Serum carnitine concentrations correlated to clinical outcome parameters in chronic hemodialysis patients

Carnitine metabolism and the therapeutic use of carnitine has been a major area of interest in dialysis patients. The purpose of this study was to determine whether any correlations exist between carnitine status and selected clinical parameters in hemodialysis (HD) patients. This study was an observational study of data from patients receiving HD at a Midwest dialysis center. The subjects (n=49) were 60+/-16 (mean+/-SD) years of age and 48% male. Fifteen percent of the subjects had type 1 diabetes mellitus (DM), 29% had type 2 DM, and 25% had left ventricular hypertrophy (LVH). The serum-free and total carnitine, and acylcarnitine concentrations were: 40.3+11.8 microm/l, 22.8+/-7.3, and 17.5+/-5.9 microm/l, respectively. The serum acylcarnitine to free carnitine ratio (A/F) was 0.80+/-0.27. Blood urea nitrogen (BUN), parathyroid hormone and ejection fraction were positively correlated and age and left atrial dilation (cm) were negatively correlated with serum total carnitine (P<0.05). BUN and hematocrit were positively correlated (P<0.05) and age was negatively correlated with free carnitine. Subjects who used mannitol or were male had significantly higher concentrations of both free and total carnitine, respectively (P<0.05). Subjects using aspirin had lower concentrations of serum total carnitine (P<0.10). These results suggest certain subgroups of patients may need to be targeted for further studies with carnitine replacement therapy, i.e. long-term patients, older patients, patients with left verticular hypertrophy and left atrial enlargement, females and patients on aspirin therapy.