Relationship Between Insulin-Like Growth Factor Binding Protein-2 and Left Ventricular Stroke Volume in Patients With Aortic Stenosis

Abstract

BackgroundLower plasma insulin-like growth factor binding protein (IGFBP)-2 levels have been associated with altered metabolism linked to visceral obesity. These abnormalities have been linked with worsening of left ventricle (LV) remodelling and dysfunction in patients with aortic stenosis (AS). Whether IGFBP-2 is involved in these relationships is currently unknown. The objective of this study was to examine the relationship between circulating IGFBP-2 and LV pump function measured according to stroke volume index in AS patients with preserved LV ejection fraction. MethodsTwo hundred eight patients with mild to moderate AS were prospectively recruited in the Metabolic Determinants of the Progression of Aortic Stenosis (PROGRESSA) study and underwent Doppler-echocardiography. Stroke volume index (SVi) was calculated using Doppler in the LV outflow tract and was indexed to body surface area. Plasma circulating IGFBP-2 levels were measured using an enzyme-linked immunosorbent assay. ResultsPatients with lower IGFBP-2 levels were younger (P < 0.0001), had a higher body mass index (P = 0.0003), larger waist circumference (P = 0.01), higher homeostatic assessment model index (P = 0.0005), and lower high-density lipoprotein cholesterol (P = 0.01). Moreover, SVi was decreased in patients with low IGFBP-2 (P = 0.009). After multivariable adjustment for age, sex, LV mass index, aortic valve area, and LV ejection fraction, a lower plasma IGFBP-2 level was independently related with lower SVi (P < 0.001). After further adjustment for other traditional cardiometabolic risk factors, plasma IGFBP-2 remained independently associated with SVi (all P < 0.05). ConclusionsIn this study, we documented that lower IGFBP-2 levels are independently associated with lower SVi, a powerful predictor of worse outcomes in the mild to moderate AS population.