IGF1 as predictor of all cause mortality and cardiovascular disease in an elderly population

Background: IGF1 is believed to influence ageing and development of cardiovascular disease (CVD) through complex mechanisms. Reduced IGF1 levels might be causally associated with conditions,accompanying ageing including development of CVD. However, in animal models reduced GH-IGF1 signalling increases lifespan. Reduced IGF1 activity might also be associated with longevity in humans. Objective: The objective was to investigate if plasma IGF1 levels were associated with all cause mortatity, and the development of chronic heart failure (CHF) and a major CV event. Patients and design: A population based study of 642 individuals, aged 50-89 years. Development of CHF was evaluated in 5 76 individuals with normal systolic function assessed by echocardiography and without the history of CHF or myocardial infarction. Development of the first major CV event was evaluated in 504 individuals with normal systolic function and without prevalent CVD. Outcomes were ascertained after 5 years using hospital discharge diagnoses. Results: Adjustment for risk factors IGF1 values in the fourth quartile versus values below the fourth quartile was associated with increased mortality (n= 103), hazard ratio (HR) 1.52 (95% confidence interval (Cl) 1.01 -2.28; P=0.044). IGF1 in the fourth quartile was also independently associated with risk of development of CHF (n=19), HR 5.02 (95% CI 2.00-12,64; P=0.001) but showed no association with the overall incidence of major CV events (n=58), HR 1.05 (950% Cl 0.59-1.90; P=0.861). Conclusions: High IGF1 levels were independently associated with increased all cause mortality and risk of development of CHF whereas no relation with the overall incidence of CVD was observed.