Investigating the role of growth differentiation factor-15 as a biomarker of inflammation in patients with atherosclerotic vascular disease.

Inflammatory pathways in vascular disease are the focus of intense interest. Accumulating evidence suggests a role for GDF-15 in the atherosclerotic process. In this study we measured circulating levels of IL-6 and GDF-15 in a cohort of 20 vascular surgical patients with atherosclerotic disease presenting for surgical revascularisation and in a similar number of age-matched healthy volunteers. A cross-sectional analysis of prospectively collected data was performed, with serum GDF-15 and IL-6 levels measured and assessed using enzyme-linked immunosorbent assays (ELISA). We observed substantial circulating levels of GDF-15 in most patients (17/20). In contrast, only 1 healthy control participant had a borderline high GDF-15. Indeed, the mean serum GDF-15 level between patients (2515 pg/mL, SD 906) and healthy controls (1016 pg/mL, SD 219) was highly significant (p-value <0.001). On the other hand, although IL-6 levels between patients [mean 3.6, SD 2.54 pg/mL] and healthy controls [mean 2.2, SD 0.67 pg/mL] were significantly different (p = 0.020), only 7 patients had values above the reference range upper limit of 3.4 pg/ml. These results suggest that GDF-15, but not IL-6, is a strong candidate for use as a biomarker of atherosclerotic vascular disease and may allow for earlier risk factor modification.