Objective:

To identify clinical characteristics associated with obstructive sleep apnea (OSA) in adults with epilepsy (AWE).

Background:

The prevalence of OSA in AWE exceeds that of the general population. A 2017 meta-analysis found OSA in 40% of AWE, 2.4 times more common than age matched controls. The possibility that untreated OSA may impact epilepsy outcomes necessitates better understanding of characteristics which should prompt screening in AWE.

Design/Methods:

This is a retrospective cohort of AWE who underwent polysomnography (PSG). Baseline data including age, sex, body mass index, epilepsy classification, seizure type, seizure frequency, antiseizure medication (ASM) type, ASM dosage, antidepressant use, and Epworth Sleepiness Scale (ESS) were collected. Baseline characteristics are summarized using mean and standard deviations or medians and quartiles for continuous measures and frequencies and percentages for categorical factors. ASM standardized dose was determined using the Defined Daily Dose (DDD), a measure obtained from the World Health Organization website to compare the average maintenance dose of ASM.  OSA was defined as AHI ≥ 5.

Results:

The cohort included 197 AWE (focal N=134, 68.0%, generalized N=50, 25.4%, and unknown N=13, 6.6%). Patients with OSA (N=122, 62%) were older (47.8±13.6 vs. 37.5±14.5 yr, p<0.001), had higher BMI (33.2±7.8 vs. 27.5±6.9 kg/m2, p<0.001), and were more likely to be male (53.3% vs 22.7 %, p<0.001), and non-white (21.7% vs. 8.5%, p=0.048) than patients without OSA. No significant difference was observed in epilepsy type, seizure frequency, antidepressant use, standardized ASM, ESS score (median 8.0 [6.0, 12.0] vs. 7.0 [4.0, 10.0], p = 0.055), or ESS score ≥ 10 (38.7% vs. 32.4%, p =0.39).

Conclusions:

OSA risk factors in AWE are similar to the general population except daytime sleepiness which is commonly reported in AWE without OSA.  No significant difference was observed in seizure frequency or ASM burden suggesting that OSA risk is not limited to more refractory populations.