Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study.

BACKGROUND: The associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults. METHODS: A total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011-2020). Functional disability was ascertained using the national database of Japan's Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants' waists. RESULTS: During follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios (95% confidence intervals) of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability (hazard ratio [95% confidence interval]: 0.88 [0.84‒0.92]). No significant association was observed between sedentary bout length and functional disability. CONCLUSION: Higher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.

Associations between various types of activity and physical frailty in older Japanese: a cross-sectional study.

BACKGROUND: Physical activity is known to help prevent physical frailty, but it is not clear which physical activities practiced alone or in combination are most closely associated with a lower risk of physical frailty. We investigated differences in the associations of exercise habit, social participation, and moderate-to-vigorous physical activity (MVPA) with physical frailty and its components among community-dwelling older Japanese adults. SUBJECTS AND METHODS: A total of 831 older adults participated in this cross-sectional study. Physical frailty was defined based on the Fried et al. criteria. Exercise habit was defined as exercising ≥ 30 min per day for ≥ 2 days per week for ≥ 1 year. Social participation was defined as participating in community activities ≥ 1/week. MVPA was defined as ≥ 300 min/week of moderate physical activity (MPA) or 150 min/week of vigorous physical activity (VPA). We classified the participants into eight groups according to the presence/absence of these activities, and we performed a logistic regression analysis to investigate the association between different activities, both alone and in combination, and physical frailty. RESULTS: The prevalence of physical pre-frailty + frailty was 74.8% in the None group, 65.0% in the Exercise habit group, 76.3% in the Social participation group, 56.5% in the MVPA group, 58.7% in the Exercise habit + Social participation group, 44.0% in the Exercise habit + MVPA group, 41.3% in the Social participation + MVPA group, and 38.0% in the All group. Compared to the None group, the groups in which participants were engaged in any combination of two or more types of activity, as well as the MVPA-alone group had significantly lower risks of physical pre-frailty + frailty. CONCLUSION: Community-dwelling older Japanese adults who engaged in MVPA or any combination of two or more types of physical activity as defined herein had lower risks of physical pre-frailty and frailty.

Effect of Isometric Tongue Lifting Exercise on Oral Function, Physical Function, and Body Composition in Community-Dwelling Older Individuals: A Pilot Study.

INTRODUCTION: It is known that oral frailty is one of the risk factors for physical frailty. Therefore, early detection, appropriate treatment, and prevention of oral frailty are really important. Tongue lifting exercise has been identified as a well-known method for improving decreased tongue pressure, one of the factors for oral frailty. However, few reports have investigated how tongue-strengthening exercises affect physical function and body composition. The aim of this study was to investigate the effects of isometric tongue lifting exercises on oral function, physical function, and body composition. METHODS: Participants were 49 elderly people aged 68-79 years, who had previously participated in the "Itoshima Frail Study." Participants performed isometric tongue lift exercises for 3 months. Oral function (tongue pressure and oral diadocokinesis), physical function (grip strength, open-eyed one-leg standing, sit-to-stand motion time, 5-m gait speed, and 3-m Timed up and go [TUG]), and body composition were measured at baseline and post-intervention, and the extent of changes in each item was statistically analyzed. Furthermore, participants were divided into physical frailty/pre-frailty and robust groups based on the Japanese version of the frail scale proposed by [BMC Geriatr. 2015 Apr;15:36] and were compared in terms of the extent of changes in each item baseline and the post-intervention. RESULTS: After the intervention, oral function increased significantly together with a significant improvement in physical function, open-eyed one-leg standing time, sit-to-stand motion, and 3-m TUG. For body composition, visceral fat level and basal metabolic rate decreased significantly. Although no significant change in body composition was observed in the physical frailty/pre-frailty group after the intervention, significant improvements in several items were observed in the robust group. CONCLUSION: Isometric tongue lifting exercise can effectively improve oral function. Furthermore, it might affect physical function and body composition.

Association between oral function and physical pre-frailty in community-dwelling older people: a cross-sectional study.

