Angiopoietin-2 Is Associated with Aortic Stiffness in Diabetes Patients in Ghana: A Case-Control Study

Abstract

Objective. Impaired angiogenesis, measured as serum levels of angiogenic growth factors, may be among the mechanisms underlining aortic stiffness in diabetes patients. We studied the association between aortic stiffness and circulating angiogenic growth factors in type 2 diabetes (T2DM) patients without any organ damage. Methods. In a case-control design, aortic pulse wave velocity (PWV), augmentation index (AIx), and aortic blood pressures (BPs) were measured in 140 T2DM patients and 110 nondiabetic controls. Fasting blood samples were collected to measure the levels of angiopoietin- (Ang-) 1, Ang-2, and vascular endothelial growth factor-A (VEGF). Results. Compared to nondiabetes participants, T2DM patients had increased PWV ( $8.7\pm 1.5$ vs. $7.6\pm 1.3$ , $p=0.031$ ), aortic pulse BP ( $58\pm 20$ vs. $49\pm 17$ , $p=0.011$ ), Ang-2 (838 (473–1241) vs. 597 (274–1005), $p=0.018$ ), and VEGF (72.2 (28–201.8) vs. 48.4 (17.4–110.1), $p=0.025$ ) but reduced levels of AIx ( $21.7\pm 13.8$ vs. $34\pm 12.9$ , $p<0.001$ ) and Ang-1 (33.1 (24.7–42.1) vs. 41.1 (30–57.3), $p=0.01$ ). In all study participants, compared to those in the lower tertile, participants in the upper tertile of Ang-2 had increased odds of PWV (2.01 (1.17–3.84), $p=0.004$ ), aortic systolic BP (1.24 (1.04–1.97), $p=0.011$ ), and aortic pulse BP (1.19 (1.04–1.82), $p=0.041$ ) but reduced odds of AIx (0.84 (0.71–0.96), $p=0.014$ ) in multivariable-adjusted models. Conclusion. In our study population, increased circulating Ang-2 was associated with increased levels of aortic stiffness parameters.