Serum parathormone, vitamin D and cardiovascular risk factors and markers: A pilot study

Vitamin D deficiency is a common cause of secondary hyperparathyroidism, particularly in elderly people. The aim of this study was to evaluate the associations of serum vitamin D and parathormone (PTH) concentrations with blood pressure values and hypertension-mediated target organ damage (HMOD), including left ventricular (LV) hypertrophy and carotid plaque (CP).

We enrolled consecutive patients admitted to the Hypertension Center of Federico II University Hospital in Naples, Italy. All patients underwent carotid doppler ultrasound and echocardiography, measurement of vitamin D and PTH levels and main clinical and laboratory parameters. A total of 126 patients (mean age 54 years, 68% males) were enrolled. Pearson's correlation analysis indicated that PTH levels directly correlated with age, diabetes, dyslipidemia, hypertension, fasting glucose, and LV mass, and inversely with glomerular filtration rate, LDL cholesterol, and vitamin D. Vitamin D levels correlated inversely with PTH, diabetes and CP. Multivariate regression models indicated that an increased LV mass was associated with the presence of obesity (β = 0.342; P = 0.001). Maximal intima-media thickness was significantly associated with older age (β = 0.303; P = 0.033). Combined presence of low vitamin D/high PTH levels were associated with more than 4-fold increased risk of having CP in both univariate (OR = 4.77, p = 0.0001) and multivariate regression analysis (OR = 4.52, p = 0.014).

In a population at high cardiovascular risk, vitamin D and PTH levels were not directly associated with blood pressure values and HMOD. Secondary hyperparathyroidism due to vitamin D deficiency is associated with carotid atherosclerosis independently of other common cardiovascular risk factors.