Effect of exercise on in vitro immune function: a 12-month randomized, controlled trial among postmenopausal women.
Cross-sectional studies suggest that moderate physical activity is associated with enhanced resting immune function; however, few randomized controlled trials have investigated this link. We investigated the effect of 12-mo aerobic exercise, relative to stretching control, on in vitro immune function in a randomized, controlled trial of 115 postmenopausal, overweight, or obese sedentary women, aged 50-75 yr. The exercise goal was > or =45 min/day, 5 days/wk. Control women participated in 1 day/wk stretching classes. Immune markers (natural killer cell cytotoxicity, T-lymphocyte proliferation, immune cell counts and phenotypes, and serum immunoglobulins) were assessed at baseline, 3 mo, and 12 mo under strict blood-draw criteria. General estimation equations evaluated intervention effects at 3 and 12 mo, controlling for baseline. Of the 115 women who began the trial, blood samples were available from 109 at 3 mo (95%) and 108 at 12 mo (94%). From baseline to 12 mo, the exercise group participated in 87% of the prescribed physical activity minutes per week and increased maximal O(2) uptake by 13.8%; controls experienced no change in fitness. The main outcomes, natural killer cell cytotoxicity and T-lymphocyte proliferation, did not differ between groups at 3 and 12 mo. Secondary outcome and subgroup (e.g., stratification by baseline categories of body mass index, immune status, C-reactive protein, and age) analyses did not show any clear patterns of association. This 12-mo randomized, controlled trial showed no effect of aerobic exercise on in vitro immune function, despite excellent retention, high adherence, and demonstrable efficacy of the exercise intervention.
Campbell
Peter T
PT
Fred Hutchinson Cancer Research Center, Cancer Prevention Program, Seattle, WA 98109-1024, USA.
Wener
Mark H
MH
Sorensen
Bess
B
Wood
Brent
B
Chen-Levy
Zehava
Z
Potter
John D
JD
McTiernan
Anne
A
Ulrich
Cornelia M
CM
D000368:Aged; D049109:Cell Proliferation; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D007136:Immunoglobulins / Q000097:blood*; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008875:Middle Aged; D009765:Obesity / Q000276:immunology*; D050177:Overweight / Q000276:immunology*; D010641:Phenotype; D017698:Postmenopause / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
D007136:Immunoglobulins