Impact of various intensities and frequencies of non-occupational physical activity on the risk of dementia among physically independent older adults: the Japan Gerontological Evaluation Study.

OBJECTIVES: The aim of this study was to investigate the association between different intensities and frequencies of non-occupational physical activity (PA) and the risk of dementia among Japanese older adults. STUDY DESIGN: This was a prospective cohort study. METHODS: A total of 2194 participants aged ≥65 years from the Japan Gerontological Evaluation Study were followed up between 2010 and 2016. The standardised dementia scale of the long-term care insurance system was used to identify incident dementia, whereas non-occupational PA (<2 or ≥2 times/week on each intensity: light, moderate and vigorous) was assessed using a questionnaire. Cox regression was used to compute the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia. RESULTS: After adjustment for sociodemographic and medical characteristics, the following frequencies and intensities of non-occupational PA, compared with no non-occupational PA at all, were associated with a reduced risk of dementia: light PA ≥2 times/week (HR = 0.61, 95% CI: 0.38-0.97), moderate PA <2 times/week (HR = 0.46, 95% CI: 0.28-0.76), moderate PA ≥2 times/week (HR = 0.57, 95% CI: 0.36-0.91), vigorous PA <2 times/week (HR = 0.40, 95% CI: 0.21-0.74) and vigorous PA ≥2 times/week (HR = 0.29, 95% CI: 0.15-0.57). In the sex-specific analysis, moderate PA <2 times/week and vigorous PA ≥2 times/week were associated with a reduced risk of dementia in men, whereas light and moderate PA ≥2 times/week and all frequencies of vigorous PA were associated with a reduced risk of dementia in women. CONCLUSIONS: Practicing non-occupational PA was associated with a reduced risk of dementia among Japanese older adults.

School-based psychoeducation and storytelling: Associations with long-term mental health in adolescent survivors of the Wenchuan earthquake.

AIMS: We explored the factors promoting long-term mental health among adolescent survivors of the 2008 Wenchuan earthquake in China. We examined the associations of their long-term mental health with disaster-related storytelling and school-based psychoeducation, and of school-based psychoeducation with disaster-related storytelling. METHODS: A secondary school-based cross-sectional survey was conducted 6 years after the disaster. Participants with traumatic experiences such as injury, loss, witnessing someone's death/injury and home destruction (N = 1028, mean age 15, standard deviation 1.38, male 51%) were eligible. Mental health/disaster education (MHE/DE) was defined as taking one or more lessons in MHE and/or DE at school since the earthquake. Experiences of storytelling about the disaster involved expressing distressing memories and feelings regarding the earthquake since the disaster happened, according to four groups: never expressed distressing memories and feelings, expressed them through writing/drawing, expressed them through talking to lay supporters and expressed them through talking to health professionals. Analysis of covariance was used to compare mean scores on five selected subscales of the Symptom Checklist-90 (SCL-90), the Athens Insomnia Scale (AIS) and the Psychotic-Like Experiences (PLEs) scale among the four storytelling groups. Linear regression analysis was used to identify the relationships between MHE/DE and current mental health as measured by the SCL-90, AIS and PLEs. The relationship between education and storytelling was probed by χ2 test. RESULTS: The talked-to-lay-supporters group showed better mental health on the SCL-90 (p ⩽ 0.001), AIS (p < 0.001) and PLEs (p = 0.004), while the consulted-health-professionals group showed worse mental health on the three dimensions of the SCL-90: depression (p = 0.05), anxiety (p = 0.02) and fear (p = 0.04), and on PLEs (p = 0.02) compared with the never-expressed group. MHE and DE were inversely associated with SCL-90, AIS and PLE scores. Participants who received these forms of education talked about their disaster experiences to lay supporters more than those who did not. CONCLUSIONS: MHE and DE at school may promote adolescents' mental health after a disaster. Experience of storytelling about the disaster to lay supporters may be helpful for long-term psychological recovery, and may be a potential mediating factor for school-based education and better mental health. Because of the cross-sectional nature of this study, causality cannot be inferred; therefore, further prospective intervention studies are needed to elucidate the effect of these factors on adolescent survivors' mental health.

