been reported to be directly or inversely proportional to blood pressure (BP). To explain this inconsistent relationship, we assumed effect-modification by body mass index (BMI). METHODS AND RESULTS: We examined 1,673 Japanese male local government employees who were not taking antihypertensive drugs or had no history of cardiovascular disease. BP and BMI were recorded at yearly health checkups. Exposure to mental stress, smoking, drinking, exercising, and salty taste were checked by questionnaire in 1997 and 2002. The main effect and interaction of stress and BMI on the averages and changes of resting systolic and diastolic BPs over the 5 years were assessed by a general linear model by adjusting for confounders. Obesity (BMI ≥25kg/m(2)) was significantly related with higher average systolic and diastolic BPs (P<0.001, P<0.001, respectively), whereas mental stress was not, showing a significantly different relationship dependent on BMI (P for interaction =0.002, 0.004): a significant and directly proportional association with systolic and diastolic BPs (P=0.001, 0.001) in the obese, but borderline significant and inversely proportional association (P=0.07, 0.08) in the lean. Only BMI was significantly related to the degree of BP change. CONCLUSIONS: Whereas BMI was proportionally associated with BP, BMI was a modifier which, depending on its level, inverted the direction of the association between chronic mental stress and resting BP.

Positive association between high-sensitivity C-reactive protein and incidence of type 2 diabetes mellitus in Japanese workers: 6-year follow-up.

BACKGROUND: Elevated high-sensitivity C-reactive protein (hs-CRP), a marker of low-grade systemic inflammation, may be involved in the etiology of type 2 diabetes mellitus (T2DM). However, whether inflammation precedes development of T2DM independent of cigarette smoking and obesity remains to be confirmed. METHODS: We studied 4213 civil servants in a local government in Japan aged 35-66 years at baseline in 2002, who donated blood samples and were followed 6 years. Hazard ratios (HR) of T2DM according to the hs-CRP quartiles [range Q1: 0.02-0.18 (reference), Q2: 0.18-0.33, Q3: 0.33-0.67 and Q4: 0.67-9.62 mg/L) were estimated by Cox proportional hazards model adjusted for gender, age, body mass index, alcohol intake, smoking status (current, past and never), number of cigarettes per day, physical activity, family history of diabetes (Model 1) and variables in Model 1 + glucose (Model 2). RESULTS: The geometric mean [95% confidence interval (CI)] of hs-CRP was 0.36 mg/L (0.34-0.37). During the follow-up, 156 new T2DM cases were confirmed. In total sample, Model 2 HRs (95% CIs) for hs-CRP quartiles Q2-Q4 compared with Q1 were 0.69 (0.36-1.26), 1.47 (0.91-2.39) and 1.78 (1.10-2.88), respectively (p for linear trend = 0.014). Stratified analysis revealed that a statistically significant association was observed only in normal weight non-current smokers with Model 2 HRs (CIs) being 0.79 (0.29-2.17), 2.63 (1.25-5.56) and 3.19 (1.49-6.86) for Q2-Q4 compared with Q1, respectively (p for linear trend = 0.0006). The relationship did not change materially after further adjusting for log-homeostasis model assessment or exclusion of past smokers. CONCLUSIONS: These findings imply that higher hs-CRP itself or existence of chronic systemic inflammation precedes onset of T2DM independent of obesity and smoking.

Associations of protein, fat, and carbohydrate intakes with insomnia symptoms among middle-aged Japanese workers.

BACKGROUND: Diet is a modifiable factor that may affect sleep, but the associations of macronutrient intakes with insomnia are inconsistent. We investigated the associations of protein, fat, and carbohydrate intakes with insomnia symptoms. METHODS: In this cross-sectional analysis of 4435 non-shift workers, macronutrient intakes were assessed by the brief-type self-administered diet history questionnaire, which requires the recall of usual intakes of 58 foods during the preceding month. Presence of insomnia symptoms, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and poor quality of sleep (PQS) were self-reported. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs adjusted for demographic, psychological, and behavioral factors, as well as medical histories. RESULTS: Low protein intake (<16% vs ≥16% of total energy) was associated with DIS (OR 1.24, 95% CI 0.99-1.56) and PQS (OR 1.24, 95% CI 1.04-1.48), while high protein intake (≥19% vs <19% of total energy) was associated with DMS (OR 1.40, 95% CI 1.12-1.76). Low carbohydrate intake (<50% vs ≥50% of total energy) was associated with DMS (OR 1.19, 95% CI 0.97-1.45). CONCLUSIONS: Protein and carbohydrate intakes in the daily diet were associated with insomnia symptoms. The causality of these associations remains to be explained.

