This study examined the association of physical activity (PA) and sedentary behavior (SB) with chronic low back pain (CLBP) in older adults. Cross-sectional data were collected from 715 elders aged 65 years and over living in Dazaifu, Japan. CLBP was defined as pain that sustains more than 1-3 months within the past year. PA and SB were objectively measured using a triaxial accelerometer (Omron Healthcare, Active style Pro (HJA 350IT)). Participants were categorized into four groups (2 groups of PA×2 groups of SB) according to their levels of PA and SB (divided into 2 levels; low and high levels around the median). Logistic regression analysis was used to examine effect of PA/SB with CLBP. In the analyses, sex, age, body mass index, smoking, educational attainment, falls, handgrip strength, knee pain and non-locomotive activities were treated as potential confounders. The prevalence of CLBP was 35%. After adjustment of confounding factors, significantly higher risk of CLBP was shown only in Low PA/High SB group (odds ratio : 1.66, 95% confidence interval : 1.02-2.70), compared with that of the reference group (High PA/Low SB group). These results suggest that the combination of low PA and high SB might be the risk of CLBP. Future studies should try to clarify whether CLBP is a cause or a consequence of inactivity.

The purpose of the present study was to investigate the relationships of physical fitness, body mass index (BMI), waist-hip ratio (WHR) and sex hormone binding globulin (SHBG) with lipid and glucose metabolism in premenopausal obese women aged 32 to 49 yrs (n=24) . WHR was significantly correlated with HDL-C, HDL₂-C and Apo B, but not correlated with BMI %fat, maximal oxygen uptake (VO₂max), triglyceride (TG), very low density lipoprotein % fat, and Apo A 1. VO₂max/kg was significantly associated with BMI, TG, HDL-C, HDL₂-C, Apo Al, low density lipoprotein (LDL), SHBG, glucose metabolism at rest and during oral glucose tolerance test (OGTT) . The SHBG was strongly correlated with HDL-C, HDL₂-C and Apo A 1. In multiple regression analysis, it was observed that SHBG was one of the independ-ent predictor of HDL-C, HDL₂-C and Apo Al, that VO₂max was good predictor of LDL, Apo B and glucose metabolism at rest and during OGTT, and that BMI was one of the determinat of TG and VLDL. From these results, we concluded that lipid metabolism was independently associated with aerobic work capacity, SHBG, BMI as well as WHR, and that glucose metabolism was independently associated with aerobic work capacity.

Very few studies have reported an independent association of the physical activity-related indices with the psychological stress reaction. The present study therefore investigated the association of fitness and screentime as one of the indices of sedentary behavior with the four types of psychological stress reactions and the number of days absent from school for 249 children at a local public school and a metropolitan private school while considering confounding factors. No significant difference was observed in the fitness level of both schools; however, the rate of obesity, the screentime and the level of all psychological stress reactions were significantly worse in the public school. Further, significant differences and trends among the groups classified by fitness level were recognized in the rates of participation in after school activities, feeling of powerlessness and days of absence per year. In addition, the odds ratio of the screentime for depressive and anxiety symptoms was 1.004 (95%CI: 1.000-1.007, p=0.039), while the odds of the fitness level for high feeling of powerlessness and more than five days of absence were 1.582 (95%CI: 1.045-2.396, p=0.030) and 1.434 (95%CI: 1.045-2.396, p=0.015), respectively, after adjusting for the school type, differences in lifestyle and participation in after school activities. In conclusion, the fitness level and the screentime were associated with high psychological stress reactions and the days of absence, independent of the above-mentioned adjusting factors among the children in the present study. Prospective and interventional studies to verify these results are needed.

The purpose of the present study was to investigate the baseline characteristics related to the participation status in a longitudinal epidemiological study for the elderly. Nine hundred twenty-six self-supporting older adults lived in a local city located southwest in Japan were classified into the following 3 groups; non-participants (NP, n=170), participants for the baseline measurements (PB, n=278), and participants for both the baseline and follow-up measurements after two-years (PBF, n=478). The basic attributes including socioeconomic status, depressive symptoms, cognitive function, sleep quality, fitness, objectively- measured physical activity, habitual behavior, psychosocial characteristics and functional problems in daily life were assessed. Regarding the NP group, data were collected by questionnaire or home visits. According to the results of a multinomial logistic regression analysis adjusted for age, sex and years of education, significant odds ratios which indicate a poor status in most of the assessment items were observed in both the NP and PB groups in comparison to the PBF group. We concluded that sex (female), a higher age, fewer years of education, a cognitive function decline, depressive symptoms, a low fitness level, physical activity and daily living function, and poor psychosocial backgrounds were related to the non-participation and dropouts. These results should be considered in a longitudinal data analysis of the present study, as well as in the design setting of epidemiological studies dealing with physical activity indexes and care risk factors. Furthermore, these findings are also considered to be useful as basic data for such care prevention activities in the community.

A study was conducted to investigate the contribution of physical fitness evaluated by speed at onset of blood lactate accumulation (OBLA-SP), sex hormones and sex hormone-binding globulin (SHBG) on high-density lipoprotein cholesterol (HDL-c) in 12 young male endurance athletes. These athletes has a higher level and wide range of intraindividual variance (44 to 93 mg/dl) for HDL-c. The serum estradiol level was significantly and positively correlated with the level of apoprotein AI (Apo AI), and serum testosterone level was significantly and positively associated with the levels of both HDL3-c and apoprotein All (Apo All) . The SHBG level was positively associated with the levels of both HDL-c and HDL2-c. Age, certain anthropometric parameters such as percentage body fat, body mass index, and body fat distribution evaluated by waist to hip ratio, and physical fitness levels were not associated with HDL-c and other lipids and apoproteins. These results suggest that the HDL-c level in endurance athletes is strongly associated with not only male but also female hormones, and SHBG, being independent of age, body composition and physical fitnesss level.

