[Analysis of association between appendicular skeletal muscle mass index and main anthropometric parameters among overweight and obese adults in China].

Objective: To investigate the associations between the appendicular skeletal muscle mass index and main anthropometric parameters, and to provide clues for preventing the reduction of skeletal muscle mass among overweight and obese adults in China. Methods: 1 488 volunteered participants who resided in Beijing longer than one year, between 22 and 55 years old, with self-report BMI ≥24 kg/m(2) were recruited from April to May 2014. 171 participants whose BMI ≤24 kg/m(2) or with organic diseases at the first physical examination were excluded, finally 1 317 overweight/obese participants (male and female were 507, and 810, respectively) were enrolled into the present study. After measuring the anthropometric parameters and body composition by the DXA, Pearson correlation analysis and multiple linear regression models were used to analyze the associations between the appendicular skeletal muscle mass index and main anthropometric parameters. Results: The average age of males and females was (35.6±8.4) and (38.2±9.4) years old, respectively. The females' mean levels of body fat percentage, BMI, waist circumference, hip circumference, and bone mineral density were (41.59±4.14)%, (29.00±3.75) kg/m(2), (92.56±9.00) cm, (101.74±6.75) cm, and (1.20±0.10) g/cm(2), respectively; and the males' mean levels were (34.22±4.61)%, (30.07±4.12) kg/m(2), (99.63±9.49) cm, (102.93±7.28) cm, and (1.28±0.11) g/cm(2), respectively. The mean level of appendicular skeletal muscle mass and skeletal muscle mass index in males were (26.98±3.88), and (8.96±1.02) kg, respectively, which were significantly higher than it in females ((18.57±2.61), and (7.26±0.83) kg, respectively) ( P< 0.001). For male, the correlation coefficients of skeletal muscle mass index with BMI, waist circumference, hip circumference, body fat percentage and bone mineral density were 0.814, 0.601, 0.637, 0.558, and 0.434, respectively; for female, the correlation coefficients of skeletal muscle mass index with BMI, waist circumference, hip circumference, body fat rate and bone mineral density were 0.761, 0.534, 0.585, 0.610, and 0.304, respectively. The correlations were statistically significant ( P< 0.001). Multiple linear regression analysis showed that the skeletal muscle mass index of male decreased with the increase of age (β=-0.01, 95 %CI: -0.01-0.00) and body fat percentage (β=-0.13, 95 %CI: -0.15--0.12) ( P< 0.05), while increased with the increase of BMI (β=0.31, 95 %CI: 0.29-0.32) and bone mineral density (β=0.54, 95 %CI: 0.10-1.01) ( P< 0.05). The skeletal muscle mass index of female decreased with the increase of age (β=-0.01, 95 %CI: -0.01-0.00) and body fat percentage (β=-0.12, 95 %CI: -0.14--0.12) ( P< 0.05), while increased with the increase of BMI (β=0.26, 95 %CI: 0.25-0.28) and hip circumference (β=0.01, 95 %CI: 0.00-0.02) ( P< 0.05). Conclusion: The skeletal muscle mass index of male was higher than it of female. For male, the skeletal muscle mass index might be associated with age, BMI, body fat percentage and bone mineral density. While for female, the skeletal muscle mass index might be associated with age, BMI, body fat percentage and hip circumference.