The renin–angiotensin system and kidney function during initial insulin treatment in diabetic man

Abstract

Glomerular filtration rate, renal plasma flow, active renin, renin substrate and angiotensin II concentrations were monitored in nine consecutive patients (3 women, 6 men, mean age 31 years) with newly diagnosed, insulin-dependent diabetes. Measurements were performed before and during the initial eight days of intensive insulin treatment. All patients had ketonuria but none had acidosis. Glomerular filtration rate and renal plasma flow were significantly increased at the time of diagnosis as compared with values from normal subjects. A highly significant decline in glomerular filtration rate from 16019 (SEM) to 13315 ml/min×1.73 m² was seen during the initial eight days of treatment (p<0.01). Likewise renal plasma flow declined from 601±33 to 558±35 ml/min×1.73 m² (p<0.05). Plasma concentration of renin was within normal range at day 0, and remained unchanged during the eight day study. Also renin substrate concentration was normal and unchanged during the observation period, whereas angiotensin II concentration was low and unchanged. Our study does not support the suggestion that the reninangiotensin system contributes to the hyperfiltration characteristically found in newly diagnosed insulin-dependent diabetic patients.

Key Words:

• glomerular hyperfiltration
• insulin dependent diabetes mellitus
• renin-angiotensin system