Self-Reported Sleep Duration and Bedtime Are Associated with Dementia Risk in Community-Dwelling People Aged 40-74 Years: The Murakami Cohort Study.

Background: Sleep is a potentially modifiable factor associated with dementia, including Alzheimer's disease, but current evidence supporting this is insufficient. Objective: This study aimed to determine whether sleep duration and bedtime patterns are associated with the risk of dementia among middle-aged and older people. Methods: This cohort study had an eight-year follow-up period. Participants were 13,601 community-dwelling people aged 40-74 years living in Murakami (Niigata, Japan). Data were collected using a self-administered questionnaire. Predictors were self-reported sleep duration and bedtime, and the outcome was newly-diagnosed dementia determined using the long-term care insurance database. Covariates were demographic characteristics, body mass index, smoking, alcohol consumption, total physical activity, insomnia symptoms, disease history, and either bedtime or sleep duration. Cox proportional hazard models were used to calculate hazard ratios (HRs). Results: The mean age of participants at baseline was 59.2 years. Over a mean follow-up period of 8.0 years, 319 cases of dementia were observed. A long self-reported sleep duration relative to the reference sleep duration (7 hours) was associated with increased dementia risk, with the "8 hours" group (adjusted HR = 1.30, 95% CI:0.99-1.73) and "≥9 hours" group (adjusted HR = 1.46, 95% CI:1.00-2.15) having an increased risk (marginally significant) relative to the reference group. Early bedtime was associated with increased dementia risk (adjusted p for trend = 0.0010), with the "21 : 00 or earlier" group (adjusted HR = 1.61, 95% CI:1.14-2.28) having an increased risk relative to the reference ("23 : 00"). Conclusions: A long self-reported sleep duration and early bedtime are both associated with increased dementia risk in middle-aged and older people.

Low plasma 25-hydroxyvitamin D levels are not associated with a high risk of recurrent falls in community-dwelling Japanese adults: the Murakami cohort study.

Reports on the association between vitamin D levels and fall risk have been mixed, and long-term follow-up studies are lacking. This 5-year cohort study of 5,343 community-dwelling Japanese people aged 40-74 years found that low vitamin D levels are not associated with a high risk of recurrent falls. PURPOSE: Findings of cohort studies on the association between plasma 25-hydoxyvitamin D (25[OH]D) levels and fall risk have been mixed, and long-term follow-up studies are lacking. The present study investigated whether low plasma 25(OH)D levels are longitudinally associated with a high risk of recurrent falls in adults. METHODS: This 5-year cohort study included 5,343 community-dwelling Japanese people aged 40-74 years. Baseline blood collection and a questionnaire survey were conducted in 2011-2013. Plasma 25(OH)D levels were determined and divided into quintiles after stratification by season, sex, and age group. Information on recurrent falls occurring in the year before the survey 5 years later was obtained, and participants with two or more falls were considered to have experienced recurrent falls. Covariates were sex, age, marital status, education, occupation, BMI, total physical activity levels, calcium intake, vitamin K intake, smoking, drinking, and disease history. RESULTS: Mean age and 25(OH)D levels were 60.9 years and 50.9 nmol/L, respectively. In the follow-up survey, 209 recurrent falls were reported. Plasma 25(OH)D levels were not significantly associated with the occurrence of recurrent falls in men, women, or men/women-combined (adjusted P for trend = 0.1198, 0.8383, and 0.2355, respectively). In men and men/women-combined, adjusted ORs for recurrent falls in the lowest quintile were significantly lower (adjusted OR = 0.42 and 0.59, respectively) than the middle quintile (reference). CONCLUSION: Low plasma 25(OH)D levels are not associated with a high risk of recurrent falls in middle-aged and older people. Further longitudinal studies will be needed to confirm our findings in other populations.

Chronic Pain in the Lower Extremities and Low Back is Associated With Recurrent Falls in Community-Dwelling Japanese People Aged 40-74 Years.

