Cortisol circadian rhythm and 24-hour Holter arterial pressure in OSAS patients.

Obstructive sleep apnea syndrome (OSAS) is a syndrome in which the principal symptom is apnea during sleep. Hypoxia in OSAS is a stress condition, which when prolonged in time, could alter hypothalamo-hypophysial-suprarenal control and the cortisol cicadian rhythm. We studied 28 patients with OSAS (30-60 years old), 20 female and 8 male. We calculated the OSAS class according to the Simmons classification. Twenty of the 28 patients maintained unmodified cortisol circadian rhythms, while 8 had cortisol levels more elevated in late and nocturnal hours. Holter monitoring showed arterial hypertension in 8 of the 28 patients (the same patients with cortisol circadian rhythm alteration). Our data seem to indicate that when the OSAS patients lack cortisol circadian rhythm they are having arterial hypertension.