Endocrine Abstracts

Background: AdipoQ gene is located at the 3rd chromosome and encodes foradiponectin which is involved in fat metabolism and insulin sensitivity and plays a protective role in diabetes and atherogenesis. AdipoQgene variants have been reported to be associated with hypertriglyceridemia and risk of diabetes in different studies. We aimed to study whether polymorphism of rs2241766 polymorphic form of AdipoQ gene & its expression in adipose tissue is associated with post prandial hypertriglyceridemia and glucose intolerance.

Methodology: Polymorphism study of AdipoQ gene rs2241766 was carried out by using PCR-RFLP method in 200 age and sex matched subjects who were recruited in three groups {NGT (n = 67), Prediabetes(n = 66) and T2DM(n = 67} with varying glucose tolerance following 75 gm OGTT. Gene expression studies using Real Time PCR were also done in subcutaneous and omental adipose tissue in 10 subjects from each group who were scheduled to undergo abdominal surgery. A Standardized oral fat challenge test was performed in all the study subjects to determine their post prandial Tg responses besides measurement of anthropometric (BMI, Waist) and Glycaemic (Fasting, Postprandial plasma glucose and HbA1c) indices and fasting serum insulin.

Results: The mean age of study subjects were 40.25 ± 8.27 years and their mean BMI was 28.12 ± 4.89 kg/m². There were 93 males and 107 females. TT geno types of rs2241766 polymorphic form of AdipoQ gene showed significantly lower 2 hr PPTg (190 ± 84 vs 244 ± 98 mg/dl P = 0.008), Triglyceride area under curve (2445 ± 1139 vs 2993 ± 1436 mg dl^–1 2 hr^-1 P = 0.05), fastingplasma glucose (99 ± 13 vs 111 ± 35 mg/dl P < 0.001) and postprandial plasma glucose (140 ± 46 vs 173 ± 79 mg/dl P = 0.002) as compared to GG + GT genotypes. Distribution of TT genotype of rs 2241766 polymorphic form of AdipoQ gene was found to be significantly lower inthe T2DM subjects (71% vs 79% P = 0.01) as compared to NGT subjects. AdipoQ gene expression was 3.1 fold lower in prediabetes group (P<0.01) and 2.6 fold lower in T2DM group (P = 0.003) as compared to NGT group in subcutaneous adipose tissue which correlated significantly with postprandial plasma glucose levels (r = −0.48 P < 0.04)

Conclusion: The findings of the present study indicate that TT allele of rs2241766 polymorphic form of AdipoQ gene is associated with lower postprandial triglyceride levels and a lesser degree of glucose intolerance in Asian Indian subjects. Glucose intolerant subjects also display lower AdipoQ gene expression in adipose tissue.