ESPE Abstracts

Background: Impaired glucose tolerance ((IGT), glucose ≥140mg/dl at 120’ in the oral-glucose-tolerance-test (OGTT)) is prevalent in childhood obesity. It is frequently reversed after weight loss, although an eventual role for metformin treatment has been postulated.

Objective: To evaluate the benefits of metformin addition to conservative treatment on weight loss and IGT in obese children.

Patients and methods: We studied 87 obese (BMI>+2SDS) children (mean 11.20±2.63 years; 46% females/ 54% males) with IGT, at diagnosis and after 1 year follow-up with (MET, n=40) or without (No-MET, n=47) metformin added to conservative treatment. Anthropometric and biochemical features including fasting and post-OGTT surrogate indexes of insulin resistance (IR): HOMA; insulinogenic-index and the area under the curve (AUC) for glucose and insulin were analyzed.

Results: At baseline MET group showed higher age (12.16±1.81 vs 10.37±2.93 years, P<0.001), raw, but not standardized, BMI (31.00±5.25 vs 27.36±3.20 kg/m², P<0.05) and both fasting (HOMA: 5.81±5.58 vs 3.67±1.98; P<0.05) and post-OGTT IR (insulin-AUC: 309.46±200.78 vs 214.01±110.06 mcU/ml, P<0.01). At 1-Year, the drop-out rate was 15% in MET (34/40 patients remaining, 6 (15%) still with IGT) and 42.6% (27/47 remaining, 3 (15%) still with IGT) in No-MET (P<0.01). Both groups reduced their BMI-SDS significantly (P<0.001) in a similar fashion (BMI-SDS reduction: MET:−1.11±0.86 vs No-MET:−0.85±1.00 SDS) although a higher rate of ‘intense weight losers’ (>1 BMI-SDS from baseline) was observed in the MET group (21/34 vs 9/27; P<0.05). Both groups significantly reduced their post-OGTT insulin secretion at 1-Year (P<0.001), with a more intense decrease in the insulin-AUC and insulinogenic-index (both P<0.05) in MET. However, only MET group improved fasting IR after 1 year (HOMA 1-Year: 3.30±1.21 vs 5.09±3.42 at baseline, P<0.01).

Conclusion: Weight loss is effective in resolving obesity-associated IGT and can be enhanced by the addition of metformin treatment, with further improvement of fasting IR.