Concomitant obstructive sleep apnea and chronic obstructive pulmonary disease: study design--the OLIN OSAS-COPD study.

BACKGROUND

Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are both common disorders. Concomitant disease, overlap syndrome, is reported to cause a more severe condition.

AIM: To describe a study designed to evaluate the prevalence of overlap syndrome in the general population, and further, to assess the impact of overlap syndrome on cardiovascular morbidity and health-related quality of life. A secondary aim is to evaluate screening oxygen saturation (Sa02) by pulse oxymetry.

MATERIAL AND METHOD: From the last examination of the OLIN-studies (Obstructive Lung Disease in Northern Sweden), cohorts I-IV all subjects with FEV1 < or = 50 percent predicted or Sa02 < or = 93 percent predicted were identified (Phase 1). They are invited to a program including lab tests, spirometry, arterial blood gases, chest x-ray, echocardiography, sleep studies and health-related quality of life (HRQL) questionnaires. In Phase 2, a random sample of subjects reporting snoring as a problem (n = 100) will be invited to a limited program above all including sleep studies and HRQL questionnaires; and in Phase 3, a random sample (n = 100) will be invited to a similar program.

SUMMARY: The collection of data in Phase 1 is in progress and will be completed by the end of year 2007. Phase 2 will start year 2008.