BACKGROUND: Few studies have examined the relationship between oral functions and the physical pre-frailty status, classified using physical function tests. This cross-sectional study aimed to clarify this association among community-dwelling older people from the Itoshima Frail Study in Itoshima Fukuoka Prefecture. METHODS: Of the 1,555 individuals invited to join the study, 381 (188 males and 193 females) enrolled. Their physical pre-frailty was assessed with a classification system consisting of two physical indicators (fatigue and unintentional weight loss, determined with a questionnaire), two functional components (declined walking speed and muscle weakness, determined using a body function measuring instrument), and declined physical activity (examined using a triaxial accelerometer). Subsequently, the individuals were classified into three groups: robust, pre-frailty, and frailty. Along with the number of teeth remaining, oral functions, such as masticatory performance, tongue pressure strength, and oral diadochokinesis (ODK), were examined. Data regarding social activity and exercise habits were collected, and the individuals' body compositions were measured. Odds ratios (ORs) and 95% confidence intervals (CIs) for the physical pre-frailty were calculated using logistic regression models. RESULTS: In this study, 126 (33%) participants presented with physical pre-frailty. The participants in the robust group were younger, had stronger maximum handgrip strength, and walked faster than those in the physical pre-frailty group (p < 0.001). The robust group presented with better oral functions (masticatory performance, p = 0.015; oral ODK /ta/, p = 0.004). The physical pre-frailty status was significantly associated with age (OR, 1.111; 95% CI, 1.048-1.178; p < 0.001), masticatory performance (OR, 0.819; 95% CI, 0.680-0.986; p = 0.035), low ODK/ta/ (OR, 1.864; 95% CI, 1.069-3.250; p = 0.028), and low social activity (OR, 2.273; 95% CI, 1.308-3.951; p = 0.004). CONCLUSION: This study indicated that older people with higher age, lower anterior tongue movement, lower masticatory performance, and lower social activity are positively associated with physical pre-frailty.

Prevalence and Mortality of Sarcopenia in a Community-dwelling Older Japanese Population: The Hisayama Study.

BACKGROUND: The prevalence of sarcopenia defined using the Asian Working Group for Sarcopenia (AWGS) criteria in Asian communities has not been fully addressed. Moreover, few studies have addressed the influence of sarcopenia on mortality. METHODS: A total of 1,371 and 1,597 residents aged 65 years or older participated in health surveys in 2012 and 2017. Sarcopenia was determined using the AWGS definition. Factors associated with the presence of sarcopenia were assessed using a logistic regression model in participants in the 2012 survey. Subjects in the 2012 survey were followed-up prospectively for a median of 4.3 years. Mortality risk for subjects with sarcopenia was examined using the Cox proportional hazards model. RESULTS: The crude prevalence of sarcopenia was 7.4% and 6.6% in participants at the 2012 and 2017 surveys, respectively; there was no significant difference between surveys (P = 0.44). The prevalence of sarcopenia increased significantly with age in both sexes (both P for trend <0.001). Subjects with sarcopenia were more likely to exercise less regularly, to intake less total energy, and to exhibit a disability in activity of daily living than those without. The multivariable-adjusted hazard ratio for all-cause mortality was 2.20 (95% confidence interval, 1.25-3.85) in subjects with sarcopenia, compared to those without. CONCLUSIONS: Approximately 7% of older subjects had sarcopenia in a community-dwelling older Japanese population. Moreover, subjects with sarcopenia had an increased mortality risk. Our findings suggest that a public health strategy for sarcopenia is needed to extend healthy life expectancy.

Potential utility of physical function measures to improve the risk prediction of functional disability in community-dwelling older Japanese adults: a prospective study.

