Parathyroid hormone and mineral homeostasis during propranolol therapy for essential hypertension

Propranolol has been shown to inhibit acutely PTH release, and chronic use has been implicated in lowering basal PTH levels in human and animals. We measured serum PTH, calcium and phosphate in 39 hypertensives before and during 2-4 weeks of propranolol (40 mg BID). Mean PTH levels were 77.7±(SD) 17 μlEq/ml prior to and 78.2±17 during therapy. Serum calcium was unchanged. Serum phosphate increased (p<0.01; 3.0±0.4, control and 3.3±0.4, treated). Propranolol failed to suppress PTH levels in spite of sufficient beta-blockade to suppress (p<0.001) plasma renin activity and lower blood pressure (p<0.001). These results suggest that the sympathetic nervous system is not the primary modulator of parathyroid hormone levels in essential hypertensives. We conclude that moderate doses of propranolol do not alter the PTH levels in subjects with essential hypertension.