Patients with idiopathic intracranial hypertension (IHH) are at increased risk of obstructive sleep apnea (OSA), according to a new study from the UK.
A team led by Andreas Yiangou, BSc, MBBS, Metabolic Neurology, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, assessed the prevalence of obstructive sleep apnea in patients with idiopathic intracranial hypertension and assessed the diagnostic Performance of obstructive sleep apnea instruments in this patient population and the relationship between weight loss and the two diseases over 1 year.
The link between diseases
Obesity is a known risk factor for a number of diseases, including obstructive sleep apnea and idiopathic intracranial hypertension. IHH is increased intracranial pressure with no apparent cause that generally occurs in young women with obesity. Symptoms can include headache, temporary visual disturbances, pulsating tinnitus, cognitive impairment, back and neck pain, and double vision.
The incidence of OSA in each grade in the general population ranges from 9-38% but is higher with age, body mass index, and male gender.
“A comorbid relationship between IIH and OSA is well described, but how often this occurs and the relevance for IIH is uncertain,” the authors write.
Examination of the data
In the sub-study of a multicenter, randomized, controlled, parallel group study, the investigators compared the effects of bariatric surgery with community-based weight control interventions on IIH-related outcomes over a period of 12 months. They also assessed obstructive sleep apnea, defined as apnea-hypopnea index (AHI) 15 or ≥ 5 with excessive daytime sleepiness (Epworth Sleepiness Scale ≥ 11), using home polygraphy at baseline and after 12 months.
66 women were identified with IHH, 46 of whom were included in the study. The prevalence of obstructive sleep apnea was 47% (n = 19). The STOP-BANG had a higher sensitivity (84%) compared to both the Epworth Sleepiness Scale (69%) and Berlin (68%) to detect obstructive sleep apnea.
In addition, the bariatric surgery led to a greater reduction in the Apeana-Hypopbea Index compared to the Community Weight Management intervention group (median AHI reduction of –2.8; 95% CI, –11.9 to 0.7; P = 0.017).
After 12 months there was a positive association between changes in papillary edema and AHI (r = 0.543; P = 0.045). This remained true even after adjusting for changes in body mass index (R2 = 0.522, P = 0.017).
“Our data also suggest that treating OSA in patients with IIH can improve optic disc edema,” the authors write. “The high prevalence of OSA in IIH is higher than previously reported in the historical literature. The higher prevalence in our cohort may reflect the larger cohort size, but also trends towards increasing BMI in IIH patients in line with the global obesity epidemic. “
The authors said more research is needed to assess whether treating obstructive sleep apnea has a positive impact on optic disc edema, the swelling of the optic nerve.
The study, “Obstructive Sleep Apnea in Women with Idiopathic Intracranial Hypertension: A Sub-Study of the Weight-Controlled Idiopathic Intracranial Hypertension Study (IIH: WT)” was published online in the Journal of Neurology.