Leptin Rs7799039 polymorphism is associated with type 2 diabetes mellitus Egyptian patients

Leptin (LEP) is an anti-obesity hormone that regulates food intake, energy expenditure, and glucose metabolism. The genetic variants in LEP and the LEP receptor (LEPR) gene may play an important role in the pathogenesis of type 2 diabetes mellitus (T2DM) and obesity. The current study aimed to investigate the association of serum LEP levels, and LEP polymorphisms in LEP (rs7799039, 2548 G/A) with T2DM in Egyptian patients.

A total of 205 subjects were included in the present case-control study, consisting of 100 T2DM patients and 105 healthy controls. The anthropometric, psychometric, and biochemical measurements were taken from all the subjects. The genotyping of LEP gene variants was carried out by polymerase chain reaction TaqMan technology. Serum LEP levels were measured by the ELISA technique.

T2DM patients had significantly elevated levels of glycated haemoglobin (HbA1c), fasting blood sugar (FBS), postprandial blood sugar (PPBS), international normalisation ratio (INR), creatinine, urea, cholesterol, triglyceride (TG), and low-density lipoproteins (LDL) and significantly decreased high-density lipoprotein (HDL) compared to healthy subjects. serum LEP levels were significantly decreased p (<0.001) as compared to the control group. LEP gene SNP rs7799039 was associated with an increased diabetic risk with A allele being more frequent in T2DM patients than control subjects. The distribution of the AA genotype and GA genotype of LEP SNP rs7799039 was higher in the diabetic group than control one. In addition, AA + GA genotype carriers had significantly elevated HbA1c, FBS, PPBS, TG, and LDL levels and on the contrary, decreased serum LEP levels compared to GG homozygotes.

The genetic polymorphism rs7799039 showed a highly significant correlation with blood LEP. The co-dominant and dominant models of the LEP genetic polymorphism (rs7799039, 2548 G/A) were shown to have a significant correlation with complicated and uncomplicated diabetes individuals, but we have found that serum LEP levels were inversely related with control and diabetes patients. A positive significant association was found between LEP genetic polymorphism (rs7799039, 2548 G/A) and serum LEP in patients and controls. LEP levels and its rs7799039 genetic variant may play a vital role in increasing T2DM susceptibility.