title: Blood biomarkers of endocrine, immune, inflammatory, and metabolic systems in obstructive sleep apnea.
abstract: OBJECTIVE
  Obstructive sleep apnea (OSA) is a common disorder, affecting over 100 million adults. Untreated OSA leads to serious health consequences and perturbations in endocrine, immune, inflammatory, and metabolic systems. Study objectives are to evaluate the association between OSA and biomarkers, and to test the hypothesis that a combination of markers may be useful in screening for OSA.
  
  
  METHODS
  A multicenter trial was conducted enrolling symptomatic male patients with suspected OSA. All subjects underwent in-laboratory overnight polysomnography. A non-symptomatic control group was also obtained. Eleven biomarkers were tested: HbA1c, CRP, EPO, IL-6, uric acid, cortisol, hGH, prolactin, testosterone, DHEA (Beckman Coulter UniCel DxC 600i Synchron® Access® Clinical Systems), IGF-1.
  
  
  RESULTS
  73 male subjects were enrolled; 26 had moderate/severe OSA. ROC curve analysis showed HbA1c, CRP, EPO, IL-6, and Uric Acid (AUCs: 0.76, 0.73, 0.65, 0.65, 0.61) were superior to the Epworth Sleepiness Scale (AUC: 0.52). Concurrent elevation of HbA1c and CRP provide even greater predictive power. A combination of elevated HbA1c, CRP, and EPO provided 0.08 increase in AUC (0.84 [0.75 - 0.94]) over individual markers (p<0.05), with high sensitivity (85%), and specificity (79%) for moderate/severe OSA.
  
  
  CONCLUSIONS
  OSA induces characteristic endocrine, immune, inflammatory, and metabolic disturbances that can be detected with blood biomarkers. These biomarkers are superior to standard screening questionnaires. Various clusters of these biomarkers have an even greater association with OSA and thus may represent physiologic signatures of the disorder that may have value in initial screening for OSA as well as for follow-up of therapy response.
authors.affiliation: Sleep Center Orange County, 4980 Barranca Pkwy, Ste 170, Irvine, CA 92604, USA. Electronic address: flemingwesley@gmail.com.
authors.forename: Wesley Elon
authors.initials: WE
authors.lastname: Fleming
authors.affiliation: San Diego Sleep and Sinus Clinic, 477 N El Camino Real, D-308, Encinitas, CA 92024, USA. Electronic address: aliya.s.ferouz-colborn@kp.org.
authors.forename: Aliya
authors.initials: A
authors.lastname: Ferouz-Colborn
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: mksamoszuk@beckman.com.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Samoszuk
authors.affiliation: Sleep Center Orange County, 4980 Barranca Pkwy, Ste 170, Irvine, CA 92604, USA. Electronic address: armaghan23@yahoo.com.
authors.forename: Armaghan
authors.initials: A
authors.lastname: Azad
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: jiuliu.lu@beckman.com.
authors.forename: Jiuliu
authors.initials: J
authors.lastname: Lu
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: john.riley@beckman.com.
authors.forename: John S
authors.initials: JS
authors.lastname: Riley
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: acruz@beckman.com.
authors.forename: Amabelle B
authors.initials: AB
authors.lastname: Cruz
authors.affiliation: Sleep Center Orange County, 4980 Barranca Pkwy, Ste 170, Irvine, CA 92604, USA. Electronic address: svoyer_sleepcenteroc@hotmail.com.
authors.forename: Susann
authors.initials: S
authors.lastname: Podolak
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: djclark@beckman.com.
authors.forename: Doni J
authors.initials: DJ
authors.lastname: Clark
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: kurt.bray@prometheuslabs.com.
authors.forename: Kurtis R
authors.initials: KR
authors.lastname: Bray
authors.affiliation: Beckman Coulter, Inc., 250 South Kraemer Blvd, Brea, CA 92821, USA. Electronic address: pcsouthwick@beckman.com.
authors.forename: Paula C
authors.initials: PC
authors.lastname: Southwick
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D004700:Endocrine System Diseases / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D007154:Immune System Diseases / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D007249:Inflammation / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008875:Middle Aged; D017286:Polysomnography; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000150:complications
chemical_list: D015415:Biomarkers
keywords: Biomarkers; CRP; Diagnosis; Erythropoietin; HbA1c; OSA; Obstructive sleep apnea; Screening