HLA-DQB1*06:02 allele frequency and clinic-polysomnographic features in Saudi Arabian patients with narcolepsy.

BACKGROUND: Narcolepsy is an uncommon neurological disorder characterised by irresistible spells of sleep associated with abnormal rapid eye movement (REM) sleep. The association between narcolepsy and human leukocyte antigen HLA- DQB1*06:02 has been established elsewhere but remains to be investigated among Saudi Arabian patients with narcolepsy. METHODS: A total of 29 Saudi patients with type I or type 2 narcolepsy comprising of 23 (79%) males and 6 (21%) females with a mean age of 17.2 ± 9.6 years were included in this study. Type 1 or type 2 narcolepsy was diagnosed by full polysomnography followed by a multiple sleep latency test in accordance with International Classifications of Sleep Disorders-3 criteria. HLA typing for DQB1 alleles was performed by polymerase chain reaction and hybridization with sequence-specific oligonucleotide probes. Differences in clinical and sleep parameters were compared by univariable analyses. HLA-DQB1*06:02 frequency was systematically compared with the published literature. RESULTS: Type 1 narcolepsy was diagnosed in 19/29 (65.5%) patients, whereas 10/29 (34.5%) patients had type 2 narcolepsy. DQB1*06:02 was present in 25/29 (86.2%) patients; 15/19 (78.9%) narcolepsy type 1 patients and 10/10 (100%) narcolepsy type 2 patients harboured the DQB1*06:02 allele. REM latency was significantly lower in DQB1*06:02-positive patients compared to DQB1*06:02-negative patients (17.6 ± 32.3 min vs. 106.0 ± 86.0 min; p = 0.025). Epworth Sleepiness Scale scores were significantly higher among type 1 than type 2 narcolepsy patients (19.7 ± 3.2 vs 15.3 ± 3.6; p = 0.02). CONCLUSIONS: DQB1*06:02 allele frequencies among Saudi patients with narcolepsy were consistent with previously published data.

Long-term adherence to continuous positive airway pressure in patients with rapid eye movement-only obstructive sleep apnea: a prospective cohort study.

BACKGROUND: Obstructive sleep apnea (OSA) during rapid eye movement (REM) sleep is a special form of OSA that occurs predominantly during REM sleep. No study has assessed the long-term adherence to continuous positive airway pressure (CPAP) among patients with REM-only OSA. To objectively assess the long-term adherence to CPAP therapy among patients with REM-predominant (REM-only) OSA. METHODS: This was a prospective observational cohort study that included consecutive patients who were diagnosed with OSA. Patients were divided into the following two groups: (I) REM-only OSA [an apnea hypopnea index (AHI) of ≥5, with a REM-AHI/NREM-AHI of >2, an NREM-AHI of <15, and a minimum of 15 min of REM-sleep duration], and (II) non-stage specific OSA. Follow-up was performed at 1, 6 and 12 months after the initiation of CPAP-therapy. RESULTS: The study included 175 patients; 30 met the criteria for REM-only OSA, and the remaining patients constituted the non-stage specific OSA group. The number of hours of CPAP use per day was significantly lower in the REM-only OSA group at 1, 6 and 12 months compared to the non-stage specific OSA group. At 12 months, the number of hours used per day was 3.8±1.8 and 5.1±2.1 hours in the REM-only and non-stage specific OSA groups, respectively (P=0.003). Approximately 80% of the enrolled participants in both groups were still using CPAP at the end of the study; 23.3% of REM-only OSA patients met the criteria for good adherence (>4 hours/day), and 56.7% met the criteria for partial adherence. CONCLUSIONS: CPAP adherence is lower among patients with REM-only OSA compared to patients with non-stage specific OSA.

The success rate of split-night polysomnography and its impact on continuous positive airway pressure compliance.

OBJECTIVES: With the increased volume of referrals of patients with obstructive sleep apnea (OSA) for sleep studies, there is a great need for alternatives of the standard two-night polysomnography (PSG) like split-night PSG. Therefore, we conducted this study to determine the success rate of continuous positive airway pressure (CPAP) titration during split-night PSG, and to determine the predictors of titration success and the impact on subsequent CPAP compliance in Saudi patients with OSA. METHODS: This is a prospective cohort study that included consecutive patients who were diagnosed with OSA and underwent a split-night PSG (n = 454). A subgroup of patients who used CPAP therapy, agreed to come for follow-up after 4 and 10 months (n = 130). This subgroup was compared with a matched group of OSA patients who underwent a two-night sleep study protocol (n = 80). RESULTS: The study group had a mean age of 48.7 ± 13.3 years, body mass index (BMI) of 37.5 ± 10.1 kg/m(2) and apnea hypopnea index of 58.4 ± 35.0 events/h. Successful CPAP titration was achieved in 350 (77%) patients. In a full adjusted model, "BMI >35 kg/m(2)" and "known cardiac disease" remained significant predictors of a lower success rate of CPAP titration. After 10 months, 88% of the patients in the split-night protocol met the set criteria for good compliance versus 85% in the two-night protocol. CONCLUSION: Split-night protocol is an effective protocol for diagnosing OSA and titrating CPAP. CPAP compliance rate showed no difference between the split-night and the two-night protocols.