title: C-reactive protein and heart rate recovery in middle-aged men with severe obstructive sleep apnea.
abstract: OBJECTIVE
  The study aimed to evaluate whether the inflammatory marker "high-sensitivity C-reactive protein (hsCRP)" level was associated with impaired heart rate recovery at 1 min after exercise termination (HRR-1) in middle-aged patients with severe obstructive sleep apnea (OSA).
  
  
  METHODS
  Thirty middle-aged male patients (40-64 years old) with severe OSA (apnea-hypopnea index [AHI] ≥ 30 h(-1)) and 30 subjects without OSA (AHI < 5 h(-1)), matched with age and body mass index (BMI), were recruited. All subjects underwent an overnight polysomnography and completed a symptom-limited maximal exercise test. Cardiopulmonary parameters included peak oxygen consumption (VO(2peak)) and heart rate response during and immediately after exercise. Fasting blood samples were drawn for hsCRP analysis.
  
  
  RESULTS
  Patients with severe OSA had significantly higher hsCRP levels (0.18 vs. 0.07 mg/dl, P < 0.01), lower reduced HRR-1, peak heart rate, and VO(2peak) values than those in the controls. The hsCRP levels significantly correlated with HRR-1 in the OSA group (r = -0.69, P < 0.01) after adjustment for VO(2peak) (r = -0.66, P < 0.01). Furthermore, stepwise multiple regression analysis showed that HRR-1 and AHI were significant predictors of hsCRP levels in all participants (adjusted R(2) = 0.53, P < 0.01).
  
  
  CONCLUSIONS
  Blunted HRR was shown in middle-aged men with severe OSA, and it was associated with high hsCRP levels significantly.
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Meng-Yueh
authors.initials: MY
authors.lastname: Chien
authors.forename: Peilin
authors.initials: P
authors.lastname: Lee
authors.forename: Yuan-Feen
authors.initials: YF
authors.lastname: Tsai
authors.forename: Pan-Chyr
authors.initials: PC
authors.lastname: Yang
authors.forename: Ying-Tai
authors.initials: YT
authors.lastname: Wu
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology; D002097:C-Reactive Protein / Q000378:metabolism*; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology*; D013223:Statistics as Topic; D013564:Sympathetic Nervous System / Q000503:physiopathology
chemical_list: D018836:Inflammation Mediators; D002097:C-Reactive Protein