Effects of Two Different School-Based Training on Serum miR15b Expression and Lipid Profile of Adolescents with Obesity

BACKGROUND: Some circulating microRNAs, such as miR15b, are predictors of diseases associated with adulthood obesity. This study aimed to evaluate the effect of two selected school-based and high-intensity interval training (HIT) on miR15b expression and lipid profile of obese adolescents. METHODS: Thirty-eight adolescent males (12 ± 1 years) with obesity (body mass: 74.7 ± 13.2 kg, body mass index (BMI): 26.0 ± 2.3 kg/m(2), and body fat (BF): 27.2 ± 3.6%) were randomly assigned to the following based on the age-related body mass index: (i) HIT (n = 13), (ii) school-based exercises (SBE, n = 13), and (iii) control (n = 12) groups. Mir15b was extracted using the RT-PCR system, and lipid profile was studied using the enzymatic colorimetric method before and after 12 weeks. Three training sessions were held each week during the course. RESULTS: Following the exercise interventions, in both training groups, miR15b (HIT: –63.8 vs. SBE: –56. 7%; P = 0.001), cholesterol (HIT: –8.8 vs. SBE: –9.2%; P = 0.025), and low-density lipoproteins levels (SBE: –13.1 vs. –20.8%; P = 0.48) decreased; however, the peak oxygen uptake of subjects increased (HIT: 4.0 vs. SBE: 4.0%; P = 0.003). However, there were no significant differences in triglyceride (HIT: –16.9 vs. SBE: –8.3%; P = 0.134), and high-density lipoprotein (HIT: 3.1 vs. SBE: 4.8%; P = 0.479) levels between both intervention and control groups (P > 0.05). CONCLUSIONS: The results showed that both types of exercises had almost similar effects on reducing miR15b expression and improving the lipid profile. Hence, based on the difficult nature of HIT for children with obesity, further use of school-based exercises is suggested.