BACKGROUND: While gait speed, one-leg standing balance, and handgrip strength have been shown to be independent predictors for functional disability, it is unclear whether such simple measures of physical function contribute to improved risk prediction of functional disability in older adults. METHODS: A total of 1,591 adults aged ≥ 65 years and without functional disability at baseline were followed up for up to 7.9 years. Functional disability was identified using the database of Japan's Long-term Care Insurance System. Maximum gait speed, one-leg standing time, and handgrip strength were measured at baseline. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) for the association of physical function and functional disability incidence. The incremental predictive value of each physical function measure for risk prediction was quantified using the difference in overall C-statistic, category-free net reclassification improvement (NRI), and integrated discrimination improvement (IDI) index. RESULTS: During follow-up (median: 7.8 years), functional disability was identified in 384 participants. All of the physical function measures were inversely associated with the risk of functional disability, independent of potential confounding factors. The multivariable adjusted HRs (95 % CIs) for functional disability per one standard deviation increment of maximum gait speed, one-leg-standing time, and hand grip strength were 0.73 (0.65-0.83), 0.68 (0.59-0.79), and 0.72 (0.59-0.86), respectively. Incorporation of each of maximum gait speed, one-leg-stand time, and hand grip strength into a basic model with other risk factors significantly improved C-statistic from 0.770 (95 % CIs, 0.751-0.794) to 0.778 (0.759-0.803), 0.782 (0.760-0.805), and 0.775 (0.756-0.800), respectively (all p < 0.05). A model including all three measures had the highest C-statistic of 0.787 (0.765-0.810). The improvements in risk prediction were also confirmed by category-free NRI and IDI index. CONCLUSIONS: Adding any of the three measures to a basic model with other known risk factors significantly improved the prediction of functional disability and addition of all three measures provided further improvement of the prediction in older Japanese adults. These data provide robust evidence to support the practical utility of incorporating these simple physical function measures into functional disability risk prediction tools.

Associations of Objectively Measured Patterns of Sedentary Behavior and Physical Activity with Frailty Status Screened by The Frail Scale in Japanese Community-Dwelling Older Adults.

The objective of this study was to investigate the association between objectively measured patterns of sedentary behavior (SB) and physical activity (PA) and frailty status in Japanese community-dwelling older adults. Data was from 65-75 years older adults from the baseline of Itoshima Frail Study were used. Frailty was assessed using a Japanese version of the FRAIL scale. SB and PA were measured using an accelerometer. Multinomial logistic regression and receiver operating characteristic curve analyses were used to investigate the associations of SB and PA patterns with frailty status. Of the total 819 older adults, half were female (51.8%). The prevalence of robust, pre-frailty and frailty was 60.2%, 27.8%, and 12.0%, respectively. SB variables including total sedentary time, sedentary time in bouts of ≥ 10 min and ≥ 30 min, and mean sedentary bout duration were not associated with frailty status. Except LPA and moderate-to-vigorous physical activity (MVPA) in bouts of < 10 min, PA variables including total MVPA time, MVPA in bouts of ≥ 10 min (bouted MVPA), and steps were significantly associated with lower prevalence of frailty. Area under the curves (AUCs) of total MVPA time, bouted MVPA, and steps were 0.64 (P < 0.001), 0.67 (P < 0.001), and 0.66 (P < 0.001), respectively. The optimal cut-off value of total MVPA time, bouted MVPA, and steps to discriminate between frailty and non-frailty were 43.25 min/day, 9.13 min/day, and 3841 steps/day, respectively. Higher levels of total MVPA time, bouted MVPA, and daily steps were negatively associated with frailty. Lower amounts of bouted MVPA (70 min/week) or steps (4000 steps/day) may be achievable initial targets in older adults for frailty management.

Long-term regular exercise and intraocular pressure: the Hisayama Study.

