Prevalence of sarcopenia and associated factors among Thai population.

The purpose of this study was to determine the prevalence of sarcopenia using the skeletal muscle index (SMI) criteria in the Thai population. The secondary objective was to demonstrate factors influencing low SMI in this population. Femoral neck bone mass density (BMD) was measured by dual-energy X-ray absorptiometry (GE Lunar, Madison, WI, USA) in 435 urban and 397 rural subjects (334 men and 498 women) between 20 and 84 years of age. Body mass index (BMI) was calculated from weight and height. The respective prevalence of sarcopenia among men and women was 35.33 % (95 % CI, 29.91, 40.41) and 34.74 % (95 % CI, 30.56, 39.10). Factors associated with sarcopenia using multiple logistic regression analyses in both sexes were (a) living in the city, (b) higher BMI, and (c) older age. Living in an urban area was the strongest factor, with an odds ratio (OR) of 17.26 ± 7.12 (95 % CI, 7.68, 38.76) in men and 8.62 ± 2.74 (95 % CI, 4.62, 16.05) in women (p < 0.05). The prevalence rate ratio for persons living in urban compared to rural areas was 2.01 (95 % CI, 1.14, 3.53) in men and 1.69 (95 % CI, 1.31, 2.17) in women (p < 0.05). Sarcopenia, as based on SMI, occurs frequently in the Thai population and increases with age. The prevalence of sarcopenia is particularly high among pre-retirement women (50-59 years of age) whereas the number of men with sarcopenia gradually rises with age. An urban environment is the most predictive factor for sarcopenia, followed by high BMI and age. Given the aging population, early recognition of this condition can be beneficial for prevention of an epidemic of sarcopenia-related disability.