This prospective study was designed to clarify the association between the incidence of falls and physical fitness in healthy community-dwelling elderly people without history of fall-related injuries within 1-5 years before the baseline assessment. Six hundred and one elderly subjects aged 60-79 years who lived independently participated in baseline assessments from March 2002 to March 2004, and were followed up for one year to detect falling. Demographic items (age and sex), chronic disease, self-rated health, difficulty in performing any activity, tendency to stay at home, body mass index (BMI), %vital capacity, handgrip and knee extension strength, stepping rate, one-leg standing with eyes opened, trunk flexion at sitting position, maximum walking speed, instrumental activity of daily living (IADL), and General Health Questionnaire (GHQ30) were assessed at baseline. Four hundred and eighty-one participants (80.0%) completed the 1-year follow-up.The fall incidence was 13.1%. In men, fallers had lower BMI and decreased maximum walking speed, however, neither showed significant odds ratio (OR) for fall. In women, fallers had lower knee extension strength and the ratio of weak side to strong side (WS/SS ratio) in knee extension strength compared to non-fallers. The age-adjusted OR for fallers in the lowest quartile (knee extension strength＜0.681kg/BW) was 3.07 (95%CI : 1.02-9.22) compared to highest quartile (＞0.980 kg/BW), while the multiple-adjusted OR was not significant (OR＝2.88, 95%CI : 0.94-8.79). However, the multiple-adjusted OR for fallers in the lowest quartile of the WS/SS ratio in knee extension strength (＜0.771) was 4.49 (95%CI : 1.40-14.37) compared to highest quartile (＞0.947).As for conclusion, without history of fall-related injuries, only a weak association between falls and physical fitness was observed in men. In women, the unbalanced knee extension strength was associated with falls. The WS/SS ratio in knee extension strength might be a key factor in predicting falls in women.

Prevention of functional disabilities leading to long-term care and support needs in older population is one of the most urgent social issues facing Japan today. Frailty has been recognized as a pre-stage of functional disabilities leading to long-term care and support needs, and so, it is often treated as a target in their preventive interventions. Furthermore, because reductions of daily physical activities and physical fitness are considered as part of the major causes of physical frailty, their improvements have been also explored in community-based measures to prevent long-term care and support needs. This review paper aimed to summarize present findings regarding associations of frailty, physical activity, and physical fitness with incident long-term care and support needs in community-dwelling older Japanese adults. Through the review of literature, most of the previous prospective cohort studies showed that community-dwelling older Japanese adults who are free from frailty or maintain good physical activities and physical fitness have a reduced risk for the incidence of long-term care and support needs. These findings support an expectation that prevention of frailty and/or improvements of daily physical activities and physical fitness can be effective strategies to prevent older people from undergoing long-term care and support needs. It should be, however, understood that the associations found in the previous studies are not causal. Future prospective cohort studies defining exposure variables based on multipoint observations, as well as well-designed interventional studies are needed to validate the expectation.

BACKGROUND: The burden of dementia is growing rapidly and has become a medical and social problem in Japan. Prospective cohort studies have been considered an effective methodology to clarify the risk factors and the etiology of dementia. We aimed to perform a large-scale dementia cohort study to elucidate environmental and genetic risk factors for dementia, as well as their interaction. METHODS: The Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD) is a multisite, population-based prospective cohort study of dementia, which was designed to enroll approximately 10,000 community-dwelling residents aged 65 years or older from 8 sites in Japan and to follow them up prospectively for at least 5 years. Baseline exposure data, including lifestyles, medical information, diets, physical activities, blood pressure, cognitive function, blood test, brain magnetic resonance imaging (MRI), and DNA samples, were collected with a pre-specified protocol and standardized measurement methods. The primary outcome was the development of dementia and its subtypes. The diagnosis of dementia was adjudicated by an endpoint adjudication committee using standard criteria and clinical information according to the Diagnostic and Statistical Manual of Mental Disorders, 3rd Revised Edition. For brain MRI, three-dimensional acquisition of T1-weighted images was performed. Individual participant data were pooled for data analyses. RESULTS: The baseline survey was conducted from 2016 to 2018. The follow-up surveys are ongoing. A total of 11,410 individuals aged 65 years or older participated in the study. The mean age was 74.4 years, and 41.9% were male. The prevalence of dementia at baseline was 8.5% in overall participants. However, it was 16.4% among three sites where additional home visit and/or nursing home visit surveys were performed. Approximately two-thirds of dementia cases at baseline were Alzheimer's disease. CONCLUSIONS The prospective cohort data from the JPSC-AD will provide valuable insights regarding the risk factors and etiology of dementia as well as for the development of predictive models and diagnostic markers for the future onset of dementia. The findings of this study will improve our understanding of dementia and provide helpful information to establish effective preventive strategies for dementia in Japan.
Aged ; Alzheimer Disease/genetics* ; Dementia/genetics* ; Environment ; Female ; Humans ; Incidence ; Japan/epidemiology* ; Male ; Middle Aged ; Prevalence ; Prospective Studies ; Risk Factors