Effects of exercise habits in adolescence and older age on sarcopenia risk in older adults: the Bunkyo Health Study.

BACKGROUND: Sarcopenia, defined as an age-associated loss of skeletal muscle mass and function, is a major risk factor for requiring long-term care. Because physical activity in adolescence and older age enhances peak muscle function in youth and prevents muscle function decline in older age, older adults with exercise habits during both periods may be at a lower risk for sarcopenia. We investigated the relationship between exercise habits in adolescence and older age and sarcopenia and its components in community-dwelling older Japanese adults. METHODS: This study included 1607 community-dwelling individuals (aged 65-84, medians 73 years, 679 men and 928 women) with complete health examinations, including measurements of skeletal muscle index, handgrip strength and gait speed, who were enrolled in the Bunkyo Health Study. We divided the participants into four groups according to exercise habits in adolescence and older age: no exercise in either period (none-none; NN), exercise only in adolescence (active-none; AN), exercise only in older age (none-active; NA) and exercise in both periods (active-active; AA). Multivariate-adjusted logistic regression models were used to estimate the odds ratios (ORs) and associated 95% confidence intervals (CIs) in each group for the prevalence of sarcopenia, defined as low muscle mass and low muscle performance, as compared with the NN group. Low muscle performance was defined as low muscle strength and/or low gait speed. RESULTS: The total prevalence of sarcopenia was 6.6% (45/679) in men and 1.7% (16/928) in women, the total prevalence of low muscle mass was 14.3% (97/679) in men and 5.2% (48/928) in women, and the total prevalence of low muscle performance was 25.6% (174/679) in men and 19.6% (182/928) in women. In men, the ORs (95% CIs) for sarcopenia, low muscle mass and low muscle performance were significantly lower in the AA group (sarcopenia: 0.29 [0.09-0.95], P = 0.041; low muscle mass: 0.21 [0.09-0.52], P = 0.001; and low muscle performance: 0.52 [0.28-0.97], P = 0.038). In women, the OR (95% CI) for low muscle performance was significantly lower in the AA group than in the other groups (0.48 [0.27-0.84], P = 0.010), whereas none of the ORs for sarcopenia and low muscle mass were significant. CONCLUSIONS: Older men with exercise habits in both adolescence and older age were at a lower risk of sarcopenia, low muscle mass and low muscle performance, whereas older women with exercise habits at both time periods were at a lower risk of low muscle performance.

Neuroimaging findings related to glymphatic system alterations in older adults with metabolic syndrome.