Association between maternal alcohol consumption during pregnancy and risk of preterm delivery: the Japan Environment and Children's Study.

OBJECTIVE: To examine the association between maternal alcohol consumption during pregnancy and the risk of preterm delivery. DESIGN: Prospective cohort study. SETTING: The Japan Environment and Children's Study (JECS). POPULATION: A total of 94 349 singleton pregnancies. METHODS: Participants completed questionnaires detailing alcohol consumption during the first trimester and during the second and third trimesters. Participants were divided into four categories according to alcohol consumption (non-drinkers, consumers of 1-149 g, 150-299 g and ≥300 g ethanol/week). We examined the effect of alcohol consumption during different stages of pregnancy on the risk of preterm delivery. Odds ratios (OR) and 95% CI were calculated relative to non-drinkers using logistic regression. MAIN OUTCOME MEASURES: Medical record-based preterm delivery. RESULTS: Alcohol consumption during the second and third trimesters, but not during the first trimester, was associated with increased risk of preterm delivery. Heavy alcohol consumption (≥300 g ethanol/week) during the second and third trimesters was associated with a four-fold higher risk compared with non-drinkers (multivariable OR 4.52; 95% CI 1.68-12.2). Light alcohol consumption (1-149 g ethanol/week) tended to be associated with lower risk of preterm delivery (multivariable OR 0.78; 95% CI 0.60-1.00). CONCLUSIONS: Heavy alcohol consumption during the second and third trimesters was associated with increased risk of preterm delivery among pregnant women. TWEETABLE ABSTRACT: Heavy drinking during pregnancy may increase the risk of preterm delivery.

Dietary intake of antioxidant vitamins and risk of stroke: the Japan Public Health Center-based Prospective Study.

BACKGROUND/OBJECTIVES: Epidemiologic evidence on the relationship between antioxidant vitamin intake and stroke is limited. We aimed to investigate the association between dietary intake of antioxidant vitamins and the incidence of total stroke and ischemic stroke. SUBJECTS/METHODS: The subjects were 82 044 Japanese men and women aged 45-74 years under the Japan Public Health Center-based Prospective Cohort Study. Between 1995 and 1997, dietary assessment was done using a food frequency questionnaire. During 983 857 person-years of follow-up until the end of 2009 we documented 3541 incident total strokes and 2138 ischemic strokes. RESULTS: Dietary intakes of α-carotene, ß-carotene, α-tocopherol and vitamin C were not inversely associated with the incidence of total stroke and ischemic stroke adjustment for cardiovascular risk factors and selected lifestyle variables. When stratified by current smoking status, the inverse association between dietary vitamin C intake and incidence of total stroke observed among non-smokers but not smokers, with respective multivariable hazard ratios for the highest versus lowest quintiles of vitamin C of 0.81 (95% confidence interval (CI), 0.68-0.96; P-trend=0.03) among non-smokers; and 1.03 (0.84-1.25; P-trend=0.55) among smokers. As for ischemic stroke, the corresponding multivariable hazard ratios were 0.76 (0.60-0.96; P-trend=0.02) among non-smokers; and 1.00 (0.78-1.28; P-trend=0.61) among smokers. CONCLUSIONS: Dietary vitamin C intake was inversely associated with the incidence of total stroke and ischemic stroke among non-smokers.

Association of cigarette smoking with a past history and incidence of herpes zoster in the general Japanese population: the SHEZ Study.

