Alpha-2 beta-adrenergic receptor (301–303 I/D) gene polymorphism in hypertension and type 2 diabetes mellitus diseases among Saudi cases in the Qassim region

The hypertension (HTN) and type 2 diabetes mellitus (T2DM) are a common multifactorial disease due to genetics and environmental factors. The alpha 2B adrenergic receptor (α2B-AR) has relationship with secretion of insulin and mediates the vasoconstriction that elevate blood pressure. This study aimed to determine the association between α2B-AR gene polymorphism with HTN and T2DM in Saudi cases. 200 cases and 100 healthy controls from Saudi population were recruited from the Internal Medicine clinic, Qassim University. The patients were grouped into: 72 HTN without T2DM; 62 HTN with T2DM and 66 T2DM only. Full medical history, examination and biochemical assays were performed for all participants. Genomic DNA was isolated from blood lymphocytes of all subjects for detection of α2B-AR gene polymorphism by using polymerase chain reaction (PCR). The results found a significant association between D carriers genotype and HTN with T2DM cases (p < 0.05) as well as with T2DM-only cases, (p < 0.05) compared to control. Regardless of HTN status, only cases with HTN and T2DM as well as those with T2DM were significantly associated with the recessive model DD versus II+ID (p < 0.05). So, D carriers genotype was significantly associated with total cases of HTN and T2DM (p < 0.05) compared to controls. Our results suggested that there is a relationship between the α2B-AR I/D gene polymorphism and the risk for T2DM with or without HTN, but no such comparable relationship is evident with HTN-only cases among Saudi population in Qassim region.