Association between the 110-kDa C-terminal agrin fragment and skeletal muscle decline among community-dwelling older women.

BACKGROUND: C-terminal agrin fragment (CAF) is a biomarker for neuromuscular junction degradation. This study aimed to investigate whether 110-kDa CAF (CAF110) was associated with the presence and incidence of low muscle mass and strength. METHODS: This cross-sectional retrospective cohort study comprised women aged ≥65 years. We measured muscle mass using a dual-energy X-ray absorptiometry scanner, hand-grip strength, and blood sampling between 2011 and 2012. A follow-up study with the same measurements was conducted between 2015 and 2017. Low muscle mass and strength were defined as an appendicular skeletal muscle mass index <5.4 kg/m2 and hand-grip strength <18 kg, respectively. The CAF110 level was measured using enzyme-linked immunosorbent assay kits. RESULTS: In total, 515 women (74.3 ± 6.3 years) were included in this cross-sectional analysis. Of these, 101 (19.6%) and 128 (24.9%) women presented with low muscle mass and strength, respectively. For low muscle mass, the odds ratios (ORs) of the middle and highest CAF110 tertile groups, compared with the lowest group, were 1.93 (95% confidence interval: 1.09-3.43; P = 0.024) and 2.15 (1.22-3.80; P = 0.008), respectively. After adjusting for age, the ORs remained significant: 1.98 (1.11-3.52; P = 0.020) and 2.27 (1.28-4.03; P = 0.005), respectively. Low muscle strength ORs of all the CAF110 tertile groups were not significant. In the longitudinal analysis, 292 and 289 women were assessed for incidents of low muscle mass and strength, respectively. Of those, 34 (11.6%) and 20 (6.9%) women exhibited low muscle mass and strength, respectively. For incident low muscle mass, the crude OR of the CAF110 ≥ the median value group was marginally higher than that of the CAF110 < median value group (median [interquartile range]: 1.98 [0.94-4.17] (P = 0.072). After adjusting for age and baseline muscle mass, the OR was 2.22 [0.97-5.06] (P = 0.058). All low muscle strength ORs of the median categories of CAF110 were not significant. CONCLUSIONS: CAF110 was not associated with low muscle strength. However, CAF110 may be a potential marker for the incidence of low muscle mass.

Risk factors for future osteoporosis in perimenopausal Japanese women.

OBJECTIVE: The aims of this study were to investigate trends in bone mineral density (BMD) loss and related factors in early postmenopausal women in Japan, identify risk factors for future osteoporosis, and predict osteoporosis before it occurs. METHODS: The study population consisted of women who were 50 to 54 years old at the time of the survey in 2002 or 2006. The study included a questionnaire and physical measurement findings (BMD, height, body weight [WT], body mass index [BMI], and handgrip strength). One hundred sixty-seven women continued to participate in the study and had BMD measurements at the 9- or 10-year follow-up of the Japanese Population-based Osteoporosis study. Statistical analyses were performed using Pearson correlation to examine each factor of physical measurement and BMD for lumbar spine (LS) and femoral neck (FN). The receiver operating characteristic curve of this data was also predictive of osteoporosis in 2011 for 2002 data; BMD at the age of 50 to 54 years was then used to predict the likelihood of being diagnosed with osteoporosis 9 and 10 years later. RESULTS: At the baseline in 2002 and 2006, WT, BMI, height, and handgrip strength were positively correlated with BMD. The optimal cutoff values for BMD in 2006 to predict osteoporosis in 2016 were LS less than 0.834 g/cm 2 and FN less than 0.702 g/cm 2 . These data were also predictive of osteoporosis in 2011 for 2002 data; applying this to the 2002 data, LS/FN had a sensitivity of 92%/100%, a specificity of 87%/81%, a positive predictive value of 55%/48%, and a negative predictive value of 98%/100%. The larger WT and BMI also resulted in a greater decrease in BMD of FN after 9 or 10 years. CONCLUSIONS: We have identified a cutoff value for BMD to predict future osteoporosis in menopausal women and found a negative correlation between WT and BMI in menopausal women and changes in BMD of the FN over the next 10 years.

Natto Intake is Inversely Associated with Osteoporotic Fracture Risk in Postmenopausal Japanese Women.

