Use of ACE inhibitors is associated with elevated levels of IGFBP-3 among hypertensive older adults: Results from the IlSIRENTE study

OBJECTIVE: Several studies in vitro or in rodent models have suggested a potential relationship between angiotensin-converting enzyme (ACE) inhibition and the insulin-like growth factor 1 (IGF-1) axis. However, this relationship has only rarely been investigated in humans. The aim of the present cross-sectional study was to assess the association of ACE inhibitors with free IGF-1 and IGFBP-3 in the blood of older hypertensive adults. METHODS: Data are from the baseline evaluation of the IlSIRENTE study, which enrolled 364 subjects aged 80 or older. For the present study we selected a subpopulation of 264 hypertensive participants without congestive heart failure. Free IGF-1 and IGFBP-3 in the blood were measured by a radioimmunoassay method. Analyses of covariance were performed to evaluate the differences in free IGF-1 and IGFBP-3 levels according to the use of ACE inhibitors. RESULTS: The mean age of participants was 85.7 years (SD: 4.9), 170 (64%) were women and 123 (47%) were using an ACE inhibitor. Following adjustment for potential confounders, the concentration of free IGF-1 was slightly, but not significantly higher among ACE inhibitor users than among non-users (0.74 vs. 0.65 ng/mL; p=0.20). In contrast, ACE inhibitor users had a significantly higher IGFBP-3 serum levels than non-users (4821 vs. 4330 ng/mL; p=0.005). In addition, the concentration of IGFBP-3 was significantly higher among ACE inhibitors users than among non-users of antihypertensive drugs (p=0.02) and users of other antihypertensive drugs (p=0.01). CONCLUSION: Among hypertensive older adults, ACE inhibitors use is associated with higher IGFBP-3 levels.