A genetic polymorphism in the CYP19A1 gene and the risk of hypertension among midlife women

Objective: To test whether a synonymous single nucleotide polymorphism (A→G; rs700518) in the CYP19A1 gene, which encodes the enzyme aromatase, is associated with an increased risk for hypertension of midlife women.

Methods: In a cross-sectional study, 639 midlife women were recruited. Eligible women had their blood pressure, weight and height measured, and donated a blood sample for hormone and genetic analyses. The participants also completed a detailed study survey. Women were grouped according to their genotype, blood pressure measurements, and medical history. The data were analyzed using logistic and linear regression models. The study had 80% power to detect small differences in mean systolic blood pressure (SBP; 4.5 mmHg) and diastolic blood pressure (DBP; 3 mmHg).

Results: The selected polymorphism was significantly associated with hypertension and SBP in unadjusted analyses. Interestingly, women with hypertension were more likely to be homozygous for the A allele (AA) compared to women who were not categorized as having hypertension. Further, the mean SBP was significantly higher for women who were homozygous for the A allele when compared to women carrying the other genotypes (AG or GG). The unadjusted association between DBP values and genotype was of borderline statistical significance (p=0.07). However, after adjustment for potential confounders (age, race, body mass index (BMI), smoking and physical activity), the associations between genotype and hypertension/blood pressure were attenuated and not statistically significant.

Conclusion: The rs700518 polymorphism in the CYP19A1 is not associated with hypertension in our sample of midlife women. Other factors, including race and BMI, appear to play a greater role.