Longitudinal Study on the Progression of Muscle Status Among Community-Dwelling Ambulatory Older Multiethnic Asians With Type 2 Diabetes Mellitus
Abstract Background:Muscle health decline with age, but its deterioration in older persons with type-2 diabetes mellitus (T2DM) over time is not well-established. This study aimed to determine the change in muscle mass, grip strength and gait speed over a period of observation among community-dwelling ambulatory older multi-ethnic Asian patients with T2DM and their associated factors.Methods:Among 387 eligible patients aged 60-89 years who were recruited at baseline, 348 (89.9%) were reviewed at a public primary care clinic in Singapore in the subsequent 9 to 34 months. The change in their clinical and functional status, levels of physical activity and muscle status (mass, grip strength and gait speed based on the Asian Working Group for Sarcopenia criteria) were recorded and compared. Their physical activity levels were assessed using the Physical Activity Scale for the Elderly (PASE) and International Physical Activity Questionnaire (IPAQ). Their quality of life was evaluated based on the World Health Organization Quality of Life (WHOQOL) domains. Linear regression analysis was used to identify the factors associated with muscle health change.Results:The study population comprised men (52.9%), Chinese (69.3%), Malay (15.5%), Indian (8.6%), mean age of 68.4±SD5.6 years and had at least secondary education (76.4%). Overall, their mean muscle mass significantly decreased by 0.7±SD1.2kg/m2, mean grip strength by 1.0±SD4.6kg and negligible change in gait speed. Their mean weight significantly decreased by 0.5±SD3.9kg, waist and hip circumferences by 2.5±SD6cm and 3.2±SD5.1cm respectively, with no change in BMI. Linear regression shows significant associations between muscle mass and education level (β=0.29, p=0.040, 95%CI=0.01-0.56), BMI (β=0.10, p=0.001, 95%CI=0.04-0.16) and review interval (β=-0.003, p<0.001, 95%CI=-0.004--0.002); gait speed is associated with singlehood (β=-0.12, p=0.035, 95%CI=-0.23--0.01) and WHOQOL physical health (β=0.01, p=0.028, 95%CI=0.00-0.02) domain. No factor is associated with hand grip strength change.Conclusions:The study population showed significant decline in their mean weight, waist and hip circumferences, mean muscle mass and mean grip strength but gait speed was unaffected. Muscle mass change was associated with education level, BMI and length of review interval. Grip strength was not correlated with any significant factor. Gait speed was associated with singlehood and physical health.