BACKGROUND: The direct association between intake of Japanese fermented soybeans, namely natto, and bone mineral density (BMD) is known. However, the association with osteoporotic fractures has not been studied. OBJECTIVE: This study aimed to investigate whether habitual natto intake is associated with a risk of osteoporotic fractures. METHODS: This prospective cohort study included 1417 postmenopausal Japanese women who were enrolled in the Japanese Population-Based Osteoporosis cohort study in 1996, 1999, 2002, and 2006 and were aged ≥45 y at baseline. The intake of natto, tofu, and other soybean products was surveyed with use of a FFQ at baseline. Fractures were ascertained in follow-up surveys conducted in 1999, 2002, 2006, and 2011/2012. Osteoporotic fracture was the primary outcome and was defined as a clinical fracture occurring without strong external force, diagnosed with radiographs by a medical doctor. HRs with 95% CIs were estimated with Cox proportional hazard models. RESULTS: During the 17,699 person-years of follow-up (median, 15.2 y), 172 women experienced osteoporotic fractures. After adjustment for age and BMD at the total hip, the HRs compared with those of < 1 pack (approximately 40 g)/wk natto intake were 0.72 (95% CI: 0.52, 0.98) and 0.51 (95% CI: 0.30, 0.87) for 1-6 and ≥7 packs/wk, respectively. After further adjustment for BMI, history of osteoporotic fractures, history of myocardial infarction or stroke, diabetes mellitus, current smoking, alcohol intake, frequency of tofu and other soybean product intakes, and dietary calcium intake, the HRs were 0.79 (95% CI: 0.56, 1.10) and 0.56 (95% CI: 0.32, 0.99) for 1-6 and ≥7 packs/wk, respectively. Frequency of tofu or other soybean product intakes had no association with the risk of osteoporotic fractures. CONCLUSIONS: Habitual natto intake may be associated with a reduced risk of osteoporotic fractures independent of confounding factors, including BMD, in Japanese postmenopausal women. This trial was registered at umin.ac.jp as UMIN 000032869.

Decreased bone mineral density and osteoporotic fractures are associated with the development of echogenic plaques in the carotid arteries over a 10-year follow-up period: The Japanese Population-based Osteoporosis (JPOS) Cohort Study.

OBJECTIVES: To investigate whether low bone mineral density (BMD) and history of fracture at baseline are associated with the development of echogenic carotid plaques over a 10-year follow-up period. STUDY DESIGN: A prospective cohort study. MAIN OUTCOME MEASURES: Development of echogenic plaques identified by ultrasonography of the carotid arteries. METHODS: Among 1048 women aged 40 or more who completed the baseline survey of the Japanese Population-based Osteoporosis (JPOS) cohort study, 500 women who completed the first decade of follow-up and 267 women who completed the second decade of follow-up were included. We identified history and incidence of clinical osteoporotic fracture during the follow-up through medical interviews, and determined vertebral fractures by morphometry of absorptiometric images. RESULTS: We identified 67 (13.4%) and 31 (11.6%) women with echogenic plaques at the end of first and second decade of follow-up, respectively. Participants with echogenic plaques were significantly older, exhibited lower spine BMD, and had a higher prevalence of osteoporotic fracture, diabetes, and hypertension. A generalized estimating equation analysis was used to combine the participants from the two follow-up periods into a single cohort, and showed that osteoporotic BMD and osteoporotic fractures were significantly associated with the development of echogenic plaques, after adjusting for atherosclerosis risk factors (odds ratio (OR): 2.15, 95% confidence interval (95% CI): 1.04, 4.44; OR: 1.84, 95% CI: 1.03, 3.28, respectively). CONCLUSION: Osteoporotic BMD and osteoporotic fracture history were significantly, and independently, associated with an increased occurrence of echogenic plaques. Ultrasonographic screening of the carotid artery may benefit patients with osteoporosis.

Association between hand-grip strength and site-specific risks of major osteoporotic fracture: Results from the Japanese Population-based Osteoporosis Cohort Study.

