The Effect of Hyperparathyroid State on Platelet Functions and Bone Loss

OBJECTIVE Coagulation and fibrinolysis defects were reported in primary hyperparathyroid patients. However, there are not enough data regarding platelet functions in this group of patients. Our aim was to evaluate the platelet functions in primary and secondary hyperparathyroid patients and to compare them with healthy subjects. MATERIALS AND METHODS In our study 25 subjects with primary hyperparathyroidism (PHPT), 25 subjects with secondary hyperparathyroidism (SHPT), and 25 healthy controls were included. Platelet functions of the subjects were evaluated by using platelet-rich plasma and platelet aggregation tests induced with epinephrine, adenosine diphosphate (ADP), collagen, and ristocetin. Serum P selectin levels, which indicate platelet activation level, were measured in all subjects. Bone mineral densitometry was performed for all patients. RESULTS There was no significant difference between the groups with PHPT and SHPT and the control group regarding the platelet aggregation tests and serum P selectin levels. There was also no significant correlation between parathormone levels and aggregation parameters (ristocetin, epinephrine, collagen, and ADP: respectively p=0.446, 0.537, 0.346, and 0.302) and between P selectin (p=0.516) levels. When we separated the patients according to serum calcium levels, there was also no significant difference between aggregation parameters and serum P selectin levels between the patients with hypercalcemia and the patients with normocalcemia. We could not find any significant correlation between aggregation parameters, P selectin levels, and serum calcium levels in this group of patients. Bone loss was greater in patients with PHPT. CONCLUSION There is no significant effect of PHPT or SHPT and serum calcium levels on platelet functions when evaluated by aggregation tests.