Background: IRS consists of ≥3 of the following components: obesity (BMI >98th centile), abnormal insulin glucose homeostasis, hypertension, dyslipidaemia. Elevated serum alanine aminotransferase (ALT) is a marker of NAFLD.
Objective: To define the prevalence of IRS and NAFLD in obese children referred to our centre.
Methods: subjects: mean BMI-SDS +6 (+0.6 to +14), median age 13.4 years (319), female 66%, British Asian 24%, underwent an oral glucose tolerance test with results categorised by WHO criteria: impaired fasting glucose (IFG), impaired glucose tolerance (IGT), T2DM. Fasting hyperinsulinaemia (FH) and 120 minute hyperinsulinaemia (HI) were defined >26 and >95 mIU/l respectively. HOMA-IR was calculated (normal <2.5). Fasting lipids were measured in 42, ALT in 29 and blood pressure in 24. Abnormalities were defined: cholesterol > 95th centile for age and sex, triglycerides ≥ 1.75 mmol/l, ALT>45 IU/l, systolic BP> 95th centile for age and sex.
Results: Abnormalities of glucose and insulin homeostasis were observed in: IFG 4%, IGT 13%, T2DM 6% (only one child with IGT was identified with IFG), HOMA-IR >2.5 78%, FH 42%, HI 38% and acanthosis nigricans 40%. British Asians were more likely than British White to have acanthosis nigricans (OR 4.1, 95%CI 1.312.7). Elevated lipids, ALT and BP were identified in 33.5% (cholesterol 9.5%, triglycerides 24%), 42% and 54% respectively. BP was correlated with BMI (r2 =0.17, P=0.05) and HOMA-IR contributed 16% to the variance of ALT (P=0.04). Controlling for age and puberty, HOMA-IR was determined by female sex (P=0.002), acanthosis nigricans (P=0.002) and BMI-SDS (P=0.04). 36% had obesity alone, 43% had 2 components IRS and 21% had ≥3 components IRS. The number of components of IRS was determined by increasing age (P=0.03) and family history of T2DM (P=0.02).
Conclusion: In obese children, female sex, British Asian background, increasing age and family history of T2DM appear to be risk factors for IRS. Increased insulin resistance was observed in children with NAFLD.
01 - 05 Apr 2006
European Society of Endocrinology