OBJECTIVES: To investigate the association between hand-grip strength and site-specific risks of major osteoporotic fracture. STUDY DESIGN: Prospective cohort study. MAIN OUTCOME: Associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip. MEASURES: We enrolled 1342 postmenopausal women aged 50 years or more into baseline and follow-up surveys of the Japanese Population-based Osteoporosis Cohort Study in 1996, 1999, 2002, or 2006. Fracture events were ascertained by follow-up surveys until 2011 or 2012. The Cox proportional hazards model was used to estimate hazard ratios (HRs) of hand-grip strength on fracture event. RESULTS: During a median follow-up of 15.2 years, 162 women sustained at least one osteoporotic fracture and 135 of these women sustained at least one major osteoporotic fracture, the larger group including 65, 38, 35, and 8 women with fractures of the distal forearm, vertebrae, hip, and proximal humerus, respectively. In the crude models, the associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip were significant; the HRs (95% confidence interval) of the lowest tertile of hand-grip strength were 2.02 (1.10-3.71), 11.35 (4.07-31.63), and 4.72 (1.79-12.47), respectively. Age adjustment attenuated the significance of hip fracture risk, and adjusting for bone mineral density attenuated the significance of distal forearm fracture risk. After additional adjustment for body mass index, history of diabetes mellitus, and calcium intake, the HR for vertebral fracture risk was 4.55 (1.56-13.27). When limiting the follow-up period to 5 and 10 years, low hand-grip strength was associated with an increased risk of distal forearm fracture independently of the aforementioned covariates; the HRs were 4.22 (1.12-15.95) and 2.52 (1.03-6.17), respectively. CONCLUSIONS: Low hand-grip strength is specifically associated with the risk of distal forearm fractures within 10 years and clinical vertebral fractures within 15 years or more in Japanese postmenopausal women.

Does Trabecular Bone Score (TBS) improve the predictive ability of FRAX® for major osteoporotic fractures according to the Japanese Population-Based Osteoporosis (JPOS) cohort study?

This study examined whether bone microarchitecture determined by Trabecular Bone Score (TBS) is associated with the risk of major osteoporotic fractures independent of FRAX® in Japanese women. Participants included 1541 women aged ≥ 40 at baseline. Major osteoporotic fractures during a 10-year follow-up period were documented by the Japanese Population-based Osteoporosis Cohort Study. TBS and areal bone mineral density (aBMD) were calculated for the same spinal regions at baseline. To compare the predictive ability of FRAX® model when used alone versus in combination with TBS, Akaike information criterion (AIC), the area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated. We identified 67 events of major osteoporotic fractures. The skeletal sites of the first fracture event were as follows: hip (11), vertebrae (13), radius (42), and humerus (1). The model incorporating FRAX® [1.35 (95% CI 1.09-1.67) for 1 standard deviation (SD) increase] with TBS [1.46 (95% CI 1.08-1.98) for 1 SD decrease] demonstrated better fit compared to a model consisting of FRAX alone (AIC 528.6 vs 532.7). NRI values for classification accuracy showed significant improvements in the FRAX® and TBS model, as compared to FRAX® alone [0.299 (95% CI 0.056-0.541)]. However, there were no significant differences in AUC or IDI between these models. The TBS score is associated with a risk of major osteoporotic fracture independent of FRAX® score obtained with or without BMD values among Japanese women during a 10-year follow-up period.

Muscle strength is associated with bone health independently of muscle mass in postmenopausal women: the Japanese population-based osteoporosis study.

There are conflicting reports on whether muscle strength is associated with bone mineral density (BMD) independently of muscle mass. Here, we examined the association between muscle strength and BMD in a representative population of Japanese women. Cross-sectional data from 680 postmenopausal women, who were participants in the 15th-year follow-up survey of the Japanese Population-based Osteoporosis cohort study, were analyzed. Areal BMD (aBMD) at the femoral neck and lumbar spine, whole-body bone mineral density, and appendicular skeletal muscle mass (ASM, kg) were measured by dual-energy X-ray absorptiometry. The ASM index (ASMI, kg/m2) was calculated as ASM divided by height squared (m2). Grip strength (kg) was measured as an indicator of muscle strength. Grip strength showed significantly (P < 0.05) positive relationships with aBMDs at several skeletal sites after adjusting for ASMI and age (standardized partial regression coefficient (ß) = 0.102 at femoral neck, ß = 0.126 at lumbar spine). Adjusted means of aBMD at the femoral neck and lumbar spine showed significant increasing trends from the lowest to highest tertile of grip strength. Our findings indicate that muscle strength is associated with aBMD at several sites independently of muscle mass in Japanese postmenopausal women. Thus, postmenopausal women with strong muscle strength tend to have a healthy bone status regardless of muscle size.

Low bone mineral density is associated with an elevated risk of developing increased arterial stiffness: A 10-year follow-up of Japanese women from the Japanese Population-based Osteoporosis (JPOS) cohort study.