OBJECTIVE: To determine the longitudinal association between chronic pain in the lower extremities and low back and the odds of recurrent falls in middle-aged and older people. DESIGN: A cohort study. SETTING: Communities in Japan. PARTICIPANTS: Participants were 7540 community-dwelling volunteers aged 40-74 years (N=7540). The baseline survey was a self-administered questionnaire conducted between 2011-2013. Predictors were presence of chronic pain in the knee, foot or ankle, and low back, with the degree of pain categorized as none, very mild/mild, moderate, or severe/very severe. Covariates in the multivariate model of chronic pain in a site were demographics, body mass index, physical activity level, disease history, and chronic pain in the other 2 sites. Logistic regression analysis was used to calculate odds ratios (ORs). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Recurrent falls in the year before the 5-year follow-up survey. RESULTS: Mean participant age was 60.2 years. Higher degrees of chronic pain were associated with higher odds of recurrent falls for the knee (P=.0002) with a higher OR of 1.48 (95% CI: 1.11-1.97), for the foot or ankle (P=.0001) with a higher OR of 1.97 (95% CI: 1.36-2.86), and for the low back (P=.0470) with a higher OR of 1.45 (95% CI: 1.09-1.91) in those with any degree of pain relative to those without pain. Higher degrees of chronic knee pain were associated with higher odds of recurrent falls in women (P=.0005), but not in men (P=.0813). Meanwhile, higher degrees of chronic low back pain were associated with the odds of recurrent falls in men (P=.0065), but not in women (P=.8735). CONCLUSIONS: Chronic pain in the knee, foot or ankle, and lower back was independently and dose-dependently associated with a higher risk of recurrent falls. A marked sex-dependent difference was also noted in the association.

Body mass index, height, and osteoporotic fracture risk in community-dwelling Japanese people aged 40-74 years.

INTRODUCTION: The association between body size and fracture risk is complex and varies by sex and ethnicity. This study aimed to examine associations of body mass index (BMI) and height with osteoporotic fracture risk in middle-aged and older people. MATERIALS AND METHODS: This 10-year cohort study included 13,151 community-dwelling Japanese people aged 40-74 years. A self-administered questionnaire survey was conducted at baseline to obtain information on demographic characteristics, body size, lifestyle, and disease history. BMI (kg/m2) was categorized as underweight (< 18.5), low-normal (18.5-21.7), high-normal (21.8-24.9), overweight (25.0-29.9), and obese (≥ 30.0). Height was categorized into quartiles. All incident cases of major osteoporotic fractures, including fractures of the distal radius, neck of the humerus, neck or trochanter of the femur, and vertebrae, were obtained from medical records during follow-up. RESULTS: Mean participant age was 58.8 years. In men, the underweight group had a significantly higher hazard ratio (HR) for total fracture (adjusted HR = 2.46), and the obese group had significantly higher HRs for total (adjusted HR = 3.01) and vertebral (HR = 3.77) fractures relative to the reference (overweight) group. No significant associations were observed between BMI and risk of any fracture in women. Higher quartiles of height were associated with higher vertebral fracture risk (adjusted P for trend = 0.023) only in women. CONCLUSION: BMI and osteoporotic fracture risk showed a U-shaped association in men, whereas higher height was associated with higher vertebral fracture risk in women, suggesting sex-dependent differences in these associations.

Association between Physical Activity in Rural Life and Sarcopenia in Community-Dwelling Middle-Aged and Older Japanese Adults: A Cross-Sectional Study.

Physical activity is crucial to prevent sarcopenia, but there is scant data on the link between sarcopenia and physical activity in rural communities. Therefore, this study investigated associations of farming activity and snow removal with sarcopenia in a middle-aged and older population in rural Japan. This cross-sectional study enrolled 3,056 residents aged ≥ 40 years (49.2% men; mean age, 64.2 years) in Yuzawa, Japan. Information on farming activity and snow removal were collected via questionnaire from May through November and from December through April, respectively. Sarcopenia was assessed by the SARC-F (strength, ambulation, rising from a chair, stair climbing, and history of falling) score. Associations of farming activity and snow removal with sarcopenia were assessed using multivariable logistic regression analysis with adjustment for potential confounders. Participants who engaged in farming activity, snow removal, and both accounted for 3.8%, 40.5%, and 29.4% of the total, respectively. In the multivariable logistic regression analysis, adjusted odds ratios [95% confidence intervals (CI)] of sarcopenia for farming activity and snow removal were 0.80 (0.63-1.03) and 0.68 (0.53-0.87), respectively. Compared with participants who did not engage in farming activity or snow removal, participants who engaged in both had a significantly lower adjusted odds ratio of sarcopenia [0.63 (95% CI 0.47-0.86)]. Participants who engaged in snow removal and those who engaged in both farming activity and snow removal showed inverse associations with sarcopenia. Our findings further support the importance of physical activity in preventing or mitigating sarcopenia in rural communities.

