Exercise Speeds Cutaneous Wound Healing in High-Fat Diet-Induced Obese Mice

PENCE, B. D., L. A. DIPIETRO, and J. A. WOODS. Exercise Speeds Cutaneous Wound Healing in High-Fat Diet-Induced Obese Mice. Med. Sci. Sports Exerc., Vol. 44, No. 10, pp. 1846-1854, 2012. Purpose: Obesity has been shown to impair cutaneous wound healing, which is associated with increased wound inflammation. Exercise is known to decrease obesity-associated inflammation and has been shown to speed cutaneous wound healing in aged mice. Therefore, we investigated whether treadmill exercise could speed cutaneous wound healing in obese, high-fat diet-fed mice. Methods: We fed female C57B1/6J mice a high-fat diet (45% calories from fat) for 16 wk to induce a state of obesity and insulin resistance. Mice then ran on a treadmill for 3 d before excisional wounding. On day 4, mice were wounded 1 h after exercise. Mice then exercised for 5 d after wounding, and healing was assessed by photo-planimetry for 10 d. Results: As described previously, obesity impaired wound healing, with significantly larger wound sizes measured from days 3 to day 10 after wounding (P < 0.05). Exercise did not improve healing in lean mice fed a normal chow diet. However, wound size was significantly smaller in exercised obese mice compared with their lean counterparts (P < 0.05 at day 1, day 4, and day 5 after wound). Surprisingly, we were unable to detect any differences in gene or protein expression of proinflammatory cytokines interleukin-1 beta and tumor necrosis factor-alpha or the anti-inflammatory cytokine interleukin-10 in the wounds. Likewise, there were no differences in gene expression of chemokines monocyte chemoattractant protein-1 and keratinocyte chemoattractant or of growth factor platelet-derived growth factor in wounds of exercise and sedentary mice. Conclusion: This suggests an effect of exercise independent of alterations in inflammation. Future work should focus on early events after wounding, including exercise effects on hemostasis and myofibroblast function.