Association between masticatory function, frailty, and functional disability: an observational study.

BACKGROUND: Increase in functional disability in aging societies is an international medical and public health issue. Masticatory function may be a potential risk factor for functional disability, but the role of frailty in the association has not been clarified. METHODS: Forty thousand five hundred sixty-two community-dwelling older adults aged 65 years and over who were insured by public health insurance as of April 2018 were followed up for a median of 3.0 years. Masticatory function was categorized as good, moderate, or poor based on a self-reported questionnaire. The development of functional disability was defined as a new certification of the need for long-term care. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and their 95% confidence intervals (CIs). RESULTS: During the follow-up period, 1,397 individuals experienced functional disability. After adjusting for age, sex, comorbidities, medical history, and lifestyle behaviors, the HR for incident functional disability was significantly higher in the moderate and poor groups compared to the good group (moderate, HR 1.21 [95% CI, 1.07-1.37]; poor, HR 1.64 [95% CI, 1.03-2.62]). However, after additional adjustment for frailty-related factors-namely, underweight, regular exercise, and gait speed-the association was attenuated in both the moderate group (HR 1.06 [95% CI, 0.94-1.21]) and the poor group (HR 1.51 [95% CI, 0.94-2.41]). CONCLUSIONS: Masticatory dysfunction was significantly associated with incident functional disability in a community-dwelling older Japanese population. Our findings suggest that masticatory dysfunction may be a surrogate of frailty rather than a direct cause of functional disability.

Long-term association of vegetable and fruit intake with risk of dementia in Japanese older adults: the Hisayama study.

BACKGROUND: Several prospective Western studies have reported an inverse association of vegetable and fruit intake with dementia risk. However, there is limited epidemiologic evidence in Asians. This study investigated the association of intakes of vegetables, fruits, and their nutrients on the risk of incident dementia and its subtypes in a Japanese community. METHODS: A total of 1071 participants (452 men and 619 women) aged ≥60 years without dementia at baseline were prospectively followed up for 24 years. Intakes of vegetables, fruits, and nutrients were evaluated using a 70-item semiquantitative food frequency questionnaire at baseline and were categorized into quartiles separately by gender. The outcome measure was the development of dementia and its subtypes-namely, Alzheimer's disease (AD) and vascular dementia (VaD). The risk estimates of incident dementia were computed using a Cox proportional hazards model. RESULTS: During the long-term follow-up period, 464 subjects developed dementia, of whom 286 had AD and 144 had VaD. Higher vegetable intake was associated gradually with lower risk of developing dementia and AD (both P-trend < 0.05), but not VaD, after adjusting for confounders. Subjects allocated the highest quartile of vegetable intake had 27 and 31% lower risk of dementia and AD, respectively, than those with the lowest quartile. The risk of dementia decreased significantly with higher intakes of vitamin A, riboflavin, vitamin C, magnesium, calcium, and potassium (all P-trend < 0.05). Subjects with higher total dietary fiber intake tended to be at decreased risk for total dementia (P-trend = 0.07). Meanwhile, there were no significant associations between fruit intake and the risk of dementia and its subtypes. CONCLUSION: Higher intakes of vegetables and their constituent nutrients were associated with a lower risk of dementia in Japanese older adults. A diet rich in vegetables may be beneficial in reducing the dementia risk in Asians.

Comparison of the contributions of impaired beta cell function and insulin resistance to the development of type 2 diabetes in a Japanese community: the Hisayama Study.

AIMS/HYPOTHESIS: Our aim was to compare the contributions of impaired beta cell function (IBF) and insulin resistance with the development of type 2 diabetes in a Japanese community. METHODS: A total of 2094 residents aged 40-79 years without diabetes underwent a health examination including a 75 g OGTT in 2007. Participants were divided into four groups according to the presence or absence of IBF (insulinogenic index/HOMA-IR ≤28.5) and insulin resistance (HOMA-IR ≥1.61) and were followed up for 7 years (2007-2014). Cox's proportional hazards model was used to estimate HRs and 95% CIs for type 2 diabetes. The population attributable fractions (PAFs) due to IBF, insulin resistance, and their combination were calculated. RESULTS: At baseline, the prevalence of isolated IBF, isolated insulin resistance, and both IBF and insulin resistance were 5.4%, 24.1% and 9.5%, respectively. During the follow-up period, 272 participants developed type 2 diabetes. The multivariable-adjusted HRs (95% CI) and PAFs (95% CI) for type 2 diabetes were 6.3 (4.3, 9.2) and 13.3% (8.7, 17.7) in the participants with isolated IBF, 1.9 (1.3, 2.7) and 10.5% (4.0, 16.6) in those with isolated insulin resistance, and 8.0 (5.7, 11.4) and 29.3% (23.0, 35.1) in those with both IBF and insulin resistance, respectively, compared with the participants without either. CONCLUSIONS/INTERPRETATION: The present study suggests that the combination of IBF and insulin resistance makes the main contribution to the development of type 2 diabetes in Japanese communities.

