Insulin and mineralocorticoids influence on extrarenal potassium metabolism in chronic hemodialysis patients.

Insulin-mineral corticoids effects on extrarenal K+ metabolism in dialysis patients. During the inter-dialytic interval in dialyzed patients, hydrogen and potassium ions are regulated by extrarenal mechanisms. We studied the hormonal and acidotic effects on the extrarenal potassium metabolism, in selected, anuric and stable, hemodialysis patients. Fifteen patients, were grouped according to the mean mid-week pre-dialysis K+ over the past 12 months: > 6.0 mEq/L (G1, n=5), = 5.1-6.0 mEq/L (G2, n=5), < or = 5.0 mEq/L (G3, n=5). After a mid-week hemodialysis session and 12 h fasting, they received 1 g/Kg glucose p.os (A). Insulin, aldosterone, renin, pH, HCO3-, glucose, body weight, blood pressure and heart rate were measured before and 60' after the meal. We recorded the same parameters, except insulin, in 15 patients, similarly grouped, before hemodialysis (T0) and on 3 consecutive off dialysis days (T1-T3); G1 received fluorohydrocortisone (FHC) 0.1 mg-0.3 mg/day, according to body weight and G3 spironolactone (SLT) 200 mg per day. G2 were controls (B). (A) A significant rise in glycemia (81 +/- 23 to 157 +/- 52 mg/dL, P<0.001) and insulin (11.8 +/- 6.2 to 46.8 +/- 19.5 microU/mL, P<0.001), with a drop in K+ (5.1 +/- 0.6 to 4.8 +/- 0.7 mEq/L, P=0.001) and aldosterone (453 +/- 373 to 383 +/- 364 pg/mL, P<0.01), were noted at T60 vs. T0, in all groups. Insulin levels correlated negatively (r=-0.54, P<0.04) to serum K+ at T60, in all patients. (B) No major pH, HCO3 and aldosterone changes were observed in the 3 groups. Despite that, K+ dropped in G1 by FHC (6.7 +/- 0.9 to 5.9 +/- 0.6 mEq/L, P<0.05), rose in G3 by SLT (4.4 +/- 0.4 to 5.4 +/- 0.3 mEq/L, P<0.05) and remained unchanged in controls (5.8 +/- 0.2 to 5.8 +/- 0.6 mEq/L), (T0 vs T3 pre-dialysis values). Glucose significantly lowered K+ by promoting adequate insulin secretion. Drugs affecting aldosterone action significantly influenced potassium metabolism. Acid-base balance was not important in K+ handling in steady state anuric dialysis patients.

Renal diseases in the Hippocratic era.

Hippocrates and the medical school of Kos were mainly concerned with the common elements of various diseases and the accurate description of symptoms and signs, as well as their prognostic implications. In contrast, the medical school of Knidos (in neighbouring Asia Minor) and its chief member Euryphon were interested in the systematic classification of diseases according to the systems involved. Galen mentions that Knidian physicians were familiar with four renal diseases, probably the same described in the book About Inner Sufferings, whose author is not known with certainty; most investigators attribute it to the Knidian school (5th century BC), while others consider it to be a Hippocratic work. Both theories are logical and possible, since Hippocrates himself was familiar with the work of the Knidian school and a rival of Euryphon. The first renal disease described in the book is nephrolithiasis with renal colic. Its description is considered a classic one and it is well known for its accuracy and clarity. The second disease corresponds to renal tuberculosis, while the remaining two are somewhat unclear, the third resembles either renal vein thrombosis or bilateral papillary necrosis. The fourth disease, described in the greatest detail of all, corresponds to a chronic suppurative renal infection or a sexually transmitted urethritis, complicated by renal involvement. Some statements concerning treatment follow; they consist of diet modification, physical exercise, ingestion of herbal extracts and surgery, as a last resort. It is therefore evident that Hippocrates is the father of clinical nephrology and that Hippocratic medicine lies at the root of the development of clinical nephrology.