The Relationship between Circulating Irisin and Oxidative Stress in Gastric and Colorectal Cancer Patients.

OBJECTIVE: Gastric and colorectal cancers are two obesity-related cancers. Irisin is a dipo-myokine with an important role in the body's energy homeostasis. Oxidative Stress has a crucial role in tumorigenesis. Therefore, this study aims to investigate the association of circulating irisin with oxidative stress in gastric and colorectal cancer patients. METHODS: A case-control study involving 62 gastric and colorectal cancers and 22 healthy individuals was carried out. Serum irisin and Total Antioxidant Capacity were measured by sandwich enzyme-linked immunosorbed assay (ELIZA) kits.  Total Oxidative Stress (TOS) was measured using colorimetric methods and oxidative stress index (OSI) was also calculated. RESULTS: Serum irisin decreased significantly (p<0.0001) in gastric and colorectal cancer cases compared to healthy individuals. The TOS and OSI levels increased significantly (p<0.0001) in gastric and colorectal cancer cases compared to healthy individuals. No significant correlation was found in terms of irisin, TOS, TAC, and OSI in gastric and colorectal cancer cases and control groups. CONCLUSION: Circulating irisin decreases and oxidative stress increases in gastric and colorectal cancers. There is no correlation between irisin and oxidative stress. The mechanism by which irisin is associated with oxidative stress is still not clear.

Effect of Long-Term Moderate Physical Exercise on Irisin between Normal Weight and Obese Men.

BACKGROUND: Irisin is a myokine that has a beneficial effect on obesity and glucose metabolism by increasing energy expenditure. This study aims to investigate the effect of long-term moderate physical exercise on irisin levels and its correlations with body mass index (BMI), waist circumferences (WC), and metabolic parameters in normal weight and obese males. Material and method. A follow-up case-control study of sixty male participants, comprised of thirty normal weight and thirty obese, who had undergone supervised long-term moderate physical exercises for six months. Serum irisin levels, fasting blood glucose, serum insulin, homeostatic model assessment of the insulin resistance index (HOMA-IR), and ß-cell function (HOMA-B2) were assessed. RESULTS: Long-term moderate exercise induced elevation of the irisin level significantly (P < 0.0001) with significant reduction of the BMI, WC, fasting blood glucose, insulin, HOMA-IR, and HOMA-B2 levels (P < 0.0001) in comparison between obese and normal weight groups. There are significant differences for each parameter in each obese and normal weight group before and after physical exercise with exception of the BMI and WC in the normal group. Significant negative correlations were shown between irisin and blood glucose and insulin and HOMA-IR levels in the obese group and normal weight group. CONCLUSION: Irisin improves glucose homeostasis after long-term moderate physical exercises, suggesting that irisin could have regulatory effect on glucose, insulin resistance, and obesity and it could be used as a potential therapy for obesity and insulin resistance.