[Effect of age on body composition in healthy Beijing women].

ABSTRACT

OBJECTIVE: To observe the effect of age and menstrual status on body composition in healthy Beijing women. METHODS: We measured body composition with dual-energy X-ray (GE Lunar Prodigy) in 316 healthy Beijing females aged 20 to 74 years (5-7 cases per age). Parameters provided by the software were as following total body bone mineral content, lean mass, fat mass and fat percentage (%fat). Local regions measured included arm, leg, trunk, android region and gynoid region. Body mass index (BMI), fat mass index (FMI), free fat mass index (FFMI) and A/G were calculated. Volunteers were assigned to 6 groups according age by every ten years a group. RESULTS: BMC peaked during the 4th decade, LM peaked during the 5th decade, with a decline of 18.1% and 5.2% respectively at age 74 years. Total body fat mass and %fat showed a general increase with aging throughout the studied age range. Total body fat mass increased from 16+/-5 kg at age 20-29 years to 24+/-6 kg at age 70-74 years, while %fat increased from 31.3% to 39.5%. All local region %fat increased with aging at different extents. Android region %fat showed the largest raise extent (32.2%). BMI increased gradually from 21.1 kg/m2 at age 20-29 years to 26.1 kg/m2 at age 70-74 years. FMI changed more obviously than FFMI. A/G increased from 0.85 at age 20-29 years to 1.02 at age 70-74 years. Different menstrual status in women of 40-59 years had obvious effect on A/G and BMC (P<0.05), while it had no significant effect on BMI, body weight and waist circumference (P>0.05). CONCLUSIONS: Aging and menstrual status have evident effect on body composition distribution in healthy Beijing women.