Association of Serum 25-Hydroxyvitamin D and Parathyroid Hormone With Hypertension in Middle-Aged and Older Korean Adults

BACKGROUND Previous studies have suggested that serum 25-hydroxyvitamin D [25(OH) D] and parathyroid hormone (PTH) levels are associated with hypertension. However, the associations have yet to be studied in Koreans. This study explored the relationship among serum 25(OH) D, PTH concentrations, and the presence of hypertension in middle-aged and older Korean adults using the most recent nationally representative survey data. METHODS A population-based, cross-sectional study was conducted with data collected from 5,260 Korean adults (aged >= 50 years) who participated in the 2010 and 2011 Korean National Health and Nutrition Examination Surveys. Hypertension was defined as a systolic blood pressure >= 140 mm Hg, diastolic blood pressure >= 90 mm Hg, or current use of antihypertensive medication. RESULTS The prevalence of hypertension significantly increased according to the quartiles of serum PTH levels (P < 0.0001), but not of serum 25(OH)D levels. In multivariable logistic analysis, the adjusted odds ratios (ORs) for hypertension were significantly higher among participants in the highest quartile than among those in the lowest quartile of serum PTH level, after adjusting for potential confounders (OR = 1.26, 95% confidence interval: 1.02-1.56, P = 0.03). The adjusted ORs for hypertension tended to decrease across the quartiles of serum 25(OH)D level, but the associations were not significant. CONCLUSION Serum 25(OH)D was not associated with the presence of hypertension, whereas serum PTH was positively associated, suggesting that serum PTH may be an independent risk factor for hypertension in middle-aged and older Korean adults.