[Determination of the metabolic condition in diabetics with renal insufficiency by means of the fructosamine test]. / Beurteilung der Stoffwechsellage niereninsuffizienter Diabetiker mit dem Fructosamin-Test.

We determined HBA1 (microcolumn method) and glycosylated albumin (fructosamine) in 23 healthy subjects, 35 patients with renal insufficiency without diabetes and 14 patients with diabetes mellitus and renal insufficiency. All patients with renal insufficiency required dialysis. All diabetics were of type I and had been compensated on insulin. The HBA1 in the nondiabetic patients with renal insufficiency (9.4 +/- 1.4%) was significantly raised compared to that in the control group with healthy metabolism (7.3 +/- 0.6%). Irrespective of the quality of compensation, the diabetic patients had HBA1 values of more than 11% of average. On the other hand, the concentrations of glycosylated albumin in healthy nondiabetic patients and in diabetic patients with renal insufficiency did not differ (1.3 +/- 0.5 as compared to 1.1 +/- 0.4 mmol/l) and were all in the normal range. Well-adjusted diabetics with renal insufficiency had a fructosamine concentration of 1.9 +/- 0.7 mmol/l (theoretical value for a good compensation 2.0 to 2.8). We conclude that determination of HBA1 in pronounced renal insufficiency does not provide reliable values because carbamylated hemoglobin is also registered and determination of fructosamine (which only indicates the metabolic situation in the last three weeks, however) is to be preferred in this situation.

Comparison of long-term renal hemodynamic effects of methyldopa and propranolol in patients with hypertension and renal insufficiency.

Studies were carried out in 15 patients with renal insufficiency and hypertension to compare the long-term effects of methyldopa and propranolol on renal hemodynamics. Inulin and PAH clearance measurements were made under baseline conditions and four to six months of antihypertensive therapy with each of the two drugs. Eight of the 15 patients (group I) were started on methyldopa and then switched to propranolol; and in the other seven (group II), the sequence was reversed. There were no statistical differences in blood pressure or inulin or PAH clearances under baseline conditions between the two groups of patients. Blood pressure was controlled equally with the two drugs in combination with furosemide. In group I, there was no significant effect of either antihypertensive drug on inulin clearance, but PAH clearance was significantly higher during methyldopa than propranolol therapy. In group II, the same higher PAH clearance was found with methyldopa, even though the sequence of drug administration was opposite to that of group I. Challenge with iv furosemide resulted in a greater 3-hour natriuresis during methyldopa than propranolol treatment. The observations indicate that glomerular filtration rate (GFR) is not significantly affected by long-term treatment with methyldopa or propranolol but that renal plasma flow (RPF) is higher during treatment with methyldopa in patients with renal insufficiency and hypertension. The higher RPF apparently enhances the acute natriuretic effect of iv furosemide.