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Obstructive sleep apnoea is common in adults with biopsy-proven non-alcoholic fatty liver disease
Sleep Medicine 16 (2015) 1026
Contents lists available at ScienceDirect
Sleep Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / s l e e p
Letter to the Editor Obstructive sleep apnoea is common in adults with biopsy-proven non-alcoholic fatty liver disease To the Editor: Non-alcoholic fatty liver disease (NAFLD) is increasing in prevalence [1]. There is evidence that obstructive sleep apnoea (OSA) is an independent risk factor for NAFLD [2]. Cohort studies have demonstrated a high incidence of fatigue and OSA symptoms in those with NAFLD [3,4]. We collected data from a large, well-defined, biopsy-proven cohort of 385 patients with NAFLD. Liver biopsies were examined by specialist pathologists and scored for the level of fibrosis and necrosis. Case notes were retrospectively reviewed; 47 patients were referred for respiratory polygraphy (Embletta). They had significantly higher Epworth Sleepiness Scale scores than those not referred (mean 13.3 vs. 6.9, p = 0.004), suggesting this was the reason for referral. Of the 44 who attended for sleep studies, 38 had OSA, which is 86% of those completing investigations and 10% of the whole cohort. Twelve had mild OSA [apnoea–hypopnoea index (AHI) ≥ 5–15 per hour], 14 moderate, and nine severe OSA. AHI was missing for three subjects, but the results were ‘consistent with OSA’. In total, 29 patients commenced continuous positive airway pressure (CPAP) with 17 (59%) continuing long term. There were no significant differences in any clinical characteristic, biochemical measure or liver histology score between the group with no investigations, the group with OSA and the group with no OSA. In the group with OSA, there was no correlation of AHI with any liver-specific blood tests. This indicates that, overall, there were no specific indices that could be used to prospectively identify people with OSA. The high positive diagnostic rate of those screened suggests that the prevalence of OSA in people with NAFLD is far higher and currently mostly undiagnosed. All patients with NAFLD should be considered for screening sleep studies. A recent meta-analysis of CPAP versus sham CPAP on metabolic biomarkers included two studies with no significant change in liver enzymes, but neither study included people with known NAFLD, so the effects of CPAP in this specific group are still unknown [5].
Grant support: None. Disclosures and writing assistance: None. Author contributions: Authors 1, 2 and 5 (in order as listed above) were involved in the study concept and design and acquisition of data. Authors 1 and 5 were additionally involved in data analysis, statistical analysis and drafting of the manuscript. Authors 2, 3 and 4 were involved in critical revision of the manuscript.
http://dx.doi.org/10.1016/j.sleep.2015.04.003 1389-9457/© 2015 Elsevier B.V. All rights reserved.
Conflict of interest None to declare. The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2015.04.003.
References [1] Marchesini G, Bugianesi E, Forlani G, et al. Nonalcoholic fatty liver, steatohepatitis, and the metabolic syndrome. Hepatology 2003;37:917–23. [2] Tanne F, Gagnadoux F, Chazouilleres O, et al. Chronic liver injury during obstructive sleep apnoea. Hepatology 2005;41:1290–6. [3] Newton JL, Jones DEJ, Henderson E, et al. Fatigue in non-alcoholic fatty liver disease (NAFLD) is significant and associates with inactivity and excessive daytime sleepiness but not with liver disease severity or insulin resistance. Gut 2008;57:807–13. [4] Singh H, Pollock R, Uhanova J, et al. Symptoms of obstructive sleep apnea in patients with non-alcoholic fatty liver disease. Dig Dis Sci 2005;50:2338– 43. [5] Jullian-Desayes I, Joyeux-Faure M, Tamisier R, et al. Impact of obstructive sleep apnea treatment by continuous positive airway pressure on cardiometabolic biomarkers: a systematic review from sham CPAP randomized controlled trials. Sleep Med Rev 2015;21:23–38. [Epub ahead of print]. pii: S10870792(14)00078-1.