PURPOSE: To investigate the association between long-term regular exercise (exercise frequency and exercise time) and 5-year changes in intraocular pressure in a general Japanese population. METHODS: This population-based, cohort study was conducted in 2007. A total of 3119 Japanese community dwellers aged ≥ 40 years underwent eye examinations including intraocular pressure measurement with a noncontact tonometer. Of these, 1871 subjects (801 men and 1070 women) who underwent intraocular pressure measurement in 2012 participated. We assessed the associations of exercise frequency and exercise time with intraocular pressure using a linear regression model, adjusted for age and possible risk factors that can affect intraocular pressure. RESULTS: The mean 5-year intraocular pressure change ± standard deviation was - 0.84 ± 1.9 mmHg. After adjustment for age, sex, systolic blood pressure, diabetes, total cholesterol, high-density lipoprotein cholesterol, body mass index, waist circumference, smoking habit, alcohol intake, work intensity levels, and intraocular pressure at baseline, we observed that increased exercise frequency (times/week) and increased exercise time (min/week) were both significantly associated with reduced intraocular pressure (p < 0.05 each). In the subgroup analyses based on the presence/absence of possible confounding risk factors, there was no evidence of heterogeneity among all subgroups (p for heterogeneity > 0.2). CONCLUSIONS: Increased exercise frequency levels and increased exercise time are both independently associated with reduced intraocular pressure levels after adjustment for confounding factors.

Patterns and Levels of Sedentary Behavior and Physical Activity in a General Japanese Population: The Hisayama Study.

BACKGROUND: The purpose of this cross-sectional study was to describe the patterns and levels of sedentary time and physical activity (PA) in a general Japanese population. METHODS: A total of 1,740 community-dwelling Japanese adults aged ≥40 years participated in this study. Sedentary time and PA were assessed for 7 consecutive days using a tri-axial accelerometer. Daily patterns and levels of sedentary time and PA were calculated by sex, age group (40-64, 65-74, and ≥75 years), and body mass index (BMI; <25 and ≥25 kg/m2). RESULTS: Participants spent half of their waking time being sedentary, 32.7% of which was accumulated in prolonged bouts ≥30 minutes, versus only 54.4 minutes/day (7% of waking time) as moderate-to-vigorous PA (MVPA) (11.8 minutes/day in bouts ≥10 minutes). In addition to total sedentary time, men had longer prolonged sedentary bouts and fewer breaks per sedentary hour than women. Similar trends were observed in participants aged ≥75 years and those with a higher BMI (≥25 kg/m2) compared to those with a younger age and lower BMI. Moreover, participants aged ≥75 years and those with a higher BMI accumulated fewer MVPA minutes in bouts ≥10 minutes. Only 34.8% of the population met the recommended level of ≥150 minutes/week MVPA in bouts ≥10 minutes. CONCLUSION: Japanese adults accumulated a large proportion of total sedentary time in prolonged bouts but few minutes in sustained bouts of MVPA, and few of them met the current PA guideline.

Serum Angiopoietin-Like Protein 2 Is a Novel Risk Factor for Cardiovascular Disease in the Community: The Hisayama Study.

OBJECTIVE: Angiopoietin-like protein 2 (ANGPTL2), a proinflammatory mediator, has been reported to accelerate the development of insulin resistance, endothelial dysfunction, and atherosclerosis in mice. However, no cohort studies have examined the relationship between serum ANGPTL2 levels and the development of cardiovascular disease (CVD) in a general population. APPROACH AND RESULTS: A total of 3005 community-dwelling Japanese aged ≥40 years without a history of CVD were divided into 4 groups according to the quartiles of serum ANGPTL2 concentrations (Q1, lowest and Q4, highest) and followed up for 10 years. The hazards ratios and their 95% confidence intervals for the development of CVD (coronary heart disease or stroke) were estimated using a Cox proportional hazards model. During the follow-up, 219 first-ever CVD events were observed. The risk of CVD increased significantly with elevating ANGPTL2 levels after adjustment for age, sex, serum total cholesterol, use of lipid-lowering agents, ECG abnormalities, smoking habits, alcohol intake, and regular exercise (hazards ratios [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.27 [0.80-2.04]; Q3, 1.48 [0.95-2.32]; and Q4, 1.85 [1.20-2.85]; P=0.003 for trend). After additional adjustment for metabolic syndrome components and serum high-sensitivity C-reactive protein levels as an inflammatory marker, the association was attenuated but remained significant (hazards ratios [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.21 [0.76-1.94]; Q3, 1.38 [0.87-2.17]; and Q4, 1.66 [1.05-2.60]; P=0.02 for trend). CONCLUSIONS: Our findings suggest that elevated serum ANGPTL2 levels are a novel risk factor for the development of CVD in the general population. This association is partially mediated by metabolic disorders and inflammation.