Few studies have examined the impact of cigarette smoking on the risk for herpes zoster. The Shozu Herpes Zoster (SHEZ) Study is a community-based prospective cohort study over 3 years in Japan aiming to clarify the incidence and predictive and immunological factors for herpes zoster. We investigated the associations of smoking status with past history and incidence of herpes zoster. A total of 12 351 participants provided valid information on smoking status and past history of herpes zoster at baseline survey. Smoking status was classified into three categories (current, former, never smoker), and if currently smoking, the number of cigarettes consumed per day was recorded. The participants were under the active surveillance for first-ever incident herpes zoster for 3 years. We used a logistic regression model for the cross-sectional study on the association between smoking status and past history of herpes zoster, and a Cox proportional hazards regression model for the cohort study on the association with risk of incidence. The multivariable adjusted odd ratios (95% CI) of past history of herpes zoster for current vs. never smokers were 0·67 (0·54-0·80) for total subjects, 0·72 (0·56-0·93) for men and 0·65 (0·44-0·96) for women. The multivariable adjusted hazard ratios (95% CI) of incident herpes zoster for current vs. never smokers were 0·52 (0·33-0·81) for total subjects, 0·49 (0·29-0·83) for men and 0·52 (0·19-1·39) for women. Smoking status was inversely associated with the prevalence and incidence of herpes zoster in the general population of men and women aged ⩾50 years.

History of diabetes and risk of suicide and accidental death in Japan: The Japan Public Health Centre-based Prospective Study, 1990-2012.

AIM: This study looked at whether a history of diabetes mellitus (DM) is associated with a higher risk of externally caused death (by suicide and accident), using data for a large population-based prospective cohort from an Asian population. METHODS: Data collected between 1990 and 2012 from the Japan Public Health Centre-based Prospective Study were analyzed, and Poisson regression models were used to calculate adjusted risk ratios (RR) for external causes of death. RESULTS: The population-based cohort comprised 105,408 Japanese residents (49,484 men and 55,924 women; mean age: 51.2 [SD 7.9] years). At baseline, 3250 (6.6%) men and 1648 (3.0%) women had a history of DM. During the follow-up period, 113 external deaths (41 suicides and 72 accidents) were noted among those with a history of DM, with 1304 external deaths (577 suicides and 727 accidents) among those without such a history. A higher risk of external death (men, RR: 1.4, 95% CI: 1.2-1.8; women, RR: 1.6, 95% CI: 1.01-2.4) was observed in those with a history of DM. Also, among those aged 40-49 years (RR: 1.9, 95% CI: 1.3-2.7) and 50-59 years (RR: 1.4, 95% CI: 1.05-1.9) at baseline, the risk of external death was significantly higher in those with a history of DM. CONCLUSION: Compared with people with no history of DM, those with such a history had a significantly greater risk of externally caused death (particularly accidental deaths) in both genders and in those aged≤59 years at baseline.

Modification of the excess risk of coronary heart disease due to smoking by seafood/fish intake.

Seafood/fish intake has been regarded as a protective factor for coronary heart disease (CHD), while smoking is a strong risk factor. To examine whether associations between smoking and risk of CHD are modified by seafood/fish intake, we studied 72,012 Japanese men and women aged 45-74 years who completed 2 food frequency questionnaires, 5 years apart, during the period 1995-2009. After 878,163 person-years of follow-up, 584 incident cases of CHD (101 fatal and 483 nonfatal), including 516 myocardial infarctions, were documented. There was a clear dose-response association between smoking and CHD risk among subjects with a low seafood/fish intake (<86 g/day) but not among those with a high seafood/fish intake (≥86 g/day). Compared with never smokers, the multivariable hazard ratios in light (1-19 cigarettes/day), moderate (20-29 cigarettes/day), and heavy (≥30 cigarettes/day) smokers were 2.39 (95% confidence interval (CI): 1.60, 3.56), 2.74 (95% CI: 1.90, 3.95), and 3.24 (95% CI: 2.12, 4.95), respectively, among low seafood/fish eaters and 1.13 (95% CI: 0.64, 1.99), 1.29 (95% CI: 0.95, 2.04), and 2.00 (95% CI: 1.18, 3.51), respectively, among high seafood/fish eaters. Compared with heavy smokers with a low seafood/fish intake, light smokers with a high seafood/fish intake had substantially reduced risk of CHD (hazard ratio = 0.57, 95% CI: 0.32, 0.98). High seafood/fish intake attenuated the positive association between smoking and risk of CHD.

Relationship between vegetable and carotene intake and risk of prostate cancer: the JACC study.