Sarah Wiscombe Newcastle Regional Sleep Service, Newcastle Upon Tyne, UK Julia Newton Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, UK Christopher Day Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK John Gibson Newcastle Regional Sleep Service, Newcastle Upon Tyne, UK Sophie West * Newcastle Regional Sleep Service, Newcastle Upon Tyne, UK * Address: Newcastle Regional Sleep Service, Freeman Hospital, Freeman Road, Newcastle Upon Tyne NE7 7DN, UK. Tel.: +0191 233 6161; fax: +0191 2137397. E-mail address: [email protected] (S. West). Available online 20 April 2015
Contents lists available at ScienceDirect
Sleep Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / s l e e p
Letter to the Editor Obstructive sleep apnoea is common in adults with biopsy-proven non-alcoholic fatty liver disease To the Editor: Non-alcoholic fatty liver disease (NAFLD) is increasing in prevalence [1]. There is evidence that obstructive sleep apnoea (OSA) is an independent risk factor for NAFLD [2]. Cohort studies have demonstrated a high incidence of fatigue and OSA symptoms in those with NAFLD [3,4]. We collected data from a large, well-defined, biopsy-proven cohort of 385 patients with NAFLD. Liver biopsies were examined by specialist pathologists and scored for the level of fibrosis and necrosis. Case notes were retrospectively reviewed; 47 patients were referred for respiratory polygraphy (Embletta). They had significantly higher Epworth Sleepiness Scale scores than those not referred (mean 13.3 vs. 6.9, p = 0.004), suggesting this was the reason for referral. Of the 44 who attended for sleep studies, 38 had OSA, which is 86% of those completing investigations and 10% of the whole cohort. Twelve had mild OSA [apnoea–hypopnoea index (AHI) ≥ 5–15 per hour], 14 moderate, and nine severe OSA. AHI was missing for three subjects, but the results were ‘consistent with OSA’. In total, 29 patients commenced continuous positive airway pressure (CPAP) with 17 (59%) continuing long term. There were no significant differences in any clinical characteristic, biochemical measure or liver histology score between the group with no investigations, the group with OSA and the group with no OSA. In the group with OSA, there was no correlation of AHI with any liver-specific blood tests. This indicates that, overall, there were no specific indices that could be used to prospectively identify people with OSA. The high positive diagnostic rate of those screened suggests that the prevalence of OSA in people with NAFLD is far higher and currently mostly undiagnosed. All patients with NAFLD should be considered for screening sleep studies. A recent meta-analysis of CPAP versus sham CPAP on metabolic biomarkers included two studies with no significant change in liver enzymes, but neither study included people with known NAFLD, so the effects of CPAP in this specific group are still unknown [5].
Grant support: None. Disclosures and writing assistance: None. Author contributions: Authors 1, 2 and 5 (in order as listed above) were involved in the study concept and design and acquisition of data. Authors 1 and 5 were additionally involved in data analysis, statistical analysis and drafting of the manuscript. Authors 2, 3 and 4 were involved in critical revision of the manuscript.
http://dx.doi.org/10.1016/j.sleep.2015.04.003 1389-9457/© 2015 Elsevier B.V. All rights reserved.
Conflict of interest None to declare. The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2015.04.003.
References [1] Marchesini G, Bugianesi E, Forlani G, et al. Nonalcoholic fatty liver, steatohepatitis, and the metabolic syndrome. Hepatology 2003;37:917–23. [2] Tanne F, Gagnadoux F, Chazouilleres O, et al. Chronic liver injury during obstructive sleep apnoea. Hepatology 2005;41:1290–6. [3] Newton JL, Jones DEJ, Henderson E, et al. Fatigue in non-alcoholic fatty liver disease (NAFLD) is significant and associates with inactivity and excessive daytime sleepiness but not with liver disease severity or insulin resistance. Gut 2008;57:807–13. [4] Singh H, Pollock R, Uhanova J, et al. Symptoms of obstructive sleep apnea in patients with non-alcoholic fatty liver disease. Dig Dis Sci 2005;50:2338– 43. [5] Jullian-Desayes I, Joyeux-Faure M, Tamisier R, et al. Impact of obstructive sleep apnea treatment by continuous positive airway pressure on cardiometabolic biomarkers: a systematic review from sham CPAP randomized controlled trials. Sleep Med Rev 2015;21:23–38. [Epub ahead of print]. pii: S10870792(14)00078-1.
Sarah Wiscombe Newcastle Regional Sleep Service, Newcastle Upon Tyne, UK Julia Newton Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, UK Christopher Day Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK John Gibson Newcastle Regional Sleep Service, Newcastle Upon Tyne, UK Sophie West * Newcastle Regional Sleep Service, Newcastle Upon Tyne, UK * Address: Newcastle Regional Sleep Service, Freeman Hospital, Freeman Road, Newcastle Upon Tyne NE7 7DN, UK. Tel.: +0191 233 6161; fax: +0191 2137397. E-mail address: [email protected] (S. West). Available online 20 April 2015