Leisure-time physical activity and reduced plasma levels of obesity-related inflammatory markers

Obes Res. 2003 Sep;11(9):1055-64. doi: 10.1038/oby.2003.145.


Objective: This study investigated the relationship between physical activity and the obesity-related inflammatory markers C-reactive protein, interleukin-6, and soluble tumor necrosis factor receptors (sTNF-Rs) 1 and 2. Furthermore, we examined the relationship between physical activity and insulin sensitivity (insulin, C-peptide, and hemoglobin A(1c) levels) and whether inflammatory markers mediate this association.

Research methods and procedures: Biomarkers were measured in 405 healthy men and 454 healthy women from two large ongoing prospective studies. Information about physical activity and other variables was assessed by questionnaires.

Results: After adjustment for other predictors of inflammation, physical activity was inversely associated with plasma levels of sTNF-R1, sTNF-R2, interleukin-6, and C-reactive protein (p = 0.07, p = 0.004, p = 0.04, and p = 0.009). After further adjustment for BMI and leptin, as a surrogate for fat mass, most of these associations were no longer significant. Physical activity was also inversely related to insulin and C-peptide levels (p = 0.008 and p < 0.001); however, in contrast to BMI and leptin, levels of inflammatory markers explained only very little of this inverse relationship.

Discussion: These results suggest that frequent physical activity is associated with lower systemic inflammation and improved insulin sensitivity. These associations can partially be explained by a lower degree of obesity in physically active subjects. Although inflammatory markers may mediate obesity-dependent effects of physical activity on inflammatory related diseases such as type 2 diabetes or coronary heart disease, our study suggests that they do not directly account for the beneficial effects of physical activity on insulin resistance.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Biomarkers / blood
  • Body Mass Index
  • C-Peptide / blood
  • C-Reactive Protein / analysis*
  • Cohort Studies
  • Cross-Sectional Studies
  • Exercise / physiology*
  • Female
  • Glycated Hemoglobin A / analysis
  • Humans
  • Insulin / blood
  • Interleukin-6 / blood*
  • Leptin / blood*
  • Male
  • Middle Aged
  • Obesity / blood*
  • Prospective Studies
  • Receptors, Tumor Necrosis Factor / metabolism


  • Biomarkers
  • C-Peptide
  • Glycated Hemoglobin A
  • Insulin
  • Interleukin-6
  • Leptin
  • Receptors, Tumor Necrosis Factor
  • C-Reactive Protein