OBJECTIVE: The glymphatic system is a glial-based perivascular network that promotes brain metabolic waste clearance. Reduced glymphatic flow has been observed in rat models of type 2 diabetes and hypertension, indicating the role of vascular risk factors in the glymphatic system. However, little is known about how vascular risk factors affect the human glymphatic system. The present study aims to assess the relationships between metabolic syndrome (MetS), a cluster of vascular risk factors, and the glymphatic system function using diffusion magnetic resonance imaging (MRI)-based measures of water diffusivity in the glymphatic compartments, including the brain interstitial space and perivascular spaces around the deep medullary vein. We hypothesized that vascular risk factors are associated with glymphatic dysfunction, leading to cognitive impairment in older adults. METHODS: This cross-sectional study assessed 61 older adults (age range, 65-82 years) who had participated in the Bunkyo Health Study, including 15 healthy controls (mean age, 70.87 ± 4.90 years) and 46 individuals with MetS (mean age, 71.76 ± 4.61 years). Fractional volume of extracellular-free water (FW) and an index of diffusion tensor imaging along the perivascular space (DTI-ALPS) were used as indirect indicators of water diffusivity in the interstitial extracellular and perivenous spaces of white matter, respectively. RESULTS: After adjusting for age, sex, years of education, total Fazekas scale, Pittsburgh sleep quality index (PSQI) score, and intracranial volume (ICV), a significantly (P = 0.030; Cohen's d = 1.01) higher FW was observed in individuals with MetS than in the healthy controls. Furthermore, individuals with MetS had a significantly (P = 0.031; Cohen's d = 0.86) lower ALPS index than the healthy controls, with age, sex, years of education, total Fazekas scale, PSQI score, ICV, fractional anisotropy, and mean diffusivity included as confounding factors. Higher FW was significantly associated with lower ALPS index (r = -0.37; P = 0.004). Multiple linear regression (MLR) with backward elimination analyses showed that higher diastolic blood pressure (BP; standardized ß = 0.33, P = 0.005) was independently associated with higher FW, whereas higher fasting plasma glucose levels (standardized ß = -0.63, P = 0.002) or higher Brinkman index of cigarette consumption cumulative amount (standardized ß = -0.27, P = 0.022) were associated with lower ALPS index. The lower ALPS index (standardized ß, 0.28; P = 0.040) was associated with poorer global cognitive performance, which was determined using the Japanese version of the Montreal Cognitive Assessment (MOCA-J) scores. Finally, partial correlation analyses showed a significant correlation between higher FW and lower MOCA-J scores (r = -0.35; P = 0.025) and between higher FW and higher diastolic BP (r = 0.32, P = 0.044). CONCLUSION: The present study shows the changes in diffusion MRI-based measures reflected by the higher FW and lower ALPS index in older adults with MetS, possibly due to the adverse effect of vascular risk factors on the glymphatic system. Our findings also indicate the associations between the diffusion MRI-based measures and elevated diastolic BP, hyperglycemia, smoking habit, and poorer cognitive performance. However, owing to the limitations of this study, the results should be cautiously interpreted.

Prevalence of dry eye syndrome and risk factors in physical education and sports science graduates.

PURPOSE: There are only a few epidemiological studies of dry eye syndrome (DES) in populations with a common academic background. in this study, the prevalence of DES and associated factors were evaluated separately in men and women physical education and sports science graduates. STUDY DESIGN: Cross-sectional survey. METHODS: A questionnaire about the diagnosis of DES and associated factors was mailed to 9507 graduates of the Faculty of Health and Sports Science, Juntendo University. The questions covered subjective DES using Schaumberg et al.'s questionnaire and the prevalence of diagnosed DES. Associated factors, age, sex, smoking, alcohol consumption, body mass index, daily screen viewing time, and contact lens (CL) use were analyzed. RESULTS: A total of 2048 valid responses were received. The prevalence of diagnosed DES was 2.9% in men and 9.3% in women. For subjective DES, the prevalence was 14.8% in men and 39.8% in women. The odds ratio for DES was high in men and women who used CLs and women whose daily screen viewing time was ≥ 4 h. CONCLUSION: Both diagnosed and subjective DES were highly prevalent in men and women of all ages, particularly among those in their 20 and 30s. CL use was associated with DES in both men and women. Measures to deal with the factors that can be corrected might have a positive effect on the ocular health and quality of life of physical education and sports science graduates.

Prediabetes is an independent risk factor for sarcopenia in older men, but not in older women: the Bunkyo Health Study.

