Vitamin D and subsequent systolic hypertension among women.

BACKGROUND: We examined data from a cohort of Caucasian women for evidence of an association between serum vitamin D (25-hydroxyvitamin D (25(OH)D)) insufficiency and greater risk of systolic hypertension in the population-based longitudinal Michigan Bone Health and Metabolism Study (MBHMS).
METHODS: The cohort includes 559 women aged 24-44 years in 1992; annual blood pressure (BP) measurements and data collection began in 1992 and is ongoing. A single-time serum 25(OH)D level was measured in 1993. Using logistic regression, vitamin D insufficiency (<80 nmol/l) was related to systolic hypertension (≥140 mm Hg) measures identified in 1993 and in 2007. Further, the relationship between vitamin D at baseline and the trajectory of systolic BP across the ensuing 14 years was assessed using longitudinal mixed modeling.
RESULTS: Vitamin D insufficiency was not significantly associated with concurrent systolic hypertension in 1993 (odds ratio (OR) 1.3; 95% confidence interval (CI) (0.32, 5.1)). However, vitamin D insufficiency was associated with increased risk of systolic hypertension in 2007 (OR 3.0; 95% CI (1.01, 8.7)) after adjusting for age, body fat percentage, antihypertensive medication use, and smoking. Baseline vitamin D status was not associated with rate of BP change over the 14-year period.
CONCLUSIONS: Consistent with previous animal and human studies, we found a single-time measure of vitamin D among young adult women was associated with systolic hypertension 14 years later. These prospective results suggest the need for further study of the role vitamin D insufficiency in early adulthood as a risk factor in subsequent hypertension among women.