High Serum Folate Concentrations Are Associated with Decreased Risk of Mortality among Japanese Adults.

BACKGROUND: Folate and vitamin B-12 are essential nutrients for normal cell growth and replication, but the association of serum folate and vitamin B-12 concentrations with mortality risk remains uncertain. OBJECTIVE: This study was performed to investigate the associations of serum folate and vitamin B-12 concentrations with mortality risk and test whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism modifies these associations. METHODS: A total of 3050 Japanese community residents aged ≥40 y were prospectively followed-up for mortality between 2002 and 2012. Cox proportional hazards models and restricted cubic splines were used to estimate HRs and 95% CIs of mortality. RESULTS: During a median follow-up period of 10.2 y, 336 participants died. Higher serum folate concentrations were associated with lower risks of all-cause mortality [multivariable-adjusted HR: 0.73; 95% CI: 0.56, 0.96 for the second tertile (8.8-12.2 nmol/L; median 10.4 nmol/L) and HR: 0.61; 95% CI: 0.46, 0.80 for the third tertile (≥12.5 nmol/L; median 15.6 nmol/L) serum folate concentrations compared with the first tertile (≤8.6 nmol/L; median 7.0 nmol/L)]. This association remained significant in all sensitivity analyses. Spline analyses showed a steady decline in all-cause mortality risk with increasing serum folate concentrations up to 20-25 nmol/L. This association persisted regardless of the MTHFR C677T genotypes. For serum vitamin B-12, the multivariable-adjusted HR of 1.32 (95% CI: 0.97, 1.79) of all-cause mortality was marginally significantly greater in the first tertile compared with the second tertile. This association was attenuated and nonsignificant after the exclusion of participants with a history of cardiovascular disease or cancer, or participants aged ≥85 y at baseline, or deaths in the first 3 y of follow-up. CONCLUSIONS: Serum folate concentrations were inversely associated with the risk of all-cause mortality in Japanese adults. Serum vitamin B-12 concentrations were not consistently associated with all-cause mortality risk after accounting for reverse-causation bias.

Risk Prediction Model for Incident Atrial Fibrillation in a General Japanese Population　- The Hisayama Study.

BACKGROUND: The risk prediction of incident atrial fibrillation (AF) is useful to prevent AF and its complications. The aim of this study is to develop a new risk prediction model for incident AF using the prospective longitudinal data from a general Japanese population.Methods and Results:A total of 2,442 community-dwelling AF-free residents aged ≥40 years were followed up from 1988 to 2012 (46,422 person-years). The development of AF was confirmed by a standard 12-lead electrocardiogram at repeated health examinations and by medical records at clinics or hospitals. The risk prediction model for incident AF was developed using a Cox proportional hazards model. During the follow up, 230 AF events were confirmed. Age, sex, systolic blood pressure, waist circumference, estimated glomerular filtration rate, abnormal cardiac murmur, high R-wave amplitude, and arrhythmia other than AF were selected for inclusion in the model. This model showed good discrimination (Harrell's c statistics: 0.785) and calibration (Greenwood-Nam-D'Agostino test: P=0.87) for AF risk at 10 years. CONCLUSIONS: The new risk prediction model showed good performance on the individual risk assessment of the future onset of AF in a general Japanese population. As this model included commonly used clinical parameters, it may be useful for determining the requirements for the careful evaluation of AF, such as frequent electrocardiogram examinations in clinical settings, and subsequent reductions in the risk of AF-related complications.

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.

Urinary N-terminal pro-B-type natriuretic peptide as a biomarker for cardiovascular events in a general Japanese population: the Hisayama Study.

