Objective: To analyse hyperinsulinemia in Bartter syndrome.
Methods: Twenty-three cases of Bartter syndrome [age (27 ± 9) years; fasting serum potassium (2.8 ± 0.5) mmol/L], 20 patients of aldosterone-producing adenoma [APA, age (45 ± 11)years, fasting serum potassium (3.0 ± 0.4) mmol/L], 20 patients of idiopathic hyperaldosteronism [IHA, age (51 ± 11) years, fasting serum potassium (3.4 ± 0.2) mmol/L] were diagnosed in Peking Union Medical College Hospital from September 2003 to May 2008. All patients underwent 3-hours oral glucose tolerance test (3hOGTT), postural stimulation test and calculated HOMA-insulin resistance (HOMA-IR) and HOMA-insulin sensitivity (HOMA-IS) by Homeostasis model.
Results: The insulin area under curve[(229.0 ± 162.4) mIU×L(-1)×h] was significantly higher than APA group [(121.2 ± 81.1) mIU×L(-1)×h, P < 0.05] and were similar to the aged-matched patients with IHA [(227.7 ± 158.6) mIU×L(-1)×h]. But HOMA-IR in Bartter group were similar to APA group (1.96 ± 1.14 vs 1.41 ± 0.91), and HOMA-IR in APA group was lower than IHA group (1.96 ± 1.14 vs 2.40 ± 1.60, P < 0.05). There was no deference in HOMA-IS among three groups, but APA group had lower level. In all three groups, the peak of insulin secretion was delayed.
Conclusion: Bartter syndrome patients commonly present with hyperinsulinemia.