BACKGROUND: We examined the associations of intakes of vegetables and carotenes with risk of prostate cancer in Japanese. METHODS: A total of 15,471 Japanese men participating in the Japan Collaborative Cohort study completed a questionnaire including food intake. Of them, 143 incident prostate cancers were documented. We examined the associations stated above by using Cox proportional hazard model. RESULTS: Vegetable intake was not associated with the risk of prostate cancer, but so was dietary alpha-carotene intake. The multivariable hazard ratio (95%CI) in the secondary highest and highest quintiles of alpha-carotene intake was 0.50 (0.26-0.98) (P=0.043) and 0.46 (0.22-0.97) (P=0.041) (P for trend=0.224), respectively. Beta-carotene intake was not associated with the risk of prostate cancer. CONCLUSION: Alpha-carotene intake was associated with lower risk of prostate cancer among Japanese.

Dietary patterns and risk of cardiovascular deaths among middle-aged Japanese: JACC Study.

BACKGROUND AND AIMS: Little evidence showed the association between dietary patterns and cardiovascular disease among Japanese. The objective of this study was to examine whether dietary patterns are associated with cardiovascular disease among middle-aged Japanese. METHODS AND RESULTS: At baseline (1988-1990), 26,598 men and 37,439 women aged 40-79 years enrolled in the Japan Collaborative Cohort (JACC) Study. During the follow-up through 2003, 578 men and 499 women died from stroke, and 272 men and 207 women died from coronary heart disease. We identified three major dietary patterns, 'vegetable', 'animal food' and 'dairy product', by factor analysis for both sexes. The multivariable hazard ratio (HR) and 95% confidence intervals of mortality from total cardiovascular disease in the highest versus lowest quintiles of the vegetable pattern were 0.93 (0.78-1.13), p for trend=0.73 for men and 0.82 (0.67-1.00), p for trend=0.04 for women. The respective HRs of mortality from stroke in the highest versus lowest quintiles of the dairy product pattern were 0.65 (0.49-0.86), p for trend=0.01 for men and 0.70 (0.51-0.97), p for trend=0.02 for women, and those of total cardiovascular disease were 0.89 (0.74-1.08), p for trend=0.23 for men and 0.76 (0.61-0.94), p for trend=0.01 for women. The animal food pattern was not associated with mortality from stroke, coronary heart disease or total cardiovascular disease for either sex. CONCLUSION: We found that 'vegetable' and 'dairy product' patterns were associated with lower morality from cardiovascular disease, while the 'animal food' pattern was not associated with mortality from cardiovascular disease among Japanese.

Assessment of skin test with varicella-zoster virus antigen for predicting the risk of herpes zoster.

The Shozu Herpes Zoster (SHEZ) Study was designed to clarify the incidence of and predictive and immunological factors for herpes zoster in a defined community-based Japanese population. As part of this series, a total of 5683 residents aged ≥50 years received a varicella-zoster virus (VZV) skin test with VZV antigen, and 48 h later, the erythema and oedema were assessed by measuring the longest diameter. The diameters of both the erythema and oedema decreased with the increasing age of the subject. Sixty-three subjects contracted herpes zoster within a year after receiving the VZV skin test. Analysis of the herpes zoster incidence rate vs. the skin test reaction revealed that the shorter the diameter of erythema or oedema, the greater the likelihood of herpes zoster. These results demonstrated that the VZV skin test is an excellent surrogate marker for predicting the risk of herpes zoster.

Meat consumption in relation to mortality from cardiovascular disease among Japanese men and women.

