Abstract:

Objective To analyze the changing characteristics with age of bone strength and body composition in Gansu Yugur adults and to explore the correlation. Methods From July 2015 to August 2016, a total of 725 Yugur adults in Yugur autonomous county of Gansu province were selected by the stratified random sampling method and their bone strength and body composition indexes were measured by an ultrasonic bone mineral density meter and body composition analyzer respectively. Results The bone strength in Yugur male adults was lower than in female adults in 20-29 age group (P<0.05), and it was higher than female adults after 50 years old (P<0.01). The muscle mass of males in each age group was higher than females (P<0.01). Total fat mass and subcutaneous fat mass in males were lower than in females in each age group (P<0.01). Visceral fat mass in males were lower than in females in 20-29 age group and after 70 years old (P<0.01). The bone strength peak in Yugur male and female adults was 30-39 and 20-29 age group respectively. The bone strength in males and females decreased after 40 and 30 years old respectively, and there had been significant difference than before from 50-59 and 40-49 age group respectively (P<0.05). It was lower than foregoing groups after 70 years old and 50 years old respectively (P<0.01). The double peaks of total, trunk and limbs muscle mass in males were in 40-49 and 60-69 age group, and one peak in females was in 40-49 age group. The peaks of fat mass in parts of body in male and female adults were 60-69 and 50-59 age group respectively. Bone strength was positively correlated with limbs muscle mass and subcutaneous fat mass (P<0.01), and negatively correlated with visceral fat mass (P<0.01) by multiple linear stepwise regression analysis. Conclusion There is synchronous change of body composition in parts of body of Gansu Yugur adults with age, and female bone strength decrease earlier and faster than males. The bone strength of Gansu Yugur adults is determined by muscle and fat mass, and associated with the distribution of them. Gansu Yugur males over 70 years old and females over 50 years old are the focus of prevention and treatment for Osteoporosis, and the male adults after 50 years old and female adults after 40 yeas old should strengthen the exercise, increase limbs muscle mass, and cut down visceral fat for osteoporosis prevention.

Key words: Gansu, Yugur, Bone strength, Body composition, Bioelectrical impedance analysis method, Adult