Glucose metabolism parameters during an oral glucose tolerance test in patients with autosomal dominant polycystic kidney disease.

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.