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Previous studies have estimated an overall prevalence for narcolepsy between 15 and 70 cases per 100 000 inhabitants. We aimed to estimate the prevalence of narcolepsy in Catalunya (Catalonia), a north-east region of Spain (7 424 754 inhabitants), on 31 December 2014 by identifying all living subjects diagnosed with narcolepsy. First, we identified patients diagnosed by one of the 13 sleep, paediatric or neurological departments that perform tests regularly to diagnose narcolepsy. In a second phase, we searched for additional patients with narcolepsy in a clinical database of the primary health-care system. Clinical files were reviewed and narcolepsy diagnosis validated according to the Brighton Collaboration case definitions. Three hundred and twenty-five patients had a validated diagnosis of narcolepsy in the specialized centres (mean age: 44.6 years, range: 6-89; male: 60.3%; 85% with narcolepsy type 1), including 17.8% cases in Brighton, definition level 1, 62.5% in level 2, 15.4% in level 3 and 4.3% in level 4a. The overall prevalence for narcolepsy was 4.4; 3.7 for narcolepsy type 1 and 0.7 cases per 100 000 inhabitants for narcolepsy type 2. Fifty-six additional narcoleptic patients were identified in the primary health-care system, increasing the overall prevalence to 5.2 cases per 100 000 inhabitants. Prevalence rates for narcolepsy type 1 increased from childhood to adulthood, but in subjects aged more than 50 years there was a substantial drop in prevalence rates, suggesting the presence of a significant pool of undiagnosed cases in this population. Narcolepsy can be considered a rare neurological disorder in Catalunya., (© 2017 European Sleep Research Society.)

Obstructive sleep apnoea (OSA) is common in patients with resistant hypertension, but understanding of the pathogenic mechanisms linking both conditions is limited. This study assessed the prevalence of OSA and the relationships between OSA and 24-h blood pressure (BP) in 62 consecutive patients with resistant hypertension, defined as clinic BP values ≥ 140/90 despite the prescription of at least three drugs at adequate doses, including a diuretic. In order to exclude a 'white coat effect', only patients with ambulatory 24-h BP values ≥ 125/80 were recruited. Patients underwent polysomnography, 24-h ambulatory BP monitoring and completed the Epworth sleepiness scale (ESS). OSA was defined as an apnoea-hypopnoea index (AHI) ≥ 5 and excessive daytime sleepiness (EDS) by an ESS ≥ 10. A multiple linear regression analysis was used to assess the association of anthropometric data, OSA severity measures and ESS with 24-h systolic and diastolic BP. Mean 24-h BP values were 139.14/80.98 mmHg. Ninety per cent of patients had an AHI ≥ 5 and 70% had an AHI ≥ 30. Only the ESS was associated with 24-h diastolic BP [slope 0.775, 95% confidence interval (CI) 0.120-1.390, P < 0.02); age was associated negatively with 24-h diastolic BP (slope -0.64, 95% CI -0.874 to -0.411, P < 0.001). Compared with those without EDS, patients with EDS showed a significantly higher frequency of diastolic non-dipping pattern (69.2% versus 34.7%, P < 0.032). Our results demonstrate a high prevalence of severe OSA in patients with resistant hypertension and suggest that EDS could be a marker of a pathogenetic mechanism linking OSA and hypertension., (© 2010 European Sleep Research Society.)