Morbidity prior to a diagnosis of sleep-disordered breathing: a controlled national study

Sleep-disordered breathing (SDB) causes burden to the sufferer, the healthcare system, and society. Most studies have focused on cardiovascular diseases (CVDs) after a diagnosis of obstructive sleep apnea (OSA) or obesity hypoventilation syndrome (OHS); however, the overall morbidity prior to an SDB diagnosis has not been evaluated. The aim of this study was to identify morbidity prior to a SDB diagnosis to identify patients at risk for having/developing SDB.

Using data from the Danish National Patient Registry (1998-2006), we identified all patients nationwide given a diagnosis of OSA (19,438) or OHS (755) in all hospitals and clinics. For each patient, we randomly selected 4 citizens matched for age, sex, and socioeconomic status from the Danish Civil Registration System Statistics.

Patients with OSA or OHS presented with increased morbidity at least 3 years prior to their SDB diagnosis. The most common contacts with the health system (odds ratio [OR]/confidence interval [CI]) for OSA/OHS were due to musculoskeletal system (1.36[1.29-1.42]/1.35[1.05-1.74]); CVD (1.38[1.30-1.46]/1.80[1.38-2.34]); endocrine, nutritional, and metabolic diseases (1.62[1.50-1.76]/4.10[2.90-5.78]); diseases of the nervous system (1.62[1.0-1.76]/3.54[2.56-4.88]); respiratory system (1.84[1.73-1.96]/2.83[2.07-3.89]); skin and subcutaneous tissue (1.18[1.07-1.30]/2.12[1.33-3.38]); gastrointestinal (1.17[1.10-1.24]/NS); infections (1.20[1.08-1.33]/NS); genitourinary system (1.21[1.13-1.30]/NS); and ear, nose, and throat (1.44[1.32-1.56]/NS).

Patients with SDB show significant morbidities several years prior to a diagnosis of OSA or OHS. OSA should be considered in all medical specialties as an important comorbidity. In our study, evidence points to particular emphasis for considering this diagnosis in endocrinology and metabolic specialties.