Sex Differences in the Association Between Body Mass Index and Dementia Risk in Community-Dwelling Japanese People Aged 40-74 Years.

BACKGROUND: The association between body mass index (BMI) and dementia risk is heterogeneous across age groups and might be influenced by sex. OBJECTIVE: This study aimed to clarify sex differences in the association between BMI and dementia risk in community-dwelling people. METHODS: This cohort study with an 8-year follow-up targeted 13,802 participants aged 40-74 years at baseline in 2011-2013. A self-administered questionnaire requested information on body size, including height, weight, and waist circumference (the values of which were validated by direct measurement), socio-demographics, lifestyle, and disease history. BMI was calculated and categorized as < 18.5 (underweight), 18.5-20.6 (low-normal), 20.7-22.6 (mid-normal), 22.7-24.9 (high-normal), 25.0-29.9 (overweight), and≥30.0 kg/m2 (obese). Incident cases of dementia were obtained from the long-term care insurance database. A Cox proportional hazards model was used to calculate multivariable-adjusted hazard ratios (HRs). RESULTS: The mean age of participants was 59.0 years. In men, higher BMI was associated with lower dementia risk (fully-adjusted p for trend = 0.0086). In women, the association between BMI and dementia risk was U-shaped; the "underweight," "low-normal," and "overweight" groups had a significantly higher risk (fully-adjusted HR = 2.12, 2.08, and 1.78, respectively) than the reference ("high-normal" group). These findings did not change after excluding dementia cases which occurred within the first four years of the follow-up period. CONCLUSION: Overweight/obese women, but not men, had an increased risk of dementia, suggesting that sex differences in adiposity might be involved in the development of dementia.

Alcohol consumption, smoking, and risk of dementia in community-dwelling Japanese people aged 40-74 years: The Murakami cohort study.

OBJECTIVE: Alcohol drinking and tobacco smoking have impacts on lifestyle-related diseases, but their association with dementia remains a debated topic. This study aimed to examine longitudinal associations between alcohol consumption, smoking, and dementia risk in middle-aged and older Japanese people. METHODS: This study used a cohort design with an 8-year follow-up. Participants were community-dwelling Japanese people (N = 13,802) aged 40-74 years. The baseline survey, including a self-administered questionnaire, was conducted in 2011-2013. Predictors were alcohol consumption and tobacco smoking. The outcome was incident dementia obtained from a long-term care insurance database. Covariates were demographics, lifestyle factors, body mass index, general health status, and history of stroke, diabetes, and depression. RESULTS: Participant mean age was 59.0 years. The 1-149, 150-299, and 300-449 g ethanol/week groups had significantly lower adjusted hazard ratios (HRs) (0.62, 0.59, and 0.47, respectively) compared with the reference group, with no significant linear association. HRs increased toward 1 when past-drinkers and those with poor health status and a disease history were excluded (0.80, 0.66, and 0.82, respectively). Higher smoking levels were dose-dependently associated with a higher HR (adjusted P for trend = 0.0105), with the ≥20 cigarettes/day group having a significantly higher adjusted HR (1.80). Heavy drinkers (≥449 g ethanol/week) with smoking habits, but not those without smoking habits, had higher dementia risk (P for interaction = 0.0046). CONCLUSION: Light-to-moderate alcohol consumption is associated with decreased dementia risk, and smoking is dose-dependently associated with increased dementia risk, with an interaction between high alcohol consumption and smoking on dementia risk.

Chronic kidney disease awareness and its determinants in middle-aged and older Japanese adults: Observations from a 5-year follow-up of the Uonuma cohort study.

