title: Revisiting the relationship between blood pressure and insulin-like growth factor-1.
abstract: Conflicting evidence exists on the relationship between blood pressure (BP) and insulin-like growth factor-1 (IGF-1). We reviewed available articles and pooled extrapolated regression coefficients for the association between BP and total IGF-1 as reported in the literature and included additional data from 912 individuals from the general population. We identified 20 studies including 11 704 subjects. We also measured total IGF-1, insulin-like binding protein-3, and BP in 912 black and white men and women from South Africa (aged 20-70 years). When plotting positive and negative weighed regression coefficients (29 data points) against IGF-1, we found a significant positive relationship (r=0.31; P<0.001; n=11 704) intercepting the 0 point at 191 ng/mL IGF-1, suggesting an inverse BP/IGF-1 relationship in low IGF-1 conditions, and a positive relationship in overtly high IGF-1 conditions. In conclusion, our findings suggest that the relationship between BP and IGF-1 is dependent on, or related to, IGF-1 concentrations, as an expression of direct or reverse causality. Low IGF-1 bioavailability (associated with aging and vascular deterioration), resistance to IGF-1, and the complex interplay between IGF-1 and other vasoactive hormones could mask the vasoprotective functions of IGF-1 in cross-sectional studies or could modify their functions in prospective studies.
authors.affiliation: Hypertension in Africa Research Team, North-West University, Hoffman St, Private Bag X6001, Potchefstroom 2520, South Africa. Alta.Schutte@nwu.ac.za.
authors.forename: Aletta Elisabeth
authors.initials: AE
authors.lastname: Schutte
authors.forename: Massimo
authors.initials: M
authors.lastname: Volpe
authors.forename: Giuliano
authors.initials: G
authors.lastname: Tocci
authors.forename: Elena
authors.initials: E
authors.lastname: Conti
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D019869:Phosphatidylinositol 3-Kinases
keywords: acromegaly; aging; hypertension; vasodilation