Effects of hyperglycaemia on kidney function, atrial natriuretic factor and plasma renin in patients with insulin-dependent diabetes mellitus

In normoalbuminuric patients with insulin-dependent diabetes mellitus, plasma atrial natriuretic factor (ANF), cyclic GMP and active renin and the renal clearances of [99Tcm] diethylenetriaminepentaacetic acid (DTPA) lithium and sodium were studied on a hyperglycaemia day and a euglycaemia day. Baseline euglycaemia was achieved by an overnight variable insulin infusion, which during study days was fixed at the rate necessary to maintain euglycaemia in the morning. After a baseline euglycaemic clearance period of 90 min, measurements were repeated in a new 90-min period beginning 150 min later. On the hyperglycaemia day i.v. infusion of 20% glucose was started at the end of the euglycaemic baseline period, increasing blood glucose (5.3±1.3 vs 12.1±1.2 mmol l-1, p<0.01). On the euglycaemia day blood glucose declined (5.1±1.0 vs 4.2±1.0 mmol 1-1, p<0.02). Glomerular filtration rate (GFR) was unchanged by acute hyperglycaemia (127+16 vs 129±24 ml min-1, NS), but nearly normalized during maintained euglycaemia...