Findings of a Berlin Questionnaire survey: Comparison between patients seen in an asthma clinic versus internal medicine clinic

BackgroundObstructive sleep apnea (OSA) and asthma are common and share similar nocturnal symptoms. We hypothesized that the prevalence of OSA symptoms would be greater in asthmatics compared to a general internal medicine population.MethodsPatients in the Asthma Clinics (n = 177) and Internal Medicine Clinics (n = 328) at MetroHealth Medical Center, an urban academic institution, were surveyed for OSA risk. Patients completed the Berlin Questionnaire, a validated questionnaire with a positive predictive value (ppv) of 0.89 for determining the presence of OSA in primary care populations. All asthmatics had spirometry performed.ResultsThe asthma group had more females (p = 0.01) and a higher mean body mass index (33.2 vs. 31.2 kg/m2, p = 0.02). However, the percentage with a body mass index >30 kg/m2 was not different between the groups (p = 0.19). The internal medicine group had a much higher rate of hypertension (p = 0.002) and diabetes (p < 0.001). Asthmatics were more likely to report frequent snoring (18.5% vs. 8.0%, p < 0.001) and chronic sleepiness (46.1% vs. 34.3%, p = 0.01). OSA risk, as determined by the Berlin Questionnaire, was higher in the asthma group than in the internal medicine group (39.5% vs. 27.2%, p = 0.004). In the asthma group, risk for OSA did not correlate with asthma severity (p = 0.183).ConclusionsThis study suggests a possible association between asthma and OSA. There is a higher prevalence of OSA symptoms in an asthmatic population when compared to a primary care population, independent of the severity of the asthma.