OBJECTIVE: Only a few longitudinal studies have assessed the relationship between bone mineral density (BMD) and arteriosclerosis. This study aimed to determine whether low BMD at baseline is associated with the development of increased arterial stiffness, as evaluated by brachial-ankle pulse wave velocity (baPWV), in Japanese women. METHODS: A baPWV value of ≥1800 cm/s was adopted as the criterion for increased arterial stiffness, i.e., the outcome of the study. Of the 725 women aged ≥50 years who completed the baseline survey, we excluded the 166 who already met this criterion. Of the remaining women, we analyzed data from the 446 who completed at least one of the follow-up surveys conducted 5 or 10 years after baseline. BMD at the lumbar spine (LS) and total hip (TH) was measured by dual-energy X-ray absorptiometry in the baseline survey. baPWV was measured both at baseline and at follow-up. Multivariate logistic regression was used to evaluate the independent effect of BMD at baseline on developing the outcome during 10-year follow-up. RESULTS: We identified 166 women who newly developed increased arterial stiffness. The odds ratios (OR) for a 1 SD decrease in BMD at LS and TH for developing the outcome were 1.20 (95% confidence interval [CI]: 0.91-1.50), and 1.44 (95% CI: 1.14-1.81), respectively, after adjusting for age and systolic blood pressure. After additionally adjusting for baPWV at baseline, the OR for a 1 SD decrease in BMD at TH remained significant (1.33, 95% CI: 1.02-1.72). CONCLUSION: Low BMD at TH was significantly associated with the development of increased arterial stiffness during a 10-year follow-up of Japanese women.

Relative Importance of Central and Peripheral Adiposities on Cardiometabolic Variables in Females: A Japanese Population-Based Study.

In epidemiological studies, there is little evidence regarding the relative impact of central adiposity and peripheral adiposity on cardiometabolic risk factors, especially in Asian populations. This study investigated associations between central-to-peripheral fat ratios and cardiometabolic variables using data from a population-based study of Japanese women. The source population was composed of 1800 women aged 50 yr or older at the 15th- to 16th-yr follow-up survey of the Japanese Population-Based Osteoporosis Cohort Study. This study analyzed cross-sectional data from 998 women for whom complete information about body fat variables according to dual-energy X-ray absorptiometry, cardiometabolic variables, and potential confounding factors was available. Both before and after adjusting for potential confounding factors, trunk-to-appendicular fat ratios showed significant (p < 0.05) correlations with brachial-ankle pulse wave velocity, serum lipids, and hemoglobin A1c levels. Relationships between fat ratios and cardiometabolic variables were independent of relationships between fat volumes (in whole body or in trunk) and cardiometabolic variables. Furthermore, relationships between trunk-to-appendicular fat ratios and cardiometabolic variables were observed among women in the lowest tertile of total body fat (brachial-ankle pulse wave velocity, ß = 0.08; high-density lipoprotein cholesterol, ß = -0.32; low-density lipoprotein cholesterol, ß = 0.15; and hemoglobin A1C, ß = 0.16; p < 0.05, respectively). Central adiposity is more related to cardiometabolic variables than peripheral adiposity. Information on central-to-peripheral fat ratios is particularly valuable for the evaluation of relatively thin Japanese women.

Cohort Profile: The Japanese Population-based Osteoporosis (JPOS) Cohort Study.

The Japanese Population-based Osteoporosis (JPOS) Cohort Study was launched in 1996 to produce a reference database of areal bone mineral density (aBMD) by dual energy X-ray absorptiometry (DXA) and bone turnover markers in the Japanese female population and to determine risk factors for osteoporotic fractures. At baseline, 3984 women aged 15 to 79 years were randomly selected to provide representative bone status data and aBMD values for the diagnosis of osteoporosis. Follow-up surveys were conducted in 1999, 2002, 2006 and 2011/12 to determine changes in aBMD and identify incident morphometry-confirmed vertebral fractures and clinical fractures. These outcomes were obtained from 2174 women who participated in at least one follow-up survey. JPOS is a unique resource of individual-level bone health information with radiological and biological archives that include DXA images, and serum, plasma and DNA for future analyses with emerging radiological and biological techniques. The JPOS dataset is not freely available, but new collaborations are encouraged. Potential collaborators are invited to contact the Secretary General (M.I.) at the administrative office of the JPOS Study Group.

