Vitamin D deficiency, self-reported physical activity and health-related quality of life: the Comprehensive Dialysis Study

Abstract

Background. As research has identified a wide array of biological functions of vitamin D, the consequences of vitamin D deficiency in persons with chronic kidney disease has attracted increased attention. The objective of this study was to determine the extent of 25-hydroxyvitamin D (25-OH vitamin D) deficiency and its associations with self-reported physical activity and health-related quality of life (HRQoL) among participants of the Comprehensive Dialysis Study (CDS). Methods. The nutrition substudy of the CDS enrolled patients new to dialysis from 68 dialysis units throughout the USA. Baseline 25-OH vitamin D concentration was measured using the Direct Enzyme Immunoassay (Immunodiagnostic Systems Inc.). Physical activity was measured with the Human Activity Profile (HAP); the Medical Outcomes Study Short Form-12 (SF-12) was employed to measure HRQoL. Results. Mean age of the participants (n ¼ 192) was 62 years. There were 124 participants (65%) with 25-OH vitamin D concentrations < 15 ng/mL, indicating deficiency, and 64 (33%) with 25-OH vitamin D! 15 to <30 ng/mL, indicating insufficiency. After adjusting for age, sex, race/ ethnicity, diabetes, season and center, lower 25-OH vitamin D concentrations were independently associated with lower scores on the HAP and on the Mental Component Summary of the SF-12 (P < 0.05 for both), but not with the Physical Component Summary of the SF-12. Conclusion. In a well-characterized cohort of incident dialysis patients, lower 25-OH vitamin D concentrations were associated with lower self-reported physical activity and poorer self-reported mental health.

Effects of Cholecalciferol on Functional, Biochemical, Vascular, and Quality of Life Outcomes in Hemodialysis Patients

“…Low 25(OH)D levels have been associated with reduced HRQOL in CKD-5D (19), but an earlier study that assessed only the Short Form-36 physical component score reported no effect after 6 months of ergocalciferol supplementation (39). In this study, HRQOL scores using the KDQOL-36 did not change significantly with treatment allocation.…”

“…Some of these actions may be mediated by local conversion of 25(OH)D to 1,25(OH) 2 D at target sites, including muscles, blood vessels and parathyroid glands (14,15). This could explain associations described in CKD-5D, between 25(OH)D levels and pulse wave velocity (PWV), a surrogate for vascular calcification (16), bone mineral density (17), early mortality on dialysis (6), muscle strength, falls risk, and quality of life (18,19).…”

Low 25-Hydroxyvitamin D Levels and Cognitive Impairment in Hemodialysis Patients

“…In dialysis patients, there are very few data relating 25(OH)D levels to cognitive function. In one large study of incident dialysis patients, lower 25(OH)D levels were associated with lower self-reported physical activity and self-reported mental health in adjusted analyses (28).…”

Comparison of vitamin D deficiency in Saudi married couples

“…Similarly, Ardawi et al 20 found that sedentary life and lack of physical activity are associated with lower levels of vitamin D. Nonetheless, it is not clear whether the physical activity is a factor that leads to increases in vitamin D level, or conversely it is vitamin D that improves physical activity. In fact, studies of dialysis patients 25,26 and older frail people 27,28 demonstrated an amelioration of the abilities of physical exertion, and subsequently improved the quality of life of these persons. Such a reciprocal relation cannot be disentangled in cross-sectional or retrospective designs, and needs prospective research.…”