C-Reactive protein is inversely related to physical fitness in middle-aged subjects.
BACKGROUND
Physical fitness has a protective effect with regard to the risk of developing coronary disease or diabetes. C-reactive protein (CRP) levels are directly related to increased risk of coronary disease and diabetes. However, data on the association between physical fitness and CRP are sparse.


METHODS
Physical fitness was assessed in a population-based cross-sectional study (n = 892; age 50 +/- 9 years) using the Bruce treadmill protocol. CRP was measured using a high-sensitivity assay.


RESULTS
Geometric mean CRP levels were calculated across quartiles of physical fitness after adjustment for age, gender, body mass index, smoking habit, presence of diabetes and hypertension, HDL cholesterol and triglyceride levels, and use of hormone replacement therapy, statins, and aspirin. CRP levels decreased with increasing quartiles of fitness (P for trend <0.0001). When used as a continuous variable in a stepwise linear regression model, the geometric mean of CRP decreased by 0.061 mg/L (95% confidence interval (CI) 0.034-0.089 mg/L) for each 1 unit increase in metabolic equivalents (METs). Multivariate logistic regression models showed that compared to subjects in the lowest fitness quintile, subjects in the highest fitness quintile had significantly lower adjusted odds of having a high-risk (>3 mg/L) CRP level (OR 0.53; 95% CI 0.39-0.71, P = 0.007).


CONCLUSIONS
CRP concentration decreases continuously with increasing levels of physical fitness. The health-related salutary effects of physical fitness may be mediated, in part, through an antiinflammatory mechanism.
Department of Cardiology, Rambam Medical Center and Rappaport Faculty of Medicine, POB 9602, Haifa 31096, Israel. daronson@netvision.net.il
Doron
D
Aronson
Muhammad
M
Sheikh-Ahmad
Ophir
O
Avizohar
Arthur
A
Kerner
Ron
R
Sella
Peter
P
Bartha
Walter
W
Markiewicz
Yishai
Y
Levy
Gerald J
GJ
Brook
D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000276:immunology / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000276:immunology / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000276:immunology / Q000378:metabolism*; D010809:Physical Fitness / Q000502:physiology*; D012044:Regression Analysis; D012307:Risk Factors
D002097:C-Reactive Protein