Characteristics of hypertension-related factors in female home caregivers in Japan-comparison with general community non-caregivers.

AIMS AND OBJECTIVES: To examine the characteristics of hypertension-related factors in female family caregivers in Japan who provide care in the home, in comparison with general community non-caregivers. BACKGROUND: Hypertension is more frequently encountered in female caregivers than in non-caregivers. Lifestyle factors including sleep and eating habits differ in Japanese female caregivers and the general population. Therefore, hypertension-related factors in caregivers may also differ from those in the general population. DESIGN: A cross-sectional study. METHODS: The subjects were 150 female caregivers (aged 62·4, SD 12·2 years) who provided home care for persons with physical impairments and/or dementia and 154 female controls (aged 62·7, SD 2·2 years) who did not provide home care. Persons with a history of ischaemic heart disease or cerebral stroke were excluded. Subjects were examined using a self-reporting questionnaire that included a food frequency questionnaire and the tri-axial coping scale. Urine examinations and blood pressure measurements were also done. Logistic regression analysis was conducted for each group with the same variables as explanatory variables. RESULTS: Hypertension was present in 46·7% of caregivers and 34·4% of controls (p<0·05). Menopause was a factor related to hypertension in both the caregivers and controls. In the caregiver group, hypertension was associated with the estimated 24-h Na excretion in urine and the carbohydrate-energy ratio for nutriti. BMI was associated with hypertension in the control group, but not in the caregiver group. CONCLUSIONS: Hypertension was associated with nutritional factors, such as greater Na excretion in urine and higher carbohydrate energy ratio, in Japanese female caregivers and with obesity in non-caregivers. RELEVANCE TO CLINICAL PRACTICE: To prevent hypertension, it is necessary to carefully monitor salt intake and nutritional balance in female caregivers in Japan.

Inverse relationship of serum adiponectin concentration with type 2 diabetes mellitus incidence in middle-aged Japanese workers: six-year follow-up.

BACKGROUND: It was suggested that inflammation may mediate or modify biological effects of adiponectin. Few studies examined the association between circulating adiponectin levels and type 2 diabetes (T2DM) while controlling for variables related to inflammation. In addition, East Asians were reported to have lower adiponectin levels but higher diabetes prevalence at a given degree of obesity than Caucasians, raising some possibility that the adiponectin-diabetes association may differ by race. Therefore, we prospectively investigated the associations with a number of covariates including C-reactive protein and smoking status in a cohort of Japanese workers aged 35-66 years. METHODS: Serum adiponectin concentration and other covariates were obtained in 2002 for 3008 civil servants free of T2DM at baseline in urban/suburban Japan. T2DM incidence was defined as the year when annually assessed fasting blood glucose level first exceeded 126 mg/dL or self-reported initiation of medication through 2007. T2DM incidence was examined in relation to the adiponectin quintile. RESULTS: Age- and sex-adjusted homeostasis model assessment insulin resistance was inversely associated with adiponectin quintiles at baseline. During six years of follow-up, 164 individuals developed T2DM. In a fully adjusted model, hazard ratios (95% confidence intervals) of T2DM in Q2 to Q5 compared with that in Q1 were 0.62 (0.41-0.94), 0.44 (0.25-0.77), 0.40 (0.20-0.78) and 0.85 (0.48-1.49), respectively. CONCLUSIONS: Low adiponectin was related to increased incidence of T2DM independent of baseline levels of blood glucose, insulin and C-reactive protein as well as other confounding variables in middle-aged Japanese. Whether high adiponectin is linearly associated with decreased T2DM risk needs further investigation.

