Exercise-induced modulation of IGF-1 in healthy, obese, and cancer populations: a systematic review and meta-analysis

Abstract

BackgroundThis systematic review and meta-analysis evaluated the effects of chronic exercise on circulating insulin-like growth factor 1 (IGF-1) across different populations, including, healthy adults, individuals with obesity, and cancer patients or survivors. To minimize confounding, we excluded trials combining exercise with medications, hormone therapy, or structured dietary interventions.Materials and MethodsPubMed and Embase were searched through July 2024 for randomized controlled trials (RCTs) in adults (>= 18 years) with exercise interventions lasting >= 8 weeks, a non-exercise control group, and reported changes in serum IGF-1. Twenty-one RCTs with 1376 participants met the inclusion criteria. Pooled weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated, and trial sequential analysis was used to assess robustness.ResultsExercise significantly increased IGF-1 in healthy individuals (WMD=21.41, 95% CI 8.01-34.81) and in those with obesity (WMD=15.46, 95% CI -1.07-31.99), consistent with metabolic and anabolic benefits via the GH-IGF-1 axis. In contrast, exercise significantly reduced IGF-1 in cancer patients or survivors (WMD=-14.71, 95% CI -19.77 to -9.65). In studies reporting both IGF-1 and IGF-binding protein 3 (IGFBP-3), exercise increased IGFBP-3 in healthy and cancer populations, suggesting a modulatory role of IGFBP-3 in IGF-1 regulation, particularly in cancer.ConclusionChronic exercise exerts health status-dependent effects on circulating IGF-1, supporting metabolic benefits in healthy and obese individuals and potentially contributing to cancer care by reducing IGF-1 in cancer patients or survivors. These findings demonstrate the complex endocrine response to exercise and support the therapeutic potential of tailored exercise prescriptions. .