Background: There are no studies that relate BsmI polymorphism of the vitamin D receptor (VDR) gene and with vitamin D to blood pressure (BP).
Objective: To analyze if this polymorphism and 25-hydroxyvitamin D levels (25OHD3) influence BP in a population of healthy subjects.
Design: Transversal study on healthy population. Stepwise multiple regression analysis was performed to assess the association of BP with several clinical and biochemical data.
Setting: Industrial employees, blood donors, and army cadets from Lleida, Spain were recruited in October 2001.
Individuals: A total of 590 apparently healthy subjects (260 males and 330 females).
Measurements: Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were determined as the mean of three measurements. We also included age, gender, body mass index (BMI), serum levels of creatinine, calcium, phosphorus, intact parathyroid hormone (by two-site chemiluminometric assay), 25-hydroxyvitamin D (by radioimmunoassay) and BsmI genotype.
Results: Since gender was strongly associated with both SBP and DBP, a separate analysis was performed for men and women. In males, SBP was associated with BMI, 25OHD3 (beta: 0.37, P < 0.000) and genotype (beta: -4.1, P < 0.001); and DBP with 25OHD3 (beta: 0.19, P < 0.008) and age. SBP was higher in men with bb genotype than in the other genotypes (P < 0.006). Moreover, there was a statistically significant positive correlation between 25OHD3 and both SBP (r: 0.53, P < 0.002) and DBP (r: 0.48, P < 0.005) in men with genotype BB. In women, neither 25OHD3 nor genotype were associated with BP levels.
Conclusions: BsmI polymorphism of the VDR gene influences BP in healthy men. A positive relationship between serum 25-hydroxyvitamin D levels and BP is present only in men with the BB genotype.