Coffee, green tea, black tea and oolong tea consumption and risk of mortality from cardiovascular disease in Japanese men and women.

BACKGROUND: The effects of coffee and green, black and oolong teas and caffeine intake on cardiovascular disease (CVD) mortality have not been well defined in Asian countries. METHODS: To examine the relationship between the consumption of these beverages and risk of mortality from CVD, 76,979 individuals aged 40-79 years free of stroke, coronary heart disease (CHD) and cancer at entry were prospectively followed. The daily consumption of beverages was assessed by questionnaires. RESULTS: 1362 deaths were documented from strokes and 650 deaths from CHD after 1,010,787 person-years of follow-up. Compared with non-drinkers of coffee, the multivariable HR and 95% CI for those drinking 1-6 cups/week, 1-2 cups/day and ≥ 3 cups/day were 0.78 (0.50 to 1.20), 0.67 (0.47 to 0.96) and 0.45 (0.17 to 0.87) for strokes among men (p = 0.009 for trend). Compared with non-drinkers of green tea, the multivariable HR for those drinking 1-6 cups/week, 1-2 cups/day, 3-5 cups/day and ≥ 6 cups/day were 0.34 (0.06-1.75), 0.28 (0.07-1.11), 0.39 (0.18-0.85) and 0.42 (0.17-0.88) for CHD among women (p = 0.038 for trend). As for oolong tea, the multivariable HR of those drinking 1-6 cups/week and ≥ 1 cups/day were 1.00 (0.65-1.55) and 0.39 (0.17-0.88) for total CVD among men (p = 0.049 for trend). Risk reduction for total CVD across categories of caffeine intake was most prominently observed in the second highest quintile, with a 38% lower risk among men and 22% among women. CONCLUSIONS: Consumption of coffee, green tea and oolong tea and total caffeine intake was associated with a reduced risk of mortality from CVD.

[Blood pressure control through awareness of hypertension among female in-home caregivers].

OBJECTIVES: Our purpose was to clarify the situation regarding blood pressure control through awareness of hypertension among female groups of in-home caregivers and non-caregivers. METHODS: We used one existing data generated between December 2005 and April 2007. The subjects were females who were suffering from hypertension (66 caregivers were aged 49-84 years; 52 non-caregivers were aged 47-81 years). We defined persons suffering from hypertension on the basis of results of a self-administered questionnaire and blood pressure values. On the question of awareness of hypertension, we defined the persons who replied positively to any one of "I have hypertension," "I have suffered from hypertension," or "I take antihypertensive agents" as belonging to the "awareness group." We categorized the other respondents, who replied to all three questions in the negative as belonging to the "non-awareness group." We used blood pressure values, to build an index of the control with the chi2 test and the t-test for statistical comparisons. Values of P < 0.05 were considered statistically significant. RESULTS: The results showed that blood pressure values of caregivers in both the awareness group and the non-awareness group were high (awareness group vs non-awareness group overall SBP: 148 +/- 20 mmHg vs 154 +/- 9 mmHg, DBP: 79 +/- 13 mmHg vs 82 +/- 10 mmHg, P > 0.05). Furthermore, values were significantly lower for the awareness than non-awareness group with respect to the non-caregivers (SBP: 135 +/- 15 mmHg vs 149 +/- 7 mmHg, DBP: 73 +/- 10 mmHg vs 78 +/- 6 mmHg). Caregivers who took the antihypertensive agent in the awareness group demonstrated high values exceeding SBP 140 mmHg, which was the hypertensive standard value, not different from the values for caregivers not taking such medication. (taking vs non-taking SBP: 148 +/- 21 mmHg vs 149 +/- 8 mmHg). CONCLUSION: Among the caregivers, it was not only the members of the non-awareness group but also those of the awareness group who were found to have high blood pressure values. Though the caregivers took antihypertensive agents, their blood pressure values remained high.

[Association of obesity and other cardiovascular risk factors with stroke the Japan Arteriosclerosis Longitudinal Study--Existing Cohorts Combined (JALS-ECC)].

