The Association Between Hypovitaminosis D Status with Muscle Strength and Functional Capacity in a Brazilian Community-Dwelling Elderly Population: A Cross- Sectional Study

Abstract

Background: Although there have been studies on the association between hypovitaminosis D status with muscle strength and functional capacity, there were few studies on Brazilian community-dwelling elderly population. Therefore, this study aims to assess the association of hypovitaminosis D with muscle strength and functional capacity in a sample Brazilian community-dwelling elderly population.Methods: An analytical, cross-sectional observational study with a convenience sample was conducted. The 25(OH)D levels were assessed using an enzyme-linked fluorescent assay and classified according to the standardization of the Brazilian Society of Clinical Pathology/Laboratory Medicine. Hand grip strength (HGS) and isometric quadriceps strength (IQS) were measured using manual Jamar® and Lafayette® 01165 dynamometers, respectively. Functional capacity was evaluated using the Short Physical Performance Battery (SPPB). Multiple linear regression models were used to assess the association of hypovitaminosis D with the HGS, IQS, and SPPB score via the Enter method. The models were adjusted for age, sex, presence of pain, level of physical activity, and use of vitamin D supplementation. Results: A total of 150 elderly individuals (age: 67.18±5.33 years) were included. According to the 25(OH)D levels, 60.7% had hypovitaminosis D (insufficient: 48%, deficient: 12.7%), and 39.3% had sufficient levels. No associations were found between hypovitaminosis D and the HGS (p=0.84), LogIQS (p=0.462), and SPPB score (p=0.617). In the regression model, the influence of the vitamin D levels on functional capacity was not significant, demonstrating no association between them.Conclusion: Hypovitaminosis D was not associated with decreased muscle strength and functional capacity in the sample Brazilian community-dwelling elderly population. Longitudinal studies with measurement of the time of use and levels of vitamin D are encouraged.