title: Markers of inflammation are inversely associated with VO2 max in asymptomatic men.
abstract: We investigated whether markers of inflammation, including a cytokine (IL-6), acute-phase reactants [C-reactive protein (CRP) and fibrinogen], and white blood cell (WBC) count are associated with maximal O(2) consumption (Vo(2 max)) in men without coronary heart disease (CHD). In asymptomatic men (n = 172, 51 +/- 9.3 yr old), Vo(2 max) was measured during a symptom-limited graded treadmill exercise test. Physical activity level was assessed by a standardized questionnaire. IL-6 and CRP were measured by immunoassays, fibrinogen by the Clauss method, and WBC count with a Coulter counter. IL-6 and CRP were logarithmically transformed to reduce skewness. Multivariable regression was used to assess whether markers of inflammation were associated with Vo(2 max) after adjustment for age, body mass index, CHD risk factors, and lifestyle variables (physical activity level, percent body fat, and alcohol intake). Vo(2 max) was 34.5 ml.kg(-1).min(-1) (SD 6.1). Log IL-6 (r = -0.38, P < 0.001), log CRP (r = -0.40, P < 0.001), fibrinogen (r = -0.42, P < 0.001), and WBC count (r = -0.22, P = 0.004) were each correlated with Vo(2 max). In separate multivariable linear regression models that adjusted for age, body mass index, CHD risk factors, and lifestyle variables, log IL-6 [beta-coeff = -1.66 +/- 0.63 (SE), P = 0.010], log CRP [beta-coeff = -0.99 +/- 0.33 (SE), P = 0.003], fibrinogen [beta-coeff = -1.51 +/- 0.44 (SE), P = 0.001], and WBC count [beta-coeff = -0.52 +/- 0.30 (SE), P = 0.088] were each inversely associated with Vo(2 max). In conclusion, higher circulating levels of IL-6, CRP, and fibrinogen are independently associated with lower Vo(2 max) in asymptomatic men.
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo College of Medicine, Rochester, Minnesota, USA. kullo.iftikhar@mayo.edu
authors.forename: Iftikhar J
authors.initials: IJ
authors.lastname: Kullo
authors.forename: Mahyar
authors.initials: M
authors.lastname: Khaleghi
authors.forename: Donald D
authors.initials: DD
authors.lastname: Hensrud
mesh_terms: D000209:Acute-Phase Proteins / Q000032:analysis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003324:Coronary Artery Disease / Q000503:physiopathology; D005340:Fibrinogen / Q000032:analysis*; D006801:Humans; D007249:Inflammation / Q000473:pathology / Q000503:physiopathology*; D015850:Interleukin-6 / Q000097:blood*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010807:Physical Endurance; D010809:Physical Fitness; D013223:Statistics as Topic
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D015850:Interleukin-6; D005340:Fibrinogen; D010100:Oxygen