Overlap syndrome: Association of chronic obstructive pulmonary disease and obstructive sleep apnea syndrome

COPD and the OSAHS are both common diseases affecting respectively 10% and 5% of the adult population over 40 years of age. Their coexistence, which is denominated as «overlap syndrome», can occur in about 0.5% of this population.Aim and materialsTo assess the existence of a prevalence of OSAHS in patients with COPD through a prospective analysis: 70 had a confirmed isolated OSAHS (group A) and 11 had an OS (group B), all were compiled from January 2007 to June 2012.ResultsThe prevalence of OS in our study was 13.6%, OS patients were older than the isolated OSAHS patients (p < 0.05) with a male predominance in the Overlap arm (p < 0.05), and BMI was similar between the 2 groups (p = 0.22). Tobacco is retained as a risk factor and 81.8% of patients with Overlap were smoking (p < 0.05). Clinical signs most reported are nocturnal snoring and daytime sleepiness. The Epworth Sleepiness Scale was higher than 10 in the 2 groups (p < 0.05). The Berlin questionnaire realized in 30 subjects in group A, was positive (40% of cases) and was positive in 63.6% of 7 subjects in group B. Spirometry showed that vital capacity, FEV1 and FEV1/CV were significantly decreased in the Overlap group (p < 0.001). The recording shows a sleep apnea–hypopnea index (AHI) similar in the two groups (p < 0.05).ConclusionThere was no correlation between COPD and OSAHS. The latter is a risk factor for the first.