Central obesity is associated with lower prevalence of sarcopenia in older women, but not in men: a cross-sectional study.

Background: Obesity is a chronic disease that causes various medical health problems, increases morbidity, and reduces the quality of life. Obesity (especially central obesity) in older adults is expected to act with the development of sarcopenia. However, the relationship between obesity, central obesity, and sarcopenia remains controversial. This study aimed to investigate the impact of obesity on sarcopenia.

Methods: In this cross-sectional study, we used data from the Korean Frailty and Aging Cohort Study; 1,827 community-dwelling older adults (883 men and 944 women) aged 70-84 years were recruited. The Asian Working Group for Sarcopenia (AWGS) criteria were used to evaluate sarcopenia. Subjects with a low appendicular skeletal muscle mass index (ASMI; men: < 7.0 kg/m, women: < 5.4 kg/m) and either low handgrip strength (HGS; men: < 28 kg, women: < 18 kg) or low Short Physical Performance Battery (SPPB; ≤ 9) were diagnosed with sarcopenia. Obesity was defined as a body mass index (BMI) of ≥ 25 kg/m, while central obesity was defined as WC measurements of ≥ 90 cm in men and ≥ 85 cm in women. Logistic regression analyses were performed to evaluate the impact of obesity and central obesity on sarcopenia and the parameters of sacropenia.

Results: In both sexes, the obese group, defined based on the BMI, had a significantly low prevalence of low ASMI (odds ratio [OR] = 0.14, 95% confidence interval CI = 0.10-0.20 in men, OR = 0.17, 95% CI = 0.12-0.25 in women) and sarcopenia (OR = 0.28, 95% CI = 0.16-0.50 in men, OR = 0.17, 95% CI = 0.08-0.35 in women) in the multivariable logistic regression analysis. In women, the central obese group had a low prevalence of sarcopenia (OR = 0.46, 95% CI = 0.27-0.77) in the multivariable logistic regression analysis. Meanwhile, the obese group had a significantly higher prevalence of low SPPB in women (OR = 1.75, 95% CI = 1.18-2.59).

Conclusions: Obesity may have a protective effect on low ASMI and sarcopenia, as defined by the AWGS criteria. Central obesity was associated with a low prevalence of sarcopenia in women only. However, obesity did not have a positive impact on functional parameters of sarcopenia including muscle strength and physical performance.