The AGT and the GNB3 polymorphisms and insulin resistance in prehypertension

OBJECTIVE This study surveyed the frequencies of single nucleotide polymorphisms (SNPs) M235T AGT and C825T GNB3, and their association with insulin resistance, other biochemical markers and qualitative variables in subjects with high normal blood pressure and/or prehypertension in the Greek population. DESIGN 330 men and women of Greek origin were divided into 3 groups: a) hypertensive, b) prehypertensive and c) control group. These groups were genetically tested for these polymorphisms and insulin resistance with the HOMA index. RESULTS No statistically significant differences were found among the polymorphisms of the compared groups. However, the T allele carriers (CT/TT vs. CC) of the C825T polymorphism were associated with an increased BMI in all 3 groups (p = 0.004). The HOMA index was higher in the hypertensive (p = 0.006) and prehypertensive (p = 0.016) versus the control group, and similar results were found for insulin (hypertensive vs. control p=0.012, prehypertensive vs. control p = 0.001) without statistical significance between the first 2 groups (p = 0.522). Additionally, there was a statistically significant difference between the control group and the hypertensive and prehypertensive groups regarding cholesterol (control vs. hypertensive p=0.001, control vs. prehypertension p = 0.018) and triglycerides (control vs. hypertensive p = 0.0001, control vs. prehypertension p = 0.007). Differences were also noted between the control and the hypertensive group regarding the value of HDL (p = 0.005) and LDL (p = 0.013). CONCLUSION This study failed to demonstrate a correlation between specific SNPs, blood pressure and insulin resistance in the 3 groups. However, T allele carriers of the polymorphism C825T were found to have an increased BMI. similarly, increased insulin resistance and lipidemia were more common in the hypertensive and prehypertensive populations.