Effects of a 12-week home-based exercise program on the level of physical activity, insulin, and cytokines in colorectal cancer survivors: a pilot study

Purpose The purposes of this study are to examine (1) the feasibility and efficacy of two different home-based exercise protocols on the level of physical activity (PA), and (2) the effect of increased PA via home-based exercise program on biomarkers of colorectal cancer. Methods Seventeen patients (age 55.18 ± 13.3 years) with stage II–III colorectal cancer completed the 12-week home-based exercise program. Subjects were randomized into either casually intervened home-based exercise group (CIHE) or intensely intervened home-based exercise group (IIHE). The primary outcome was the level of PA. Furthermore, insulin, homeostasis model assessment of insulin resistance, insulin-like growth factor axis, and adipocytokines were measured. Results Both CIHE and IIHE program significantly increased the level of PA at 12 weeks compared to its level at baseline (CIHE, 10.00 ± 8.49 vs. 46.07 ± 45.59; IIHE, 12.08 ± 11.04 vs. 35.42 ± 27.42 MET hours per week). Since there was no difference in PA change between groups ( p = 0.511), the data was combined in analyzing the effects of increased PA on biomarkers. Increase in PA significantly reduced insulin (6.66 ± 4.58 vs. 4.86 ± 3.48 μU/ml, p = 0.006), HOMA-IR (1.66 ± 1.23 vs. 1.25 ± 1.04, p = 0.017), and tumor necrosis alpha-α (TNF-α 4.85 ± 7.88 vs. 2.95 ± 5.38 pg/ml, p = 0.004), and significantly increased IGF-1 (135.39 ± 60.15 vs. 159.53 ng/ml, p = 0.007), IGF binding protein (IGFBP)-3 (2.67 ± 1.48 vs. 3.48 ± 1.00 ng/ml, p = 0.013), and adiponectin (6.73 ± 3.07 vs. 7.54 ± 3.96 μg/ml, p = 0.015). Conclusion CIHE program was as effective as IIHE program in increasing the level of PA, and the increase in PA resulted in significant change in HOMA-IR, IGF-1 axis, TNF-α, and adiponectin levels in stage II–III colorectal cancer survivors.