Circulating leptin and adiponectin levels in patients with primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) has been associated with high cardiovascular morbidity and mortality; its pathogenesis is not fully understood. Moreover, many metabolic abnormalities are frequently present in patients with PHPT. Several substances (such as leptin and adiponectin) are secreted from adipocytes, which may contribute to regulate energy homeostasis and the development of cardiovascular diseases. We examined the relationship between leptin and adiponectin levels and metabolic disorders in 67 newly diagnosed never-treated patients with PHPT and in 46 healthy subjects (HS). Twenty (29.8%) patients with PHPT presented a metabolic syndrome (as defined by Adult Treatment Panel III criteria). Serum leptin and adiponectin levels in HS were 6.28 ± 3.3 ng/mL (range, 1.7-19.2 ng/mL) and 6.65 ± 1.7 μg/mL (range, 3.72-10.86 μg/mL), respectively. In all patients with PHPT, the mean leptin levels (34.28 ± 20.4 ng/mL) were significantly higher than those of HS (P < .01) and, in particular, in PHPT patients with metabolic syndrome (52.63 ± 31.2 ng/mL) and positively correlated with body mass index, waist circumference, and cholesterol. The mean adiponectin level was significantly lower (4.34 ± 3.5 μg/mL) only in PHPT patients with metabolic syndrome (P < .005) and negatively correlated with waist circumference and fasting glucose. We concluded that increased serum level of leptin and decreased serum level of adiponectin coexist in patients with PHPT and may represent a pathogenetic factor for cardiovascular disease in this condition.