Effect of gender on intra-abdominal fat in teenagers and young adults

Abstract

Adult men accumulate greater intra-abdominal fat (IAF) than adult women, a difference closely related to gender differences in cardiometabolic disease risk in the elderly. However, the time when this gender difference appears is a matter of controversy. We examine the influence of gender on IAF deposition in lean, overweight and obese teenagers and young adults. We measured subcutaneous abdominal fat (SAF) and IAF in 505 healthy sexually mature teenagers and young adults (254 males, 251 females; 15-22 years) using a single CT scan at the level of the umbilicus. Regardless of body size, young females had greater SAF values than young males. Although lean females had higher IAF values than lean males (13.7 ± 7.8 vs. 11.2 ± 5.4; P = 0.001), overweight and obese females and males had strikingly similar IAF values (23.4 ± 11.1 vs. 23.1 ± 9.5; P = 0.88 and 36.5 ± 20.4 vs. 38.8 ± 13.2; P = 0.59, respectively). In contrast, the ratio of IAF/SAF was greater in males than females, except in the very obese. Multiple regression analysis indicated that while gender was a strong predictor of SAF in lean and overweight subjects (P's < 0.0001), it did not influence IAF after adjusting for height and weight (P = 0.35 and 0.65, respectively) in overweight and obese subjects. Overweight and obese young women have similar absolute amounts of IAF as young men.