BACKGROUND/OBJECTIVES: Although high or low (no) meat consumption was associated with elevated or reduced mortality from cardiovascular disease, respectively, few studies have investigated the association between moderate meat consumption and cardiovascular disease. We aimed to evaluate the associations between moderate meat consumption and cardiovascular disease mortality. SUBJECTS/METHODS: We conducted a prospective cohort study of 51,683 Japanese (20,466 men and 31,217 women) aged 40-79 years living in all of Japan (The Japan Collaborative Cohort Study; JACC Study). Consumptions of meat (beef, pork, poultry, liver and processed meat) were assessed via a food frequency questionnaire administrated at baseline survey. Hazard ratios (HRs) of mortality from cardiovascular disease were estimated from Cox proportional hazards regression models according to quintiles of meat consumption after adjustment for potential confounding variables. RESULTS: During 820,076 person-years of follow-up, we documented 2685 deaths due to total cardiovascular disease including 537 ischemic heart diseases and 1209 strokes. The multivariable HRs (95% confidence interval) for the highest versus lowest quintiles of meat consumption (77.6 versus 10.4 g/day) among men were 0.66 (0.45-0.97) for ischemic heart disease, 1.10 (0.84-1.43) for stroke and 1.00 (0.84-1.20) for total cardiovascular disease. The corresponding HRs (59.9 versus 7.5 g/day) among women were 1.22 (0.81-1.83), 0.91 (0.70-1.19) and 1.07 (0.90-1.28). The associations were similar when the consumptions of red meat, poultry, processed meat and liver were examined separately. CONCLUSION: Moderate meat consumption, up to ~100 g/day, was not associated with increased mortality from ischemic heart disease, stroke or total cardiovascular disease among either gender.

Dietary fiber intake and risk of cardiovascular disease in the Japanese population: the Japan Public Health Center-based study cohort.

BACKGROUND/OBJECTIVES: There has been no study with regard to the association between dietary fibers and the incidence of stroke and coronary heart disease (CHD) in Asia. We investigated the association between dietary fiber and the risk of cardiovascular disease (CVD), which we defined as stroke or CHD, in a Japanese population. SUBJECTS/METHODS: We studied 86 387 Japanese subjects (age 45-65 years, without CVD or cancer in 1995 as Cohort I and in 1998 as Cohort II) and used a self-administered questionnaire to follow-up the participants until the end of 2004. Dietary fiber intake was estimated from food-frequency questionnaires comprising 138 food items. RESULTS: After 899 141 person-years of follow-up, we documented the incidence of 2553 strokes and 684 cases of CHD. Multivariable-adjusted hazard ratios (95% confidence intervals (CIs)) of CVD for the third to fifth quintiles of total fiber were 0.79 (0.63-0.99), 0.70 (0.54-0.89) and 0.65 (0.48-0.87) in women, respectively, compared with the lowest quintile. Total fiber intake was inversely associated with the incidence of stroke, either cerebral infarction or intracerebral hemorrhage in women. The results for insoluble fiber in women were similar to those for total fiber, whereas those for soluble fiber were weak. An inverse association of total fiber with CVD was observed primarily in non-smokers (P for trend=0.045 and 0.001) and not in smokers (probability values for interaction between total fiber and smoking were 0.06 and 0.01 in men and women, respectively). CONCLUSIONS: Higher total dietary fiber was associated with reduced risk of CVD in Japanese non-smokers.

Body mass index, weight change and risk of stroke and stroke subtypes: the Japan Public Health Center-based prospective (JPHC) study.

OBJECTIVE: The Japan Public Health Center-based prospective Study examined the association of body mass index (BMI) and weight change with incident stroke in Japanese individuals, for whom BMI levels are generally low. METHODS: We used initial data from 1990 to 1994 and 5-year follow-up surveys from 1995 to 1999. We calculated weight change over a 5-year period for 32,847 men and 38,875 women, aged 45-74 years, with no history of cardiovascular disease or cancer. Subjects were followed from the 1995-1999 survey to the end of 2005, and hazard ratios of self-reported BMI levels and weight change for incident stroke were estimated using Cox's proportional hazard models adjusted for potential confounders. RESULTS: During the follow-up period (median 7.9 years) there were 2019 incident strokes, including subtypes. Multivariable-adjusted hazard ratios for all stroke events by BMI levels of 27.0-29.9 and ≥ 30 kg m(-2) versus 23.0-24.9 kg m(-2) were 1.09 (95% confidence interval 0.88, 1.36) and 1.25 (0.86, 1.84) in men (P for trend=0.22), and 1.29 (1.01, 1.65) and 2.16 (1.60, 2.93) in women (P for trend <0.001), respectively. A weight change of ≥ 10% in the previous 5 years was associated with total strokes and ischemic strokes in women. CONCLUSION: Higher BMI levels and a weight gain of ≥ 10% over 5 years were associated with an increased risk of stroke in women, whereas this association was weak in men.

