Sonographically Assessed Intra-Abdominal Fat And Cardiometabolic Risk Factors in Adolescents with Extreme Obesity

OBJECTIVE: The metabolic and cardiovascular risk of obesity is predominantly defined through the amount of intra-abdominal fat (IAF). Regarding this risk and the benefits of weight reduction gender-specific differences have been described. The aim of this study was to examine the gender-specific relationship between IAF assessed via ultrasound and the cardiometabolic risk profile in extremely obese adolescents before and after weight loss. METHODS: In 107 consecutively admitted adolescents (n = 59 girls, mean age 15.4 ± 2.6 years boys and 15.1 ± 2.1 years girls, mean BMI z-score 3.2 ± 0.6 boys and 3.5 ± 0.6 girls) anthropometric and fasting laboratory chemical parameters were measured before and after an in-patient long-term therapy (mean durance 5.6 ± 2.3 months). IAF was determined by measuring the intra-abdominal depth (IAD) via ultrasound. RESULTS: IAD was higher in boys as compared to girls (58.0 ± 22.4 mm vs. 51.3 ± 16.0 mm). IAD values were positively associated with BMI-z scores, waist circumferences, HOMA-IR and serum levels of γGT, hs-CRP and IL-6 in both genders. In boys, but not in girls, IAD was significantly correlated with systolic and diastolic blood pressure, serum levels of triglycerides, ALT as well as adiponectin and HDL-cholesterol. After a marked mean weight loss of −27.1 ± 16.2 kg (−20.1 ± 7.9%) in boys and of −20.5 ± 11.5 kg (−17.3 ± 7.1%) in girls, IAD decreased by −20.7 ± 16.2 mm (−-32.4 ± 16.9%) in boys and by −18.4 ± 12,7 mm (−34.3 ± 18.4%) in girls, resulting in more pronounced ameliorations of cardiovascular risk factors in boys than in girls. CONCLUSIONS: The present study indicates that IAF assessed by ultrasound is a good indicator for the cardiometabolic risk factor profile in extremely obese adolescents. Associations between IAF and risk factors are more pronounced in boys than in girls.