title: TST, as a polysomnographic variable, is superior to the apnea hypopnea index for evaluating intermittent hypoxia in severe obstructive sleep apnea.
abstract: The polysomnography (PSG) index of the apnea hypopnea index (AHI) is considered the 'gold standard' for stratifying the severity of obstructive sleep apnea (OSA). However, AHI cannot reflect the true characteristic of chronic intermittent hypoxia (CIH), which may trigger systemic inflammation in some OSA patients. High-sensitivity C-reactive protein (hsCRP) is considered a biomarker of systemic inflammation in OSA patients. The aim of the present study was to evaluate the relationship between PSG variables and hsCRP in men with severe OSA. Men with severe OSA (AHI ≥ 30 events/h) diagnosed by PSG were enrolled. AHI and body mass index were matched between a high hsCRP group (hsCRP ≥ 3.0 mg/L) and a low hsCRP group. A blood sample was taken for serum hsCRP analysis. Multiple regression analysis was performed to assess independent predictors of high hsCRP. One hundred and fifty-two subjects were enrolled in the study (76 in each group). Mean serum hsCRP was 3.76 ± 2.13 mg/L. The mean percentage of total sleep time spent with SaO2 <90% (TST) in the high hsCRP group was significantly higher than in the low hsCRP group (20.99 ± 18.52 vs. 5.84 ± 7.30, p < 0.001). Multivariate analysis showed that TST was the strongest predictor, contributing to 27.7% of hsCRP variability (β = 0.496, p < 0.01). TST may be superior to AHI for evaluating CIH among OSA patients. The severity of OSA should be stratified by a combination of AHI and other hypoxia variables.
authors.affiliation: Department of Respiratory Medicine, Zhongshan Hospital, Xiamen University, Xiamen, China.
authors.forename: Xiao-Bin
authors.initials: XB
authors.lastname: Zhang
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Zen
authors.forename: Qi-Chang
authors.initials: QC
authors.lastname: Lin
authors.forename: Gong-Ping
authors.initials: GP
authors.lastname: Chen
authors.forename: Li-Da
authors.initials: LD
authors.lastname: Chen
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
mesh_terms: D005260:Female; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology
references.citation: Intern Med. 2009;48(15):1255-62
references.pmid: 19652426
references.citation: Sleep. 2007 Jan;30(1):29-34
references.pmid: 17310862
references.citation: Circulation. 2003 Mar 4;107(8):1129-34
references.pmid: 12615790
references.citation: N Engl J Med. 1993 Apr 29;328(17):1230-5
references.pmid: 8464434
references.citation: Intern Med. 2005 Aug;44(8):899-900
references.pmid: 16157997
references.citation: Med Sci Monit. 2011 Sep;17(9):CR491-7
references.pmid: 21873945
references.citation: Chest. 2009 Apr;135(4):950-956
references.pmid: 19225064
references.citation: Respiration. 2009;78(3):278-84
references.pmid: 19218786
references.citation: Sleep. 2007 Aug;30(8):997-1001
references.pmid: 17702269
references.citation: Thorax. 2010 Jun;65(6):523-7
references.pmid: 20522850
references.citation: Qual Life Res. 2002 Dec;11(8):817-21
references.pmid: 12482165
references.citation: Sleep. 1991 Dec;14(6):540-5
references.pmid: 1798888
references.citation: N Engl J Med. 2002 Nov 14;347(20):1557-65
references.pmid: 12432042
references.citation: Chest. 2007 Sep;132(3):843-51
references.pmid: 17573492
references.citation: JAMA. 1999 Dec 8;282(22):2131-5
references.pmid: 10591334
references.citation: Eur Respir J. 2009 Apr;33(4):797-803
references.pmid: 19213794
references.citation: Biochem Biophys Res Commun. 2006 May 5;343(2):591-6
references.pmid: 16554025
references.citation: Int Heart J. 2005 Sep;46(5):801-9
references.pmid: 16272771
references.citation: Am J Respir Crit Care Med. 2005 Sep 1;172(5):613-8
references.pmid: 15901608
references.citation: Circulation. 2003 Oct 21;108(16):1917-23
references.pmid: 14568885
references.citation: JAMA. 2003 Oct 8;290(14):1906-14
references.pmid: 14532320
references.citation: N Engl J Med. 2000 Oct 19;343(16):1139-47
references.pmid: 11036119
references.citation: Chest. 2009 Jul;136(1):125-129
references.pmid: 19255295
references.citation: Eur Respir J. 2008 Oct;32(4):1082-95
references.pmid: 18827154
references.citation: Sleep Med. 2008 Jan;9(2):149-56
references.pmid: 17638590
references.citation: Lancet. 1994 Sep 3;344(8923):653-5
references.pmid: 7915351
references.citation: J Sleep Res. 2012 Apr;21(2):147-54
references.pmid: 21895822
references.citation: Circulation. 2002 May 28;105(21):2462-4
references.pmid: 12034649
references.citation: Circulation. 2005 Oct 25;112(17):2660-7
references.pmid: 16246965
references.citation: JAMA. 2001 May 16;285(19):2481-5
references.pmid: 11368701
references.citation: Lancet. 1997 Feb 15;349(9050):462-6
references.pmid: 9040576