Reproducibility of 24-hour dietary recall for vitamin intakes by middle-aged Japanese men and women.

OBJECTIVE: To examine the reproducibility of 24-hour dietary recall for estimating dietary vitamin intakes by middle-aged Japanese men and women. METHODS AND RESULTS: The subjects were 132 men and 130 women aged 40-69 years, selected from participants in cardiovascular risk surveys conducted in 4 communities. The reproducibility of the 24-hour dietary recall was tested by comparing nutrient and food intake for two recalls conducted on the same season 1 year apart, designated as recalls 1 and 2. Differences in mean values between two recalls were tested using analysis of variance, and Spearman rank correlation coefficients for the two recalls were calculated for nutrient and food intakes. Mean values of energy and vitamins for both sexes were generally similar for the two recalls. The reproducibility of recall by men was high for vitamin B2, folate, pantothenic acid, and vitamin C and by women for vitamin B2, moderate by men for vitamins A, E, K, B1, B6 and niacin, and by women for vitamins A, E, K, B1, B6 and niacin, folate, pantothenic acid and vitamin C, and low by both men and women for vitamins D and B12. The reproducibility during 1985-1999 was generally lower than that of 1973-1984, but that for folate, pantothenic acid and vitamin C remained to be moderate in 1984-1999. CONCLUSIONS: Although the reproducibility of 24-hour dietary recall varies among vitamins, moderate and sustained reproducibility was observed for folate, vitamin C and pantothenic acid.

Gender difference of association between LDL cholesterol concentrations and mortality from coronary heart disease amongst Japanese: the Ibaraki Prefectural Health Study.

OBJECTIVE: The aim of this study was to examine whether LDL cholesterol raises the risk of coronary heart disease in a dose-response fashion in a population with low LDL-cholesterol levels. DESIGN: Population-based prospective cohort study in Japan. SUBJECTS AND MAIN OUTCOME MEASURES: A total of 30,802 men and 60,417 women, aged 40 to 79 years with no history of stroke or coronary heart disease, completed a baseline risk factor survey in 1993. Systematic mortality surveillance was performed through 2003 and 539 coronary heart disease deaths were identified. RESULTS: The mean values for LDL-cholesterol were 110.5 mg dL(-1) (2.86 mmol L(-1)) for men and 123.9 mg dL(-1) (3.20 mmol L(-1)) for women. Men with LDL-cholesterol > or =140 mg dL(-1) (> or =3.62 mmol L(-1)) had two-fold higher age-adjusted risk of mortality from coronary heart disease than did those with LDL-cholesterol <80 mg dL(-1) (<2.06 mmol L(-1)), whereas no such association for women was found. The multivariable hazard ratio for the highest versus lowest categories of LDL-cholesterol was 2.06 (95 percent confidence interval: 1.34 to 3.17) for men and 1.16 (0.64 to 2.12) for women. CONCLUSION: Higher concentrations of LDL-cholesterol were associated with an increased risk of mortality from coronary heart disease for men, but not for women, in a low cholesterol population.

Cross-cultural comparison of the sleep-disordered breathing prevalence among Americans and Japanese.

