|Van Der Heijden, Gert Jan|
Submitted to: Pediatric Academic Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2008
Publication Date: 5/4/2008
Citation: Van Der Heijden, G., Wang, Z.J., Sunehag, A.L. 2008. In Hispanic, obese adolescents, a controlled aerobic exercise program reduced visceral and hepatic fat and improved insulin sensitivity, while resistance training only increased lean body mass [abstract]. Pediatric Academic Societies. Abstract No. 4660.4. Available: http://www.abstracts2view.com/pasall/index.php. Interpretive Summary:
Technical Abstract: Adolescent obesity is a serious public health concern. Aerobic and/or resistance exercise are potential strategies to improve metabolism, but data are scarce on the effects of well-controlled exercise programs in adolescents. Our objective was to test the hypothesis that a 12-wk controlled aerobic or resistance exercise program without intent to weight loss reduces fat accumulation and insulin resistance in sedentary Hispanic adolescents. Thirteen Hispanic obese subjects, 5m/8f; 15+/-1y; 33+/-2kg/m2; 38+/-2% body fat (DXA) (mean+/-SE) and 8 Hispanic lean controls, 5m/3f; 16+/-1y; 22+/-1kg/m2; 22+/-2% body fat, completed a controlled 12-wk aerobic exercise program (30 min x 4/wk at 80% of VO2max). Six Hispanic obese subjects, 3m/3f; 16+/-1y; 36+/-1kg/m2; 38+/-2% body fat, completed a controlled 12-wk resistance training program (60 min x 2/wk; all muscle groups). Obese and lean subjects had equal (normal) blood glucose, but the obese had significantly higher fasting insulin, HOMA, leptin, CRP, and ALT and greater total (DXA), visceral (MRI) and hepatic (MRS) fat content. With aerobic exercise, VO2max increased in all subjects (p<0.01). In obese subjects, body weight was unchanged (as intended), but visceral and hepatic fat content decreased significantly. Five of 13 had hepatic steatosis (MRS fat/water peak >5%). In these subjects, hepatic fat decreased from 21+/-7 to 12+/-4% (p<0.05) and ALT decreased from 47+/-8 to 41+/-8 U/L (p<0.05). While plasma glucose was unchanged, fasting insulin and HOMA decreased by 16% (p<0.01). The change in fasting insulin was directly related to the decrease in visceral fat (R2=0.47; p<0.01). Leptin, Adiponectin, and CRP were unchanged. In lean controls, visceral fat decreased by 13% (p<0.05) and fasting insulin by 10% (p<0.05) (at unchanged glucose). Hepatic fat was <5% (MRS) and ALT normal in all subjects and did not change. With resistance exercise, lean body mass increased by 5%, p<0.01. Insulin was 24+/-3 (pre) vs. 21+/-3 microU/mL (post exercise) (p=0.2); 4 of 6 subjects had hepatic steatosis, 17+/-7(pre) vs. 18+/-7% (post) (MRS) and ALT 38+/-7 vs. 47+/-7 U/L, i.e., no improvement. An aerobic exercise program might be a useful tool to reduce insulin resistance and hepatic steatosis in Hispanic obese adolescents. In contrast, in a small group of obese Hispanic adolescents, a resistance training program providing an equal amount of exercise did not have any significant metabolic effects.