Low Insulin-Like Growth Factor-1 Levels Are Associated With Myocardial Mechano-Energetic Efficiency in Older Individuals

CONTEXT: Altered myocardial mechano-energetic efficiency (MEE) is a substantial predictor of cardiovascular events and heart failure. Among the potential pathophysiological factors underlying MEE impairment, insulin-like growth factor 1 (IGF-1) may be a plausible candidate due to its role in the cardiovascular system. OBJECTIVE: This study aimed to analyze the relationship between plasma IGF-1 concentrations and myocardial MEE in a cohort of individuals older than 65 years, participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study. METHODS: Myocardial MEE per gram of left ventricular mass (MEEi) was measured in 490 older participants with a broad spectrum of glucose tolerance using echocardiography. RESULTS: IGF-1 levels were positively associated with myocardial MEEi (r = 0.200; P < .001). Individuals in the highest tertile (tertile 3) of IGF-1 showed significantly lower heart rate and myocardial oxygen consumption, alongside a significant increase in myocardial MEEi compared to those in the lowest tertile. In multivariate linear regression analysis, IGF-1 levels were identified as the major determinant of MEEi, independently of well-established cardiometabolic risk factors. CONCLUSION: These findings suggest that low circulating IGF-1 levels are associated with depressed myocardial MEEi in older individuals. This highlights the potential importance of monitoring IGF-1 in clinical evaluations to assess cardiovascular health.