Abstract 10919: Plasma Carnitine Level in Heart Failure Patients With Sleep Disordered Breathing
Background: Carnitine plays an important role in the utilization of fatty acids and glucose in the myocardium. Although myocardial carnitine level decreases in the failing heart, it is still unclear about circulating levels of carnitine in chronic heart failure (CHF). Sleep disordered breathing (SDB) has a critical association with mortality and morbidity of CHF patients. We hypothesized that plasma carnitine level is increased due to the leakage from damaged cardiomyocytes or deficient carnitine transport into cells in CHF patients with SDB. Therefore, we examined the relation of plasma carnitine level with SDB in CHF.
Methods and Results: We performed polysomnography and measured apnea-hypopnea index (AHI), central apnea index, obstructive apnea index, minimum SPO2, mean SPO2 and plasma levels of carnitine and B-type natriuretic peptide (BNP) in 106 CHF patients. These patients were divided into the four groups according to AHI: group Normal (no SDB: AHI<5 times/hr, n=14), group Mild (mild SDB: 5<AHI<15 times/hr, n=23), group Moderate (moderate SDB: 15<AHI<30 times/hr, n=31) and group Severe (severe SDB: 30<AHI times/hr, n=38). Levels of plasma carnitine were significantly higher in group Severe than in groups Normal and Mild (Normal: 61.5 ± 7.4 µmol/l, Mild: 66.9 ± 19.9 µmol/l, Moderate: 70.5 ± 19.7 µmol/l, Severe: 78.2 ± 13.6 µmol/l, P<0.01, vs. Normal; P<0.05, vs. Mild). There was a positive correlation between plasma carnitine level and AHI (R=0.29, P<0.01). There were no correlations between plasma carnitine level and the other polysomnographic data such as CAI, OAI, minimum SPO2 and mean SPO2. In addition, there was no significant correlation between levels of carnitine.
Conclusions: Severe SDB is associated with higher plasma carnitine level, and thus circulating carnitine may be a novel marker for the severity of SDB in CHF.
- © 2012 by American Heart Association, Inc.