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.

Database profile of the Fukuoka-City Information Platform for Community-based Integrated Care.

BACKGROUND: The Fukuoka-City Information Platform for Community-based Integrated Care is an advanced big data platform that aggregates information on the health and medical services of Fukuoka citizens. Fukuoka City is engaged in a joint project with Kyushu University to promote policy making through a large-scale real-world data analysis. This paper describes the framework for this cooperative effort and the features of the analytical platform. METHODS: Fukuoka City is the fifth most populous ordinance-designated city in Japan, with an estimated population of approximately 1.6 million. Under an agreement with Fukuoka City, Kyushu University was granted access to a portion of the city's anonymized healthcare database as secondary-use information. The database contains information on resident registration, health insurance claims, specific health checkups and health checkups for the older adults, specific health guidance, long-term care insurance data, and cancer screenings collected after fiscal year 2012. Each of these constituent datasets can be interlinked using anonymized hashed key variables, allowing individuals to be followed across databases and over time. CONCLUSIONS: The platform allows longitudinal investigation of the complex association between various aspects of healthcare, such as medical procedures, examinations, interviews, medical costs, long-term care certifications, and care costs. The platform can provide valuable public-health information because it is relatively large for a single database, and because it allows analysis of data across multiple domains and tracing of individuals over time.

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.

Dietary fiber intake and risk of type 2 diabetes in a general Japanese population: The Hisayama Study.

AIMS/INTRODUCTION: The investigation of the influence of dietary fiber intake on the incidence of type 2 diabetes in a general Japanese population. MATERIALS AND METHODS: A total of 1,892 individuals aged 40-79 years without diabetes at baseline were prospectively followed up for 14 years. The glucose tolerance status of participants was defined by a 75-g oral glucose tolerance test with the 1998 World Health Organization criteria. Dietary fiber intake was estimated by a semiquantitative food frequency questionnaire and divided to quintile levels separately by sex. A Cox proportional hazards model was applied for computing the hazard ratios and their 95% confidence intervals for the incidence of diabetes. RESULTS: During the follow-up period, 280 participants had developed diabetes. The age-adjusted cumulative diabetes incidence decreased significantly with higher total dietary fiber intake (P-for trend = 0.01). Participants in the highest quintile of total dietary fiber intake had a 0.53-fold (95% confidence interval 0.31-0.90) lower risk of developing diabetes than those in the lowest quintile after for the adjustment with potential confounding factors. Total dietary fiber intake showed a moderate positive correlation to the intake of soybean and soybean products, green vegetables, and other vegetables. Similar associations with diabetes and food sources were observed for both of the soluble and insoluble dietary fiber intake. CONCLUSIONS: The present study showed that higher dietary fiber intake was associated with a lower risk of type 2 diabetes in a general Japanese population. The intake of high dietary fiber foods might be useful for diabetes prevention.

Intake of Coffee Associated With Decreased Depressive Symptoms Among Elderly Japanese Women: A Multi-Center Cross-Sectional Study.

BACKGROUND: Depression in elderly people is a major global concern around the world. Epidemiological evidence of the association of beverages with depressive symptoms has received research attention; however, epidemiological studies on the association of coffee and green tea consumption with depressive symptoms among the elderly population are limited. The objective of this study is to cross-sectionally examine the association of depressive symptoms with the intake of coffee, green tea, and caffeine and to verify the antidepressant effect of caffeine. METHODS: The subjects were 1,992 women aged 65-94 years. Intakes of coffee, green tea, and caffeine, as well as depressive symptoms, were assessed with a validated brief dietary history questionnaire (BDHQ) and the Center for Epidemiologic Studies Depression Scale (CES-D), respectively. Multiple logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for depressive symptoms with adjustments for potential confounders. RESULTS: Coffee intake was associated with a lower prevalence of depressive symptoms, the ORs of which for the 4th versus the 1st quartiles of intake was 0.64 (95% CI, 0.46-0.88, P for trend = 0.01) in a fully adjusted model. Caffeine intake was marginally associated with depressive symptoms, but the association was not statistically significant (OR 0.75; 95% CI, 0.55-1.02, P for trend = 0.058). CONCLUSION: The result suggests that the inverse association of coffee intake with depressive symptoms might be associated with not only caffeine intake but also some other substances in coffee or factors related to coffee intake. Because of the cross-sectional design of the present study, longitudinal studies are required to confirm the present finding.

