IGF1 and heart failure: Blood IGF-II levels remain stable lifelong; IGF-I levels decrease2,25 and the risk of heart failure increases with progressing in age.24 The mean age (78.4 years) of participants of the Framingham Heart Study, in which IGF-I was inversely associated with risk of heart failure,16 was 10 years higher than that of our participants (68.3 years).