Effect of aerobic exercise on leptin and ghrelin in patients with colorectal cancer

Aerobic exercise can improve the levels of leptin and ghrelin in healthy people, but the effect of aerobic exercise on these proteins in colorectal cancer patients is not well known. The purpose of this study was to investigate plasma leptin and ghrelin concentrations in male patients with colorectal cancer after 8 weeks aerobic exercise and after a week of detraining.

Thirty men with colorectal cancer (aged: 51.56 ± 11.28 years; ± standard deviation ( SD)) were randomly assigned to training group (n = 15) or control group (n = 15). Before the experiment, Rockport walking test was conducted in order to measure peak aerobic capacity (VO2peak) of all subjects. Exercise training program consisted of 8 weeks walking and three 45-min sessions in each week with 50-60% of target heart rate. After 8 weeks of training, subjects underwent a week of detraining. A repeated measure analysis of variance (ANOVA) was used to evaluate time-course change in variables.

The results showed that body fat percentage was decreased and VO2peak was increased in the training group compared to the control group (P < 0.05). Ghrelin concentration was increased significantly in the training group compared to the control group (P < 0.05), while plasma leptin concentration and insulin resistance did not change significantly. After a week of detraining, the variables did not change significantly in the training group.

VO2peak and ghrelin levels increased after 8 weeks aerobic exercise; however, plasma leptin and insulin resistance were not affected by this protocol in male patients with colorectal cancer.