BACKGROUND: Sarcopenia is a major cause of disability in the elderly. Although type 2 diabetes is a risk factor for increased sarcopenia, the relationship between prediabetes and sarcopenia has not been elucidated. We aimed to examine the relationship between sarcopenia and prediabetes. METHODS: The design of this study is a cross-sectional study. We evaluated glucose metabolism using the 75-g oral glucose tolerance test and glycated haemoglobin, appendicular skeletal muscle mass, and hand grip strength in 1629 older adults living in an urban area of Tokyo, Japan. We investigated the frequency of sarcopenia in participants with normal glucose tolerance (NGT), prediabetes and diabetes. A multivariable logistic regression model was used to analyse the association between glucose tolerance and the prevalence of sarcopenia. RESULTS: The mean age of participants was 73.1 ± 5.4 years. In men, 44.3% had NGT, 26.6% had prediabetes, and 29.1% had diabetes. In women, the distribution was 56.1%, 28.8% and 15.2%. The prevalence of sarcopenia was 12.7% in men and 11.9% in women. Logistic regression revealed that prediabetes and diabetes are independent risk factors for sarcopenia in men (prediabetes, odds ratio [OR] = 2.081 [95% confidence interval {CI}: 1.031-4.199]; diabetes, OR = 2.614 [95% CI: 1.362-5.018]) and diabetes, but not prediabetes, is an independent risk factor for sarcopenia in women (prediabetes, OR = 1.036 [95% CI: 0.611-1.757]; diabetes, OR = 2.099 [95% CI: 1.146-3.844]). In both sexes, higher age (men, OR = 1.086 [95% CI: 1.028-1.146]; women, OR = 1.195 [95% CI: 1.142-1.251]), higher body fat percentage (men, OR = 1.346 [95% CI: 1.240-1.461]; women, OR = 1.218 [95% CI: 1.138-1.303]) and lower body mass index (men, OR = 0.371 [95% CI: 0.299-0.461]; women, OR = 0.498 [95% CI: 0.419-0.593]) were independent risk factors for sarcopenia. CONCLUSIONS: Although we confirmed that diabetes mellitus is associated with sarcopenia in both sexes, prediabetes is associated with sarcopenia in men, but not in women.

White matter fiber-specific degeneration in older adults with metabolic syndrome.

OBJECTIVE: Metabolic syndrome (MetS) is defined as a complex of interrelated risk factors for type 2 diabetes and cardiovascular disease, including glucose intolerance, abdominal obesity, hypertension, and dyslipidemia. Studies using diffusion tensor imaging (DTI) have reported white matter (WM) microstructural abnormalities in MetS. However, interpretation of DTI metrics is limited primarily due to the challenges of modeling complex WM structures. The present study used fixel-based analysis (FBA) to assess the effect of MetS on the fiber tract-specific WM microstructure in older adults and its relationship with MetS-related measurements and cognitive and locomotor functions to better understand the pathophysiology of MetS. METHODS: Fixel-based metrics, including microstructural fiber density (FD), macrostructural fiber-bundle cross-section (FC), and a combination of FD and FC (FDC), were evaluated in 16 healthy controls (no components of MetS; four men; mean age, 71.31 ± 5.06 years), 57 individuals with premetabolic syndrome (preMetS; one or two components of MetS; 29 men; mean age, 72.44 ± 5.82 years), and 46 individuals with MetS (three to five components of MetS; 27 men; mean age, 72.15 ± 4.97 years) using whole-brain exploratory FBA. Tract of interest (TOI) analysis was then performed using TractSeg across 14 selected WM tracts previously associated with MetS. The associations between fixel-based metrics and MetS-related measurements, neuropsychological, and locomotor function tests were also analyzed in individuals with preMetS and MetS combined. In addition, tensor-based metrics (i.e., fractional anisotropy [FA] and mean diffusivity [MD]) were compared among the groups using tract-based spatial statistics (TBSS) analysis. RESULTS: In whole-brain FBA, individuals with MetS showed significantly lower FD, FC, and FDC compared with healthy controls in WM areas, such as the splenium of the corpus callosum (CC), corticospinal tract (CST), middle cerebellar peduncle (MCP), and superior cerebellar peduncle (SCP). Meanwhile, in fixel-based TOI, significantly reduced FD was observed in individuals with preMetS and MetS in the anterior thalamic radiation, CST, SCP, and splenium of the CC compared with healthy controls, with relatively greater effect sizes observed in individuals with MetS. Compared with healthy controls, significantly reduced FC and FDC were only demonstrated in individuals with MetS, including regions with loss of FD, inferior cerebellar peduncle, inferior fronto-occipital fasciculus, MCP, and superior longitudinal fasciculus part I. Furthermore, negative correlations were observed between FD and Brinkman index of cigarette consumption cumulative amount and between FC or FDC and the Trail Making Test (parts B-A), which is a measure of executive function, waist circumference, or low-density lipoprotein cholesterol. Finally, TBSS analysis revealed that FA and MD were not significantly different among all groups. CONCLUSIONS: The FBA results demonstrate that substantial axonal loss and atrophy in individuals with MetS and early axonal loss without fiber-bundle morphological changes in those with preMetS within the WM tracts are crucial to cognitive and motor function. FBA also clarified the association between executive dysfunction, abdominal obesity, hyper-low-density lipoprotein cholesterolemia, smoking habit, and compromised WM neural tissue microstructure in MetS.