Morning and Evening Blood Pressures Are Associated With Intima-Media Thickness in a General Population　- The Hisayama Study.

BACKGROUND: The association of morning and evening home blood pressures (HBPs) with carotid atherosclerosis has been uncertain in general populations, so we aimed to investigate it in a general Japanese population.Methods and Results:We performed a cross-sectional survey of 2,856 community-dwelling individuals aged ≥40 years to examine the association of morning and evening HBPs with carotid mean intima-media thickness (IMT). The age- and sex-adjusted geometric averages of carotid mean IMT increased significantly with increasing morning HBP (optimal: 0.67 mm; normal: 0.69 mm; high normal: 0.72 mm; grade 1 hypertension: 0.74 mm; and grade 2+3 hypertension: 0.76 mm) and with increasing evening HBP (0.68 mm, 0.71 mm, 0.73 mm, 0.76 mm, and 0.78 mm, respectively) (both P for trend <0.001). These associations remained significant even after adjusting for potential confounding factors. Likewise, both isolated morning hypertension (morning HBP ≥135/85 mmHg and evening HBP <135/85 mmHg) and isolated evening hypertension (evening HBP ≥135/85 mmHg and morning HBP <135/85 mmHg) as well as sustained hypertension (both morning and evening HBP ≥135/85 mmHg) were significantly associated with thicker mean IMT. CONCLUSIONS: Our findings suggested that both morning and evening HBPs were significantly associated with carotid atherosclerosis in this general Japanese population.

Association Between Serum Vitamin D and All-Cause and Cause-Specific Death in a General Japanese Population　- The Hisayama Study.

BACKGROUND: Few studies have investigated the association between serum vitamin D levels and mortality in general Asian populations.Methods and Results:We examined the association of serum 1,25-dihydroxyvitamin D (1,25(OH)2D) levels with the risk of all-cause and cause-specific death in an average 9.5-year follow-up study of 3,292 community-dwelling Japanese subjects aged ≥40 years (2002-2012). The multivariable-adjusted hazard ratio (HR) for all-cause death increased significantly with lower serum 1,25(OH)2D levels (HR 1.54 [95% confidence interval, 1.18-2.01] for the lowest quartile, 1.31 [0.99-1.73] for the 2nd quartile, 0.94 [0.70-1.25] for the 3rd quartile, 1.00 [Ref.] for highest quartile; P for trend <0.001). A similar association was observed for cardiovascular and respiratory infection death (both P for trend <0.01), but not for cancer death or death from other causes. In the stratified analysis, the association between lower serum 1,25(OH)2D levels and the risk of respiratory infection death was stronger in subjects with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2than in those with eGFR ≥60 mL/min/1.73 m2; there was a significant heterogeneity in the association between eGFR levels (P for heterogeneity=0.04). CONCLUSIONS: The findings suggested that a lower serum 1,25(OH)2D level is a potential risk factor for all-cause death, especially cardiovascular and respiratory infection death, in the general Japanese population, and that lower serum 1,25(OH)2D levels greatly increase the risk of respiratory infection death in subjects with kidney dysfunction.

The ratio of serum eicosapentaenoic acid to arachidonic acid and risk of cancer death in a Japanese community: The Hisayama Study.

