THE EFFECT OF SLEEP-APNEA ON PLASMA AND URINARY CATECHOLAMINES

Numerous studies have suggested an alteration of sympathetic nervous s ystem functioning in sleep apnea. However, most of these studies did n ot control for confounding factors such as diet, obesity, hypertension and anti-hypertensive medications. We examined plasma and urinary cat echolamines in 43 patients, including hypertensive and normotensive in dividuals with and without sleep apnea. Hypertensive patients were stu died at least 3 weeks following tapering of anti-hypertensive medicati on. All patients consumed similar diets and were of similar age and le vel of obesity. Twenty-four-hour urinary norepinephrine levels were si gnificantly higher in apneics (58.2 ng vs. 40.2 ng in nonapneics, p < 0.002). Urinary norepinephrine in apneics was increased during both da y and night. Plasma norepinephrine levels were not significantly eleva ted in apneic patients but were elevated in hypertensive patients both during sleep and in the morning (p < 0.0 5).