Saturated fatty acids are generally thought to have detrimental effects on health. However, a recent study showed that even- and odd-chain saturated fatty acids had opposite associations with type 2 diabetes. Limited studies of Western populations examined the associations of circulating saturated fatty acids with adipokines, an important role in glucose metabolism. We examined the associations of saturated fatty acids in serum phospholipids with circulating levels of adipokines among a Japanese population. A cross-sectional study was conducted among 484 Japanese employees (284 men and 200 women) aged 20–65 years. The serum fatty acid composition in the phospholipid fraction was measured by gas-chromatography. Serum leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), resistin, and visfatin were measured using a Luminex suspension bead-based multiplexed array. Multiple linear regression analysis was performed to assess the association between saturated fatty acids and adipokines, with adjustment for potential confounding variables. Even- and odd-chain saturated fatty acids were differentially associated with adipokines. Higher levels of even-chain saturated fatty acids (14:0 myristic, 16:0 palmitic, and 18:0 stearic acids) were associated with higher levels of resistin (P for trend = 0.048) and lower levels of adiponectin (P for trend = 0.003). By contrast, odd-chain saturated fatty acids (15:0 pentadecanoic and 17:0 heptadecanoic acids) showed inverse associations with leptin and PAI-1 (P for trend = 0.048 and 0.02, respectively). Visfatin was positively associated with both even- and odd-chain saturated fatty acids. The results suggest that even- and odd-chain saturated fatty acids are differentially associated with adipokine profile.

Objective: Although several studies in Western countries show that higher socioeconomic status is associated with higher diet quality, no study has observed this association in Japan. In the current study, we examined the association between diet quality and the combinations of age, sex, and household income, and also compared the dietary intake between diet quality levels according to household income.Design: Cross-sectional study.Setting: National Health and Nutrition Survey, Japan in 2014.Participants: 2785 men and 3215 women.Results: Higher Japanese Food Guide Spinning Top scores (better diet quality) were observed in older women, especially those with higher household income, whereas lower scores were observed in younger men with lower household income. Those having low quality diet, especially in low income households, had higher odds of not meeting the recommended amounts of the Japanese dietary guidelines, than those having high quality diet.Conclusions: Diet quality in Japanese adults differed by age and sex as well as by household income level. A different approach to diet quality improvement is needed according to population characteristics including not only age and sex but also social economic status.

Purpose: While the association between diet quality and mortality has been previously demonstrated, the association between frailty and diet quality has not been evaluated well. This study aimed to investigate the association between diet quality and prevalence of both physical and comprehensive frailty, using two validated tools, in a community-based cohort of older adults. Methods: We conducted cross-sectional analyses using baseline data of 7022 participants aged ≥ 65 years in the Kyoto-Kameoka study. Diet quality was assessed by calculating the adherence scores to the Japanese Food Guide Spinning Top using a validated questionnaire; the participants were stratified into quartile groups based on these scores. Physical and comprehensive frailty was assessed using the Fried phenotype model-based Frailty Screening Index and the Kihon Checklist, respectively. Multivariable logistic regression and the restricted cubic spline model were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs) for associations between adherence scores and frailty prevalence. Results: Higher adherence scores signified a higher intake of vitamin C, vegetables, dairy products, and fruits. Physical and comprehensive frailty prevalence was 14.2 and 35.8%, respectively. In a multivariable adjusted model, compared with the bottom adherence score quartile, the top quartile was associated with lower ORs of physical (OR 0.64; 95% CI 0.52–0.80) and comprehensive frailty (OR 0.60; 95% CI 0.51–0.71). These relationships were similar to results in the spline model. Conclusions: This study shows an inverse dose–response relationship between diet quality and prevalence of both physical and comprehensive frailty in older adults.

We prospectively examined the association of diabetes risk with the number of metabolic abnormalities, as well as their combinations, according to the presence or absence of impaired fasting glucose (IFG) in a large-scale Japanese working population. Participants included 55,271 workers at 11 companies who received periodic health check-ups between 2008 and 2013. The metabolic syndrome (MetS) components were defined using the 2009 Joint Interim Statement. IFG was defined as fasting plasma glucose 5.6-6.9 mmol/L. Diabetes newly diagnosed after the baseline examination was defined according to the American Diabetes Association criteria. We calculated the hazard ratios (HRs) for diabetes incidence using the Cox proportional hazards model. During the follow-up period (median 4.95 years), 3183 subjects developed diabetes. In individuals with normal fasting glucose levels, the risk of diabetes increased steadily with the increasing number of MetS components; the multivariable-adjusted HRs for incident diabetes for the number of MetS components were 2.0, 4.3, 7.0, and 10.0 for one, two, three, or four MetS components, respectively, compared with the absence of components. A similar association was observed among individuals with IFG; the corresponding HRs were 17.6, 23.8, 33.9, and 40.7. The combinations that included central obesity appeared to be more strongly associated with diabetes risk than other combinations with the same number of MetS components within the same glucose status. Our findings indicate that risk stratification of individuals by the presence or absence of IFG and the number of MetS components can detect individuals with a high risk of diabetes.