BACKGROUND: Whether the intake of eicosapentaenoic acid (EPA) or arachidonic acid (AA) affects the risk of cancer remains unclear, and the association between the serum EPA:AA ratio and cancer risk has not been fully evaluated in general populations. METHODS: A total of 3098 community-dwelling subjects aged ≥40 years were followed up for 9.6 years (2002-2012). The levels of the serum EPA:AA ratio were categorized into quartiles (<0.29, 0.29-0.41, 0.42-0.60, and >0.60). The risk estimates were computed using a Cox proportional hazards model. The same analyses were conducted for the serum docosahexaenoic acid to arachidonic acid (DHA:AA) ratio and individual fatty acid concentrations. RESULTS: During the follow-up period, 121 subjects died of cancer. Age- and sex-adjusted cancer mortality increased with lower serum EPA:AA ratio levels (P trend<0.05). In the multivariable-adjusted analysis, the subjects in the first quartile of the serum EPA:AA ratio had a 1.93-fold (95% confidence interval, 1.15-3.22) greater risk of cancer death than those in the fourth quartile. Lower serum EPA concentrations were marginally associated with higher cancer mortality (P trend<0.11), but the serum DHA or AA concentrations and the serum DHA:AA ratio were not (all P trend>0.37). With regard to site-specific cancers, lower serum EPA:AA ratio was associated with a higher risk of death from liver cancer. However, no such associations were detected for deaths from other cancers. CONCLUSIONS: These findings suggest that decreased level of the serum EPA:AA ratio is a significant risk factor for cancer death in the general Japanese population.

Serum Uric Acid as a Risk Factor for Chronic Kidney Disease in a Japanese Community　- The Hisayama Study.

BACKGROUND: Growing evidence suggests that high serum uric acid (SUA) levels are causally related to increased risk of chronic kidney disease (CKD). However, few studies have investigated the influence of elevated SUA levels on the incidence of kidney dysfunction and albuminuria separately in community-based populations. METHODS AND RESULTS: A total of 2,059 community-dwelling Japanese subjects aged ≥40 years without CKD were followed for 5 years. CKD was defined as kidney dysfunction (estimated glomerular filtration rate <60 ml/min/1.73 m(2)) or albuminuria (urine albumin-creatinine ratio ≥30 mg/g). The odds ratio (OR) for the development of CKD was estimated according to quartiles of SUA (≤4.0, 4.1-4.9, 5.0-5.8, and ≥5.9 mg/dl). During the follow-up, 396 subjects developed CKD, of whom 125 had kidney dysfunction and 312 had albuminuria. The multivariable-adjusted risk of developing CKD increased with higher SUA levels (OR 1.00 [reference] for ≤4.0, 1.21 [95% confidence interval, 0.84-1.74] for 4.1-4.9, 1.47 [1.01-2.17] for 5.0-5.8, and 2.10 [1.37-3.23] for SUA ≥5.9 mg/dl, respectively). Similarly, there were positive associations between SUA level and the adjusted risk of developing kidney dysfunction (OR 1.00 [reference], 2.30 [1.10-4.82], 2.81 [1.34-5.88], and 3.73 [1.65-8.44]) and albuminuria (1.00 [reference], 1.12 [0.76-1.65], 1.35 [0.90-2.03], and 1.81 [1.14-2.87], respectively). CONCLUSIONS: Higher SUA levels were a significant risk factor for the development of both kidney dysfunction and albuminuria in a general Japanese population. (Circ J 2016; 80: 1857-1862).

The long-term association between physical activity and risk of dementia in the community: the Hisayama Study.

We investigated the long-term influence of physical activity on the risk of dementia in an elderly Japanese population. A total of 803 community-dwelling elderly Japanese individuals without dementia aged ≥65 years were followed prospectively for 17 years. Physically active status was defined as engaging in exercise at least one or more times per week during leisure time, and participants were divided into an active group and an inactive group by the presence or absence of such physical activity. The risk estimates of physical activity on the development of all-cause dementia and its subtypes were computed using a Cox proportional hazards model. During the follow-up, 291 participants developed all-cause dementia. Of these, 165 had Alzheimer's disease (AD), 93 had vascular dementia (VaD), and 47 had other dementia. Compared with the inactive group, the active group showed significantly lower crude incidence of AD (21.8 vs. 14.2 per 1000 person-years, p = 0.01), but no significant differences were observed for all-cause dementia (35.6 vs. 30.5, p = 0.17), VaD (11.3 vs. 9.8, p = 049), and other dementia (4.6 vs. 7.1, p = 0.15). After adjusting for potential confounders, the relationship between physical activity and risk of AD remained significant (adjusted hazard ratio 0.59, 95% confidence interval 0.41-0.84, p = 0.003). Our findings suggest that physical activity reduces the long-term risk of dementia, especially AD, in the general Japanese population.