BACKGROUND: Epidemiological evidence has shown that serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations, a diagnostic biomarker for heart failure, are positively associated with cardiovascular risk. Since NT-proBNP in serum is excreted in urine, it is hypothesized that urinary NT-proBNP concentrations are correlated with serum concentrations and linked with cardiovascular risk in the general population. METHODS: A total of 3060 community-dwelling residents aged ≥ 40 years without history of cardiovascular disease (CVD) were followed up for a median of 8.3 years (2007-2015). Serum and urinary concentrations of NT-proBNP at baseline were compared. The hazard ratios (HRs) and their 95% confidence intervals (CIs) for the association between NT-proBNP concentrations and the risk of developing CVD were computed using the Cox proportional hazards model. RESULTS: The median values (interquartile ranges) of serum and urinary NT-proBNP concentrations at baseline were 56 (32-104) pg/mL and 20 (18-25) pg/mL, respectively. There was a strong quadratic correlation between the serum and urinary concentrations of NT-proBNP (coefficient of determination [R2] = 0.72): urinary concentrations of 20, 27, and 43 pg/mL were equivalent to serum concentrations of 55, 125, and 300 pg/mL, respectively. During the follow-up period, 170 subjects developed CVD. The age- and sex-adjusted risk of CVD increased significantly with higher urinary NT-proBNP levels (P for trend < 0.001). This association remained significant after adjustment for traditional cardiovascular risk factors (P for trend = 0.009). The multivariable-adjusted risk of developing CVD almost doubled in subjects with urinary NT-proBNP of ≥ 43 pg/mL as compared to those with urinary NT-proBNP of ≤ 19 pg/mL (HR 2.07, 95% CI 1.20-3.56). CONCLUSIONS: The present study demonstrated that urinary NT-proBNP concentrations were well-correlated with serum concentrations and were positively associated with cardiovascular risk. Given that urine sampling is noninvasive and does not require specially trained personnel, urinary NT-proBNP concentrations have the potential to be an easy and useful biomarker for detecting people at higher cardiovascular risk.

Genome-Wide Polygenic Score and the Risk of Ischemic Stroke in a Prospective Cohort: The Hisayama Study.

Background and Purpose- Environmental and genetic factors contribute to the development of ischemic stroke (IS). We recently developed a genome-wide polygenic risk score (PRS) for IS using case-control datasets from 4 large-scale observational studies conducted in Japan. Our objective in the present study was to confirm the association between the PRS and the risk of IS with data from an independent prospective cohort recruited from the general Japanese population. Methods- A total of 3038 subjects aged ≥40 years were followed up for 10 years (2002-2012). The genome-wide PRS was calculated using genotype data from >350 000 single-nucleotide polymorphisms. The PRS levels were divided into quintiles. High and low genetic risk groups were defined as top 60% and bottom 40% of PRS, respectively. The hazard ratio (HR) for the development of IS was estimated using a Cox proportional hazards model. Results- During the follow-up period, 91 cases developed first-ever IS. The age- and sex-adjusted HR for IS increased with higher PRS levels (P for trend, 0.03). Subjects with the highest quintile level of PRS had a 2.44-fold (95% CI, 1.16-5.12) greater risk for IS than those with the lowest quintile level after adjusting for age and sex. A similar association was observed after adjusting for environmental risk factors (P for trend, 0.03). As compared with low genetic risk group, the age- and sex-adjusted HR in high genetic risk group was 1.63 (95% CI, 1.04-2.55), which was comparable to the HR of hypertension (HR, 1.41), diabetes mellitus (HR, 1.72), and smoking (HR, 1.54). The age- and sex-adjusted HR increased with the number of environmental risk factors in both high and low genetic risk groups without significant interaction. Conclusions- A high genome-wide PRS was a significant risk factor for IS independent of environmental risk factors in a general Japanese population. This finding suggests that PRS may be useful to identify individuals at a high risk of IS.

Serum Soluble Triggering Receptor Expressed on Myeloid Cells 2 as a Biomarker for Incident Dementia: The Hisayama Study.

