Validation of simple indices to assess insulin sensitivity and pancreatic Beta-cell function in patients with renal...

Insulin resistance and hyperinsulinemia has been reported in patients with chronic renal failure. However, usefulness and validation of new indices for assessment to insulin sensitivity and pancreatic beta-cell function were unknown.

We evaluated insulin sensitivity and pancreatic beta-cell function in 61 normal glucose tolerant (NGT) and 60 diabetic (DM) subjects; both groups were subdivided as normal renal function (NRF; C(cr) >/= 70 ml/min) and impaired renal function (IRF; C(cr) <70 ml/min). Insulin sensitivity were assessed by homeostasis model assessment of insulin resistance (HOMA-IR) and plasma glucose and insulin concentrations obtained at fasting or during a 75-gram oral glucose tolerance test (insulin sensitivity index), and pancreatic beta-cell function were assessed by insulinogenic index, first-phase insulin secretion index, and area under the response curve for plasma insulin (insulin-AUC(0-180)).

There was no evidence of insulin resistance in NGT-IRF group. No differences in both insulinogenic index and first-phase insulin secretion index between NGT-NRF and NGT-IRF, but these were significantly decreased in DM-NRF and DM-IRF. There were inverse linear correlations between the insulin sensitivity index and insulin-AUC(0-180) in patients with NGT and DM, respectively. These correlations were similarly robust in NRF subjects and IRF subjects.

New indices for assessment of insulin sensitivity and pancreatic beta-cell function calculated from plasma glucose and plasma insulin concentrations after OGTT are applicable for clinical use even in patients with renal dysfunction.