Glucose metabolic disorder in primary hyperparathyroidism: a systematic review and meta-analysis

Background: Primary hyperparathyroidism (PHPT) is associated with increased morbidity and mortality of cardiovascular disease (CVD). Studies have demonstrated that patients with PHPT have more metabolic disorders than age matched healthy controls, which mainly include obesity, insulin resistance, dyslipidemia, hyperglycemia and hypertension. In this meta-analysis, metabolic disorders of PHPT patients were systematically reviewed. Methods: Databases were searched for studies published between 2005 and 2017 that reported body mass index (BMI), insulin resistance and blood glucose in PHPT patients and healthy controls. Results: A total of nine eligible studies were identified. Compared to healthy controls, PHPT patients had higher levels of plasma insulin (SMD = 0.37, CI: 0.23 similar to 0.52, P = 0.014) and insulin resistance index (HOMA-IR) (SMD = 0.65, CI: 0.27 similar to 1.02, P = 0.009). However, BMI was not statistically different between PHPT patients and healthy controls (SMD = 0.09, CI: -0.14 similar to 0.31, P = 0.32). Although fasting blood glucose (FBG) levels of PHPT patients were similar to healthy controls (SMD = 0.06, CI: -0.36 similar to 0.47, P = 0.21), subgroup analysis showed that hypercalcemic primary hyperparathyroidism (HPHPT) patients had higher FBG levels than healthy controls (SMD = 0.43, CI: 0.18 similar to 0.68, P = 0.025). Conclusions: Compared with healthy controls, PHPT patients had heavier insulin resistance, but only hypercalcemia PHPT patients had higher FBG levels. There was no significant difference in BMI between PHPT patients and healthy controls.