OBJECTIVES: To assess the relationship between metabolic risk factors and the incidence of stroke stratified by obesity, by conducting a meta-analysis using individual participant data from prospective cohort studies. METHODS: A total of 19,173 individuals from 10 cohort studies participated at baseline after 1985. Metabolic risk factors were defined using the established criteria in Japan. Participants were subdivided into five categories according to the levels of risk factors and obesity defined by BMI > or = 25 (kg/m2). Multivariate adjusted hazard ratios (HRs) for the incidence of stroke and the population attributable risk (PAR) were estimated by Poisson regression. RESULTS: During an average 7.1-year follow-up period, 374 stroke events occurred. Hypertension was highest among the risk factors not concerned with BMI stratification. The HR for stroke was 2.48 (95% CI: 1.75-3.5) for BMI < 25 with 1 other risk factor and 3.75 (2.58-5.45) with 2 or more, 2.38 while it was (1.58-3.59) for BMI > or = 25 with 0 or 1 factor and 3.26 (2.11-5.02) with 2 or more. The HR was significantly elevated in all categories with one or more risk factors. The PAR was highest in the category of BMI < 25 with 1 risk factor (23.3%) and second highest in the category of BMI < 25 with 2 or more. The respective PARs for BMI > or = 25 with 0 or 1 and 2 or more risk factors were 8.1% and 8.0%. Similar results were found from the analyses of different stroke subtypes. CONCLUSION: The HR was found to be significantly elevated with the number of risk factors both with and without obesity. The attributable risk for stroke was larger in the non-obese group. Therefore, public health intervention based only on obesity may miss many of those at high risk of stroke so the focus should not only be on obesity but also cardiovascular risk factors.

Body mass index and risk of stroke and myocardial infarction in a relatively lean population: meta-analysis of 16 Japanese cohorts using individual data.

BACKGROUND: The association of overweight/obesity with the incidence of cardiovascular diseases, especially stroke, has not been comprehensively examined in relatively lean populations in which stroke is more prevalent than coronary heart disease. METHODS AND RESULTS: Pooled individual data from 16 Japanese cohorts comprising 45 235 participants ages 40 to 89 years without previous history of cardiovascular disease were studied. During follow-up, 1113 incident strokes and 190 myocardial infarctions were identified. At baseline, mean ages of men and women were 55.4 and 56.5 years and mean body mass indices (BMI) were 23.0 and 23.4 kg/m(2), respectively. Compared with those with BMI <21.0, incidence rates of cerebral infarction in subjects with BMI ≥ 27.5 were significantly elevated in both men (hazard ratio, 1.81; 95% confidence interval [CI], 1.28 to 2.56) and women (hazard ratio, 1.65; 95% CI, 1.23 to 2.21), adjusted for age, smoking, and drinking habit. Incidence of cerebral hemorrhage was also associated positively with BMI in both men (hazard ratio, 2.51; 95% CI, 1.21 to 5.20) and women (hazard ratio, 1.98; 95% CI, 1.12 to 3.52). Adjustment for systolic blood pressure, a mediating factor, significantly attenuated most BMI association with stroke in both sexes. For myocardial infarction, the hazard ratio was 3.16 (95% CI, 1.66 to 6.01) for BMI 27.5 or greater versus less than 21.0 only in men, which appeared partly mediated by total cholesterol and SBP. CONCLUSIONS: Overweight/obesity was associated with an increased risk of cerebral infarction and hemorrhage in men and women and myocardial infarction in men. Weight control may have the potential to prevent both stroke and myocardial infarction in Japan.

Incidence of metabolic syndrome according to combinations of lifestyle factors among middle-aged Japanese male workers.

