Obstructive sleep apnea in Norwegian adults with achondroplasia: a population-based study.

BACKGROUND Previous studies have found a high prevalence of obstructive sleep apnea (OSA) in children with achondroplasia, but clinical studies on this complication in adults with achondroplasia are lacking. OBJECTIVES This population-based, cross-sectional study investigated the prevalence, severity, and predictive factors of OSA in Norwegian adults with achondroplasia. METHODS We collected clinical data on 49 participants. Participants without a preexisting diagnosis of OSA had an overnight sleep registration. OSA was defined as an apnea-hypopnea index (AHI) ≥ 5 plus characteristic clinical symptoms, or AHI ≥ 15. We used the Berlin Questionnaire to assess clinical symptoms of OSA. RESULTS OSA was found in 59% (29/49) of the participants (95% confidence interval 44 to 73%), of whom 59% (17/29) had moderate to severe OSA (AHI ≥ 15), and 48% (14/29) were previously undiagnosed. Variables predictive of OSA were: excessive daytime sleepiness; unrested sleep; loud snoring; observed nocturnal breathing stops; hypertension; age > 40 years; and BMI > 30 kg/m2. CONCLUSION OSA was highly prevalent in Norwegian adults with achondroplasia, which we believe is representative of this population worldwide. Follow-up of adults with achondroplasia should include assessment of symptoms and signs of OSA, with a low threshold for conducting an overnight sleep registration if findings suggestive of OSA are present.