Symptoms and course of chronic hypokalemic nephropathy in man.

The symptoms and clinical course of chronic hypokalemic nephropathy are described in 21 patients with longstanding potassium deficiency. In 14 patients (group A) the potassium depletion was caused by malnutrition and/or abuse of laxatives and/or diuretics. 7 patients (group B) suffered from primary (6 cases) or secondary (1 case) aldosteronism. The average duration of potassium depletion was 8.8 years in group A and 3.4 years in group B. Depending on the duration of potassium depletion, chronic renal disease develops which may end in terminal renal failure. Urinalysis is non-specific or negative. The clearance of creatinine slowly decreases. Metabolic alkalosis is a constant finding and in group A occurs with a tendency to hyponatremia and hypochloremia, with the development of metabolic acidosis only in advanced renal insufficiency. In contrast to patients of group B, patients of group A have normal or low blood pressures converting to hypertension, if at all only in the late phase. The cases of group A had secondary aldosteronism (and, correspondingly, a hyperplastic juxtaglomerular apparatus). Although urinary tract infection is a regular finding in advanced stages, the clinical, radiological and histological evidence suggests that bacterial pyelonephritis, if occurring at all, is rather a complication than the cause of the disease. In 5 patients 7 instances of acute renal failure of unknown origin were observed which was lethal in one case. Another patient died from terminal renal failure, a third from an intercurrent pneumonia. Renal histology obtained from 13 patients showed the picture of diffuse chronic abacterial interstitial nephritis.