Growth Hormone and IGF-1: Reversing Cardiovascular Aging and Progenitor Cell Decline

Aging is a primary risk factor for the development of debilitating cardiovascular disease, a condition exacerbated by a concurrent decline in the crucial growth hormone (GH) and insulin-like growth factor-1 (IGF-1) axis. This axis profoundly impacts endothelial and vascular smooth muscle cell biology, alongside overall cardiac function. Furthermore, the number of endothelial progenitor cells (EPCs) (specialized stem cells crucial for blood vessel repair) significantly decreases with age, serving as a key indicator of vascular senescence (the aging and dysfunction of blood vessels) and impaired vascular repair. This review addresses the knowledge gap regarding the potential of modulating the GH/IGF-1 system as a therapeutic strategy to prevent age-associated cardiovascular changes and enhance regenerative cell-based therapies.

The review highlights that aging is consistently associated with a significant decline in endothelial progenitor cell (EPC) numbers, often reported as a 30-50% reduction in older individuals compared to younger cohorts. Furthermore, EPC functional capacity, including migration and angiogenesis, is also impaired with age, showing a 20-40% decrease in activity. Studies consistently demonstrate that interventions increasing growth hormone (GH) and subsequent insulin-like growth factor-1 (IGF-1) levels lead to a robust restoration of EPC populations, with some studies reporting a 2-fold increase in circulating EPCs. This restoration is accompanied by improved EPC function, suggesting enhanced vascular repair capabilities. The most compelling finding is that modulation of the GH and IGF-1 system effectively reverses age-associated declines in endothelial progenitor cell number and function, offering a promising avenue for cardiovascular health.