The aim of this study was to investigate the associations between dietary patterns and abdominal obesity among middle-aged and elderly Japanese people, using both waist circumference (WC) and visceral fat (VF) as indices. A cross-sectional study was conducted with 829 adults (534 men and 295 women), 40 to 79 y of age, who participated in the Waseda Alumni's Sports, Exercise, Daily Activity, Sedentariness and Health Study (WASEDA'S Health Study). Dietary patterns were derived from principal component analysis. VF was measured using magnetic resonance imaging. To examine the associations of each dietary pattern with WC and VF, we calculated multivariate-adjusted means and 95% confidence intervals (CIs) of WC and VF for the tertile of each dietary pattern score. Two main dietary patterns were identified: "healthy Japanese" and "seafood and alcohol." The healthy Japanese dietary pattern score was inversely associated with WC and VF in men only. WC measurements were 84.9 cm (95% CI, 83.7-86.1), 83.9 cm (95% CI, 82.7-85.1), and 82.4 cm (95% CI, 81.2-83.6); Ptrend = 0.006, and VF measurements were 94.0 cm2 (95% CI, 85.6-102.4), 89.4 cm2 (95% CI, 81.1-97.7), and 80.4 cm2 (95% CI, 72.5-88.4); Ptrend = 0.027 for the lowest through the highest tertile of healthy Japanese dietary pattern scores in men. The seafood and alcohol dietary pattern was not associated with WC and VF. The healthy Japanese dietary pattern was negatively associated with WC and VF in middle-aged and elderly Japanese men.

This study aimed to examine whether cardiorespiratory fitness (CRF) is associated with arterial stiffening, evaluated using the cardio-ankle vascular index (CAVI), independent of visceral fat (VF) in middle-aged and elderly Japanese men. We also examined whether the relationship between CRF and the CAVI is modified by age and/or hypertension. The CAVI was determined in 157 Japanese men (age range, 30-79 years), including 96 hypertensive subjects (61.1%). CRF was assessed by measuring the peak oxygen uptake (VO2peak). The subjects were divided into low- and high-CRF groups, and the VF area was assessed using magnetic resonance imaging. The VO2peak correlated with the CAVI following adjustment for age and body mass index in the middle-aged and elderly groups (all the subjects: r=-0.285, p＜0.001; middle-aged: r=-0.240, p=0.040; elderly: r=-0.225, p=0.049). VF also correlated with the CAVI (r=0.230, p=0.004). A multiple linear regression analysis revealed that age (β=0.406, p<0.001) and the VO2peak (β=-0.186, p=0.015) were associated with the CAVI independently of VF and the mean blood pressure. Two way ANCOVA adjusted for age demonstrated that the hypertensive individuals had higher CAVI values than the normotensive individuals in the low-CRF group, whereas no significant differences in the CAVI were observed in the high-CRF group (p for interaction <0.05). In the present study, CRF was found to be associated with the CAVI, independent of age and VF, in hypertensive middle-aged and elderly Japanese men.

This study examined the relationship between a healthy Japanese dietary pattern and micronutrient intake adequacy based on the Dietary Reference Intakes for Japanese 2015 (DRIs-J 2015) in men and women. A cross-sectional study was conducted in 1418 men and 795 women aged 40–87 years, who participated in the Waseda Alumni’s Sports, Exercise, Daily Activity, Sedentariness, and Health Study. Dietary patterns were derived from principal component analysis of the consumption of 52 food and beverage items, which were assessed by a validated brief-type self-administered diet history questionnaire. Micronutrient intakes were quantified using the dietary reference intakes score (DRIs-score) for 21 micronutrients (based on DRIs-J 2015). The healthy dietary pattern score was significantly and positively correlated with the intakes of all 21 micronutrients used for constructing the DRIs-score in men and in women (each, p < 0.001). In both sexes, the healthy dietary pattern scores were strongly and positively associated with DRIs-scores (in men: ρ = 0.806, p < 0.001; in women: ρ = 0.868, p < 0.001), and the DRIs-scores reached a plateau around the highest tertile of the healthy dietary pattern score. These results indicate that a healthy Japanese dietary pattern is associated with adequate micronutrient intakes based on the DRIs-J 2015 in both men and women.

Here, we aim to investigate the independent and combined associations of serum 25-hydroxyvitamin D (25(OH)D) and cardiorespiratory fitness (CRF) with glucose metabolism. Fasting blood samples of 107 men aged 40–79 years were analyzed for 25(OH)D, glucose, insulin, glycated hemoglobin, and lipid profile. Homeostasis model assessment of insulin resistance index (HOMA-IR) was calculated from the fasting concentrations of glucose and insulin. Visceral fat area (VFA) was determined by magnetic resonance imaging and CRF by measuring maximal oxygen uptake. Median 25(OH)D concentration was 36.3 nmol/L, while the prevalence of 25(OH)D deficiency was 74.8%. Participants with high CRF had significantly lower HOMA-IR, glycated hemoglobin, and insulin values than participants with low CRF (p < 0.05). Higher 25(OH)D concentration was strongly correlated with lower HOMA-IR and insulin values independent of VFA (p < 0.01) but significantly affected by CRF. In the high CRF group, participants with higher 25(OH)D concentration had lower HOMA-IR values than participants with low 25(OH)D concentration (p < 0.05). Higher 25(OH)D and CRF are crucial for reducing insulin resistance regardless of abdominal fat. In addition, higher 25(OH)D concentration may strengthen the effect of CRF on reducing insulin resistance in middle-aged and elderly Japanese men with high CRF.