Childhood hyperactivity as a predictor of carotid artery intima media thickness over a period of 21 years: the Cardiovascular Risk in Young Finns Study

Objective: We investigated whether childhood temperament was able to predict carotid artery intima media thickness (IMT) and/or its risk factors in adulthood 21 years later. Methods: The subjects were the three youngest age cohorts of the population-based sample of the Cardiovascular Risk in Young Finns study, i.e., those who were aged 3 to 9 years (n = 708) at the baseline. IMT was assessed by ultrasound, and temperament in terms of negative emotionality, hyperactivity, and sociability (following Buss and Plomin). In addition, the levels of traditional risk factors for atherosclerosis were measured in both childhood and adulthood. Results: Childhood temperament was found to predict adulthood risk factors such as smoking in both genders and body mass index (BMI), systolic blood pressure (SBP), and educational level in women. In women, childhood hyperactivity predicted adulthood IMT after adjustment for childhood and adulthood risk factors for atherosclerosis. Conclusion: These findings suggest that temperament may contribute to the development of IMT in two ways: indirectly through risk factors in both genders and in women directly through a mechanism that is not considered in the present study. There were no significant gender-related differences in temperament, but it seemed to play different roles in different genders. Hyperactivity was a greater risk for girls than for boys.