Genotype screening of APLN rs3115757 variant in Egyptian women population reveals an association with obesity and insulin resistance.

Aims: Apelin is one of adipokines that plays a pivotal role in energy metabolism, insulin sensitivity and vascular integrity. A definite genetic variant of apelin gene (APLN), rs3115757, was recently introduced to potentially influence apelin expression in adipocytes. The aim of our study was to explore the sights of a potential association of this functional variant with obesity traits, insulin resistance indices as well as type 2 diabetes mellitus (T2DM) prevalence.

Methods: Genotype screening for rs3115757 variant in 151 Egyptian female samples was conducted. Fasting levels of serum insulin and lipid profile, in addition to plasma glucose were measured. Cochran-Armitage trend test was used to decide the risk allele and evaluate the association between the candidate variant and obesity using a case-control design.

Results: The homozygous G risk allele carriers showed higher values of body mass index (BMI) and waist circumference (P=0.001,0.02, respectively) as compared to CC or CG genotypes. As for GG genotype carriers, the risk of developing morbid obesity in lean subjects, (BMI<25), is twelve times the risk in subjects carrying other genotypes (OR=12.09, 95% CI: 1.4, 104.8, P=0.024). On the other hand, GG carriers are shown to be more resistant to insulin. Significantly after correction for BMI and age effects, GG genotype carriers showed 14% and 41% increment in insulin level and resistance (OR=1.14, 95% CI: 1.06, 1.23, P=0.001), (OR=1.42, 95% CI: 1.19, 1.70, P<0.001), respectively.

Conclusion: These results suggest a prospective role mediated by this variant in mounting obesity disorders and as significant as insulin resistance complications.