<qa>  What is the incretin effect that has only to a small extent been investigated in patientsThese effects may be applicable also in patients with end-stage renal disease ESRD because patients with T2DM and normal kidney function and non-diabetic patients with ESRD show several identical characteristics. These include decreased insulin sensitivity, hyperinsulinaemia and impaired beta cell function. The incretin effect has only to a small extent been investigated in patients with ESRD. 