Circulating ferritin concentrations are differentially associated with serum adipokine concentrations in Japanese men and premenopausal women.

PURPOSE: Increased iron storage, as measured by circulating ferritin, has been linked to an increased risk of various diseases including diabetes. We examined the association of circulating ferritin with serum adiponectin, leptin, resistin, plasminogen activator inhibitor-1 (PAI-1), and visfatin levels. METHODS: We conducted a cross-sectional study among 429 Japanese employees (284 men and 145 premenopausal women, mean age: 42.5 ± 10.5 years). Serum adipokines were measured using Luminex suspension bead-based multiplexed array, and serum ferritin was determined using a chemiluminescence immunoassay. Multivariable regression analysis was performed to calculate mean concentrations of adipokine according to the tertile of ferritin concentrations with adjustment for potential confounders. RESULTS: Leptin and visfatin concentrations increased with increasing ferritin concentrations in men after multivariable adjustment of physical activity, smoking, alcohol use, and body mass index (P for trend = 0.02 and 0.01 for leptin and visfatin, respectively). Serum ferritin concentrations were inversely and significantly associated with adiponectin in women (P for trend = 0.01). Resistin and PAI-1 were not appreciably associated with ferritin concentration. CONCLUSIONS: Increased iron storage may be associated with higher circulating concentrations of leptin and visfatin in men and with lower concentrations of adiponectin in women.

Dietary fiber intake and depressive symptoms in Japanese employees: The Furukawa Nutrition and Health Study.

OBJECTIVE: Dietary fiber may play a favorable role in mood through gut microbiota, but epidemiologic evidence linking mood to dietary fiber intake is scarce in free-living populations. We investigated cross-sectionally the associations of dietary intakes of total, soluble, insoluble, and sources of fiber with depressive symptoms among Japanese workers. METHODS: Participants were 1977 employees ages 19-69 y. Dietary intake was assessed via a validated, brief self-administered diet history questionnaire. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to estimate odds ratios of depressive symptoms adjusted for a range of dietary and non-dietary potential confounders. RESULTS: Dietary fiber intake from vegetables and fruits was significantly inversely associated with depressive symptoms. The multivariable-adjusted odds ratios (95% confidence intervals) for the lowest through the highest tertile of vegetable and fruit fiber were 1.00 (reference), 0.80 (0.60-1.05), and 0.65 (0.45-0.95), respectively (P for trend = 0.03). Dietary intake of total, soluble, insoluble, and cereal fiber was not associated with depressive symptoms. CONCLUSIONS: Higher dietary fiber intake from vegetables and fruits may be associated with lower likelihood of having depressive symptoms.

High levels of stearic acid, palmitoleic acid, and dihomo-γ-linolenic acid and low levels of linoleic acid in serum cholesterol ester are associated with high insulin resistance.

The association of fatty acid composition with insulin resistance and type 2 diabetes has been reported in Western populations, but there is limited evidence of this association among the Japanese, whose populace consume large amounts of fish. To test the hypothesis that high palmitic, palmitoleic, and dihomo-γ-linolenic acids and low levels of linoleic and n-3 fatty acids are associated with higher insulin resistance among the Japanese, the authors investigated the relationship between serum fatty acid composition and serum C-peptide concentrations in 437 Japanese employees aged 21 to 67 years who participated in a workplace health examination. Serum cholesterol ester and phospholipid fatty acid compositions were measured by gas-liquid chromatography. Desaturase activity was estimated by fatty acid product-to-precursor ratios. A multiple regression was used to assess the association between fatty acid and C-peptide concentrations. C-peptide concentrations were associated inversely with linoleic acid levels in cholesterol ester and phospholipid (P for trend = .01 and .02, respectively) and positively with stearic and palmitoleic acids in cholesterol ester (P for trend =.02 and .006, respectively) and dihomo-γ-linolenic acid in cholesterol ester and phospholipid (P for trend < .0001 for both). C-peptide concentrations were not associated with n-3 polyunsaturated fatty acids. C-peptide concentrations significantly increased as δ-9-desaturase (16:1 n-7/16:0) and δ-6-desaturase (18:3 n-6/18:2 n-6) increased (P for trend = .01 and .03, respectively) and δ-5-desaturase (20:4 n-6/20:3 n-6) decreased (P for trend = .004). In conclusion, a fatty acid pattern with high levels of serum stearic, palmitoleic, or dihomo-γ-linolenic acids; δ-9-desaturase (16:1 n-7/16:0) or δ-6-desaturase (18:3 n-6/18:2 n-6) activities; and low levels of serum linoleic acid or δ-5-desaturase (20:4 n-6/20:3 n-6) activity might be associated with higher insulin resistance in Japanese adults.

