The effect of eight weeks of water exercise with blood flow restriction on serum levels of C-reactive protein and insulin resistance in young obese girls

Objective: Obesity in adolescent girls is commonly accompanied by low-grade inflammation and impaired glucose regulation. This study investigated whether eight weeks of water-based exercise with blood flow restriction (WBFR) improves high-sensitivity C-reactive protein (hs-CRP) and insulin resistance more than water exercise without restriction (WEX) and a non-training control (CON). Methods: Thirty obese young girls were randomly assigned to WBFR (n=۱۰), WEX (n=۱۰), or CON (n=۱۰). Training lasted ۸ weeks (۳ sessions/week, ~۶۰ min/session). Venous blood was obtained ۲۴ h before and ۲۴ h after the intervention. Outcomes were hs-CRP, fasting glucose, fasting insulin, and HOMA-IR, plus weight, BMI, and waist circumference. Mixed group×time ANOVA with Bonferroni post-hoc tests was applied (P<۰.۰۵). Results: Group×time interactions were significant for hs-CRP (p=۰.۰۰۱), HOMA-IR (p=۰.۰۰۱), fasting glucose (p=۰.۰۰۳), fasting insulin (p=۰.۰۴۴), weight (p=۰.۰۰۸), BMI (p=۰.۰۱۲), and waist circumference (p=۰.۰۰۱). WBFR decreased hs-CRP (p=۰.۰۰۱), fasting glucose (p=۰.۰۰۲), fasting insulin (p=۰.۰۱۲), and HOMA-IR (p=۰.۰۰۱), and reduced weight (p=۰.۰۰۱), BMI (p=۰.۰۰۱), and waist circumference (p=۰.۰۰۱). WEX showed smaller reductions in hs-CRP (p=۰.۰۱۸), fasting glucose (p=۰.۰۴۱), and HOMA-IR (p=۰.۰۴۸), and reduced weight (p=۰.۰۳۴), BMI (p=۰.۰۳۹), and waist circumference (p=۰.۰۲۱), while fasting insulin did not change (p=۰.۲۹۰). CON showed no significant changes (hs-CRP p=۰.۶۲۰; glucose p=۰.۷۱۰; insulin p=۰.۸۳۰; HOMA-IR p=۰.۶۶۰). Conclusion: Eight weeks of WBFR produced superior improvements in systemic inflammation and fasting insulin resistance compared with non-restricted aquatic exercise and control, indicating WBFR as a practical low-impact approach for reducing cardiometabolic risk in obese young girls. These findings warrant larger trials.