AIM: Despite global efforts in public health campaigns concerning chronic kidney disease (CKD), awareness of the condition remains low. We evaluated CKD awareness and related factors to identify an effective way to raise awareness. METHODS: This study assessed laboratory-confirmed CKD and self-reported CKD using a population-based cohort (baseline from 2012 to 2014, age ≥40 years) in Niigata, Japan. Self-reported CKD was obtained at a 5-year follow-up survey and laboratory-confirmed CKD was diagnosed when an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or dipstick urinary protein ≥1+ was observed in at least two health check-ups during the 5-year period. CKD awareness was defined as a match between laboratory-confirmed and self-reported CKD. The association between characteristics and CKD awareness was tested by multivariable logistic regression analysis with adjustment for eGFR and other potential confounders. RESULTS: The analytic population comprised 7472 individuals (mean age, 65.6 years old, 51.2% women) and 19.4% with laboratory-confirmed CKD. The sensitivity and specificity of the survey question concerning self-reported CKD were 12.4% and 98.2%, respectively. Among the participants with laboratory-confirmed CKD, significant factors associated with CKD awareness were male sex (adjusted odds ratio [95% confidence interval], 1.81 [1.27, 2.59]), a history of urinary tract stone (1.86 [1.06, 3.26]), age (0.97 [0.95, 0.99]), and married status (0.66 [0.44, 0.99]). CONCLUSION: Our findings suggest that known lifestyle-related diseases that could cause CKD are not associated with CKD awareness independently of kidney function and that a sex-dependent approach may help to raise CKD awareness in community-dwelling Japanese adults.

Low plasma 25-hydroxyvitamin D levels are associated with an increased risk of depressive symptoms in community-dwelling Japanese people aged between 40 and 74 years: The Murakami cohort study.

BACKGROUND: Association between vitamin D levels and the occurrence of depression are not always consistent. The present cohort study aimed to determine this association in older adults, using a method for measuring vitamin D levels which is more accurate than those used in previous studies. METHODS: Participants were 3447 individuals aged 40-74 years without depressive symptoms at baseline who participated in the 5-year follow-up survey. The baseline investigation, including a self-administered questionnaire survey and blood collection, was conducted in 2011-2013. Plasma 25-hydroxyvitamin D (25[OH]D) levels were measured, and divided into overall quartiles summed up by sub-quartiles and stratified by age, sex, and season. The outcome was depressive symptoms determined by the CES-D (11-item, cut-off score of 6/7) 5 years later. Covariates were demographics, lifestyles, baseline CES-D score, and disease history. RESULTS: Mean plasma 25(OH)D levels were 58.0 nmol/L in men and 45.7 in women (P < 0.0001), and cumulative incidences of depressive symptoms were 249/1577 (15.8 %) in men and 313/1870 (16.7 %) in women (P = 0.4526). The lower 25(OH)D quartile group had higher adjusted ORs in men and women combined (P for trend = 0.0107) and women (P for trend = 0.0003), but not in men. Adjusted ORs of the lowest quartile group were significantly higher than the highest group in men and women combined (OR = 1.39, 95 % CI: 1.06-1.81) and women (OR = 1.89, 95 % CI: 1.31-2.72). LIMITATION: Depressive symptoms were self-reported. CONCLUSIONS: Low vitamin D levels were associated with a high risk of depressive symptoms, especially in women. Women are thus considered a major target for preventing vitamin D deficiency to address depression.

Urinary A- and C-megalin predict progression of diabetic kidney disease: an exploratory retrospective cohort study.

AIMS: Megalin, a proximal tubular endocytosis receptor, is excreted in urine in two forms: ectodomain (A-megalin) and full-length (C-megalin). We explored whether urinary megalin levels can be used as independent prognostic biomarkers in the progression of diabetic kidney disease (DKD). METHODS: The associations between baseline urinary A-megalin/creatinine (Cr) and/or C-megalin/Cr levels and the subsequent estimated glomerular filtration rate (eGFR) slope were analyzed using a generalized estimating equation. Patients were categorized into higher or lower groups based on the optimal cutoff values, obtained from a receiver operating characteristic curve, of the two forms of urinary megalin. RESULTS: We retrospectively analyzed 188 patients with type 2 diabetes. The eGFR slopes of the higher A-megalin/Cr and higher C-megalin/Cr groups were - 0.904 and -0.749 ml/min/1.73 m2/year steeper than those of the lower groups, respectively. Moreover, the eGFR slope was -1.888 ml/min/1.73 m2/year steeper in the group with both higher A- and higher C-megalin/Cr than in the other group. These results remained significant when adjusted for known urinary biomarkers (albumin, α1-microglobulin, ß2-microglobulin, and N-acetyl-ß-d-glucosaminidase). CONCLUSIONS: Urinary A- and C-megalin/Cr levels are likely to be prognostic biomarkers in the progression of DKD independent of other urinary biomarkers.