Sedentary bout durations and metabolic syndrome among working adults: a prospective cohort study.

BACKGROUND: This study aimed to examine the associations between time spent in prolonged and non-prolonged sedentary bouts and the development of metabolic syndrome. METHODS: We used data from a prospective study of Japanese workers. Baseline examination was conducted between 2010 and 2011. A total of 430 office workers (58 women) aged 40-64 years without metabolic syndrome were followed up by annual health checkups until 2014. Metabolic syndrome was defined as having ≥ 3 out of 5 diagnostic criteria from the Joint Interim Statement 2009 definition. Sedentary time was assessed using a tri-axial accelerometer. Time spent in total, prolonged (accumulated ≥ 30 min) and non-prolonged sedentary bouts (accumulated < 30 min) was calculated. Cox proportional hazards models were used to estimate the risk of developing metabolic syndrome. RESULTS: During a median follow-up of 3 years, 83 participants developed metabolic syndrome. After adjustment for age, sex, education, smoking, and family income, positive associations were observed between time spent in prolonged sedentary bouts and the development of metabolic syndrome. After additional adjustment for moderate-to-vigorous physical activity, those in the three highest quartiles of time spent in prolonged sedentary bouts showed higher risk of metabolic syndrome compared to the lowest quartile group, with adjusted hazard ratios (95 % confidence intervals) of 2.72 (1.30 - 5.73), 2.42 (1.11 - 5.50), and 2.85 (1.31 - 6.18), respectively. No associations were seen for time spent in total and non-prolonged sedentary bouts. CONCLUSIONS: Sedentary behavior accumulated in a prolonged manner was associated with an increased risk of metabolic syndrome. In devising public health recommendations for the prevention of metabolic disease, the avoidance of prolonged uninterrupted periods of sedentary behavior should be considered.

Identifying associations between sedentary time and cardio-metabolic risk factors in working adults using objective and subjective measures: a cross-sectional analysis.

BACKGROUND: Sedentary behavior has been reported to be associated with metabolic and vascular health independent of moderate-to-vigorous physical activity (MVPA). In order to select appropriate options to measure sedentary behavior in practice and research settings, it is worthwhile to characterize the extent to which objective and subjective measures of sedentary behavior quantify adverse health risks in the same population. This cross-sectional analysis compared accelerometer-derived and self-reported sedentary time to identify their association with cardio-metabolic risk factors. METHODS: Cross-sectional analysis was conducted using data from 661 Japanese workers (145 women) aged 20-64 years. Participants wore a tri-axial accelerometer device for 10 consecutive days and completed the Japan Atherosclerosis Longitudinal Study Physical Activity Questionnaire. Data on body mass index, waist circumference, resting blood pressure, triglycerides, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, total:HDL cholesterol ratio, blood glucose, and glycosylated hemoglobin (HbA1c) were obtained from annual health examinations. RESULTS: Both accelerometer-derived and self-reported sedentary time were deleteriously associated with triglycerides, HDL-cholesterol, total:HDL ratio, and HbA1c after adjustment for potential confounders including MVPA. There were no significant differences in regression coefficients between the two measures. Thus, the magnitude of the associations of both measures with cardio-metabolic risk factors was similar, despite poor agreement between them. Occupational sedentary time was correlated with both measures of total sedentary time, and more consistently associated with cardio-metabolic risk factors than sedentary leisure time. CONCLUSIONS: Both accelerometer and self-report measurements are similarly associated with cardio-metabolic risk factors in a Japanese working adult population. Subjective and objective measures of sedentary behaviors appear to capture different aspects of behaviors. Further efforts to establish data processing methods integrating objective and subjective measures are needed to more effectively assess sedentary time's relationship to health outcomes.

Association of the Combination of Moderate-to-Vigorous Physical Activity and Sleep Quality with Physical Frailty.

