Obstructive sleep apnoea in women with idiopathic intracranial hypertension: a sub-study of the idiopathic intracranial hypertension weight randomised controlled trial (IIH: WT)

Abstract

Objective: Obesity is a risk factor for idiopathic intracranial hypertension (IIH) and obstructive sleep apnoea (OSA). We aimed to determine the prevalence of OSA in IIH and evaluate the diagnostic performance of OSA screening tools in IIH. Additionally, we evaluated the relationship between weight loss, OSA and IIH over 12 months.

Methods: A sub-study of a multi-centre, randomised controlled parallel group trial comparing the impact of bariatric surgery vs. community weight management intervention (CWI) on IIH-related outcomes over 12 months (IIH:WT). OSA was assessed using home-based polygraphy (ApneaLink Air, ResMed) at baseline and 12 months. OSA was defined as an apnoea-hypopnoea index (AHI) ≥ 15 or ≥ 5 with excessive daytime sleepiness (Epworth Sleepiness Scale ≥11 ).

Results: Of the 66 women in the IIH: WT trial, 46 were included in the OSA sub-study. OSA prevalence was 47% (n = 19). The STOP-BANG had the highest sensitivity (84%) compared to the Epworth Sleepiness Scale (69%) and Berlin (68%) to detect OSA. Bariatric surgery resulted in greater reductions in AHI vs. CWI (median [95%CI] AHI reduction of - 2.8 [ - 11.9, 0.7], p = 0.017). Over 12 months there was a positive association between changes in papilloedema and AHI (r = 0.543, p = 0.045), despite adjustment for changes in the body mass index (R2 = 0.522, p = 0.017).

Conclusion: OSA is common in IIH and the STOP-BANG questionnaire was the most sensitive screening tool. Bariatric surgery improved OSA in patients with IIH. The improvement in AHI was associated with improvement in papilloedema independent of weight loss. Whether OSA treatment has beneficial impact on papilloedema warrants further evaluation.

Trial registration number: IIH: WT is registered as ISRCTN40152829 and on ClinicalTrials.gov as NCT02124486 (28/04/2014).

Keywords: Bariatric surgery; Idiopathic intracranial hypertension; Obstructive sleep apnoea; Papilloedema; Screening.

Conflict of interest statement

Nicholls, Chong, Vijay, Lavery have no conflicts of interest to declare that are relevant to the content of this article. Yiangou reports receiving speaker fees from Teva, UK outside the submitted work. Mitchell reports receiving grants from the National Institute of Health Research during the conduct of the study and grants from the UK Ministry of Defence outside the submitted work. Wakerley reports receiving consultancy fees from Invex Therapeutics outside the submitted work. Lavery reports receiving funding through a Wellcome Trust Senior Fellowship during the conduct of the study. Mollan reports receiving personal fees from Allergan, Chiesi Farmaceutici, Heidelberg Engineering, Invex Therapeutics, Neurodiem, Novartis, Roche, Santen Pharmaceutical, Scope Ophthalmics and Santhera Pharmaceuticals outside the submitted work. Tahrani reports grants, personal fees, and travel support from Sanofi, grants, personal fees and educational events grants from Novo Nordisk, travel support from Merck Sharp and Dohme, personal fees and travel support from Boehringer Ingelheim, personal fees from Lilly, AstraZeneca, Bristol-Myers Squibb, and Janssen, equipment and travel support from ResMed, equipment from Philips Resporinics, Impeto Medical, and ANSAR Medical Technologies, grants and non-financial support from Napp, and equipment and support staff from BHR Pharmaceuticals Ltd. Tahrani is currently an employee of Novo Nordisk. This work was performed before Tahrani becoming a Novo Nordisk employee and Novo Nordisk had no role in this study. Sinclair reports receiving personal fees (salary and stock options) from Invex therapeutics, during the conduct of the study but outside the submitted work; and receiving grants from the Medical Research Council of the United Kingdom and funding through a Sir Jules Thorn Award for Biomedical Science during the conduct of the study.

© 2021. The Author(s).

Figures

Fig. 1

Study flow diagram. IIH idiopathic intracranial hypertension, WT Weight trial, OSA Obstructive sleep apnoea

Fig. 2

Obstructive sleep apnoea parameters. A. Presence and severity of obstructive sleep apnoea (OSA) based on the apnoea–hypopnoea index in IIH patients. B. Apnoea-hypopnoea index in patients with IIH at baseline comparing the two arms of community weight management intervention (CWI) and bariatric surgery. Level of the bars represents median and error bars interquartile range. Wilcoxon signed ranks test to assess differences between baseline and 12 months in the two groups. Mann–Whitney test to assess differences between arms at 12 months. C, D. Linear regression analysis showing the percentage change (Δ) of apnoea–hypopnoea index against percentage change (Δ) in intracranial pressure and OCT optic nerve head central thickness at 12 months after baseline in IIH patients. Spearman’s rank order used to assess correlations. *Denotes statistical significance p < 0.05, difference between apnoea–hypopnoea index of the bariatric surgery group at 12 months compared to baseline. IIH idiopathic intracranial hypertension, ICP intracranial pressure, OCT optical coherence tomography, AHI apnoea–hypopnoea index

Fig. 3

Changes according to OSA status at baseline. Mean changes (Δ) of key parameters at 12 months according to OSA status at baseline. Error bars represent standard error of the mean (SEM). OSA at baseline (n = 10), No OSA (n = 9) for A, C and D. OSA at baseline (n = 7), No OSA (n = 7) for B. OSA obstructive sleep apnoea, RNFL retinal nerve fibre layer