The effect of interval, continuous and combined aerobic exercise on IGF-1 hormone and body composition in type 2 diabetic patients with NAFLD

Background. IGF-1 hormone decreases in patients with type 2 diabetes and NAFLD. The effect of exercise on this hormone requires further researches. The purpose of this study was to compare the effects of the interval, continuous, and combined aerobic exercise on IGF-1 hormone and body composition in type 2 diabetic patients with NAFLD. Methods. In this study, forty female type 2 diabetes patients with NAFLD (mean age 50.6 ± 4.5 years, height 1.58 ± 0.07 m, weight 74.4 ± 9.9 kg) were randomized into four groups. The exercise training groups performed exercises by cycle ergometer three days a week for eight weeks. The groups included: interval aerobic exercise group (75-80% maximum heart rate), continuous aerobic exercise group (60-75% maximum heart rate), combined exercise group (interval and continuous), and control group. Variance analysis was used for analysis and comparison between groups. The t-dependent test was used for intra-group compression (α≤0.05). Results. Decreased body weight, BMI, waist circumference, waist circumference, waist-to-height ratio, body fat percentage, body fat mass, and increased IGF-1 were significant in all three exercise groups (P≤0.05). In the control group, increased hip circumference and decreased IGF-1 were significant (P≤0.05). Among the three exercise groups, the interval aerobic exercise group had the most effect on improving type 2 diabetic patients with NAFLD. Comparing between the groups, IGF-1, body mass index, waist circumference, hip circumference, and waist-to-height ratio were significant in the interval, continuous, and combined aerobic exercise groups compared to the control group (P≥0.05). Conclusion. Interval, continuous, and combined aerobic exercise improves body composition and hormone IGF-1, and according to the findings, interval aerobic exercise had the greatest effect on diabetic patients with NAFLD. Therefore, it is recommended that these patients participate in aerobic exercise regularly, especially interval aerobic exercise.