Physical activity and recurrent fall risk in community-dwelling Japanese people aged 40-74 years: the Murakami cohort study.

BACKGROUND: Falls are important causes of injury and mortality in older people, and associated medical costs can be enormous. Physical activity (PA) is a potential preventive factor for falls. However, few studies have examined the effect of different types of PA on fall prevention. This study aimed to evaluate the association between PA levels and the incidence of recurrent falls by type of PA in middle-aged and older people. METHODS: This cohort study targeted 7,561 community-dwelling individuals aged 40-74 years who did not experience recurrent falls in the year before baseline. Information on PA levels, demographics, body size, lifestyle, and fall/disease history was obtained using a self-administered questionnaire in the baseline survey. Levels of total PA, leisure-time PA, and non-leisure-time PA (occupation, commuting, and housework) were estimated using metabolic equivalent (MET) scores (MET-h/day; hours spent on a given activity per day multiplied by its MET intensity). PA levels were categorized into four groups. Falls were recorded as none, once, or twice or more (recurrent falls). The outcome of the study was the incidence of recurrent falls in the past year before a survey conducted 5 years after the baseline survey. Logistic regression analyses were performed to calculate odds ratios for recurrent falls. RESULTS: Higher total PA and non-leisure-time PA levels were associated with a higher risk of recurrent falls (P for trend = 0.0002 and 0.0001, respectively), with the highest total PA and non-leisure-time PA groups having a significantly higher adjusted OR (1.96 [95%CI:1.33-2.88] and 2.15 [95%CI:1.48-3.14], respectively) relative to the lowest group (reference). As for leisure-time PA, the medium group had a significantly lower adjusted OR (0.70 [95%CI:0.49-0.99]) relative to the reference group. By sex, the adjusted OR in the medium leisure-time PA group was significantly lower relative to the reference group in women (0.50 [95%CI: 0.29-0.85]) but not in men. CONCLUSIONS: Medium level leisure-time PA reduces the risk of recurrent falls in middle-aged and older people, whereas higher level non-leisure-time PA is associated with a higher risk of recurrent falls.

Associations of Urinary and Dietary Sodium-To-Potassium Ratios with Albuminuria in Community-Dwelling Japanese Adults: A Cross-Sectional Study.

INTRODUCTION: The urinary sodium-to-potassium ratio is an indicator of dietary sodium intake and has been associated with reduced kidney function. However, less is known about its association with albuminuria, the other key component of chronic kidney disease, in the community-dwelling adult population. We examined the association of the spot urinary sodium-to-potassium ratio with albuminuria and compared spot urinary and dietary sodium-to-potassium ratios. METHODS: We quantified the association of the urinary sodium-to-potassium ratio with albuminuria in 6,274 Japanese adults (aged 40-97 years; 50.9% women) based on spot urine samples. We performed linear and logistic regression modeling to account for potential confounders. Elevated albuminuria was defined as a spot urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g. We secondarily evaluated the dietary sodium-to-potassium ratio based on a food-frequency questionnaire. RESULTS: The median spot urinary and dietary sodium-to-potassium ratios were 2.70 (interquartile interval, 1.87-3.83) and 1.50 (1.21-1.84), respectively. The median ACR was 11.0 (6.0-24.0) mg/g. In a multivariable linear regression model, the spot urinary sodium-to-potassium ratio (per increment) was significantly associated with the natural logarithm of the ACR (regression coefficient, 0.023 [95% confidence interval {95% CI}, 0.007-0.038]). This result was consistent in a multivariable logistic regression model (adjusted odds ratio, 1.08 [95% CI: 1.04-1.12]). The corresponding estimates for the dietary sodium-to-potassium ratio were 0.139 (95% CI: 0.087-0.191) and 1.28 (95% CI: 1.14-1.45), respectively. CONCLUSIONS: Both spot urinary and dietary sodium-to-potassium ratios were associated with elevated albuminuria in community-dwelling Japanese adults. Our findings further support the potential usefulness of the spot urinary sodium-to-potassium ratio as an indicator of sodium intake and suggest a link between sodium intake and kidney damage.