BACKGROUND: The association of the individual and combined effects of moderate-to-vigorous physical activity (MVPA) and sleep quality with physical frailty in community-dwelling older adults is still unknown. SUBJECTS AND METHODS: A cross-sectional study was conducted with a sample of older adults who had not required nursing care or support services. Physical frailty was assessed using Liu's definition based on Fried's concept. MVPA was measured by a triaxial accelerometer, and individuals who met either moderate physical activity (MPA) for ≥300 min/week, vigorous physical activity (VPA) for ≥150 min/week, or both were defined as "MVA+". "SLP+" was defined as a Pittsburgh Sleep Quality Index score of <5.5 points. RESULTS: A total of 811 participants were included in the final analysis. After adjusting for the multivariable confounding factors, the odds ratios (ORs) and 95% confidence intervals (CIs) for physical pre-frailty and frailty in the MVA-SLP+ (OR, 2.56; 95%CI, 1.80-3.62) and the MVA-SLP- group (OR, 3.97; 95%CI, 2.33-6.74) were significantly higher compared with the MVA+SLP+ group. CONCLUSION: Community-dwelling older adults who did not meet the MVPA criteria, regardless of sleep quality, had a higher prevalence of physical frailty.

The Relationships Among Chronic Pain Subtypes, Motor Function, and Physical Activity in Community-Dwelling Japanese Older Adults: A Cross-Sectional Study.

PURPOSE: We investigated the relationships among motor function, physical activity, and the characteristics of chronic pain (the number of pain sites, pain intensity, and pain-type). DESIGN: Cross-sectional study. SETTING: An ongoing community-based prospective study conducted in Itoshima, Japan. SUBJECTS: Community-dwelling Japanese aged 65-75 years (n = 805; 401 men, 404 women). MEASURES: Chronic pain subtypes were examined in terms of the number of pain sites, pain intensity, and pain type. Motor function was evaluated by handgrip strength, walking speed, and the 5 Times Stand-up and Sit Test (FTSST). Locomotive activity, non-locomotive activity, and sedentary time were evaluated by a tri-axial accelerometer as physical-activity parameters. ANALYSIS: Multiple regression model adjusting for age, sex, education level, employment status, subjective economic status, body mass index, cognitive function, comorbidity, current tobacco use, current alcohol consumption, and regular exercise. RESULTS: In a multivariate analysis, the subjects' walking speed was negatively associated with multisite, moderate-to-severe, and neuropathic-like pain. The FTSST was positively associated with single-site, moderate-to-severe, and neuropathic-like pain. There was no significant association between handgrip strength and any chronic pain subtypes. Locomotive activity was negatively related to multisite, moderate-to-severe, and neuropathic-like pain, but there was no clear association between the amount of non-locomotive activity, sedentary time, and chronic pain subtypes. CONCLUSION: Severe chronic pain was associated with decreased locomotion-related motor function and physical activity.

Association between mental health and academic performance among university undergraduates: The interacting role of lifestyle behaviors.

OBJECTIVES: Impaired mental health status tends to be associated with poor academic performance, but few prospective studies have examined the association between mental health and academic performance among undergraduates while considering the interacting roles of multiple lifestyle behaviors. PARTICIPANTS AND METHODS: A total of 1823 Japanese undergraduate students (67% men) were followed up for 4 years. Their mental health status was measured by the six-item Kessler Psychological Distress Scale (K6). We defined poor academic performance as a grade point average (GPA) <2.0. Cox proportional hazards models were used to determine the relationship between the students' mental health status and the incident risk of poor academic performance. RESULTS: Our analyses revealed that impaired mental health status in the first semester of university study significantly predicted an increased incident risk of poor academic performance during the overall undergraduate period. This association remained significant when the health lifestyle behaviors were adjusted, and the hazard ratio (95% confidence interval) for poor academic performance was 1.62 (1.18-2.23). This significant association disappeared in the low-lifestyle-behavior-risk group. CONCLUSION: Impaired mental health status in the first semester significantly predicts an increased incident risk of poor academic performance during the undergraduate period.