Association of endothelial proliferation with the magnitude of weight loss during calorie restriction

Objectives: Substantial weight loss through intense dietary regimens is thought to ameliorate endothelial dysfunction in obesity. It is less clear whether similar improvements can be achieved with modest dietary interventions. This study aimed to identify the parameters of endothelial cell status in obesity that are affected by mild calorie restriction. Methods: Human umbilical vein endothelial cells (EA.hy926 line) in culture were exposed pairwise to serum from 57 individuals with simple obesity (BMI > 30 kg/m²) collected before and after 8-week dietary intervention with energy deficit of 300–500 kcal/day. Results: Analysis of endothelial transcriptome suggested that the intervention could impact on endothelial cell growth. Cell proliferation was measured with the MTT test and verified by [³H]-thymidine incorporation. The participants were categorized according to a change in proliferation over time. Significant decrease in endothelial cell proliferation correlated with the extent of weight loss in men, but not in women. This effect corresponded with changes in serum levels of leptin and adiponectin, but was not related to serum concentrations of several known angiogenic mediators (VEGF, MCP-1, TSP-1, MMP-9, angiopoietin-2). Conclusion: Direction and magnitude of changes in serum-induced endothelial cell proliferation identifies patients with the greatest weight loss in response to modest calorie restriction.