The effect of blood flow restriction training on abdominal visceral fat and plasma N-lactoylphenylalanine among adults with obesity

Abstract Background Obesity has been designated as one of the diseases that threaten global human health. Blood flow restriction (BFR) exercise may promote the secretion of N-lactoylphenylalanine (Lac-phe) by increasing metabolic stress, and plasma Lac-phe levels may serve as a biomarker associated with fat mass modulation. This study seeks to investigate the effects and mechanisms of moderate-intensity continuous training (MICT) combined with BFR on abdominal visceral adipose tissue (VAT). Methods Young adults with obesity were randomly divided into three groups: the non-intervention control group (C group), the MICT intervention group (M group), and the MICT combined with BFR intervention group (B group). After the baseline test, a 12-week exercise intervention was carried out. Before and after the intervention, morning fasting blood samples were collected for the analysis of plasma non - targeted metabolomics and proteomics data, and the body composition, abdominal subcutaneous adipose tissue (SAT), and VAT area were assessed. Results After 12 weeks of intervention, the reduction in VAT in the B group was significantly greater than that in the C group. Exploratory multi-omics analyses identified differences between the B group and the M group, with the most prominent enrichment in the glycine, serine and threonine metabolism pathway. Correlation analysis revealed associations between Lac-phe and multiple indicators, including positive correlations with blood lactic acid, glycine and APOA1, and negative correlations with VAT, SAT and leucine (nominal p < 0.05). Conclusion Compared with traditional MICT, 12-week BFR intervention can significantly reduce abdominal VAT area, and its mechanism may be associated with increased metabolic stress and subsequent secretion of lipolytic hormones. All omics and correlation results are exploratory due to the low sample size and lack of correction for multiple comparisons. Plasma Lac-phe is preliminarily suggested as a candidate biomarker for VAT response to BFR training, which requires validation in larger targeted studies. Trial registration ISRCTN registry (Approval number: ISRCTN11246966, http://www.isrctn.org/ ) on May 8, 2025. Clinical trial number This study was prospectively registered in the ISRCTN registry (Approval number: ISRCTN11246966, http://www.isrctn.org/ ) on May 8, 2025. The first participant was enrolled on May 15, 2025, and the trial intervention was initiated on May 31, 2025, after the completion of all participant enrollment and baseline assessments. The primary outcome prespecified in the registry was the change in abdominal VAT area after 12-week intervention, and the secondary outcomes included changes in SAT area, plasma untargeted/targeted metabolomics and proteomics.