Trabecular bone score (TBS) predicts vertebral fractures in Japanese women over 10 years independently of bone density and prevalent vertebral deformity: the Japanese Population-Based Osteoporosis (JPOS) cohort study.

Bone strength is predominantly determined by bone density, but bone microarchitecture also plays an important role. We examined whether trabecular bone score (TBS) predicts the risk of vertebral fractures in a Japanese female cohort. Of 1950 randomly selected women aged 15 to 79 years, we analyzed data from 665 women aged 50 years and older, who completed the baseline study and at least one follow-up survey over 10 years, and who had no conditions affecting bone metabolism. Each survey included spinal imaging by dual-energy X-ray absorptiometry (DXA) for vertebral fracture assessment and spine areal bone mineral density (aBMD) measurement. TBS was obtained from spine DXA scans archived in the baseline study. Incident vertebral fracture was determined when vertebral height was reduced by 20% or more and satisfied McCloskey-Kanis criteria or Genant's grade 2 fracture at follow-up. Among eligible women (mean age 64.1 ± 8.1 years), 92 suffered incident vertebral fractures (16.7/10(3) person-years). These women were older with lower aBMD and TBS values relative to those without fractures. The unadjusted odds ratio of vertebral fractures for one standard deviation decrease in TBS was 1.98 (95% confidence interval [CI] 1.56, 2.51) and remained significant (1.64, 95% CI 1.25, 2.15) after adjusting for aBMD. The area under the receiver operating characteristic curve of TBS and aBMD combined was 0.700 for vertebral fracture prediction and was not significantly greater than that of aBMD alone (0.673). However, reclassification improvement measures indicated that TBS and aBMD combined significantly improved risk prediction accuracy compared with aBMD alone. Further inclusion of age and prevalent vertebral deformity in the model improved vertebral fracture prediction, and TBS remained significant in the model. Thus, lower TBS was associated with higher risk of vertebral fracture over 10 years independently of aBMD and clinical risk factors including prevalent vertebral deformity. TBS could effectively improve fracture risk assessment in clinical settings.

Sex inequalities in physical and mental functioning of British, Finnish, and Japanese civil servants: role of job demand, control and work hours.

In general, women report more physical and mental symptoms than men. International comparisons of countries with different welfare state regimes may provide further understanding of the social determinants of sex inequalities in health. This study aims to evaluate (1) whether there are sex inequalities in health functioning as measured by the Short Form 36 (SF-36), and (2) whether work characteristics contribute to the sex inequalities in health among employees from Britain, Finland, and Japan, representing liberal, social democratic, and conservative welfare state regimes, respectively. The participants were 7340 (5122 men and 2218 women) British employees, 2297 (1638 men and 659 women) Japanese employees, and 8164 (1649 men and 6515 women) Finnish employees. All the participants were civil servants aged 40-60 years. We found that more women than men tended to have disadvantaged work characteristics (i.e. low employment grade, low job control, high job demands, and long work hours) but such sex differences were relatively smaller among employees from Finland, where more gender equal policies exist than Britain and Japan. The age-adjusted odds ratio (OR) of women for poor physical functioning was the largest for British women (OR = 2.08), followed by for Japanese women (OR = 1.72), and then for Finnish women (OR = 1.51). The age-adjusted OR of women for poor mental functioning was the largest for Japanese women (OR = 1.91), followed by for British women (OR = 1.45), and then for Finnish women (OR = 1.07). Thus, sex differences in physical and mental health was the smallest in the Finnish population. The larger the sex differences in work characteristics, the larger the sex differences in health and the reduction in the sex differences in health after adjustment for work characteristics. These results suggest that egalitarian and gender equal policies may contribute to smaller sex differences in health, through smaller differences in disadvantaged work characteristics between men and women.

Tracking of appendicular bone mineral density for 6 years including the pubertal growth spurt: Japanese Population-based Osteoporosis kids cohort study.

