Effect of Blood Glucose Control on Increased Glomerular Filtration Rate and Kidney Size in Insulin-Dependent Diabetes

Abstract

To investigate the relation between blood glucose control on the one hand and an increased glomerular filtration rate and enlarged kidneys on the other, we studied 12 patients with insulin-dependent diabetes and an increased glomerular filtration rate for a year after they were randomly assigned either to continuous subcutaneous insulin infusion or to unchanged conventional therapy. Glycemic control, measured by mean plasma concentrations of glucose and glycosylated hemoglobin, was rapidly and significantly improved (P less than 0.001) in the pump group but did not change in the conventional-treatment group. In the pump group, the glomerular filtration rate fell significantly in the study period (P less than 0.001) and became normal in four of the six patients. It did not change in the conventional-treatment group. There was no change in kidney volume in either group. At the end of a year, a return to conventional insulin treatment in the pump group resulted in both metabolic deterioration and a significant rise in the mean glomerular filtration rate toward base-line values. We conclude that in patients with established insulin-dependent diabetes, strict glycemic control normalizes the glomerular filtration rate, although the kidneys may remain enlarged.

The clinical significance of hyperfiltration in diabetes

“…Mean GFR decreased from 150 to under 130 ml min −1 1.73 m −2 and was maintained at this level over 12 months, whereas GFR was unchanged in the control group. At 1 month after cessation of insulin pump therapy, GFR rebounded into the hyperfiltration range [1]. This indicates that glycaemic control remains an active modulator of GFR several years after onset of diabetes.…”

“…There is clear evidence that prolonged intensive insulin therapy, even after 12 years of diabetes, can normalise hyperfiltration [1]. In a prospective study of 12 patients with type 1 diabetes, hyperfiltration and mean HbA 1 over 10%, six were randomised to insulin pump therapy and six to conventional therapy for 12 months.…”

“…This state of 'hyperfiltration' reflects hyperglycaemia and can be reversed with intensive insulin therapy [1]. Although patients with newly diagnosed type 1 diabetes may have increased AER at presentation, hyperfiltration usually precedes changes in albuminuria by several years [2].…”

Quantitative morphology of the rat kidney during diabetes mellitus and insulin treatment

“…In diabetic patients, the size of the kidney is increased during insulin treatment and in most studies it remains 20-30 % larger [12,13,14]. Complete normalization of kidney size is not achieved in patients even after intensive treatment [14][15][16][17]. In experimental diabetes, preserving kidney weight by insulin treatment from the beginning of the disease is possible [18] but if treatment is started later the kidney weight cannot be completely normalized [6,19].…”

Paracetamol elimination in patients with non‐insulin dependent diabetes mellitus.

“…Mogensen et al (1983) found that during the first three stages of diabetic nephropathy (up to 10-15 years after diagnosis), glomerular filtration rate (GFR) is increased by 20-40%, which may be related to increased kidney size (Mogensen & Anderson, 1973), and may be normalised by strict glycaemic control (Wiseman et al, 1985). All of our patients had normal or near normal plasma creatinine values (see Table 1) and did not suffer from polyuria.…”