Dietary patterns and C-peptide concentrations in a Japanese working population.

OBJECTIVE: It remains unsettled whether dietary patterns play a role in insulin resistance. We assessed the association of major dietary patterns with C-peptide concentrations in a Japanese working population. METHODS: A cross-sectional study was conducted in 456 municipal employees (270 men and 186 women) 21 to 67 y old who participated in a health survey at the time of their periodic checkup. The dietary patterns were derived by using the principal component analysis of the consumption of 52 food and beverage items, which was assessed by a validated brief dietary history questionnaire. Multiple regression analysis was used to estimate the means of C-peptide concentrations across tertiles of each dietary pattern score with the adjustment of potential confounders, including age, body mass index, physical activity, smoking, alcohol drinking, and energy intake. RESULTS: We identified three dietary patterns: healthy, animal food, and Westernized breakfast patterns. The Westernized breakfast pattern was characterized by high intakes of bread, confectionaries, and milk and yogurt but low intakes of rice and alcohol and was inversely associated with C-peptide concentrations in women but not in men. The multivariable-adjusted means of C-peptide concentrations were 1.03 ng/mL (95% confidence interval 0.95-1.12), 0.95 ng/mL (95% confidence interval 0.88-1.03), and 0.89 ng/mL (95% confidence interval 0.82-0.97) for the lowest through the highest tertiles of the Westernized breakfast pattern score (P for trend = 0.015) in women. Other dietary patterns were not appreciably associated with C-peptide concentrations. In a subgroup, similar associations were observed between dietary patterns and the homeostasis model assessment of insulin resistance. CONCLUSION: The Westernized breakfast pattern may be associated with a lower insulin resistance in Japanese women.

PUFAs in serum cholesterol ester and oxidative DNA damage in Japanese men and women.

BACKGROUND: PUFAs are susceptible to lipid peroxidation and play a role in inflammation, both of which can induce oxidative stress. However, the relation of PUFA to oxidative DNA damage in humans is elusive. OBJECTIVE: We examined the association between concentrations of circulatory PUFAs and urinary 8-oxo-7,8-dihydroguanine (8-oxoGua) in Japanese men and women. DESIGN: The subjects were 495 participants (290 men and 205 women) in a cross-sectional study in 2 municipal offices in Japan. Serum cholesterol ester (CE) and phospholipid fatty acid composition were measured by gas-liquid chromatography. Urinary 8-oxoGua concentrations were measured by HPLC, and 8-oxoGua values for each tertile of PUFA after adjustment for covariates were calculated by multiple regression. RESULTS: Urinary 8-oxoGua concentrations increased with increasing concentrations of n-3 (omega-3) PUFAs, EPA, and DHA in serum CE (P-trend = 0.001, 0.01, and 0.009, respectively), whereas they decreased with increasing concentrations of n-6 PUFAs and linoleic acid (P-trend = 0.02 and 0.051, respectively). CONCLUSION: Oxidative DNA damage may be greater with higher concentrations of long-chain n-3 PUFAs but lower with higher concentrations of n-6 (omega-6) PUFAs.

Eating behavior in relation to prevalence of overweight among Japanese men.

