Effect of oral glucose administration on serum potassium concentration in hemodialysis patients.
BACKGROUND
Extrarenal potassium disposal is particularly critical in patients with end-stage renal disease. Exogenous insulin stimulates this disposal by enhancing potassium uptake into cells in hemodialysis (HD) patients and healthy subjects. However, the effect of physiological levels of endogenous insulin on this disposal in these patients or healthy subjects is unknown.


METHODS
Effects of an oral glucose tolerance test (37.5, 75, and 150 g) on serum potassium levels were determined in 13 HD patients and 7 healthy controls. Serum potassium and insulin levels and plasma aldosterone and epinephrine levels were measured before and after glucose loads.


RESULTS
In HD patients and controls, serum insulin levels increased to a similar magnitude in parallel with increased serum glucose levels, but serum potassium levels decreased significantly only in HD patients. In HD patients, plasma aldosterone or epinephrine levels were not changed significantly after a glucose load. In HD patients, the decrease in serum potassium levels was dependent on the increase in serum insulin levels and was more prominent when 150 g of glucose was administered. In HD patients, the decrease in serum potassium levels correlated negatively (r = -0.45; P < 0.001) with the increase in serum insulin levels, and maximal decrease in serum potassium levels correlated negatively (r = -0.54; P < 0.001) with maximal increase in serum insulin levels.


CONCLUSIONS
Endogenous production of physiological concentrations of insulin in response to exogenous glucose administration decreases serum potassium levels only in HD patients, independently of plasma aldosterone and epinephrine levels.
Muto
Shigeaki
S
Department of Nephrology, Jichi Medical School, Minamikawachi, Japan. smuto@jichi.ac.jp
Sebata
Kiyoko
K
Watanabe
Hitomi
H
Shoji
Fumie
F
Yamamoto
Yoshie
Y
Ohashi
Michie
M
Yamada
Takako
T
Matsumoto
Hisako
H
Mukouyama
Tomoko
T
Yonekura
Takekazu
T
Namiki
Sachiko
S
Kusano
Eiji
E
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D004837:Epinephrine / Q000097:blood; D045604:Extracellular Fluid / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D000078790:Insulin Secretion; D007668:Kidney / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011188:Potassium / Q000097:blood*; D006435:Renal Dialysis
D001786:Blood Glucose; D007328:Insulin; D000450:Aldosterone; D005947:Glucose; D011188:Potassium; D004837:Epinephrine