Influence of a meat-free diet on the urinary excretion of 3-methylhistidine and creatinine in chronic renal failure.
Urinary excretion of 3-methylhistidine has been proposed as an index of internal protein breakdown provided that the intake of exogenous 3-methylhistidine (meat) is excluded. To evaluate the potential use of 3-methylhistidine in the metabolic assessment of patients with advanced renal failure, we studied a group of 11 patients with markedly reduced renal function who were put on a meat-free diet (the protein intake was kept constant). Steady-state plasma concentration and urinary excretion of 3-methylhistidine were not achieved until 14 d after exclusion of meat from the diet. At that time the plasma concentration and urinary excretion of 3-methylhistidine had decreased by 43% and 60%, respectively. We conclude that the delay in reaching steady state makes the clinical use of urinary excretion of 3-methylhistidine in patients with advanced renal failure unpracticable as an index of protein breakdown. The exclusion of meat also resulted in a continuous decrease in the plasma level and urinary excretion of creatinine, with the result that plasma creatinine or its reciprocal become misleading for evaluation of changes in renal function until a new steady state has been reached.
Gutierrez
A
A
Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
Alvestrand
A
A
Qureshi
G A
GA
Bergström
J
J
D000328:Adult; D000368:Aged; D003404:Creatinine / Q000097:blood / Q000652:urine*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000178:diet therapy* / Q000652:urine*; D008297:Male; D008460:Meat; D008762:Methylhistidines / Q000097:blood / Q000652:urine*; D008875:Middle Aged
D008762:Methylhistidines; D003404:Creatinine; C028118:3-methylhistidine