Molecular analysis of the adiponectin gene in severely obese patients from southern Italy

Severe obesity is a major worldwide public health concern affecting 0.5-5% of the adult population. Adiponectin (Acpr30), an adipokine secreted from adipocytes, shows pleiotropic beneficial effects on obesity and related disorders. In this study, sequence analysis of Acpr30 gene (ACDC) was performed in a highly selected population of severely obese young adult patients from Southern Italy to investigate the associations between polymorphisms in the ACDC gene and the development of severe obesity concomitantly with other features of the metabolic syndrome.

The ACDC gene was analyzed by direct sequencing in the severely obese patients (n=220) and compared to healthy controls (n=116). The associations between the ACDC gene single-nucleotide polymorphisms (SNPs) and the levels of serum Acpr30 as well as the correlation with the presence of severe obesity jointly associated with other features of the metabolic syndrome were also investigated. Total serum Acpr30 concentrations were measured by the ELISA method.

ACDC gene molecular screening revealed the presence of previously described SNPs and a new nucleotide alteration, c.355T>G, leading to a protein variant, p.L119V. Measurement of serum concentration of Acpr30 demonstrated lower levels of Acpr30 in the obese population compared to controls (30.5+/-28.3 vs. 43.9+/-35.7 microg/ml, p<0.01); in particular, significantly lower Acpr30 concentrations were observed in obese patients bearing c.-11377C>G SNP CG+GG genotypes than in those with CC genotype (22.9+/-20.5 vs. 33.1+/-29.4 microg/ml, p<0.05).

Our results confirmed that low serum levels of Acpr30 are related to severe obesity and a difference in protein expression is associated with variants in ACDC gene promoter region.