Comparison of renal hemodynamics in early non-insulin-dependent and insulin-dependent diabetes mellitus

The differences in deranged renal hemodynamics in non-insulin-dependent diabetes mellitus (NIDDM) and insulin-dependent diabetes mellitus (IDDM) have never been fully investigated. Whether or not autoregulatory mechanism of renal hemodynamics in NIDDM and IDDM is preserved remains to be clarified.

In the present study we directly compared renal hemodynamics and its autoregulatory function in the early stage of NIDDM and IDDM before and after short-term glycemic control. Before glycemic control, mildly exaggerated glomerular filtration rate (GFR), subnormal renal plasma flow (RPF), and elevated filtration fraction (FF) were found in NIDDM as well as in IDDM; but there were no differences in these parameters of renal hemodynamics between the two types of diabetics. Glycemic control decreased GFR, whereas it did not alter RPF, resulting in normalization of FF in NIDDM and in IDDM. Before glycemic control, mean blood pressure was significantly correlated with GFR, but was not correlated after glycemic control in either type of diabetes. In conclusion, hyperglycemia induced glomerular hyperfiltration evenly and disturbed autoregulation of renal hemodynamics in NIDDM and in IDDM.