OBJECTIVE: To investigate the association between serum soluble triggering receptor expressed on myeloid cells 2 (sTREM2), a soluble type of an innate immune receptor expressed on the microglia, and the risk of dementia. METHODS: A total of 1,349 Japanese community residents aged 60 and older without dementia were followed prospectively for 10 years (2002-2012). Serum sTREM2 levels were quantified by using an enzyme-linked immunosorbent assay and divided into quartiles. Cox proportional hazards model was used to estimate the hazard ratios (HRs) of serum sTREM2 levels on the risk of dementia. RESULTS: During the follow-up, 300 subjects developed all-cause dementia; 193 had Alzheimer's disease (AD), and 85 had vascular dementia (VaD). The age- and sex-adjusted incidences of all-cause dementia, AD, and VaD elevated significantly with higher serum sTREM2 levels (all p for trend < 0.012). These associations were not altered after adjustment for confounding factors, including high-sensitive C-reactive protein. Subjects with the highest quartile of serum sTREM2 levels had significantly higher multivariable-adjusted risks of developing all-cause dementia, AD, and VaD than those with the lowest quartile (HR = 2.03, 95% confidence interval [CI] = 1.39-2.97, p < 0.001 for all-cause dementia; HR = 1.62, 95% CI = 1.02-2.55, p = 0.04 for AD; HR = 2.85, 95% CI = 1.35-6.02, p = 0.006 for VaD). No significant heterogeneity in the association of serum sTREM2 levels with the development of dementia was observed among the other risk factor subgroups (all p for heterogeneity > 0.11). INTERPRETATION: The present findings suggest a significant association between increased serum sTREM2 levels and the risk of developing all-cause dementia, AD, and VaD in the general elderly Japanese population. ANN NEUROL 2019;85:47-58.

Serum homocysteine and risk of dementia in Japan.

OBJECTIVE: To examine the association between serum total homocysteine levels (tHcy) and dementia risk. METHODS: A total of 1588 Japanese adults aged ≥60 years without dementia were prospectively followed from 2002 to 2012. Cox proportional hazards models and restricted cubic splines were used to estimate the HRs of tHcy levels on the risk of dementia. RESULTS: During the follow-up, 372 subjects developed all-cause dementia; 247 had Alzheimer's disease (AD) and 98 had vascular dementia (VaD). Compared with the lowest tHcy quintile (≤6.4 µmol/L), the multivariable-adjusted HRs (95% CI) of the highest quintile (≥11.5 µmol/L) were 2.28 (1.51-3.43) for all-cause dementia, 1.96 (1.19-3.24) for AD and 2.51 (1.14-5.51) for VaD. In restricted cubic splines, the risk of all-cause dementia steadily increased between approximately 8-15 µmol/L and plateaued thereafter, with a similar non-linear shape observed for AD and VaD (all p for non-linearity ≤0.02). In stratified analyses by the most recognised genetic polymorphism affecting tHcy concentrations (methylenetetrahydrofolate reductase C677T), the positive association of tHcy with all-cause dementia persisted in both non-carriers and carriers of the risk allele, and even tended to be stronger in the former (p for heterogeneity=0.07). CONCLUSION: High serum tHcy levels are associated with an elevated risk of dementia, AD and VaD in a non-linear manner, such that an exposure-response association is present only within a relatively high range of tHcy levels. Non-genetic factors affecting serum tHcy concentrations may play important roles in tHcy-dementia associations irrespective of the genetic susceptibility for raised tHcy.

Association of Albuminuria With White Matter Hyperintensities Volume on Brain Magnetic Resonance Imaging in Elderly Japanese　- The Hisayama Study.

BACKGROUND: Both chronic kidney disease and brain white matter hyperintensities (WMH) are known to be risk factors of dementia and mortality.Methods and Results:In 2012, 1,214 community-dwelling Japanese subjects aged ≥65 years underwent brain magnetic resonance imaging (MRI) scans and a comprehensive health examination. This study investigated associations of the urinary albumin : creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) with the WMH volume to intracranial volume (WMHV : ICV) ratio, and the association of the combination of UACR and the WMHV : ICV ratio with cognitive decline and mortality risk. The geometric mean of the WMHV : ICV ratio was 0.223% in the entire study population, and increased significantly with higher UACR levels after adjusting for potential confounding factors (0.213% for normoalbuminuria, 0.248% for microalbuminuria, and 0.332% for macroalbuminuria; Ptrend=0.01). In contrast, there was no clear association between eGFR and the WMHV : ICV ratio. Compared with subjects with normoalbuminuria and a smaller WMHV : ICV ratio (<0.257% [median]), subjects with albuminuria and a larger WMHV : ICV ratio (≥0.257%) had higher probabilities of cognitive decline at baseline and all-cause death during the follow-up. CONCLUSIONS: This study suggests that subjects with albuminuria have a greater risk of WMH enlargement and that the combination of albuminuria and WMH enlargement increases the risk of cognitive decline and all-cause mortality in an elderly Japanese population.

