Exercise-induced changes in insulin sensitivity, atherogenic index of plasma, and CTRP1/CTRP3 levels: the role of combined and high-intensity interval training in overweight and obese women.

Abstract

Background: Obesity, defined as excessive body fat accumulation, is closely linked to an increased risk of metabolic disorders, cardiovascular diseases, and insulin resistance. This study investigates the effects of combined training (CT) and high-intensity interval training (HIIT) on insulin sensitivity, atherogenic index of plasma (AIP), and serum levels of C1q/TNF-related proteins (CTRP1 and CTRP3) in overweight and obese women.

Methods: Thirty-three overweight and obese women (aged 18-50 years) were randomly divided into three groups: control (CON, n = 10), HIIT(n = 9), and combined training (CT, n = 10). The HIIT protocol consisted of intervals performed at 100% of maximum aerobic velocity (MAV) and rest intervals at 50% of MAV, with a 30-s work-to-rest ratio. The CT sessions included RT followed by AT. RT comprised seven exercises performed in three sets of 10-16 repetitions at 60-75% of one-repetition maximum (1RM). AT involved running for 15-30 min at 60-75% of heart rate reserve. Subjects trained three times per week. Body composition, biochemical, and functional assessments were conducted 48 h before and after the interventions.

Results: Body mass index 1.3% and 2% (p = 0.001); TG 1.7%, 1.2% (p = 0.001);LDL 0.93%,0.83% (p = 0.012); HOMA-IR 9.5%,11.7% (p = 0.018); AST 4.2%,11.7% (p = 0.001); ALT 9.3%,10.9% (p = 0.001); 1RM 2.5%, 14.2% (p = 0.001); and maximum oxygen consumption 8%,2.4% (p = 0.001) showed significant improvements in both the HIIT and CT groups,resectively. Additionally, serum levels of CTRP 10.47%,0.34% (p = 0.007); and CTRP3 1.51%,1.53% (p = 0.011) significantly decreased in the HIIT and CT groups,resectively.

Conclusions: The results suggest that HIIT and CT are effective strategies for improving body composition, lipid profile, glycemic control, liver enzyme levels, and functional capacity. Moreover, both exercise modalities were associated with reduced serum levels of the adipokines CTRP1 and CTRP3, highlighting a potential link between these biomarkers and improvements in body composition, lipid profile, glycemic control, and liver enzyme levels.

Trial registration: Registered retrospectively in the Iranian Registry of Clinical Trials (IRCT20241207063967 N1) on 18/01/2025. Access at https:// https://irct.behdasht.gov.ir/trial/80615 .