Objective: Metabolic syndrome (MetS) is associated with impaired angiogenesis. Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis through binding to its specific receptor, VEGF receptor-2 (VEGFR-2), whereas the expression of VEGF and VEGFR-2 in the myocardium of insulin-resistant rats is down-regulated. Soluble VEGF receptor-1 (sVEGFR-1) and -2 (sVEGFR-2) have been reported to inhibit angiogenesis both in vitro and in vivo. However, the balance between circulating levels of VEGF and its soluble receptors, which may reflect and/or affect cardiovascular VEGF signaling, in subjects with MetS is unknown.
Methods and results: We carried out a cross-sectional study including 272 consecutive, apparently healthy subjects who were not receiving any drugs. Plasma levels of VEGF and serum levels of its soluble receptors were determined using enzyme-linked immunosorbent assays. VEGF and sVEGFR-1 levels did not differ between subjects with and those without MetS. However, sVEGFR-2 levels were significantly increased in MetS compared with non-MetS subjects. Stepwise regression analysis revealed that HOMA-IR was the strongest independent determinant of the sVEGFR-2 level. Accordingly, the mean sVEGFR-2 levels increased in proportion to both the accumulation of components of MetS and quartile of HOMA-IR. Interestingly, multiple regression analyses revealed that independent determinants of VEGF were the body mass index and blood pressure, whereas, in contrast, those of sVEGFR-2 were HOMA-IR and high-sensitivity C-reactive protein.
Conclusions: The correlation of sVEGFR-2 with insulin resistance supports the need for further investigations to define the clinical utility and predictive value of serum sVEGFR-2 levels in cardiovascular dysfunction in MetS.
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