Decline in Handgrip Strength From Midlife to Late-Life is Associated With Dementia in a Japanese Community: The Hisayama Study.

BACKGROUND: The association between decline in handgrip strength from midlife to late life and dementia is unclear. METHODS: Japanese community-dwellers without dementia aged 60 to 79 years (ie, individuals in late life; mean age, 68 years) were followed for 24 years (1988-2012) (n = 1,055); 835 of them had participated in a health examination in 1973-1974 (mean age, 53 years), and these earlier data were used for the midlife analysis. Using a Cox proportional hazards model, we estimated the risk conferred by a decline in handgrip strength over a 15-year period (1973-74 to 1988) from midlife to late life on the development of total dementia, Alzheimer's disease (AD), and vascular dementia (VaD) over the late-life follow-up period from 1988 to 2012. RESULTS: During the follow-up, 368 subjects experienced total dementia. The age- and sex-adjusted incidence of total dementia increased significantly with greater decline in handgrip strength (increased or unchanged handgrip strength [≥+0%] 25.1, mildly decreased [-14 to -1%] 28.4, and severely decreased [≤-15%] 38.9 per 1,000 person-years). A greater decline in handgrip strength was significantly associated with higher risk of total dementia after adjusting for potential confounding factors; subjects with severely decreased handgrip strength had 1.51-fold (95% confidence interval, 1.14-1.99, P < 0.01) increased risk of total dementia compared to those with increased or unchanged handgrip strength. Similar significant findings were observed for AD, but not for VaD. CONCLUSIONS: Our findings suggest that a greater decline in handgrip strength from midlife to late life is an important indicator for late-life onset of dementia.

Association Between Serum ß-Alanine and Risk of Dementia.

We examined the association between serum concentrations of ß-alanine, a metabolite of carnosine and anserine, and the risk of dementia in a general population of elderly Japanese persons. In 2007, 1,475 residents of Hisayama, Japan, aged 60-79 years and without dementia were divided into 4 groups according to quartiles of serum ß-alanine concentrations (quartile 1, lowest; quartile 4, highest) and followed for a median of 5.3 years. During follow-up, 117 subjects developed all-cause dementia (Alzheimer in 77 cases and vascular dementia in 31). The risk of all-cause dementia decreased with increasing serum ß-alanine levels after adjustment for potential confounding factors (quartile 2, hazard ratio (HR) = 0.73 (95% confidence interval (CI): 0.45, 1.18); quartile 3, HR = 0.50 (95% CI: 0.28, 0.89); quartile 4, HR = 0.50 (95% CI: 0.27, 0.92); P = 0.01 for trend). A similar inverse association was observed for Alzheimer disease (quartile 2, HR = 0.78 (95% CI: 0.44, 1.38); quartile 3, HR = 0.53 (95% CI: 0.26, 1.06); quartile 4, HR = 0.53 (95% CI: 0.25, 1.10); P = 0.04 for trend) but not for vascular dementia. We found that higher serum ß-alanine levels were significantly associated with lower risks of all-cause dementia and Alzheimer disease. Because serum ß-alanine levels reflect intakes of carnosine/anserine, higher intakes of carnosine/anserine might be beneficial for the prevention of dementia.

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.

Day-to-Day Blood Pressure Variability and Risk of Dementia in a General Japanese Elderly Population: The Hisayama Study.

