Abstract
We aimed to investigate whether sarcopenia and its components are associated with osteoporosis in community-dwelling older Chinese adults with different obesity levels. This cross-sectional study included 1938 participants (42.1% male) with a mean age of 72.1 ± 5.9 years. The categorization of individuals into various weight categories was based on the Working Group on Obesity in China's criteria, utilizing the body mass index (BMI) as follows: underweight, BMI < 18.5 kg/m2; normal weight, 18.5 ≤ BMI < 24 kg/m2; overweight, 24 ≤ BMI < 28 kg/m2; and obesity, BMI ≥ 28 kg/m2. In this research, the osteoporosis definition put forth by the World Health Organization (bone mineral density T-score less than or equal to -2.5 as assessed by Dual-energy X-ray absorptiometry (DXA)). Sarcopenia was defined according to the diagnostic criteria of the Asian Working Group for Sarcopenia. The prevalence of osteoporosis was highest in the underweight group and gradually decreased with increasing BMI (Underweight: 55.81% vs Normal weight: 45.33% vs Overweight: 33.69% vs Obesity: 22.39). Sarcopenia was associated with elevated odds of osteoporosis in normal-weight subjects independent of potential covariates (OR = 1.70, 95% CI = 1.22-2.35, P = .002). In normal-weight participants, a higher appendicular skeletal muscle mass index (ASMI) was associated with a reduced risk of osteoporosis (OR = 0.56, 95% CI = 0.42-0.74, P < .001). In this study, we found that the prevalence of osteoporosis was highest in the underweight group and gradually decreased with increasing BMI. Sarcopenia, body fat percentage, and ASMI were associated with elevated odds of osteoporosis in normal-weight subjects independent of potential covariates, and higher percent body fat (PBF) was associated with an increased risk of osteoporosis in overweight people, and no such association was found in other weight groups. Different amounts of adipose tissue and muscle mass may alter bone biology. Further longitudinal follow-up studies are required to more accurately assess the risk of osteoporosis and sarcopenia in different weight populations. This cross-sectional study found that the prevalence of osteoporosis was highest in the underweight group and gradually decreased with increasing BMI. Sarcopenia was associated with elevated odds of osteoporosis in normal-weight subjects independent of potential covariates.