Vitamin D Status, Muscle Strength and Physical Performance Decline in Very Old Adults: A Prospective Study.

Antoneta Granic,Mario Siervo,Ashley Adamson,Avan Sayer,John Mathers,Thomas Kirkwood,Karen Davies,Tom Hill,Carol Jagger

doi:10.3390/nu9040379

Abstract

Mixed reports exist about the role of 25-hydroxyvitamin D (25(OH)D) in muscle ageing and there are few prospective studies involving the very old (aged ≥ 85) who are at highest risk of low 25(OH)D, loss of muscle mass and strength, and physical performance decline. In the Newcastle 85+ Study (n = 845), we aimed to determine the association between 25(OH)D season-specific quartiles (hereafter SQ1–SQ4), grip strength (GS) and physical performance decline (Timed Up-and-Go Test, TUG) over 5 years using mixed models. In the time-only models with linear and quadratic slopes, SQ1 and SQ4 of 25(OH)D were associated with weaker GS initially in men (SQ1: β (SE) = −2.56 (0.96); SQ4: −2.16 (1.06)) and women (SQ1: −1.10 (0.52); SQ4: −1.28 (0.50)) (all p ≤ 0.04). In the fully adjusted models, only men in SQ1 had a significant annual decline in GS of 1.41 kg which accelerated over time (−0.40 (0.1)), (both p ≤ 0.003) compared with those in combined middle quartiles. Only women in SQ1 and SQ4 of 25(OH)D had worse TUG times initially, but the rate of TUG decline was not affected. Low baseline 25(OH)D may contribute to muscle strength decline in the very old and particularly in men.

Highlights

A number of recent epidemiological studies have indicated a role of serum 25-hydroxyvitamin D (25(OH)D) in the aetiology of health outcomes of older adults beyond skeletal health [1], includingNutrients 2017, 9, 379; doi:10.3390/nu9040379 www.mdpi.com/journal/nutrientsNutrients 2017, 9, 379 cognitive impairment [2,3], cancers, cardiovascular diseases [4,5], mortality [6], muscle weakness, gait disturbances and falls [7,8]
The aim of this study was to investigate the association between 25(OH)D concentration and muscle strength and physical performance (Timed Up-and-Go Test, TUG) in very old adults over 5 years and to test the hypothesis that these may be non-linear relationships
We considered the following confounders previously established in this cohort [42] and commonly reported in the literature in association with muscle strength and physical performance in older adults [43,44,45,46,47]

Summary

Introduction

Nutrients 2017, 9, 379 cognitive impairment [2,3], cancers, cardiovascular diseases [4,5], mortality [6], muscle weakness, gait disturbances and falls [7,8]. Identifying factors such as serum 25(OH)D [9] which may help to maintain or improve muscle strength, function, and physical performance into an advanced age in order to preserve independence, is potentially of considerable public health importance. Functional in vitro studies, have provided insights into the direct biological role of the active form of 25(OH)D, 1,25(OH2)D in regulation of genes and signalling pathways affecting calcium homeostasis, proliferation and differentiation of muscle cells [9], and positive correlation between 25(OH)D3 and expression of 24 muscle genes at the mRNA level [13]

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