Association between Sarcopenia and Depressive Symptoms in Community-Dwelling People Aged 40 Years and Older.

Several studies have reported an association between sarcopenia and depression. Their results, however, are inconsistent, partly due to small sample sizes and lack of consideration of important confounders. The present study aimed to cross-sectionally examine this association in community-dwelling people in Japan. This study used baseline data from the Yuzawa cohort study (age ≥ 40 years), with the final analysis population comprising 2,466 participants. A self-administered questionnaire was used to elicit information related to sarcopenia, depressive symptoms, demographic characteristics, anthropometrics, disease history, and lifestyles. Sarcopenia was diagnosed using SARC-F, a validated questionnaire including components of Strength, Assistance in walking, Rising from a chair, Climbing stairs, and Falls. Depressive symptoms were assessed using the 11-item version of the Center for Epidemiologic Studies Depression Scale (CES-D). For depressive symptoms, prevalence ratios (PRs) were calculated, and odds ratio (ORs) were obtained using simple and multiple logistic regression analyses. Mean age of participants was 61.7 years (standard deviation = 11.8), and 10.5% and 34.7% had sarcopenia and depressive symptoms, respectively. Sarcopenic individuals had a significantly higher PR (2.00), unadjusted OR (3.67), and adjusted OR (4.96) compared to non-sarcopenic individuals, with an estimated adjusted PR of 2.7. There was a significant dose-dependent association between SARC-F scores and depressive symptoms in sarcopenic individuals (adjusted P for trend = 0.0028). In conclusion, sarcopenia and depressive symptoms were robustly associated in community-dwelling, middle-aged and older people in Japan. However, the direction of this association is unclear, and a future cohort study will be needed to determine causality.

Leisure-Time and Non-Leisure-Time Physical Activities are Dose-Dependently Associated With a Reduced Risk of Dementia in Community-Dwelling People Aged 40-74 Years: The Murakami Cohort Study.

OBJECTIVE: Although physical activity (PA) in late life is considered a preventive factor for dementia, effects of different types of PAs on the development of dementia in early old age are unclear. This study aimed to determine the effect of leisure-time and non-leisure-time PAs on dementia risk in middle-aged and older adults during an 8-year follow-up. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: Participants were 13,773 community-dwelling individuals aged 40-74 years who completed the baseline self-administered questionnaire survey of the Murakami cohort study in 2011-2013. METHODS: Main predictors were leisure-time and non-leisure-time (commute, occupational work, and housework) PAs as assessed by MET score (MET-hour/d). The outcome was newly developed dementia determined using a long-term care insurance database. Covariates included demographics, lifestyle, body size, disease history, and PA level. Hazard ratios (HRs) were calculated using Cox proportional hazards models. RESULTS: Mean age of participants was 59.0 (SD 9.3) years. Higher levels of leisure-time PA were associated with lower HRs (adjusted P for trend <.001), with all tertiles having significantly lower HRs (low: 0.71, 95% CI 0.51-0.99; medium: 0.59, 95% CI 0.43-0.81; high: 0.55, 95% CI 0.41-0.75) relative to the reference (zero). Higher quartiles of non-leisure-time PA were associated with lower adjusted HRs for dementia (adjusted P for trend < .001), with the second-fourth quartiles having significantly lower HRs (second: 0.73, 95% CI 0.54-0.98; third: 0.59, 95% CI 0.43-0.81; fourth: 0.55, 95% CI 0.41-0.75) relative to the lowest quartile. These associations were robust regardless of sex and age group. CONCLUSIONS AND IMPLICATIONS: Both leisure-time and non-leisure-time PAs are independently and robustly associated with a reduced risk of dementia.

