Effects of weight reduction on circulating parathyroid hypertensive factor levels

This study evaluated changes in parathyroid hypertensive factor (PHF) in 18 obese individuals. PHF levels were measured prior to the onset of a low calorie diet (800 kcal/day), and at 3-4 weeks, 7-8 weeks, and 11-12 weeks after initiation of the diet. Blood pressure, forearm vascular resistance, and platelet intracellular calcium ([Ca²⁺](i)) levels were also measured at the same time. Although blood pressure, vascular resistance, and platelet [Ca²⁺](i) decreased significantly in association with the low-calorie diet and weight reduction. PHF levels did not change significantly during the 12- week diet period. We conclude that PHF levels do not track with reductions in blood pressure, vascular resistance, and platelet [Ca²⁺](i) levels in obese individuals.