Responses of Inflammatory Cytokines Following Moderate Intensity Walking Exercise in Overweight or Obese Individuals

Abstract

Chronic low‐grade inflammation is associated with physical inactivity as well as overweight and obesity. Levels of pro‐/anti‐inflammatory cytokines are affected as body fat changes. However, the response of these cytokines to short term moderate intensity exercise training is not yet known.PURPOSEThe current study investigated the effects of a 4‐week moderate intensity walking exercise on levels of C‐reactive protein (CRP), TNF‐alpha and adiponectin in overweight or obese individuals.METHODSTwenty seven (13 males and 14 females) physically inactive, overweight or obese (BMI > 25.0 kg/m2) individuals participated in the study. Each participant was randomly assigned to either exercise (EX, N=15) or control (CON, N=12) group. The exercise group performed moderate intensity walking exercise on a treadmill for 60 minutes at 70% of HRmax for 4 weeks (3 days/week), while the control group did not perform any physical activity. Overnight fasting blood samples were collected before and after the study period (PRE and Post) to analyze levels of pro‐/anti‐inflammatory cytokines such as C‐reactive protein (CRP), TNF‐α, and adiponectin. Two‐way repeated measures ANOVA and Tukey post hoc tests were used for data analysis.RESULTSCRP and adiponectin as well as body weight and body composition were not significantly altered following the 4‐week exercise intervention. However, there was a significant group*time interactions for TNF‐α. The follow‐up simple effects tests revealed that only the exercise group significantly lowered level of TNF‐α (EX : 55.18±2.57pg/mL, Mean±SE, ← 50.31±2.22 P=.0084 vs. CON : 55.50±2.88 ← 58.19±2.48, P=.25). EX Post is also significantly lower as compared to CON Post (P=.032). Values for CRP and Adiponectin were as follows; CRP (EX : 637.8±113.3ng/mL, ← 510.5±114.2 P=.060 vs. CON : 644.2±126.7 ← 654.1±127.7, P=.76) and Adiponectin (EX : 7.1±1.3 ug/mL, ← 7.2±1.3 P=.87 vs. CON : 9.8±1.5 ← 9.9±1.5, P=.83).CONCLUSIONAlthough there was no change in fat mass, 4 weeks of aerobic exercise was long enough to decrease levels of TNF‐α indicating physical activity independent from change in fat mass may affect level of inflammation . Results confirmed previous research that longer period of training accompanied with weight loss is required to induce changes in CRP and adiponectin.