Is vitamin D deficiency and insufficiency risk factors for the incidence of dinapenia in individuals aged 50 years and over?

Abstract

The aging process is marked by multiple bodily and neurophysiological changes that may cause a decrease in the neuromuscular force, which we call dynapenia. This mechanism contributes to the limitation of mobility, slowness of gait and deterioration of balance, which, together with other aspects of aging, negatively impact functional capacity and corroborate the increase in adverse outcomes. Numerous studies on the role of vitamin D (25(OH)D) in the human body have been developed, but interest has intensified after the discovery of the expression of specific vitamin D receptor (VDR) receptors in muscle cells. Although studies indicate that the expression of VDR in muscle decreases significantly with age, little is known about the effect of 25(OH)D on the incidence of dynapenia in individuals over 50 years of age. Objective: To verify whether 25(OH)D deficiency and insufficiency are risk factors for the incidence of dynapenia in individuals over 50 years of age in a four-year follow-up period. Methods: This is a longitudinal prospective study that will analyze data from the English Longitudinal Study of Aging (ELSA Study), part of the InterCoLAging (International Collaboration of Longitudinal Study of Aging) coordinated by the counselor of this proposal. The baseline will be the sixth wave of the study (2012-2013) with a sample of 9.169 individuals aged 50 and over, at which time 25(OH)D was collected for the first time and which, for our analyzes, will be considered in three strata (deficiency <30 nmol/L, insufficiency of 30 to 75 nmol/L and sufficiency> 75 nmol/L). Only those individuals with manual grip strength (FPM) e 26 Kg for men and e 16 kg for women, without the outcome in question, will be included for the incidence analysis. The incidence of dynapenia (FPM <26 kg for men and <16 kg for women) will be assessed in the eighth wave of the study, after four years of follow-up. Incidence densities will be calculated for the three 25(OH)D strata and, later, models of logistic regression and Poisson will be performed. The models will be adjusted by sociodemographic, behavioral and clinical variables. Expected results: The incidence of dynapenia is expected to be higher in individuals with 25(OH)D deficiency and insufficiency. (AU)