Blockade of the RAS increases Plasma Adiponectin in Subjects with Metabolic Syndrome and Enhances Differentiation and Adiponectin Expression of Human Preadipocytes

This observational study aimed to investigate the effects of renin-angiotensin system (RAS) blockers on plasma adiponectin in subjects with metabolic syndrome (Mets) and differentiation, adiponectin expression of human omental (OM) and subcutaneous (SC) preadipocytes. Fifty-three patients with Mets were treated with angiotensin converting enzyme inhibition (ACEI), angiotensin II receptor blocker (ARB) or nothing, lipid profile and adiponetin were measured. OM and SC preadipocytes were obtained from sixteen normal non-menopausal women undergoing elective abdominal surgery and subsequently differentiated in the presence of ACE, ARB or thiazolidinedione (TZD). Differentiation was assessed using a number of biochemical and function parameters. Plasma adiponectin was increased dramatically as a result of ACEI and ARB treatment. Most of the metabolic and differentiating parameters were improved significantly by RAS blockers or TZD. Compared with TZD, RAS blockers have stronger effects on omental preadipocytes in differentiation and insulin sensitivity. The improvement of adiponectin mRNA expression was significantly greater in ARB-treated omental preadipocytes compared with TZD-treated ones. These results suggest that adiponectin may serve as potential therapeutic targets of ACEI and ARB for treating the Mets and its related complications. It also suggests a potential benefit of RAS blockers on Mets with characteristic visceral obesity.