Anthropometric characteristics, cardiac abnormalities and adrenergic activity in patients with primary disorders of sleep.

Sixty-one patients (pts) with sleep apnea (SA), 35 with narcolepsy (N) and 24 with idiopathic hypersomnolence (H) were studied in the Clinical Research Center. The height to body weight ratio was less than normal in SA pts (0.32 +/- 0.01 vs 0.45 +/- 0.01, p less than 0.01), but normal in N and H pts (0.45 +/- 0.02 and 0.45 +/- 0.01, respectively). Twenty-four hour urinary epinephrine (E) plus norepinephrine (NE) was greater than normal (p less than 0.01), but not different among SA, N and H pts. The incidence of mitral valve prolapse (MVP) was greater in N (49%) and H (58%) compared to SA (20%) (p less than 0.01). The ratio of the pre-ejection period to the left ventricular ejection time (PEP/LVET) was abnormal (greater than 0.42) in 36% of the pts with SA and only in one pt with N and H (p = 0.02). The % shortening of the echocardiographic internal diameter (% delta D) was abnormal (less than 28%) in 28% of pts with SA and normal in all pts with N and H (p = 0.02). The incidence of malignant ventricular dysrhythmias (24 hour Holter) was 26% in SA, 3% in N and 4% in H (p = 0.04). Thus, pts with impaired alertness have high adrenergic tone despite evidence for a role of catecholamines in wakefulness. Left ventricular dysfunction, malignant dysrhythmias and obesity are common findings in SA, while MVP is very common in N and H.