Evidence of dysregulated affect indicated by high alexithymia in obstructive sleep apnea.

Alexithymia refers to dysregulation of affect characterized by difficulty in identifying and expressing emotions. Obstructive sleep apnea (OSA) is characterized by increased medical/psychiatric comorbidity and possibly by affect dysregulation. In the present case-control study, we examined alexithymia levels with the Toronto Alexithymia Scale (TAS-20) in 23 psychiatrically uncomplicated OSA outpatients and 23 same gender controls one-to-one matched for age, education and subjective depressive symptomatology. General health/quality of life was assessed with the Short-Form 36 Health Survey (SF-36) in the patient group. Hierarchical multivariate regression models were used to evaluate the association of alexithymia with the presence of OSA, and clinical and polysomnographic parameters of this condition. TAS-20 total and subscale scores were associated positively with Beck Depression Inventory (BDI)-21 and negatively with SF-36 scores. After adjusting for all confounders, OSA was positively associated with total TAS-20 score, 'expressing feelings' and 'externally oriented thinking' subscales. The latter was associated with increased sleepiness and reduced blood oxygenation in the OSA group. Finally, 'difficulty describing feelings' and 'externally oriented thinking' significantly predicted risk for OSA. Alexithymia is higher in non-psychiatrically ill patients with OSA compared with carefully matched controls even after adjustment for subjective depressive symptoms and demographic confounders. Total alexithymia is associated with greater subjective depression and poor general health/quality of life, while 'externally oriented thinking' is associated with disease severity and together with 'difficulty describing feelings' may be vulnerability factors for OSA, although reverse causality cannot be excluded.

Comparison of ketanserin, buspirone and propranolol on arousal, pupil size and autonomic function in healthy volunteers.

RATIONALE: The human pupil may be a suitable physiological test system for the assessment of excessive daytime sleepiness (EDS), but pupillometric assessment could be confounded by medication for comorbid hypertension and mood disorders. OBJECTIVES: We examined the profile of the 5HT-2/alpha1/H1 antagonist ketanserin, the 5HT1a agonist buspirone and the beta adrenoceptor antagonist propranolol on pupillary and other measures of arousal. MATERIALS AND METHODS: Ketanserin (20 mg), buspirone (10 mg) and propranolol (40 mg) were administered in three independent experiments according to a crossover, placebo-controlled, double-blind design. Resting pupil diameter (RPD) was sampled over 5-min in darkness with infrared pupillometry. Tests also included critical flicker fusion frequency (CFFF), visual analogue scales (VAS), the pupillary light reflex and heart rate/blood pressure. RESULTS: Ketanserin reduced RPD, CFFF, VAS-rated arousal and blood pressure and increased the light reflex amplitude. Buspirone reduced RPD and blood pressure. Propranolol reduced heart rate but had no effects on pupillary functions or any arousal measure. CONCLUSIONS: Ketanserin but not propranolol had a fully sedative profile and may confound pupillometric assessment of EDS. Beta adrenergic receptors do not appear to participate in arousal and pupillary functions, while 5HT1a receptors reduce pupil size without affecting arousal. Pupil size may not be used unequivocally as an index of the level of alertness in the case of drug-induced changes, when drugs interfere with the central pupil control mechanism in ways that are unrelated to their effects on arousal.