Obesity is an important risk factor for lifestyle diseases. There has been much interest in the role of eating behavior in the development of obesity, but findings from population-based epidemiologic studies are limited and inconsistent. The objective of our cross-sectional study was to examine the association between eating behavior and prevalence of overweight. Subjects were 290 men of two municipal offices in northeastern Kyusyu, Japan. A positive association was found between overweight and some eating behaviors; multivariate-adjusted odds ratios (95% confidence intervals) for overweight were 4.33 (2.46-7.64), 2.29 (1.22-4.32), and 2.01 (1.06-3.80) for the behaviors of eating quickly, eating until full and eating fatty foods, respectively. Moreover, the prevalence of overweight was further increased when these eating behaviors were combined; multivariate odds ratios (95% confidence intervals) of overweight for men with 1, 2 and ≥3 versus no high-risk eating behaviors were 2.66 (1.27-5.56), 4.32 (1.87-9.97) and 7.32 (3.01-17.84), respectively (pp<0.0001 for trend). Our findings suggest that eating quickly, eating until full and eating fatty foods are related to overweight in Japanese men.

Metabolic syndrome and depressive symptoms among Japanese men and women.

OBJECTIVES: Evidence is limited on the relation between metabolic syndrome and depressive symptoms. The aim of this cross-sectional study was to investigate the association between metabolic syndrome and depressive symptoms in a Japanese working population. METHODS: The study subjects comprised 458 municipal employees (age range 21-67 years) from two municipal offices in Japan. A modified version of the criteria of the National Cholesterol Education Program Adult Treatment Panel III was used to define metabolic syndrome. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES_D) scale. RESULTS: Depressive symptoms (CES_D ≥ 16) in both the male and female subjects were not significantly associated with metabolic syndrome nor with each component of metabolic syndrome. In men, high fasting glucose was associated with increased prevalence of severe depressive state (CES_D ≥ 23). CONCLUSIONS: Metabolic syndrome may not be associated with depressive status among Japanese employees.

Calcium, dairy foods, vitamin D, and colorectal cancer risk: the Fukuoka Colorectal Cancer Study.

Epidemiologic evidence supporting a protective role of calcium and vitamin D in colorectal carcinogenesis has been accumulating in Western populations, but it is limited in Asian populations, whose intake of calcium is relatively low. We investigated the association of intakes of these nutrients with colorectal cancer risk in Japanese. Study subjects were participants of a large-scale case-control study in Fukuoka, Japan. Diet was assessed through interview regarding 148 dietary items by showing typical foods or dishes on the display of a personal computer. In a multivariate analysis adjusting for potential confounding variables, calcium intake was significantly, inversely associated with colorectal cancer risk (P for trend=0.01); the odds ratio for the highest versus lowest quintile of calcium intake was 0.64 (95% confidence interval, 0.45-0.93). Higher levels of dietary vitamin D were significantly associated with decreased risk of colorectal cancer among those who had fewer chances of sunlight exposure at work or in leisure (P for trend=0.02). A decreased risk of colorectal cancer associated with high calcium intake was observed among those who had higher levels of vitamin D intake or among those who had a greater chance of daily sunlight exposure, but not among those with medium or lower intake of vitamin D or among those with potentially decreased sunlight exposure. These results add to support for a joint action of calcium and vitamin D in the prevention of colorectal carcinogenesis.

Meat, fish and fat intake in relation to subsite-specific risk of colorectal cancer: The Fukuoka Colorectal Cancer Study.

