title: Intrarenal hemodynamic and oxidative stress in patients with obstructive sleep apnea syndrome.
abstract: BACKGROUND
  Oxygen desaturation and reoxygenation, related to intermittent hypoxia cycles due to upper airway obstruction, are major pathophysiologic features of obstructive sleep apnea syndrome (OSAS) and are thought to be responsible for an increased risk of cardiovascular diseases. Continuous positive airway pressure (CPAP) is therefore considered the gold standard in the management of OSAS. Further data demonstrated a high prevalence of OSAS in patients with altered renal function despite the underlying pathophysiological mechanisms that have not been clarified. This study aims to provide evidence on the reported high prevalence of endothelial dysfunction and alterations of the intrarenal hemodynamic in patients affected by OSAS. Furthermore, we evaluated the effect of a CPAP therapy on these endpoints.
  
  
  METHODS
  Twenty patients were enrolled in a prospective study and underwent ultrasound examination to assess endothelial dysfunction, by collecting brachial flow-mediated dilation (FMD) and intrarenal artery stiffness, pre- and post a 30-day treatment with CPAP.
  
  
  RESULTS
  Endothelial dysfunction and intrarenal artery stiffness significantly improved in all patients after a month of CPAP. In particular, we observed a significant reduction in the renal resistance index (RI) (p < 0.001) and systolic/diastolic ratio (S/D) ratio (p < 0.001) and a significant increase of FMD (p < 0.001). The apnea-hypopnea index (AHI) showed a negative correlation with Δ FMD (p < 0.05, r = -0.46). Conversely, a positive correlation exists between Δ RI and the oxygen desaturation index (ODI) (specificare la sigla) (p < 0.05, r = 0.46).
  
  
  CONCLUSIONS
  Our study firstly showed a significant effect of CPAP on renal perfusion and endothelial function in OSAS patients without concomitant cardiovascular comorbidities.
authors.affiliation: Department of Clinical Medicine, Sapienza University of Rome, Viale dell'Università 37, 00185, Rome, Italy. liboriosardo@hotmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Sardo
authors.affiliation: Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Palange
authors.affiliation: Department of Clinical Medicine, Sapienza University of Rome, Viale dell'Università 37, 00185, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Di Mario
authors.affiliation: Department of Clinical Medicine, Sapienza University of Rome, Viale dell'Università 37, 00185, Rome, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Barbano
authors.affiliation: Department of Clinical Medicine, Sapienza University of Rome, Viale dell'Università 37, 00185, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gigante
authors.affiliation: Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Mordenti
authors.affiliation: Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Steffanina
authors.affiliation: Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bonini
authors.affiliation: Department of Clinical Medicine, Sapienza University of Rome, Viale dell'Università 37, 00185, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Amoroso
authors.affiliation: Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Vaccaro
authors.affiliation: Department of Clinical Medicine, Sapienza University of Rome, Viale dell'Università 37, 00185, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cianci
mesh_terms: D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006699:Home Care Services; D006801:Humans; D007668:Kidney / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D011446:Prospective Studies; D012077:Renal Artery / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D013223:Statistics as Topic; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance; D059289:Vascular Stiffness / Q000502:physiology; D014664:Vasodilation / Q000502:physiology
chemical_list: D010100:Oxygen
keywords: Continuous positive airway pressure; Endothelial dysfunction; Obstructive sleep apnea; Renal resistance index
references.citation: Lancet. 1992 Nov 7;340(8828):1111-5
references.pmid: 1359209
references.citation: J Hypertens. 2013 Jul;31(7):1456-64; discussion 1464
references.pmid: 23965549
references.citation: Chest. 2001 Apr;119(4):1085-91
references.pmid: 11296174
references.citation: Clin J Am Soc Nephrol. 2011 May;6(5):995-1000
references.pmid: 21415314
references.citation: Nephrol Dial Transplant. 2011 Jul;26(7):2244-50
references.pmid: 21317406
references.citation: Chest. 2000 Jun;117(6):1597-602
references.pmid: 10858389
references.citation: N Engl J Med. 1993 Apr 29;328(17):1230-5
references.pmid: 8464434
references.citation: Ann Intern Med. 1999 Mar 16;130(6):461-70
references.pmid: 10075613
references.citation: Am J Hypertens. 2012 Dec;25(12):1292-8
references.pmid: 22874890
references.citation: Dtsch Med Wochenschr. 2007 Sep;132(36):1815-9
references.pmid: 17726652
references.citation: Clin Sci (Lond). 2004 Sep;107(3):317-22
references.pmid: 15191364
references.citation: Am J Kidney Dis. 2012 Nov;60(5):823-33
references.pmid: 22727724
references.citation: Am J Kidney Dis. 1987 Jul;10(1 Suppl 1):7-12
references.pmid: 3037892
references.citation: Am J Respir Crit Care Med. 2001 Dec 15;164(12):2147-65
references.pmid: 11751180
references.citation: Nephrol Dial Transplant. 2011 Mar;26(3):914-20
references.pmid: 20682605
references.citation: Radiology. 2009 Sep;252(3):888-96
references.pmid: 19528356
references.citation: Sleep. 2009 Oct;32(10 ):1257-63
references.pmid: 19848355
references.citation: Am J Kidney Dis. 2010 Feb;55(2):281-90
references.pmid: 20116688
references.citation: Circulation. 2005 Oct 25;112(17):2735-52
references.pmid: 16157765
references.citation: Respiration. 2006;73(6):751-6
references.pmid: 16804287
references.citation: Lung. 2012 Apr;190(2):113-32
references.pmid: 22048845
references.citation: Med Sci Monit. 2012 Dec;18(12):CR747-51
references.pmid: 23197238
references.citation: Chest. 2007 Jul;132(1):325-37
references.pmid: 17625094
references.citation: Kidney Int. 2011 Oct;80(8):806-21
references.pmid: 21697815
references.citation: J Am Soc Nephrol. 2002 Jan;13(1):27-34
references.pmid: 11752018
references.citation: J Am Soc Nephrol. 2002 Mar;13(3):729-33
references.pmid: 11856778
references.citation: Am J Respir Crit Care Med. 2002 Apr 1;165(7):859-60
references.pmid: 11934709
references.citation: Clin Oral Investig. 2015 Mar;19(2):437-44
references.pmid: 24696294
references.citation: Sleep Disord. 2014;2014:798487
references.pmid: 24693440
references.citation: Semin Dial. 2004 Mar-Apr;17(2):109-14
references.pmid: 15043611
references.citation: BMJ. 2000 Feb 19;320(7233):479-82
references.pmid: 10678860