OBJECTIVE: To examine a combination of healthy lifestyles on the risk of metabolic syndrome (MetS) to inform future interventions. METHODS: A total of 1897 men aged 35-60 years participated in an annual health check-up in 2002 and 2005. MetS was defined by AHA/NCEP criteria. Logistic regression analyses were used to estimate age- and BMI-adjusted odds ratios (ORs) of MetS incidence for each healthy lifestyle (regular physical activity, adherence to healthy eating behaviors, not current smoking, and maintaining a stable weight since one's mid-twenties), separately (Model 1) and simultaneously (Model 2). A points system was developed to derive 3-year risk of MetS incidence by assigning a specific point to each healthy lifestyle. RESULTS: MetS developed in 285 (15.0%) subjects after the follow-up. The ORs of MetS for each healthy lifestyle ranged from 0.42 to 0.64 (Model 2). Three-year risk of MetS incidence was predicted to differ from 1% to 60% according to the individual point total of the points system. The population-attributable fraction of MetS in subjects whose point total was not in the highest quartile was 71%. CONCLUSION: Adherence to healthy lifestyles was associated with a lower risk of MetS among apparently healthy middle-aged Japanese male workers.

Higher dietary intake of alpha-linolenic acid is associated with lower insulin resistance in middle-aged Japanese.

OBJECTIVE: To investigate the associations between dietary intake of n-3 polyunsaturated fatty acids (plant-derived alpha-linolenic acid: ALA, and marine-derived eicosapentaenoic and docosahexaenoic acid: EPA+DHA) and insulin resistance (IR) in a lean population with high n-3 PUFA intake. METHOD: We cross-sectionally studied 3383 Japanese local government workers aged 35-66 in 2002. IR was defined as the highest quartile of homeostasis model assessment, and nutrient intake was estimated from a diet history questionnaire. The odds ratios (ORs) of IR taking the lowest quartile of ALA or EPA+DHA intake as the reference were calculated by logistic regression analysis. RESULTS: Mean age, body mass index (BMI), and dietary ALA, and median of dietary EPA+DHA were 47.9 years, 22.9 kg/m(2), and 1.90 g/day (0.88%E) and 0.77 g/day (0.36%E), respectively. The ORs of IR decreased across the quartiles of ALA intake (multivariate-adjusted OR for Q4 versus Q1=0.74, P for trend=0.01) and the association was observed only in subjects with a BMI of <25 kg/m(2) (P for interaction=0.033). However EPA+DHA showed no such associations consistently. CONCLUSION: Higher ALA intake was significantly associated with a lower prevalence of IR in normal weight individuals of middle-aged Japanese men and women.

Daytime napping and mortality, with a special reference to cardiovascular disease: the JACC study.

BACKGROUND: Daytime napping is associated with elevated risk of all-cause mortality in the elderly. However, the association with cardiovascular disease (CVD) risk is inconsistent. METHODS: From 1988 to 1990, a total of 67 129 Japanese non-workers or daytime workers (27 755 men and 39 374 women) aged 40-79 years, without a history of stroke, heart disease or cancer, completed a lifestyle questionnaire. They were followed for mortality until the end of 2003. RESULTS: During the 879 244 person-year follow-up, 9643 deaths (2852 from CVD, 3643 from cancer, 2392 from other internal causes, 738 from external causes and 18 from unspecified causes) were observed. After adjustment for possible confounders, subjects with a daytime napping habit had elevated hazard ratios (HRs) for mortality from all causes [HR 1.19, 95% confidence interval (CI) 1.14-1.24, P < 0.001], CVD (HR 1.31, 95% CI 1.22-1.42, P < 0.001), non-cardiovascular/non-cancer internal diseases (HR 1.26, 95% CI 1.16-1.37, P < 0.001) and external causes (HR 1.28, 95% CI 1.10-1.50, P = 0.001), but not for cancer death (HR 1.03, 95% CI 0.96-1.10, P = 0.400). The risk of CVD mortality associated with daytime napping was diminished among overweight subjects, but pronounced in those with weight loss after age 20 years, with non-regular employment, with lower education level and with a follow-up period <5 years. CONCLUSIONS: Daytime napping is associated with elevated risk of CVD mortality as well as non-cardiovascular/non-cancer and external deaths. Daytime napping may elevate risk of CVD death through some biological effects but, to a larger extent, some comorbid disorders causing weight loss or associated with non-regular employment and low education level could explain this association.