Endothelial dysfunction and C-reactive protein in relation with the severity of obstructive sleep apnea syndrome.
OBJECTIVE
To investigate flow-mediated dilatation (FMD) and C-reactive protein (CRP) levels in patients with obstructive sleep apnea syndrome (OSAS) in relation with the severity of respiratory disturbances and hypoxemia.


METHODS
After subjects had completed nocturnal polysomnography, FMD was measured in the brachial artery, and blood samples were obtained to determine serum CRP levels.


METHODS
Sleep laboratory in Seoul National University Bundang Hospital.


METHODS
Ninety men: 22 normal controls, 28 subjects with mild to moderate OSAS, and 40 with severe OSAS.


RESULTS
FMD was found to be correlated with oxygen desaturation index (ODI), percentage of time below 90% O2 saturation, average O2 saturation, lowest O2 saturation, systolic blood pressure, apnea hypopnea index (AHI), and body mass index. In addition, CRP was correlated with body mass index, waist-to-hip ratio, neck circumference, diastolic pressure, average O2 saturation and percentage of time below 90% O2 saturation but not with AHI. Stepwise multiple regression showed that the ODI was a significant determinant of FMD (adjusted R2 = 10%, beta = -0.33, P < 0.01). In addition, body mass index (beta = 0.25, P < 0.05) and waist-to-hip ratio (beta = 0.21, P < 0.05) were found to be significantly correlated with CRP (adjusted R2 = 12%, P < 0.05), independently of other factors. There was no correlation between FMD and CRP.


CONCLUSIONS
As a marker of nocturnal hypoxemia, ODI rather than AHI might better explain the relationship between OSAS and FMD. Because body mass index and waist-to-hip ratio were identified as risk factors of high serum CRP in OSAS, obesity should be considered when predicting cardiovascular complications in OSAS.
Chung
Seockhoon
S
Department ofNeuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Korea.
Yoon
In-Young
IY
Shin
Yoon-Kyung
YK
Lee
Chul Hee
CH
Kim
Jeong-Whun
JW
Lee
Taeseung
T
Choi
Dong-Ju
DJ
Ahn
Hee Jeong
HJ
D000328:Adult; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000175:diagnosis; D014664:Vasodilation / Q000502:physiology; D049629:Waist-Hip Ratio
D002097:C-Reactive Protein; D010100:Oxygen
Am J Respir Crit Care Med. 2006 Apr 15;173(8):897-901
16439717
Am J Respir Crit Care Med. 2001 Jan;163(1):19-25
11208620
Circulation. 1999 Mar 9;99(9):1141-6
10069780
Am J Respir Crit Care Med. 2004 Feb 1;169(3):354-60
14551166
Circulation. 2002 May 28;105(21):2462-4
12034649
Lancet. 1997 Feb 15;349(9050):462-6
9040576
J Intern Med. 2001 Jul;250(1):29-36
11454139
Am Rev Respir Dis. 1988 Apr;137(4):895-8
3354998
Am J Med. 2000 Jun 1;108(8):652-9
10856414
Curr Opin Nephrol Hypertens. 2002 Mar;11(2):141-7
11856905
Proc Natl Acad Sci U S A. 1994 May 24;91(11):5212-6
7515189
Hypertension. 1992 Aug;20(2):175-80
1639458
Coron Artery Dis. 1996 Jul;7(7):541-5
8913673
Chest. 2001 Apr;119(4):1085-91
11296174
Sleep Med Rev. 2003 Feb;7(1):35-51
12586529
N Engl J Med. 1990 Jul 5;323(1):22-7
2355955
N Engl J Med. 2000 Oct 19;343(16):1139-47
11036119
Am J Respir Crit Care Med. 1995 Aug;152(2):711-6
7633731
Circulation. 2003 Mar 4;107(8):1129-34
12615790
J Steroid Biochem Mol Biol. 2005 Aug;96(3-4):271-8
15993048
Circulation. 2000 Apr 18;101(15):1767-72
10769275
Curr Opin Neurol. 2003 Feb;16(1):87-90
12544862
Circulation. 2000 Nov 21;102(21):2607-10
11085964
Sleep. 2004 Dec 15;27(8):1507-11
15683141
Sleep Med. 2003 Sep;4(5):403-7
14592281
Clin Sci (Lond). 2005 Feb;108(2):121-8
15504106
Hypertension. 2001 Aug;38(2):274-9
11509489
Thorax. 2006 Jun;61(6):491-5
16537671
N Engl J Med. 2005 Nov 10;353(19):2034-41
16282178
Stroke. 2001 Jun;32(6):1271-8
11387486
Lancet. 2005 Nov 5;366(9497):1640-9
16271645
Am J Med. 1995 Feb;98(2):118-28
7847428
Diabetes Metab. 2003 Apr;29(2 Pt 1):133-8
12746633
Laryngoscope. 1999 Dec;109(12):1937-40
10591350
Am J Respir Crit Care Med. 2004 Feb 1;169(3):348-53
14551167
Eur Heart J. 2004 Oct;25(19):1754-60
15451155
Ital Heart J. 2003 Sep;4(9):627-32
14635381
Am J Respir Crit Care Med. 1999 May;159(5 Pt 1):1383-90
10228099
Circulation. 2002 Apr 30;105(17):2019-23
11980679
Psychiatry Clin Neurosci. 2001 Jun;55(3):305-10
11422885
Circulation. 2004 Jun 15;109(23 Suppl 1):III27-32
15198963
JAMA. 1999 Dec 8;282(22):2131-5
10591334