Prerenal azotemia in a diabetic patient with hyporeninemic hypoaldosteronism and autonomic neuropathy

Patients with hyporeninemic hypoaldosteronism show mild to moderate renal i nsufficiency, with a creatinine clearance of 20-75 ml/min, and asymptomatic hyperkalemia. A low degree of sodium wasting and mild hyperchloremic metab olic acidosis are also usually present. However, severe sodium wasting and volume depletion are not typically seen unless the patient is placed on sev ere sodium restriction or has some other cause of extrarenal sodium loss. I n fact, acute renal failure has not been reported in such patients. We desc ribe a diabetic patient with hyporeninemic hypoaldosteronism and autonomic neuropathy who developed recurrent episodes of acute renal failure due to p rerenal azotemia during acute exacerbations of diarrhoea. In our case, desp ite significant hypovolemia, the renin-aldosterone axis was markedly suppre ssed, implying that sympathetic tone played a decisive role in renin regula tion.