Effects of short-term treatment with naproxen on kidney function in insulin-dependent diabetic patients with microalbuminuria

Abstract

The renal effects of the prostaglandin synthesis inhibitor naproxen was investigated in eight patients with incipient type I diabetes nephropathy. The patients were treated with 1000 mg naproxen daily for 4 days in a placebo-controlled double-blind cross-over study. Naproxen reduced urinary prostaglandin E₂ (PGE₂) excretion by 60%, from 276 ng/24 h to 110 ng/24 h (P<0.05). Plasma renin activity (PRA) was reduced by 45% (F<0.05). Glomerular filtration (GFR) (single bolus ^99mTc-DTPA technique) and effective renal plasma flow (ERPF) (¹³¹I-Hippuran clearance) were unchanged by naproxen. Microalbuminuria and renal albumin clearance was unchanged as was also urinary excretion of sodium, glandular kallikrein and β₂-microglobulin (β₂-M). Our results show that albumin excretion in incipient diabetic nephropathy is not solely dependent on the renal prostaglandin system. The difference in action between naproxen in this study and indomethacin in previous reports, could be caused by renal actions of indomethacin independent of the prostaglandin system.

Key Words:

• diabetes mcllitus type I
• microalbuminuria
• prostglandins
• renal function