Association of metabolic syndrome traits with urinary biomarkers in Japanese adults.

BACKGROUND: Although metabolic syndrome traits are risk factors for chronic kidney disease, few studies have examined their association with urinary biomarkers. METHODS: Urinary biomarkers, including A-megalin, C-megalin, podocalyxin, albumin, α1-microglobulin, ß2-microglobulin, and N-acetyl-ß-D-glucosaminidase, were cross-sectionally assessed in 347 individuals (52.7% men) with a urine albumin-to-creatinine ratio (ACR) < 300 mg/g in a health checkup. Metabolic syndrome traits were adopted from the National Cholesterol Education Program (third revision) of the Adult Treatment Panel criteria modified for Asians. RESULTS: Participants had a mean body mass index, estimated glomerular filtration rate (eGFR), and median ACR of 23.0 kg/m2, 74.8 mL/min/1.73 m2, and 7.5 mg/g, respectively. In age- and sex-adjusted logistic regression analysis, A-megalin and albumin were significantly associated with the clustering number of metabolic syndrome traits (3 or more). After further adjustment with eGFR, higher quartiles of A-megalin and albumin were each independently associated with the clustering number of metabolic syndrome traits (adjusted odds ratio for A-megalin: 1.30 per quartile, 95% CI 1.03-1.64; albumin: 1.42 per quartile, 95% CI 1.12-1.79). CONCLUSIONS: Both urinary A-megalin and albumin are associated with the clustering number of metabolic syndrome traits. Further research on urinary A-megalin is warranted to examine its role as a potential marker of kidney damage from metabolic risk factors.

Secular changes in bone mineral density of adult Japanese women from 1995 to 2013.

INTRODUCTION: Secular changes in hip fracture incidence have been reported in the last few decades in Japan, but whether long-term bone mineral density (BMD) is also changing is unclear. This study aimed to determine whether BMD of Japanese women has changed over time. METHODS: Subjects were 10,649 adult women who underwent BMD measurement in a health check-up population in Niigata, Japan, between 1995 and 2013. BMD of the distal, non-dominant forearm was measured by dual-energy X-ray absorptiometry. Demographic information and BMI were also obtained. Secular trends were determined by linear regression analysis. RESULTS: BMD of subjects in their 40's decreased significantly in the age-adjusted model (P for trend=0.0162), but not in the age- and BMI-adjusted model (P for trend=0.2171). BMD of subjects in their 50's decreased marginally in the age-adjusted model (P for trend=0.0535), but not in the age- and BMI-adjusted model (P for trend=0.6601). BMDs of subjects in their 30's and 60's did not significantly change, while BMIs of subjects in their 40's-60's decreased significantly. CONCLUSIONS: A secular decrease in BMD, partly attributed to decreases in BMI, was observed in middle-aged Japanese women from 1995 to 2013. Measures to help maintain suitable BMI will be necessary to prevent a decrease in BMD among women.

Education, household income, and depressive symptoms in middle-aged and older Japanese adults.

BACKGROUND: Income inequality has dramatically increased worldwide, and there is a need to re-evaluate the association between socio-economic status (SES) and depression. Relative contributions of household income and education to depression, as well as their interactions, have not been fully evaluated. This study aimed to examine the association between SES and depressive symptoms in Japanese adults, focusing on interactions between education and household income levels. METHODS: This cross-sectional study used data from baseline surveys of two cohort studies. Participants were 38,499 community-dwelling people aged 40-74 years who participated in baseline surveys of the Murakami cohort study (2011-2012) and Uonuma cohort study (2012-2015) conducted in Niigata Prefecture, Japan. Information regarding marital status, education level, household income, occupation, activities of daily living (ADL), and history of cancer, myocardial infarction, stroke, and diabetes was obtained using a self-administered questionnaire. Depressive symptoms were examined using the Center for Epidemiologic Studies Depression Scale (CES-D). Logistic regression analysis was used to obtain odds ratios (ORs). Covariates included age, sex, marital status, education, household income, occupation, ADL, and disease history. RESULTS: Individuals with higher education levels had lower ORs (adjusted P for trend = 0.0007) for depressive symptoms, independently of household income level. The OR of the university-or-higher group was significantly lower than that of the junior high school group (adjusted OR = 0.79). Individuals with lower household income levels had higher ORs (adjusted P for trend< 0.0001) for depressive symptoms, independently of education level. The type of occupation was not associated with depressive symptoms. In subgroup analyses according to household income level, individuals with higher education levels had significantly lower ORs in the lowest- and lower-income groups (adjusted P for trend = 0.0275 and 0.0123, respectively), but not in higher- and highest-income groups (0.5214 and 0.0915, respectively). CONCLUSIONS: Both education and household income levels are independently associated with the prevalence of depressive symptoms, with household income levels showing a more robust association with depressive symptoms than education levels. This suggests that a high household income level may offset the risk of depressive symptoms from having a low education level.

