1. ¹Endocrinology, Department of Clinical Sciences, Università di Roma 'La Sapienza', Viale del Policlinico 155, Rome, Italy
2. ²Department of Public Health Sciences, Università di Roma 'La Sapienza', Viale del Policlinico 155, Rome, Italy

Correspondence: Professor R Buzzetti, Endocrinology, Department of Clinical Sciences, University of Rome 'La Sapienza', Viale del Policlinico 155, 00161, Rome, Italy. E-mail: raffaella.buzzetti@uniroma1.it

Received 4 February 2006; Revised 14 April 2006; Accepted 9 May 2006; Published online 27 June 2006.

Abstract

Results concerning the association of adiponectin gene polymorphisms (single-nucleotide polymorphisms, SNPs) with obesity, type 2 diabetes (T2DM), metabolic disorders and insulin resistance have not lead to definite conclusions. The aim of our study was to investigate a possible association between the -11391G>A and -11377C>G SNPs of adiponectin gene and measure of insulin sensitivity evaluated by the hyperinsulinemic-euglycemic clamp in a group of 'uncomplicated' obese subjects (with no associated comorbidities) (n=99, mean age 35 years) with a history of obesity lasting at least 10 years. The study of uncomplicated obese subjects, free of possible confounding factors that could interfere with insulin sensitivity, such as pharmacological treatment, provides a good model to assess insulin sensitivity per se. We observed that subjects homozygous for the G allele at locus -11391 had lower M (mg/kg min)/fat-free mass (FFM) index and adiponectin levels compared to subjects with GA+AA genotypes (P=0.002 and P=0.03, respectively) and subjects carrying the -11377G variant had lower M (mg/kg min)/FFM index and adiponectin levels compared to noncarriers (P=0.003 and P=0.03, respectively). Our results imply that the two promoter SNPs, -11391G>A and -11377C>G, of the adiponectin gene are associated with a reduced insulin sensitivity evaluated by hyperinsulinemic-euglycemic clamp in obese subjects.