Objective

To investigate whether C-reactive protein (CRP, a general marker of inflammation), neopterin (activated macrophages), lactoferrin (activated neutrophils), and endothelial function (flow-mediated vasodilation [FMD]) are associated with cardiorespiratory fitness (peak oxygen uptake [VO 2peak ]), sex, body mass index (BMI), and the metabolic syndrome (MetSyn) in a healthy adult population.

Patients and Methods

This was a cross-sectional association study based on the population-based HUNT3 Fitness Study performed from May 15, 2007, through June 23, 2008. Seven hundred forty self-reported healthy respondents (327 women) identified as having the MetSyn were age- and sex-matched with 692 controls (307 women) from the same cohort. Associations between the inflammatory biomarkers and VO 2peak , FMD, and the MetSyn were analyzed by multivariate linear regression.

Results

The CRP level was negatively associated with VO 2peak ( P<.001), positively associated with the MetSyn (with a stronger effect in men) ( P<.001) and BMI (with a stronger effect in women) ( P<.01), but not with FMD ( P=.34). Lactoferrin was positively associated with the MetSyn ( P<.001), but neither neopterin nor lactoferrin were associated with VO 2peak or FMD.

Conclusion