The aim of the present study was to compare the prevalence of sleep-disordered breathing among Hispanic and white Americans and Japanese. A 1-night sleep study using a single-channel airflow monitor was performed on 211 Hispanics and 246 Whites from the Minnesota field centre (St Paul, MN, USA) of the Multi-Ethnic Study of Atherosclerosis (MESA), and 978 Japanese from three community-based cohorts of the Circulatory Risk in Communities Study (CIRCS) in Japan. The respiratory disturbance index and sleep-disordered breathing, defined as a respiratory disturbance index of > or =15 events x h(-1), were estimated. The prevalence of sleep-disordered breathing was higher in males (34.2%) than females (14.7%), and among Hispanics (36.5%) and Whites (33.3%) than among Japanese (18.4%), corresponding to differences in body mass index. Within body mass index strata, the race difference in sleep-disordered breathing was attenuated. This was also true when body mass index was adjusted for instead of stratification. The strong association between body mass index and sleep-disordered breathing was similar in Japanese and Americans. The prevalence of sleep-disordered breathing was lower among Japanese than among Americans. However, the association of body mass index with sleep-disordered breathing was strong, and similar among the race/ethnic groups studied. The majority of the race/ethnic difference in sleep-disordered breathing prevalence was explained by a difference in body mass index distribution.

Nocturnal intermittent hypoxia and the development of type 2 diabetes: the Circulatory Risk in Communities Study (CIRCS).

AIMS/HYPOTHESIS: Although the associations between obstructive sleep apnoea and type 2 diabetes mellitus have been reported in cross-sectional design studies, findings on the prospective association between the two conditions are limited. We examined prospectively the association between nocturnal intermittent hypoxia as a surrogate marker of obstructive sleep apnoea and risk of type 2 diabetes. METHODS: A total of 4,398 community residents aged 40 to 69 years who had participated in sleep investigation studies between 2001 and 2005 were enrolled. Nocturnal intermittent hypoxia was assessed by pulse-oximetry and defined by the number of oxygen desaturation measurements < or =3% per h, with five to <15 per h corresponding to mild and 15 events or more per h corresponding to moderate-to-severe nocturnal intermittent hypoxia, respectively. The development of type 2 diabetes was defined by: (1) fasting serum glucose > or =7.00 mmol/l (126 mg/dl); (2) non-fasting serum glucose > or =11.1 mmol/l (200 mg/dl); and/or (3) initiation of glucose-lowering medication or insulin therapy. Multivariable model accounted for age, sex, BMI, smoking status, current alcohol intake, community, borderline type 2 diabetes, habitual snoring, excessive daytime sleepiness, sleep duration and (for women) menopausal status. RESULTS: By the end of 2007, 92.2% of participants had been followed up (median follow-up duration [interquartile range] 3.0 [2.9-4.0] years) and 210 persons identified as having developed diabetes. The multivariable-adjusted hazard ratio (95% CI) for developing type 2 diabetes was 1.26 (0.91-1.76) among those with mild nocturnal intermittent hypoxia and 1.69 (1.04-2.76) among those with moderate-to-severe nocturnal intermittent hypoxia (p = 0.03 for trend). CONCLUSIONS/INTERPRETATION: Nocturnal intermittent hypoxia was associated with increased risk of developing type 2 diabetes among middle-aged Japanese.

Calcium, vitamin D and dairy intake in relation to type 2 diabetes risk in a Japanese cohort.

AIMS/HYPOTHESIS: Calcium and vitamin D have been implicated in the development of type 2 diabetes, but epidemiological evidence is limited. We examined prospectively the relation of calcium and vitamin D intake to type 2 diabetes risk in a Japanese cohort. METHODS: Participants were 59,796 middle-aged and older men and women, who participated in the Japan Public Health Center-based Prospective Study and had no history of type 2 diabetes or other serious diseases. Dietary intake of calcium and vitamin D were estimated using a validated food frequency questionnaire. Logistic regression was used to assess the association between intake of these nutrients and self-reported newly diagnosed type 2 diabetes. RESULTS: During a 5 year follow-up, 1,114 cases of type 2 diabetes were documented. Overall, calcium intake was not associated with a significantly lower risk of type 2 diabetes; the multivariable odds ratio for the highest vs lowest quartiles was 0.93 (95% CI 0.71-1.22) in men and 0.76 (95% CI 0.56-1.03) in women. However, among participants with a higher vitamin D intake, calcium intake was inversely associated with diabetes risk; the odds ratio for the highest vs lowest intake categories was 0.62 (95% CI 0.41-0.94) in men and 0.59 (95% CI 0.38-0.91) in women. Dairy food intake was significantly associated with a lower risk of type 2 diabetes in women only. CONCLUSIONS/INTERPRETATION: Calcium and vitamin D may not be independently associated with type 2 diabetes risk. Our finding suggesting a joint action of these nutrients against type 2 diabetes warrants further investigation.

