The effects of changes in body mass and subcutaneous fat on the improvement in metabolic risk factors in obese children after short-term weight loss

The pattern of subcutaneous fat (SAT) is related to metabolic risk factors in obese children. Because weight loss improves the risk-factor profile, we sought to determine whether changes in SAT or SAT-pattern contribute to th e improvement in the risk-factor profile after 3 weeks of a low-calorie die t and physical activities. In 22 obese boys (mean age, 11.9 years) and 40 o bese girls (mean age, 12 years), fat mass (by means of impedance) and fat d istribution (waist and hip circumference) were assessed. The thickness of 1 5 different subcutaneous adipose tissue layers (SAT-layers) was measured us ing a Lipometer (Moeller Messtechnik, Graz, Austria). SAT and SAT-pattern ( arm-SAT, trunk-SAT, leg-SAT) were calculated. Blood samples were taken for the determination of insulin, glucose, triglycerides, and cholesterol. Afte r 3 weeks, fat mass, waist and hip circumference, SAT, arm-SAT, trunk-SAT ( all P < .0001), and leg-SAT (P < .01) were reduced. Besides glucose, metabo lic parameters were lowered (all P < .001) but changes in metabolic paramet er were interrelated in boys and girls. Age- and sex-adjusted regression re vealed that changes in body mass contributed to the variability in changes of insulin (adjusted R-2 =.15, P =.0015). For the change in triglycerides, changes in cholesterol together with subtle alterations in glucose and chan ges in leg-SAT were found to be the main determinants (adjusted R-2 =.587, P < .0001). The results indicate that the change in the atherogenic and met abolic risk factor profile is largely independent from the concomitant loss in SAT. The reduction in body mass explained only a small part of the vari ability in changes of insulin, but leg-SAT might participate in the lowerin g of triglycerides, especially in boys. The contribution of SAT-pattern to the risk factor profile is an issue that needs further investigation. Copyr ight (C) 2001 by W.B. Saunders Company.