Association of coffee, green tea, and caffeine with the risk of dementia in older Japanese people.

OBJECTIVES: Coffee, green tea, and caffeine are potential preventive factors for dementia, but the underlying evidence is insufficient. This study aimed to examine associations between the consumption of coffee, green tea, and caffeine and dementia risk in middle-aged and older people. METHODS: This was a cohort study with an 8.0-year follow-up. Participants were community-dwelling individuals (n = 13,757) aged 40-74 years. A self-administered questionnaire survey was conducted in 2011-2013. Predictors were the consumption of coffee/green tea, from which caffeine consumption was estimated. The outcome was incident dementia obtained from the long-term care insurance database. Covariates were demographic factors, body mass index, physical activity, energy, smoking, drinking, and disease history. Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. HRs were also calculated using a Cox model with delayed entry. RESULTS: The number of dementia cases during the study period was 309. Participants with higher coffee consumption had lower HRs (adjusted p for trend = 0.0014), with the fifth quintile (≥326 ml/day) having a significantly lower HR (0.49, 95% confidence interval [CI]: 0.30-0.79) than the first quintile (<26 ml/day, reference). Similarly, participants with higher caffeine consumption had a significantly lower HR (adjusted p for trend = 0.0004) than the reference. The Cox model with delayed entry yielded similar results. These associations were significant in men, but not in women. Moreover, participants who consumed 2-2.9 cups/day and ≥3 cups/day of coffee had lower HRs (0.69, 95% CI: 0.48-0.98 and 0.53, 95% CI: 0.31-0.89, respectively) than those who consumed 0 cup/day. The association between green tea consumption and reduced dementia risk was significant (adjusted p for trend = 0.0146) only in the 60-69 years age subgroup. CONCLUSIONS: High levels of coffee and caffeine consumption were significantly associated with a reduced dementia risk in a dose-dependent manner, especially in men. Moreover, coffee consumption of ≥3 cups/day was associated with a 50% reduction in dementia risk.

Determination of specific life changes on psychological distress during the COVID-19 pandemic.

The COVID-19 pandemic might affect many aspects of the community and a range of psychiatric risk factors due to life changes, including people's behaviors and perceptions. In this study, we aim to identify specific life changes that correlate with psychological distress within the social context of the COVID-19 pandemic in Japan. In July 2020, workers (company employees and civil servants) in Japan were recruited from local institutions that had not had any confirmed COVID-19 cases as well as neighborhoods that had only a few cases. Participants completed a COVID-19 mental health survey (N = 609; 66.9% male). Psychological distress was identified based on Kessler-6 scores (≥13). Life changes were assessed by an open-ended question about life changes in participants and their family, workplace, and community due to the COVID-19 pandemic. A convergent mixed-method approach was used to compare the context of perceived life changes in participants with psychological distress and those without. As a result, 8.9% of participants had psychological distress, and sex and age categories were different between those with psychological distress and those without. Among the participants who responded to the open-ended question, the biggest life change was "staying at home," and the next biggest life changes were "event cancellations" and "increased workload" in participants with psychological distress, and "no changes" and "mask-wearing" in those without psychological distress, respectively. Regarding emotional/perceptual changes, "stress," "fear," and "anger" were more frequently reported by participants with psychological distress than those without (P <0.001). By integrating these findings, we identified themes focusing on vulnerable characteristics related to psychological distress. This study may provide a source in society for mediating psychological distress during a pandemic.