Narcolepsy and sleep-disordered breathing

Background and purpose: There is a high incidence of sleep-disordered breathing (SDB) in narcoleptic patients. Some narcoleptics with SDB may benefit from treatment with continuous positive airway pressure therapy (CPAP). The aim of this study was to examine the prevalence of SDB in narcoleptics referred to a tertiary sleep disorders clinic and assess the effectiveness of CPAP as adjunctive therapy. Methods: A retrospective review of patients meeting ICSD-2 criteria for the diagnosis of narcolepsy from 2000 to 2009. Results: One hundred and two patients (61 women) with narcolepsy were included in the study. Twenty-nine (29) patients (eight women, 21 men) were diagnosed with obstructive sleep apnoea-hypopnoea syndrome (OSAHS) of whom 26 commenced CPAP therapy with 11 patients concurrently treated with stimulants. Patients with narcolepsy and OSAHS were older (P = 0.009) and heavier (BMI, 29.6 +/- 4.8 vs. 27.3 +/- 6, P = 0.042), but their ESS did not differ from patients with narcolepsy alone. Patients treated with both CPAP and stimulants were younger (P = 0.008) and less obese (BMI, 29.1 +/- 4.6 vs. 30.4 +/- 5.4, P = 0.044) with higher apnoea-hypopnoea index (36.15 +/- 21.9 vs. 31.5 +/- 16.7, P = 0.03) than those treated with CPAP alone. The ESS of CPAP-treated patients improved during follow-up (19 +/- 3.6 vs. 15.8 +/- 4.5, P = 0.006), but BMI increased (30.6 +/- 5 vs. 31.7 +/- 5.6, P = 0.05). The use of stimulants did not seem to improve on the effectiveness of CPAP. Conclusion: Coexisting SDB is common in narcoleptics (28.5%). CPAP therapy in narcoleptics with OSAHS remains a useful second-line adjunct to standard therapy.