Nature and Science of Sleep (Nov 2020)
Associations of OSA and Nocturnal Hypoxemia with Strength and Body Composition in Community Dwelling Middle Aged and Older Men
Abstract
David Stevens,1 Sarah Appleton,1– 3 Andrew D Vincent,4,5 Yohannes Melaku,1 Sean Martin,3,4 Tiffany Gill,4 Catherine Hill,4,6 Andrew Vakulin,1,7 Robert Adams,1,2,8 Gary Wittert2,3,5 1Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia; 2The Health Observatory, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia; 3Freemason Foundation Centre for Men’s Health, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia; 4Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia; 5Centre of Nutrition and Gastrointestinal Diseases, Nutrition Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia; 6Rheumatology Unit, The Queen Elizabeth Hospital and the Royal Adelaide Hospital, Central Adelaide Local Health Network, Adelaide, SA, Australia; 7Sleep and Circadian Research Group, Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia; 8Respiratory and Sleep Services, Southern Adelaide Local Health Network, Adelaide, SA, AustraliaCorrespondence: David StevensAdelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Level 2a, 5 Laffer Drive, Bedford Park, Adelaide, SA 5042, AustraliaTel +61 8 7221 8306Email [email protected]: Reduced hand grip strength (HGS) is associated with poorer health in chronic conditions, yet there has been little research examining the association with hand grip strength and obstructive sleep apnea (OSA). Further, these studies have not examined, nor adjusted, for muscle mass. The aim of this study was to determine associations between OSA indices, HGS, muscle mass, and fat mass.Participants and Methods: A total of 613 participants (age range 41– 88, BMI 28.6 ± 4.3) from the population-based Men Androgen Inflammation Lifestyle Environment and Stress Study underwent in-home overnight polysomnography, assessment of dominant and non-dominant HGS, and dual x-ray absorptiometry to determine whole body muscle mass and fat mass. Linear models determined cross-sectional associations of polysomnographic-derived OSA indices with hand grip strength, muscle mass, and fat mass, whilst adjusting for lifestyle information (income, smoking status, diet, self-reported physical activity), blood sample derived testosterone and systemic inflammation (C-reactive protein), cardiometabolic health (cardiovascular disease, hypertension, type 2 diabetes), and depression.Results: In adjusted models, reduced dominant HGS was associated with lower oxygen nadir (unstandardised β [B] = 0.19, 95% confidence interval [CI] 0.08 to 0.29), greater time spent below 90% oxygen saturation (B = − 0.08, 95% CI − 0.14 to − 0.02), and increased apnea duration (B = − 0.3, 95% CI − 0.23 to − 0.02). By contrast, there were no associations between HGS and both AHI and REM AHI. Fat mass was consistently associated with worsening OSA indices, whereas muscle mass demonstrated no associations with any OSA index.Conclusion: Our findings suggest impairments in HGS may be related to fat infiltration of muscle, hypoxemia-induced reductions in peripheral neural innervation, or even endothelial dysfunction, which is a common outcome of hypoxemia. Longitudinal data are needed to further examine these hypotheses and establish if reduced grip strength in patients with OSA is associated with long-term adverse health outcomes.Keywords: grip strength, muscle mass, intermittent hypoxemia, myosteatosis
