title: Relation of heart rate recovery after exercise to C-reactive protein and white blood cell count.
abstract: This study was conducted to test the hypothesis that slow and abnormal heart rate recovery (HRR), an indicator of decreased autonomic nervous system activity, after exercise is associated with inflammatory markers. Subjects who underwent exercise treadmill testing (n = 5,527, mean age 50.4 +/- 8.5 years) were studied in a cross-sectional design. HRR was calculated as the difference between maximum heart rate during the test and heart rate 1 minute after the cessation of exercise. Abnormal HRR was defined as < or =12 beats/min. Subjects with abnormal HRR had higher levels of log C-reactive protein (CRP; 1.38 +/- 0.6 vs 1.11 +/- 0.4 mg/dl, p <0.001) and higher white blood cell counts (6.9 +/- 2.1 vs 6.2 +/- 1.7 x 10(9) cells/L, p <0.001) than those with normal HRR. HRR was associated with CRP (r = -0.21, p <0.001) and white blood cell count (r = -0.19, p <0.001). HRR was independently associated with CRP (beta = -0.13, p = 0.001) in a stepwise multiple regression. In a logistic multivariate model, the group within the highest quartile of CRP (odds ratio 1.54, 95% confidence interval 1.05 to 2.27) was more likely to have abnormal HRR than those within the lowest quartile. In conclusion, slow and abnormal HRR after exercise testing is associated with inflammatory markers, which could contribute to the high incidence of cardiovascular disease in these subjects.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois, Urbana-Champaign, USA.
authors.forename: Sae Young
authors.initials: SY
authors.lastname: Jae
authors.forename: Eui Soo
authors.initials: ES
authors.lastname: Ahn
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Heffernan
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Woods
authors.forename: Moon-Kyu
authors.initials: MK
authors.lastname: Lee
authors.forename: Won Hah
authors.initials: WH
authors.lastname: Park
authors.forename: Bo
authors.initials: B
authors.lastname: Fernhall
mesh_terms: D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007958:Leukocyte Count; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020127:Recovery of Function / Q000502:physiology*; D013997:Time Factors
chemical_list: D002097:C-Reactive Protein