Calciotropic hormones and blood pressure in chronic renal failure

Many abnormalities of calcium (Ca) metabolism and calciotropic hormones have been described in chronic renal failure (CRF), including hypocalcemia and hyperphosphatemia, low serum levels of 1,25 [OH](2) vitamin D and hyperparathyroidism. Particularly, hyperparathyroidism in CRF may be secondary to reduced serum ionized Ca, and/or to phosphate retention and to reduced serum 1,25[OH]D-2(3) levels. Moreover, parathyroid hormone (PTH) may play a non secondary role in CRF patients with hypertension, since PTH appears to be directly related to mean arterial pressure. However, in contrast to the vasoconstrictory property of PTH, it has been suggested that this hormone could have a vasodilatory action, as a homeostatic response to the vasoconstrictory effect of the abnormal Ca metabolism. Finally, hyperparathyroidism in CRF patients seems of predictive value for cardiovascular complications, including pressure-overload left ventricular hypertrophy and volume-overload congestive heart failure, also in early stages of CRF, acting as an uremic toxin, directly or mediated by hypercalcemia. Therefore, parathyroidectomy may prevent and treatment with vitamin D may correct or blunt cardiac dysfunction, secondary to hyperparathyroidism, in CRF patients.