Atheroprotective Properties of Serum IGF-1 in the Carotid and Coronary Territories and Beneficial Role on the Physical Fitness of the Oldest Old

Our aim was to investigate whether physiological levels of soluble insulin-like growth factor-1 (IGF-1) associate with coronary and carotid atherosclerotic burden and physical fitness in the oldest old by means of a cross-sectional study including 100 community-dwelling individuals with no previous cardiovascular events. Linear correlation was found between IGF-1 and intima-media thickness, number of carotid plaques, and walking speed. Individuals in the upper IGF-1 tertile had smaller right and left intima-media thickness compared with the intermediate and lower tertiles, along with reduced atherosclerotic plaques. Also, walking speed was greater in the upper IGF-1 tertile. On the other hand, a nonlinear correlation was observed between IGF-1 and coronary calcification scores, with the intermediate IGF-1 tertile associated to the lowest scores of calcification and participants with lower circulating levels of IGF-1 showing higher frequency of high-risk morphology plaques. All in all, our report supports a territory-dependent, atherorefractory phenotype in the oldest old carrying middle and/or higher serum levels of IGF-1.