Insulin-Like Growth Factor Binding Protein 7 Predicts Renal and Cardiovascular Outcomes in the Canagliflozin Cardiovascular Assessment Study

Abstract

OBJECTIVE To analyze the association between concentrations of plasma insulin-like growth factor binding protein 7 (IGFBP7) with renal and cardiac outcomes among participants with type 2 diabetes and high cardiovascular risk. RESEARCH DESIGN AND METHODS Associations between IGFBP7 levels and clinical outcomes were assessed among participants in the Canagliflozin Cardiovascular Assessment Study (CANVAS) with type 2 diabetes and high cardiovascular risk. RESULTS Among CANVAS participants, 3,577 and 2,898 had IGFBP7 measured at baseline and 1 year, respectively. Per log-unit higher concentration, baseline IGFBP7 was significantly associated with the composite renal end point of sustained 40% reduction in estimated glomerular filtration rate, need for renal replacement therapy, or renal death (hazard ratio [HR] 3.51; P < 0.001) and the composite renal end point plus cardiovascular death (HR 4.90; P < 0.001). Other outcomes, including development or progression of albuminuria, were also predicted by baseline IGFBP7. Most outcomes were improved by canagliflozin regardless of baseline IGFBP7; however, those with baseline concentrations ≥96.5 ng/mL appeared to benefit more from canagliflozin relative to the first progression of albuminuria compared with those with lower baseline IGFBP7 (HR 0.64 vs. 0.95; Pinteraction = 0.003). Canagliflozin did not lower IGFBP7 concentrations by 1 year; however, at 1 year, higher IGFBP7 concentrations more strongly predicted the composite renal end point (HR 15.7; P < 0.001). Patients with rising IGFBP7 between baseline and 1 year had the highest number of composite renal events. CONCLUSIONS Plasma IGFBP7 concentrations predicted renal and cardiac events among participants with type 2 diabetes and high cardiovascular risk. More data are needed regarding circulating IGFBP7 and progression of diabetic kidney disease and its complications.