BACKGROUND: Several observational studies have reported that higher visit-to-visit blood pressure variability is a risk factor for cognitive impairment and dementia. However, no studies have investigated the association of day-to-day blood pressure variability assessed by home blood pressure measurement with the development of dementia. METHODS: A total of 1674 community-dwelling Japanese elderly without dementia, ≥60 years of age, were followed up for 5 years (2007-2012). Home blood pressure was measured 3 times every morning for a median of 28 days. Day-to-day systolic (SBP) and diastolic blood pressure variabilities, calculated as coefficients of variation (CoV) of home SBP and diastolic blood pressure, were categorized into quartiles. The hazard ratios and their 95% confidence intervals of the CoV levels of home blood pressure on the development of all-cause dementia, vascular dementia (VaD), and Alzheimer disease (AD) were computed with a Cox proportional hazards model. RESULTS: During the follow-up, 194 subjects developed all-cause dementia; of these, 47 had VaD and 134 had AD. The age- and sex-adjusted incidences of all-cause dementia, VaD, and AD increased significantly with increasing CoV levels of home SBP (all P for trend <0.05). These associations remained unchanged after adjustment for potential confounding factors, including home SBP. Compared with subjects in the first quartile of CoV levels of home SBP, the risks of the development of all-cause dementia, VaD, and AD were significantly higher in those in the fourth quartile (hazard ratio=2.27, 95% confidence interval=1.45-3.55, P<0.001 for all-cause dementia; hazard ratio=2.79, 95% confidence interval=1.04-7.51, P=0.03 for VaD; hazard ratio=2.22, 95% confidence interval=1.31-3.75, P<0.001 for AD). Similar associations were observed for CoV levels of home diastolic blood pressure. Meanwhile, home SBP levels were significantly associated with the risk of VaD but not with the risks of all-cause dementia and AD. There was no interaction between home SBP levels and CoV levels of home SBP on the risk of each subtype of dementia. CONCLUSIONS: Our findings suggest that increased day-to-day blood pressure variability is, independently of average home blood pressure, a significant risk factor for the development of all-cause dementia, VaD, and AD in the general elderly Japanese population.

Development and validation of a risk assessment tool for gastric cancer in a general Japanese population.

BACKGROUND: There have been very few reports of risk score models for the development of gastric cancer. The aim of this study was to develop and validate a risk assessment tool for discerning future gastric cancer risk in Japanese. METHODS: A total of 2444 subjects aged 40 years or over were followed up for 14 years from 1988 (derivation cohort), and 3204 subjects of the same age group were followed up for 5 years from 2002 (validation cohort). The weighting (risk score) of each risk factor for predicting future gastric cancer in the risk assessment tool was determined based on the coefficients of a Cox proportional hazards model in the derivation cohort. The goodness of fit of the established risk assessment tool was assessed using the c-statistic and the Hosmer-Lemeshow test in the validation cohort. RESULTS: During the follow-up, gastric cancer developed in 90 subjects in the derivation cohort and 35 subjects in the validation cohort. In the derivation cohort, the risk prediction model for gastric cancer was established using significant risk factors: age, sex, the combination of Helicobacter pylori antibody and pepsinogen status, hemoglobin A1c level, and smoking status. The incidence of gastric cancer increased significantly as the sum of risk scores increased (P trend < 0.001). The risk assessment tool was validated internally and showed good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test P = 0.43) in the validation cohort. CONCLUSIONS: We developed a risk assessment tool for gastric cancer that provides a useful guide for stratifying an individual's risk of future gastric cancer.

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.

Dietary Protein Intake and Stroke Risk in a General Japanese Population: The Hisayama Study.

BACKGROUND AND PURPOSE: The influence of dietary protein intake on stroke risk is an area of interest. We investigated the association between dietary protein intake and stroke risk in Japanese, considering sources of protein. METHODS: A total of 2400 subjects aged 40 to 79 years were followed up for 19 years. Dietary protein intake was estimated using a 70-item semiquantitative food frequency questionnaire. The risk estimates for incident stroke and its subtypes were calculated using a Cox proportional hazards model. RESULTS: During the follow-up, 254 participants experienced stroke events; of these, 172 had ischemic stroke, and 58 had intracerebral hemorrhage. Higher total protein intake was significantly associated with lower risks of stroke and intracerebral hemorrhage (both P for trend <0.05). With regard to sources of protein, the risks of total stroke and ischemic stroke significantly decreased by 40% (95% confidence interval, 12%-59%) and 40% (5%-62%), respectively, in subjects with the highest quartile of vegetable protein intake compared with those with the lowest one. In contrast, subjects with the highest quartile of animal protein intake had a 53% (4%-77%) lower risk of intracerebral hemorrhage. Vegetable protein intake was positively correlated with intakes of soybean products, vegetable, and algae, whereas animal protein intake was positively correlated with intakes of fish, meat, eggs, and milk/dairy products. Both types of protein intakes were negatively correlated with intakes of rice and alcohol. CONCLUSIONS: Our findings suggest that higher dietary protein intake is associated with a reduced risk of stroke in the general Japanese population.

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.

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.