High intake of red meat has been associated with increased risk of colorectal cancer in Western countries. There has been much interest in the role of n-3 polyunsaturated fatty acids (PUFA) in colorectal cancer prevention, but epidemiological findings are limited and inconsistent. The objective of our study was to examine associations of meat, fish and fat intake with risk of colorectal cancer, paying particular attention to the subsite within the colorectum. Data were from the Fukuoka Colorectal Cancer Study, a population-based case-control study, covering 782 cases and 793 controls. Diet was assessed by interview, using newly developed personal-computer software for registering semiquantitative food frequencies. The intake of beef/pork, processed meat, total fat, saturated fat or n-6 PUFA showed no clear association with the overall or subsite-specific risk of colorectal cancer. There was an almost significant inverse association between n-3 PUFA and the risk of colorectal cancer; the covariate-adjusted odds ratio for the highest (median 3.94 g/day) versus lowest (median 1.99 g/day) quintile of energy-adjusted intake was 0.74 (95% confidence interval 0.52-1.06, trend P=0.050). The consumption of fish and fish products was similarly inversely related to the risk although the association was not statistically significant. These associations were more evident for distal colon cancer; adjusted odds ratio for the highest versus lowest quintile of n-3 PUFA intake was 0.56 (95% confidence interval 0.34-0.92, trend P=0.02). Our findings do not support the hypothesis that consumption of red meat increases colorectal cancer risk but do suggest that high intake of fish may decrease the risk, particularly of distal colon cancer.

Validity and reproducibility of the PC-assisted dietary interview used in the Fukuoka Colorectal Cancer Study.

Epidemiologic studies based on quantitative estimation of food and nutrient intake have been limited in Japan. We evaluated validity and reproducibility of a personal computer (PC)-assisted dietary interview used in the Fukuoka Colorectal Cancer Study. The subjects were 28 participants as controls in a population-based case-control study. Four 7-day diet records were kept during a period from July 2001 to May 2002, and the PC-assisted dietary interview was administered before and after the diet records (May to July 2001 and July to September 2002). Intakes of total energy, 26 nutrients, and 19 food groups were estimated. Of 26 Pearson correlation coefficients for energy-adjusted nutrients, 18 for the first interview and 19 for the second interview were 0.40 or greater, with the highest correlation for saturated fat in the first interview (0.72) and vitamin C in the second interview (0.60). Validity scores were fairly high for most of the food groups with an exceptionally low correlation for potatoes (0.19 for the first and 0.13 for the second interview). Reproducibility was good for most nutrients and foods; but low correlation was noted for Vitamin D and nuts/seeds. Reproducibility was modest for fish and fish products, beef and pork, and processed meat. The PC-assisted dietary interview was fairly valid and reproducible regarding most of the nutrients and food groups. Validity and reproducibility of meat and fish intakes were probably attenuated because of the episode of bovine spongiform encephalopathy in September 2001.

[Fish, n-3 polyunsaturated fatty acid and colorectal cancer prevention: a review of experimental and epidemiological studies].

Colorectal cancer demonstrates high incidences in the developed countries and is the second largest cause of deaths from neoplasia. In Japan, about 12% of all cancer deaths are due to colorectal cancer and the rate continues to increase remarkably. Dietary factors are clearly linked to the development of tumors in the colorectum, and the increase in mortality from colorectal cancer over the last few decades in Japan has been attributed to Westernization of the diet. On the other hand, the intake of fish/n-3 polyunsaturated fatty acids has long been considered as a factor decreasing the risk of colorectal cancer. In the present study, we investigated the effect of fish/n-3 polyunsaturated fatty acids on colorectal cancer by reviewing papers on both experimental and epidemiological studies overall to obtain a perspective for research and practice for prevention. This review covers the following areas. 1. Relationships between n-3 polyunsaturated fatty acids and colon carcinogenesis in experimental studies. 1) Aberrant crypt foci (ACF). 2) Tumors. 2. Relationships between fish intake and colorectal cancer in epidemiological studies. 1) Ecological studies. 2) Case-control studies. 3) Cohort studies. 4) Randomized controlled trials. There are substantial data from experimental studies in support of anticarcinogenic effects of fish/ n-3 polyunsaturated fatty acids in the colon. Several epidemiological studies have also provided evidence that fish/n-3 polyunsaturated fatty acids have anticarcinogenic effects in the colon, but not all data are consistent. However, increasing intake of fish/n-3 polyunsaturated fatty acids for preventing colon cancer is suggested from review of experimental and epidemiological research overall. In the future, it is necessary to improve precision regarding exposure to carcinogens and fish/n-3 polyunsaturated fatty acids intake using a detoiled dietary survey and biomarkers in epidemiological studies.