Engagement in different sport disciplines during university years and risk of locomotive syndrome in older age: J-Fit+ Study.

BACKGROUND: Among former Olympic-level athletes, engagement in different sport disciplines has been associated with mortality risk in subsequent years. However, limited evidence is available on whether engagement in different sport disciplines at a young age is associated with locomotive syndrome (LS) risk later in life. This study examined the relationship between engagement in different sport disciplines during university years and LS risk in older age among former university athletes. METHODS: Participants were 274 middle-aged and 294 older men alumni who graduated from a school of physical education in Japan. LS risk was defined as answering "yes" to any of the Loco-check questions. Data on university sports club membership were collected using questionnaires. University clubs were classified into three groups of cardiovascular intensity (low, moderate, high), following the classification system of sport disciplines by the American College of Cardiology. This classification considers the static and dynamic components of an activity, which correspond to the estimated percent of maximal voluntary contraction reached and maximal oxygen uptake achieved, respectively. University clubs were grouped based on the risk of bodily collision (no, yes) and extent of physical contact (low, moderate, high). Relationships between engagement in different sport disciplines and LS risk were analyzed using Cox proportional hazards models, and adjusted for age, height, weight, joint disease, habitual exercise, and smoking and drinking status. RESULTS: Adjusted hazard ratios and 95% confidence intervals associated with the low, moderate, and high cardiovascular intensity sports were 1.00 (reference), 0.48 (0.22-1.06, P = 0.070), and 0.44 (0.20-0.97, P = 0.042) in older men, respectively; however, there was no significant association between these parameters among middle-aged men. Engagement in sports associated with physical contact and collision did not affect LS risk in either group. CONCLUSIONS: Engagement in sports associated with high cardiovascular intensity during university years may reduce the risk of LS in later life. Encouraging young people to participate in such activities might help reduce LS prevalence among older populations.

Slightly increased BMI at young age is a risk factor for future hypertension in Japanese men.

BACKGROUND: Hypertension is developed easily in Asian adults with normal body mass index (BMI) (~23 kg/m2), compared with other ethnicities with similar BMI. This study tested the hypothesis that slightly increased BMI at young age is a risk factor for future hypertension in Japanese men by historical cohort study. METHODS: The study participants were 636 male alumni of the physical education school. They had available data on their physical examination at college age and follow-up investigation between 2007 and 2011. The participants were categorized into six categories: BMI at college age of <20.0 kg/m2, 20.0-21.0kg/m2, 21.0-22.0kg/m2, 22.0-23.0kg/m2, 23.0-24.0kg/m2, and ≥24.0kg/m2, and the incidence of hypertension was compared. RESULTS: This study covered 27-year follow-up period (interquartile range: IQR: 23-31) which included 17,059 person-years of observation. Subjects were 22 (22-22) years old at graduated college, and 49 (45-53) years old at first follow-up investigation. During the period, 120 men developed hypertension. The prevalence rates of hypertension for lowest to highest BMI categories were 9.4%, 14.6%, 16.1%, 17.5%, 30.3%, and 29.3%, respectively (p<0.001 for trend), and their hazard ratios were 1.00 (reference), 1.80 (95%CI: 0.65-4.94), 2.17 (0.83-5.64), 2.29 (0.89-5.92), 3.60 (1.37-9.47) and 4.72 (1.78-12.48), respectively (p<0.001 for trend). This trend was similar after adjustment for age, year of graduation, smoking, current exercise status and current dietary intake. CONCLUSION: Slightly increased BMI at young age is a risk factor for future hypertension in Japanese men.

