The aim of this study was to evaluate the effect of obstructive sleep apnea syndrome on the cognitive performance of young and middle-aged patients. Patients were divided into two groups, one consisting of 30 patients less than 50 years of age and the other consisting of 28 patients 50 years and over. Normal subjects were similarly divided into two groups, composed of 17 younger and 24 older controls. Patients and controls were examined with all-night polysomnography and subsequently underwent cognitive testing via attention–alertness tests. Comparing young to middle-aged patients, there were statistically significant differences in cognitive performance, especially in attention tests. Younger patients’ cognitive performance was similar to their age-matched controls, while middle-aged patients showed cognitive decline in comparison with their age-matched controls. Although we studied only two age groups using 50 years of age as a cut-off, we could demonstrate that cognitive deterioration of untreated sleep apnea patients is age dependent, and several factors may contribute to this effect including brain hypoxia, sleep fragmentation, or comorbidities. Aging patients with sleep apnea demonstrate cognitive decline, while younger patients with the same disease severity are (somehow) able to compensate for this effect.
