Plasma ionized calcium and cardiovascular risk factors in mild primary hyperparathyroidism: effects of long‐term treatment with active vitamin D (Alphacalcidol)

Publisher Website
Google Scholar
Abstract
Primary hyperparathyroidism (HPT) has been associated with hypertension, hyperinsu‐linaemia, hypertriglyceridaemia and hyperuricaemia. In the present study, plasma ionized calcium (Ca2+ was studied in relation to cardiovascular risk factors in 20 subjects with mild hypertension. Plasma Ca2+ was found to be negatively correlated with fasting serum insulin, triglycerides and urate, and with diastolic blood pressure (DBP). However, after the interaction of the different risk factors had been taken into account in the multiple regression analysis, only the relationship between Ca2+ and serum insulin was significant (r = 0.55, P < 0.01). In a previous double‐blind, placebo‐controlled study 1 ug alphacalcidol, a synthetic analogue of 1,25 dihydroxy‐vitamin D3, induced a decrease in blood pressure in mild HPT subjects. In the present study, the highest dose that did not further aggravate the hypercalcaemia was given in a long‐term study over a 12‐month period to 18 mild HPT subjects (average dose, 1.75 μg daily). The treatment induced a reduction in body weight of 0.9 kg (P < 0.05) and an increase in serum urate from 330 ± 92 to 380 ± 104 mmol l‐1 (P < 0.01). A reduction in blood pressure was only observed at the end of the study, from 142 ± 17/86.6 ± 9.1 to 139 ± 13/82.9 ± 8.9 mmHg (P < 0.05 for DBP). The reduction in systolic blood pressure was significantly correlated with the reduction in body weight induced by treatment (r = 0.63, P < 0.02). No consistent changes in glucose or lipid metabolism were induced by treatment.