[Detection of LADA-type diabetes in overweight diabetic patients. Is treatment with metformin suitable?].

Objectives: To detect type-1 LADA (latent auto-immune diabetes in adults) in adults with overweight. To describe the metabolic variations in these patients after metformin treatment.

Design: Observational, multi-centre study based on a series of cases.

Setting: Health centres in Barcelona province, Spain.

Participants: Diabetic patients with overweight or obesity, diagnosed with diabetes for <2 years, aged between 35 and 65, and without clinical micro-macrovascular complications and without initial glycaemia-lowering drug treatment.

Intervention: Metformin administration (1700 mg/day).

Measurements: The metabolic control variable was HbA1c. Other variables measured were: body mass index (BMI), glucose in fast, insulinaemia, C-peptide, and insulin resistance (HOMA-IR). We determined ICA, GADAb and IA2Ab antibodies to diagnose LADA-type diabetes.

Results: In our sample of diabetics (N=103), we detected 3 type-1 LADA cases. These patients had higher levels of HbA1c, insulin and, especially, HOMA-IR. Metformin treatment for one year improved HbA1c in both groups (with and without type-1 LADA). However, the decrease in insulin one year afterwards was greater in type-1 LADA patients.

Conclusions: The percentage of type-1 LADA in our sample made us wonder whether we should search for pancreatic antibodies more often in primary care. More studies on the prevalence of type-1 LADA in our country are needed, especially in diabetic patients with overweight. Type-1 LADA patients improved their metabolic control after metformin treatment and showed a drastic decrease in insulin levels. Further studies are needed to evaluate whether metformin improves metabolic control, even though it may not protect insulin reserves, and to contrast metformin with other drugs.