ABSTRACT
Free and total carnitine serum concentrations and urinary excretion were examined in patients with various neuromuscular diseases. On a measured, low carnitine diet and during fasting, the patients did not differ from controls. Carnitine excretion in patients (3.09 +/- 1.87 mumol/kg/day) and controls (2.99 +/- 1.12) exceeded carnitine intake (patients, 2.35 +/- 0.94 mumol/kg/day; controls, 1.33 +/- 0.70). Because of heterogeneity in the patient population, carnitine excretion was assessed according to creatinine excretion, chosen as an indicator of muscle mass. Those patients with daily creatinine excretion less than 1 g/day had significantly lower carnitine excretion (106 +/- 47 versus 205 +/- 95 mumol/day, p less than 0.05), and there was a positive correlation between creatinine excretion and carnitine excretion (r = 0.82) and between muscle carnitine and carnitine excretion (r = 0.67). Urinary clearances for acylcarnitine were 10 and 20 times higher than those for free carnitine. Two patients with carnitine palmityl transferase deficiency were similar to the other patients, but the carnitine-deficient patient lost excessive carnitine during fasting, probably secondary to elevated acylcarnitine fraction in the blood.
Subject(s)
Carnitine/urine , Diet , Neuromuscular Diseases/metabolism , Adolescent , Adult , Carnitine/administration & dosage , Carnitine/deficiency , Carnitine O-Palmitoyltransferase/deficiency , Creatinine/urine , Female , Humans , Kinetics , Male , Middle Aged , Muscles/metabolismABSTRACT
Sixty-five patients were studied prospectively after jejunoileal bypass for obesity. Dietary intake pre- and postoperatively was measured either directly by weighing food or by a research dietary history. Of 65 measurements, 59 were made at least 6 months after operation, when over 75% of weight loss had been achieved. Fat absorption was measured in 42 of the patients. The entire group ate fewer calories (mean +/- SE = 2595 +/- 135) postoperatively than preoperatively (mean +/- SE = 3261 +/- 138). This difference was highly significant (P less than 0.001). Forty-eight patients ate less after their operation. The caloric deficit calculated from the observed weight loss could be accounted for entirely by the estimated decrease in intake in 22 of the 48 patients who ate less postoperatively. Moreover, measured fat malabsorption accounted for only 31% of the observed weight loss in those who ate more postoperatively and 21% in those who ate less. We conclude that a decrease in caloric intake, along with malabsorption, is an important factor in the long term postoperative weight loss (1-9 months) after jejunoileal bypass for obesity.
