Compromised bioavailable IGF-1 of black men relates favourably to ambulatory blood pressure: the SABPA study
Date
2014Author
Schutte, A.E.
Schutte, R.
Smith, W.
Huisman, H.W.
Mels, C.M.C.
Malan, L.
Fourie, C.M.T.
Malan, N.T.
Van Rooyen, J.M.
Kruger, R.
Metadata
Show full item recordAbstract
Objectives
Insulin-like growth factor-1 (IGF-1) has potent endothelial-protective, anti-platelet and anti-thrombotic activities, and also exerts mitogenic and proliferatory actions on vascular smooth muscle cells. Conflicting reports exist regarding the role of IGF-1 in vascular protection and atherogenesis. We therefore investigated the relationships of ambulatory blood pressure (BP) and carotid intima-media thickness (cIMT) with a range of components of the IGF-1 axis in a bi-ethnic population.
Methods
We included black (N = 86) and white (N = 101) men and measured growth hormone, total IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3), and pregnancy-associated plasma protein-A (PAPP-A) levels.
Results
Ambulatory BP was almost 10 mmHg higher in black men (137/88 mmHg versus 128/80 mmHg; both p < 0.001), accompanied by an adverse profile of the IGF-axis for all measured components (all p < 0.01), including reduced bioavailable IGF-1 (IGF-1/IGFBP-3; p = 0.006) and tissue IGF-1 accessibility index as represented by IGF-1.PAPP-A/IGFBP-3 (p < 0.001). Single, partial and multiple regression analyses confirmed an independent inverse association between ambulatory systolic BP and bioavailable IGF-1 in black men (R2 = 0.24; β = −0.22; p = 0.035). cIMT was similar in the ethnic groups (p = 0.34), and was negatively associated with bioavailable IGF-1 in white men (R2 = 0.42; β = −0.17; p = 0.039) prior to adjustment for γ-glutamyl transferase (R2 = 0.45; β = −0.10; p = 0.25).
Conclusion
Ambulatory systolic BP is inversely related to bioavailable IGF-1 in black men who displayed low IGF-1 concentrations. An inverse relation was found between cIMT and IGF-1 in white men, which disappeared after correction for γ-glutamyl transferase – opposing reports of a detrimental role of IGF-1 in the early stages of atherogenesis.
URI
http://hdl.handle.net/10394/17609http://dx.doi.org/10.1016/j.atherosclerosis.2013.12.025
https://pubmed.ncbi.nlm.nih.gov/24529134/
https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.998.5588&rep=rep1&type=pdf
Collections
- Faculty of Health Sciences [2385]