Bone development up to early adulthood plays an important role in determining the risk of osteoporosis later in life. However, bone development in children has not been fully documented by longitudinal studies in Japanese children. The purpose of this study is to determine the degree of tracking of areal bone mineral density (aBMD) from pre-puberty to 6-year follow-up, and to determine the target period to achieve maximal peak aBMD. This study was conducted as the pediatric part of a larger cohort study, the Japanese Population-based Osteoporosis (JPOS) study. Of 448 children aged 9-12 years who completed the baseline survey, 225 participated in the follow-up study 6 years later (follow-up rate: 50.2%). aBMD at the forearm was measured using dual-energy X-ray absorptiometry. aBMD values in pre-pubertal children at baseline showed a significant tracking correlation with aBMD obtained at 6-year follow-up in both genders (boys r = 0.655, girls r = 0.759). Although boys and girls in the lowest quartile of aBMD pre-pubertally had greater annual increases in aBMD from pre-puberty to 6-year follow-up than those in other aBMD quartiles, they still showed the lowest mean aBMD at 6-year follow-up. Children with lower pre-pubertal aBMD showed greater increases in BMD up until 6-year follow-up, but the increase was not great enough to catch up with other children. About 50% of the variance in aBMD at 6-year follow-up was determined by the aBMD achieved during the pre-pubertal period. Activities that increase aBMD are important not only for children during puberty, but also for younger pre-pubertal children.

Sex differences in physical and mental functioning of Japanese civil servants: explanations from work and family characteristics.

Poor physical and mental functioning are more common among women than men and those with disadvantaged work and family characteristics. This study aims to clarify whether sex differences in health functioning can be explained by sex differences in work and family characteristics. The subjects were 3787 civil servants (2525 men and 1262 women), aged 20-65, working in a local government on the west coast of Japan. A questionnaire survey was conducted in January 2003. Low employment grade, high demands, long work hours, shift work, being unmarried, having no young children, high family-to-work conflict and high work-to-family conflict were more common among women than men and were independently associated with poor physical and mental functioning. The age-adjusted odds ratios (ORs) of women for poor health functioning were 1.80 for poor physical functioning and 1.77 for poor mental functioning. When adjusted for employment grade and work characteristics (control, demand, support, work hours, and shift work), the sex differences in health functioning attenuated. When adjusted for family characteristics (family structure and work-family conflicts), the sex differences in health functioning further attenuated and were no longer statistically significant. Sex differences in family characteristics contributed more to sex difference in mental functioning than sex differences in work characteristics. Japan belongs to conservative welfare regimes. In such countries, men are able to concentrate on their work with relative freedom from their family tasks and responsibilities, whereas women feel difficulties in maintaining their work-life balances. Such sex differences in work- and family-related stresses may contribute to sex difference in health. Longitudinal research is necessary to clarify the causal nature of these associations.

[Alcohol drinking patterns and sleep quality of Japanese civil servants].

OBJECTIVE: The purpose of this study was to clarify whether alcohol drinking patterns were associated with sleep quality. METHODS: A cross-sectional survey was carried out by self-administered questionnaire in 2008 among 2,118 employees aged 18 to 65 years working in local government in Toyama. After excluding those without relevant data for this study, 661 men and 618 women represented the study population. Logistic regression analysis was used to evaluate whether alcohol drinking patterns (as measured by the frequency, the amount of alcohol per day and the timing of alcohol drinking) were associated with poor sleep quality (as measured by the Pittsburgh Sleep Quality Index), after adjustment for potential confounding factors: age, family structure, work characteristics (as measured by the job-demand-control-support model, shift work and occupational class), chronic disease, body mass index, smoking status and physical activity. RESULTS: In comparison with men who did not drink, the adjusted odds ratio for poor sleep quality was 0.52 (95%confidence interval: 0.32-0.85) for those who drank alcohol once a week or more, 0.32 (0.13-0.84) for those who drank 1-3 glasses daily, 0.30 (0.13-0.70) for those who drank 7-14 glasses per week, 0.37 (0.17-0.77) for those who drank only at meals. In women, the drinking patterns were not significantly associated with sleep quality. CONCLUSIONS: The results of this study suggest that some alcohol drinking patterns may affect sleep quality among men who do not use sleeping medicine.

Smoking among premenopausal women is associated with increased risk of low bone status: the JPOS Study.

