Relationship between handgrip strength and albuminuria in community-dwelling elderly Japanese subjects: the Shika Study.

PURPOSE: This study aimed to investigate the association between handgrip strength (HGS) and albuminuria in the general population of Japan as per sex and age. METHODS: This population-based, cross-sectional study enrolled 916 Japanese participants aged ≥40 years. Albuminuria was measured and expressed as the urinary albumin-to-creatinine ratio (UACR). Biochemical, nutritional, and anthropometric profiles as well as HGS were measured using standardised protocols. RESULTS: Four hundred and thirty-two (47%) of the study participants were men, and 484 were women, with respective mean ages of 62 ± 11 years and 63 ± 11 years. HGS, older age, high body mass index, presence of hypertension or diabetes, and a decreased estimated glomerular filtration rate were correlated with the log-transformed UACR in subjects of both sexes. Multivariate linear regression analysis showed that HGS was independently associated with the log UACR in both, men [beta coefficient -0.43; 95% confidence interval (CI) -0.73, -0.13] and women (beta coefficient -0.50; 95% CI -0.90, -0.10) aged ≥65 years; however, a similar association was not observed in younger participants. CONCLUSION: Low HGS was associated with albuminuria in older men and women in Japan.

Association Between Serum 25-Hydroxyvitamin D Concentrations and Chronic Pain: Effects of Drinking Habits.

PURPOSE: Although the explanation for inconsistencies in the reported association between serum 25-hydroxyvitamin D [25(OH)D] levels and chronic pain (CP) has not yet been determined, understanding this discrepancy is necessary for the development of vitamin D supplementation as an effective treatment for CP. The aim of this cross-sectional study was to examine the relationship between 25(OH)D concentrations and CP according to drinking habits in Japanese subjects. PATIENTS AND METHODS: We distributed invitation letters to 2314 individuals older than 40 years in Shika town, a rural area in Japan, and 724 subjects (386 females; mean age: 63.9 ± 10.4 years) were recruited. CP was defined as persistent pain lasting at least 3 months in any part of the body. Serum concentrations of 25(OH)D, a biomarker of the vitamin D status, were measured using a radioimmunoassay. A serum 25(OH)D level <20 ng/mL was defined as serum 25(OH)D deficiency. Drinking habits were assessed using a self-administered questionnaire. There were three choices, "rarely drink", "sometimes" and "everyday". Respondents who answered "rarely drink" were labelled as non-drinkers and the others as drinkers. RESULTS: The prevalence of CP was 40.6%. A significant interaction between CP and drinking habits on 25(OH)D concentrations was observed (p = 0.098). A one-way analysis of covariance was performed to compare 25(OH)D concentrations between the subjects with and without CP in each drinking group, and the serum 25(OH)D levels of subjects with CP were significantly lower than those without CP among drinkers (p = 0.007). A logistic regression analysis revealed a correlation between serum 25(OH)D deficiency and CP in drinkers after adjustments for several confounding factors (odds ratio: 0.499; 95% confidence interval: 0.268 - 0.927; p = 0.028). CONCLUSION: The present results suggest that low serum 25(OH)D concentrations are associated with the development of CP in drinkers.

Dietary Calcium Intake and Hypertension: Importance of Serum Concentrations of 25-Hydroxyvitamin D.

The relationship among dietary calcium, hypertension and vitamin D status currently remains unclear. This population-based cross-sectional study examined the association between dietary calcium intake and hypertension and the influence of serum concentrations of 25-hydroxyvitamin D [25(OH)D] in Japanese subjects. A total of 619 subjects aged from 40 years were recruited. Dietary intake was measured using a validated brief self-administered diet history questionnaire. Hypertension was defined as the use of antihypertensive medication or a blood pressure of 140/90 mmHg. Serum concentrations of 25(OH)D were used as the biomarker of vitamin D status. The prevalence of hypertension and low serum 25(OH)D levels (<20 ng/mL) were 55 and 32%, respectively. Dietary calcium intake inversely correlated with hypertension in subjects with serum 25(OH)D levels higher than 20 ng/mL (OR: 0.995; 95% CI: 0.991, 0.999) but it was not significant in those with serum 25(OH)D levels of 20 ng/mL or lower. Furthermore, dietary vitamin D intake correlated with serum concentrations of 25(OH)D after adjustments for various confounding factors. The present results demonstrate that the regular consumption of calcium may contribute to the prevention and treatment of hypertension in subjects with a non-vitamin D deficiency and also that dietary vitamin D intake may effectively prevents this deficiency.