Adenosine deaminase gene polymorphism is associated with obesity in Iranian population

Adenosine deaminase (ADA) is a polymorphic enzyme which has an important role in modulation of insulin bioactivity. It has been suggested that an excess of adenosine A1 receptor activity may contribute to adiposity in type 2 diabetes. Adenosine seems to have a role in facilitating insulin action on the adipocytes. ADA gene polymorphism seems to contribute to the degree of obesity in type 2 diabetes patients.

The aim of this study was to examine the role of adenosine deaminase gene polymorphism in randomly selected obese subjects in an Iranian population.

A significant increase in the frequency of ADA, AA genotype was observed in obese people compared to the controls (AA versus CA + CC, p = 0.01, OR: 3.4, 95% CI: [1.08-12.8]). There was also a significant increase in ADA gene allele A and AA genotype frequencies in patients with higher plasma cholesterol level compared to the normal controls (p = 0.0007, OR: 8.4, 95% CI [1.6-41.6]; AA versus CA + CC, p = 0.005, OR: 3.0, 95% CI [1.2-7.7], respectively). When we compared the ADA allele frequency in patients with obesity and higher plasma cholesterol level and patients with obesity and lower plasma cholesterol level there was also a significant difference (p = 0.01, OR: 2.6, 95% CI [1.08-6.8]). Also we examined the association between the frequency of ADA allele and genotype frequencies with triglyceride (TG) levels in obese patients and normal controls. We observed a significant increase in the ADA gene AA genotype frequency in obese patients with TG level ≥150 mg/dl compared to the normal controls (AA versus CA + CC, p = 0.008, OR: 4.5, 95% CI [1.2-18.7]).

Our data is supportive of a role for ADA in obesity and also points to its association with abnormal level of TG and cholesterol. Also our findings recommend adenosine receptors as important targets for new therapeutic approach in obesity and dislipidemia.