Hypomagnesemia and hypertension in primary hyperparathyroidism.

A retrospective study of 89 patients with surgically proven primary hyperparathyroidism was done to gain insight into the pathogenesis of hypertension associated with this condition. The 43 patients (48%) who were hypertensive did not differ significantly from the normotensive patients with regard to age, sex, serum calcium and phosphate levels, and creatinine clearance. However, the mean serum magnesium level was significantly lower in hypertensive hyperparathyroid patients (1.52 +/- 0.24 mEq/L) than in normotensive hyperparathyroid patients (1.76 +/- 0.18 mEq/L; P less than .001), irrespective of use of diuretics in the former group. Although some studies implicate hypomagnesemia in the pathogenesis of essential hypertension, we are unaware of any previous human study reporting a link between hypomagnesemia and hypertension associated with primary hyperparathyroidism. This study suggests that a low level of serum magnesium may play a role in the pathogenesis of hypertension associated with primary hyperparathyroidism, a finding that needs further evaluation.