Inflammatory marker changes in a yearlong randomized exercise intervention trial among postmenopausal women

Area of Science:

• Oncology
• Exercise Physiology
• Immunology

Background:

• Chronic low-grade inflammation is a potential cancer risk factor.
• Exercise may modify inflammation, but research in postmenopausal women is limited.
• Few randomized controlled trials (RCTs) isolate exercise effects on inflammation in this demographic.

Purpose of the Study:

• To investigate the isolated effects of 1 year of aerobic exercise on circulating inflammatory markers in healthy postmenopausal women.
• To compare inflammatory marker changes between an exercise group and a control group.

Main Methods:

• A 2-armed RCT involving healthy postmenopausal women.
• Intervention: 1 year of moderate to vigorous aerobic exercise vs. usual inactivity.
• Measured high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α via immunoassays and ELISAs.

Main Results:

• Significant reduction in hs-CRP levels observed in the exercise group compared to controls over 12 months (P=0.005).
• No significant changes in IL-6 or TNF-α.
• Decreasing hs-CRP trended with increased exercise adherence (P=0.021) and was stronger in fitter women (P=0.040).
• Exercise effect on hs-CRP was non-significant after adjusting for dietary fiber intake and appeared mediated by fat loss.

Conclusions:

• Moderate to vigorous aerobic exercise may lower hs-CRP, a marker of low-grade inflammation, in postmenopausal women.
• Dietary intake (fiber) and fat loss may confound or mediate the exercise-induced reduction in hs-CRP.
• Further research is needed to determine optimal exercise dosage and effect modification by body fatness and fitness.