Prevalence of comorbidities in patients with obstructive sleep apnea syndrome, overlap syndrome and obesity hypoventilation syndrome.

INTRODUCTION: Sleep-disordered breathing causes a burden to the sufferer, the health care system and the society. Most studies have focused on obstructive sleep apnea (OSA); however, the prevalence of comorbidities in patients affected by overlap syndrome (OS) and obesity hypoventilation syndrome (OHS) has not been carefully evaluated.

STUDY OBJECTIVES: The principal aim of this study was to identify the presence of comorbidities in patients suffering from OSA, OS, OHS and the differences in three groups of patients. Another purpose was to verify if sleepiness is associated with a greater prevalence of comorbidities.

METHODS: A retrospective analysis in 989 adults referred for sleep diagnostic testing to our sleep center was performed. Patients were classified in OSA (721), OS (123) and OHS (145).

RESULTS: The prevalence of comorbidities was higher in patients affected by OS and was the highest in the OHS group, while the prevalence of arterial hypertension is the highest in patients affected by OS. The probability of having more than two comorbidities follows the same trend. Excessive daytime sleepiness was associated with an increased rate of arterial hypertension, diabetes mellitus and the presence of multimorbidity in each group of patients.

CONCLUSIONS: The presence and the association of comorbidities seem to be higher in patients suffering from OSA, OS and OHS. Subjects suffering of OHS present a high prevalence of main diseases despite their younger age compared with others patients with SDB. Sleepiness may have a role, at least in a subset of these patients, into the development of comorbidities.