Relationships between lifestyle patterns and cardio-renal-metabolic parameters in patients with type 2 diabetes mellitus: A cross-sectional study.

INTRODUCTION: While individuals tend to show accumulation of certain lifestyle patterns, the effect of such patterns in real daily life on cardio-renal-metabolic parameters remains largely unknown. This study aimed to assess clustering of lifestyle patterns and investigate the relationships between such patterns and cardio-renal-metabolic parameters. PARTICIPANTS AND METHODS: The study participants were 726 Japanese type 2 diabetes mellitus (T2DM) outpatients free of history of cardiovascular diseases. The relationship between lifestyle patterns and cardio-renal-metabolic parameters was investigated by linear and logistic regression analyses. RESULTS: Factor analysis identified three lifestyle patterns. Subjects characterized by evening type, poor sleep quality and depressive status (type 1 pattern) had high levels of HbA1c, alanine aminotransferase and albuminuria. Subjects characterized by high consumption of food, alcohol and cigarettes (type 2 pattern) had high levels of γ-glutamyl transpeptidase, triglycerides, HDL-cholesterol, blood pressure, and brachial-ankle pulse wave velocity. Subjects characterized by high physical activity (type 3 pattern) had low uric acid and mild elevation of alanine aminotransferase and aspartate aminotransferase. In multivariate regression analysis adjusted by age, gender and BMI, type 1 pattern was associated with higher HbA1c levels, systolic BP and brachial-ankle pulse wave velocity. Type 2 pattern was associated with higher HDL-cholesterol levels, triglycerides, aspartate aminotransferase, ɤ- glutamyl transpeptidase levels, and diastolic BP. CONCLUSIONS: The study identified three lifestyle patterns that were associated with distinct cardio-metabolic-renal parameters in T2DM patients. TRIAL REGISTRATION: UMIN000010932.

Cardiorespiratory fitness and the incidence of type 2 diabetes: a cohort study of Japanese male athletes.

BACKGROUND: In Japan, although the incidence of overweight (BMI ≥ 25) is still low compared with that in Europe and the United States, the prevalence of type 2 diabetes has increased over the last 15 years,. In both Japanese and Caucasian populations it has been reported that a high level of cardiorespiratory fitness protects against the development of type 2 diabetes. However, there are no reports focused specifically on athletes that investigate whether high cardiorespiratory fitness at a young age can prevent disease later in life. We examined the relationship between cardiorespiratory fitness at a young age and the development of type 2 diabetes in Japanese athletes using a cohort study. METHODS: The cardiorespiratory fitness of male alumni of the physical education department of Juntendo University, as measured by stored data of a 1,500-m endurance run in college (1971-1991) was compared with their incidence of type 2 diabetes as determined by follow-up questionnaires (2007-2009). This study used Cox's proportional hazards models and adjusted for age, year of graduation, BMI, smoking, and sports club participation at college age. RESULTS: We collected data on cardiorespiratory fitness at college age and medical history survey data during 2007-2009 from 570 male alumni. The median follow-up period was 26 years (IQR: 23-29 years), and 22 men had developed type 2 diabetes. An inverse relationship was observed between incidence of type 2 diabetes and level of cardiorespiratory fitness at time of college after adjustment for age, year of graduation, BMI, smoking, and sports participation. The adjusted hazards ratio and 95% CI by category (low, medium, and high) were 1.00 (reference), 0.40 (0.14-1.13) and 0.26 (0.07-1.00) (p = 0.03 for trend). CONCLUSIONS: A high level of cardiorespiratory fitness at a young age can help prevent type 2 diabetes later in life.