A promoter polymorphism of the insulin-like growth factor-I gene is associated with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is a strong predictor of cardiovascular morbidity and mortality. Insulin-like growth factor-I (IGF-I) has an important role in the hypertrophic response of the myocardium.1 A polymorphism in the IGF-I gene promoter region has been identified which influences IGF-I production.2–4 Studying this polymorphism in relation to pathology may better reflect the effects of long term IGF-I exposure than studies on serum IGF-I concentrations, which may fluctuate considerably and are profoundly influenced by various factors. We investigated the association between this IGF-I promoter polymorphism and the occurrence of LVH on echocardiogram. The Rotterdam study is a population based cohort study in 7983 elderly people aged 55 years or over. The baseline examination was conducted in 1990–93, during which time information was obtained on age, sex, history of myocardial infarction, smoking, hypertension, diabetes mellitus, and body mass index (BMI). Cardiac ultrasound was performed in a random subpopulation of 2823 subjects. The present study was performed in subjects aged 55–75 years, without a history of myocardial infarction. The analyses were restricted to persons with an adequate echocardiogram and for whom blood specimens were available for IGF-I typing, a total of 1678 subjects. This is the first genetic case association study that uses the Rotterdam study database to investigate the phenotype of LVH on the echocardiogram. M mode echocardiography was performed …