Chronic hypokalemic nephropathy: a clinical study

Description of 23 patients (21 women, 2 men) with an average age of 36.6 (19--68) years, who were hypokalemic during 6.5 years on the average (range 1/2--16 years). The cause of the potassium depletion was malnutrition (anorexia nervosa, vomiting) and/or abuse of laxatives and/or diuretics. With increasing duration of potassium depletion renal function deteriorated; in two cases terminal renal failure developed. Histology of the kidneys (9 cases) showed the picture of chronic abacterial interstitial nephritis. Urinalysis was negative or non-specific. The blood pressure levels were normal or low, hypertensive values being exceptional. Aside of hypokalemia a tendency to hyponatriemia, hypochloremia and metabolic alcalosis was observed, the latter turning into hypokalemic normochloremic acidosis with advancing renal insufficiency. Plasma renin activity and aldosterone concentration or excretion frequently were elevated, but no close correlation was found between these parameters or with the blood pressure. Bacterial infection of the urinary tract occured, if at all, in the late phase and seems to be complication rather than the cause of the kidney disease. The discussion of other possible pathogenetic factors leads to the conclusion that the term "chronic kaliopenic nephropathy" is justified. Some diagnostic and therapeutic consequences are mentioned.