Objective: The aim of the study was to estimate the pancreatic beta cell function and insulin resistance indexes in a group of Autosomal Dominant Polycystic Kidney Disease (ADPKD) patients with normal kidney function and no previous diabetes mellitus diagnosis.
Methods: A total of 49 adult patients with ADPKD aged 36 ± 11 years, and 50 healthy controls, all of Caucasian origin, were included in the study. Blood glucose, insulin and C-peptide concentrations were measured during an oral glucose tolerance test (OGTT with 75 g glucose) performed according to WHO recommendations in all subjects.
Results: The insulin/glucose ratio at the 30th and 120th minute of the OGTT and the insulinogenic index [(insulin at 30 min - insulin at 0 min)/glucose at 30 min] were significantly lower (p = 0.018, p = 0.031 and p = 0.013, respectively) in the ADPKD group. Four other indexes of beta cell function were lower with the borderline statistical significance (p = 0.054-0.076) than in controls. None of the calculated insulin sensitivity indexes differed between the study and control groups.
Conclusions: Presence of ADPKD in patients with normal kidney function is associated with impaired beta cell function after an oral glucose load, without a significant decrease in insulin sensitivity.