The impact of smoking on peak bone density has not been conclusively established. We examined how smoking exposure influences bone mineral density (BMD) or the risk of low bone status in premenopausal women. We conducted a baseline survey with a representative sample of Japanese women in 1996. The effect of current and former smokers (ever-smoker) was investigated with 789 premenopausal women aged 20-40 years. The multiple regression with stepwise method was used to identify significant determinants for BMD or the risk of low bone status (T-score < -1) with age, height, weight, calcium intake, coffee consumption, exercise habits, level of daily activity, parity >or= 1, and smoking as explanatory variables. The smoking effect was determined after adjusting for age, height, weight, and significant variables in the multiple regression with stepwise method. Ever-smoker was significantly associated with decreased lumbar BMD adjusted for age, height, and weight. The odds ratio of an ever-smoker for low bone status at the lumbar spine was 2.03 (95% CI 1.12, 5.82) adjusted for age, height, weight, and parity. The odds ratio for low bone status at the lumbar spine was 1.59 (95% CI 0.65, 3.91) and 2.55 (95% CI 1.12, 5.82) in those with less than 3 pack-years of tobacco use and in those with 3 or more pack-years of tobacco use, respectively. These values were adjusted for age, height, weight, and parity using a never-smoker as a reference. Cumulative smoking exposure may be associated with increased risk of low bone status among premenopausal women.

Social class differences in health behaviours among employees from Britain, Finland and Japan: the influence of psychosocial factors.

This study aims to examine social class differences in smoking, heavy drinking, unhealthy food habits, physical inactivity and obesity, and work-related psychosocial factors as explanations for these differences. This is done by comparing employee cohorts from Britain, Finland and Japan. Social class differences in health behaviours are found in the two western European countries, but not in Japan. The studied psychosocial factors related to work, work-family interface and social relationships did not explain the found class differences in health behaviours.

Socioeconomic inequalities in physical and mental functioning of British, Finnish, and Japanese civil servants: role of job demand, control, and work hours.

This study aims to evaluate whether the pattern of socioeconomic inequalities in physical and mental functioning as measured by the Short Form 36 (SF-36) differs among employees in Britain, Finland, and Japan and whether work characteristics contribute to some of the health inequalities. The participants were 7340 (5122 men and 2218 women) British employees, 2297 (1638 men and 659 women) Japanese employees, and 8164 (1649 men and 6515 women) Finnish employees. All the participants were civil servants aged 40-60 years. Both male and female low grade employees had poor physical functioning in all cohorts. British and Japanese male low grade employees tended to have poor mental functioning but the associations were significant only for Japanese men. No consistent employment-grade differences in mental functioning were observed among British and Japanese women. Among Finnish men and women, high grade employees had poor mental functioning. In all cohorts, high grade employees had high control, high demands and long work hours. The grade differences in poor physical functioning and disadvantaged work characteristics among non-manual workers were somewhat smaller in the Finnish cohort than in the British and Japanese cohorts. Low control, high demands, and both short and long work hours were associated with poor functioning. When work characteristics were adjusted for, the socioeconomic differences in poor functioning were mildly attenuated in men, but the differences increased slightly in women. This study reconfirms the generally observed pattern of socioeconomic inequalities in health for physical functioning but not for mental functioning. The role of work characteristics in the relationship between socioeconomic status and health differed between men and women but was modest overall. We suggest that these differences in the pattern and magnitude of grade differences in work characteristics and health among the 3 cohorts may be attributable to the different welfare regimes among the 3 countries.

Arm span increases predictive value of models for prevalent vertebral deformities: the Japanese Population-based Osteoporosis (JPOS) Study.

OBJECTIVE: We examined anthropometric indicators to improve predictive ability of asymptomatic vertebral fracture screening models. STUDY DESIGN AND SETTING: Data were obtained from the 1996 Japanese Population-based Osteoporosis (JPOS) Study. McCloskey-Kanis criteria diagnosed vertebral deformities on X-ray absorptiometric images in 693 women aged > or =50.The multiple logistic regression model included age, height, weight, postmenopausal status, total hip BMD, and arm span (AS) or sitting height as explanatory variables. Akaike's information criterion (AIC) evaluated model goodness-of-fit. RESULTS: Age-adjusted AS and sitting height in subjects with and without vertebral deformities were 147.2+/-0.6 cm and 148.5+/-0.2 cm (P=0.055), 78.5+/-0.5 cm and 79.9+/-0.2 cm (P=0.007), respectively. Every 5-cm increase in AS indicated 1.5-fold increased risk of prevalent vertebral deformity in the model including age, height, weight, postmenopausal status, and BMD. Including the explanatory variable AS in models yielded better predictive accuracy than excluding AS (AIC, 441.7 vs 446.6, respectively). Sitting height did not significantly influence model predictive ability. CONCLUSION: Predictive accuracy of model for vertebral fracture including age, height, weight, postmenopausal status, and BMD improved when AS was added as an explanatory variable. Models to screen for asymptomatic vertebral fractures should include AS.