Markers of inflammation are inversely associated withVo2max in asymptomatic men

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 (V-O2max) in men without coronary heart disease (CHD). In asymptomatic men (n = 172, 51 +/- 9.3 yr old), V-O2max 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 immumoassays, fibrinogen by the Clauss method, and VvBC 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 V-O2max after adjustment for age, body mass index, CHD risk factors, and lifestyle variables (physical activity level, percent body fat, and alcohol intake). V-O2max 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 V-O2max. 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 V-O2max. In conclusion, higher circulating levels of IL-6, CRP, and fibrinogen are independently associated with lower V-O2max in asymptomatic men.