Genetic polymorphism within human growth hormone gene region and BMI in type 2 diabetes

Currently there is a surge of interest in the association of obesity with growth hormone (GH). Our hypothesis is that genetic variation within the hGH area could predispose to obesity in type 2 diabetes. We examined 68 Caucasian subjects with type 2 diabetes from the central area of Continental Italy. In these subjects we examined four polymorphic loci (Msp1A, Msp1B, BglIIA and BglIIB) located in the hGH gene region (chromosome 17q22-9-24). A sample of 192 adults from the population of Central Italy were studied as controls. Msp1B and Msp1A polymorphisms are associated with BMI. For both polymorphisms the proportion of overweight subjects is greater in the *1/*1 genotype than in carriers of the *2 allele (97% vs. 79% and 94% vs. 86% respectively). For both polymorphisms, the mean value of BMI is greater in the *1/*1 genotype than in carriers of the *2 allele. The mean values of age at onset of diabetes are greater in Msp1B*1/*1 and Msp1A*1/*1 genotypes than in carriers of the *2 allele. BglIIA and BglIIB polymorphisms are not associated with being overweight. The present study suggests that the structural organisation of the hGH genomic area may have an important role in being overweight associated with type 2 diabetes.