Intensity Matters for Musculoskeletal Health: A Cross-Sectional Study on Movement Behaviors of Older Adults from High-Income Scottish and Low-Income South African Communities.

Ilaria Pina,Naomi E Brooks,Paul Dudchenko,Simone A Tomaz,Iain J Gallagher,Rachel Crockett,Angus M Hunter,Julia H Goedecke,Lisa K Micklesfield,Amy E Mendham

doi:10.3390/ijerph18084310

Abstract

This study aimed to investigate differences in physical activity (PA) patterns and the associations between objectively measured 24-h movement behaviors and musculoskeletal measures (muscle strength, muscle mass, physical performance, and bone mineral density) in a high-income and a low-income community. This cross-sectional study recruited independent living older adults aged 60–85 years from high-income Scottish (n = 150) and low-income South African (n = 138) settings. Participants completed demographic and health questionnaires, and testing included body composition and bone mineral density (dual energy X-ray absorptiometry), physical performance (grip strength, gait speed), and PA (accelerometry). Participants accumulated similar amounts of weekly total PA, however, the Scottish cohort engaged in more moderate-to-vigorous intensity PA (MVPA) and sedentary behavior (SB), while the South African cohort spent more time sleeping and in light intensity PA (LPA). From compositional data analysis, more time spent in MVPA relative to the other movement behaviors was positively associated with higher muscle mass (p < 0.001) and strength (p = 0.001) in the Scottish cohort. Conversely, more time spent in MVPA was associated with faster gait speed (p < 0.001) and greater hip bone mineral density (p = 0.011) in the South African cohort. Our findings confirm the beneficial role of MVPA in both high- and low-income cohorts, however, the relationship MVPA had with components of musculoskeletal health in older adults differed between settings.

Highlights

According to the most recent World Health Organization (WHO) recommendations for physical activity (PA), the threshold of 150 min of combined moderate-to-vigorous intensity PA (MVPA) was achieved by 51.4% of the Scottish cohort and 20.3% of the South African cohort
When adjusting the model for grip strength and Appendicular skeletal muscle mass (ASM) (Table 4), we found a positive association between relative time in MVPA and femoral neck bone mineral density (BMD); when gait speed was included as a covariate, the positive association with femoral neck BMD was no longer significant
We highlight the importance of the relative time spent in MVPA across the whole day on musculoskeletal health in older adults in both low- to middle-income countries (LMICs) and high-income countries (HICs)

Summary

Introduction

The number of older adults and years lived with disabilities is increasing worldwide [1]. Primary features of ageing include decreased bone and muscle health, which contribute to reduced quality of life and loss of mobility [2]. Decreased bone mass and changes in bone integrity are referred to as osteoporosis, a condition associated with greater fracture risk and reduced mobility [3]. Sarcopenia is a progressive and generalized skeletal muscle disorder that affects physical functionality and is identified by low muscle strength, along with decreased muscle mass [4].

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