Associations between weight change since 20 years of age and sleep-disordered breathing among male truck drivers.

BACKGROUND: Limited evidence for association of weight gain with sleep-disordered breathing (SDB) has been produced for Asian populations whose body mass index (BMI) levels are lower than in western countries. OBJECTIVE: The aim of this study was to examine weight change since 20 years of age and risk of SDB among Japanese. DESIGN: Retrospective cohort study. SUBJECTS: This study includes a large sample of 5320 male Japanese truck drivers aged 30-69 years. MEASUREMENTS: The respiratory disturbance index (RDI) was selected as an indicator of SDB, and it was estimated with a one-night sleep test using an airflow monitor, and the Epworth Sleepiness Scale (ESS) was used to estimate excessive daytime sleepiness. RESULTS: Respiratory disturbance and sleepiness were more prevalent among men with BMI of 25.0-29.9 and > or =30.0 kg/m(2) than among those with BMI of 18.5-24.9; multivariable odds ratios (ORs) were 1.8(1.5-2.0), P<0.001 and 4.4(3.5-5.5), P<0.001 for RDI > or =10, and 1.2(0.9-1.4), P=0.18 and 1.5(1.1-2.1), P=0.02 for ESS > or =11, respectively. Compared with men showing BMI changes within +/-1.0, the respective multivariable ORs for those with BMI changes of 3.0-4.9 and > or =5.0 were 1.4(1.2-1.6), P<0.001 and 2.4(2.0-2.9), P<0.001 for RDI > or =10, and 1.2(0.9-1.6), P=0.22 and 2.0(1.5-2.6), P<0.001 for ESS > or =11. The corresponding ORs for weight gain of > or =10.0 kg compared with weight change less than +/-5.0 kg were 2.0(1.7-2.4), P<0.001 for RDI > or =10 and 1.5(1.2-2.0), P=0.002 for ESS > or =11. Similar trends were observed for RDI > or =20. CONCLUSION: Our results suggest that an increase in BMI of > or =5 kg/m(2) or weight gain of > or =10 kg is a risk factor for SDB and excessive daytime sleepiness among Japanese truck drivers.

Impact of weight change on specific-cause mortality among middle-aged Japanese individuals.

BACKGROUND: The aim of this study was to investigate the associations between long-term weight change after age 20 and overall mortality and cause-specific mortality in the general Asian population. METHODS: From 1990 to 2005, the Japan Public Health Center (JPHC)-based prospective study conducted a follow-up of 42 242 men and 46 177 women aged 40-69 years with no history of cardiovascular disease (CVD) or cancer. Sex-specific multivariable-adjusted hazard ratios for cause-specific mortality were computed in accordance with weight change categories from age 20, as assessed by a self-administered questionnaire, and clustered by the JPHC communities and age groups, using Cox's proportional hazard model. RESULTS: During the 12.9-year follow-up, there were 6494 deaths, including 2888 from cancer, 1011 from CVD and 2595 from other causes. In all, weight loss > or =5 kg since age 20 increased hazard ratios for all-cause mortality in men (1.44, 95% CI 1.32 to 1.56) and women (1.33, 95% CI 1.17 to 1.52) compared with maintenance of a stable weight, and elevated risk was also found within each age group. The risk of weight loss was higher for individuals in the younger age group. Weight loss predicted cancer and CVD mortality only for men > or =50 years of age. The increased risk was observed regardless of whether the individual was ill, a smoker or overweight at baseline or at age 20. There was an inverse association between weight gain and mortality risk. CONCLUSION: Weight loss strongly predicted all-cause, cancer and CVD mortality, primarily for men. An unfavourable effect of weight gain was small at the population level.