摘要：Objectives. We sought to establish whether associations between childhood cognition and risk factors for cardiovascular disease in adulthood are explained by common causes, or adult social position or health behavior. Methods. We analyzed associations between cognition at age 11 and cardiovascular disease risk factors at age 45 in the 1958 British birth cohort (n = 9377), with and without adjustment for covariates. Results. General ability was inversely associated with systolic and diastolic blood pressure, glycosylated hemoglobin, triglycerides (in women), body mass index, and waist circumference. Systolic blood pressure decreased by 0.47 mm Hg (95% confidence interval [CI] = −0.90, –0.05) for a 1-standard-deviation increase in ability. Separate adjustment for social class at birth, education level by adulthood, adult social class, and health behaviors reduced the associations respectively by 14% to 34%, 36% to 50%, 14% to 36%, and 24% to 73%. Full adjustment reduced associations between ability and risk factors at age 45 years by 43% to 92%, abolishing all associations. Conclusions. Increments across the distribution of childhood cognition are associated with improvements in cardiovascular risk profile in midlife, with associations primarily mediated through adult health behavior and social destinations. Individuals with a higher IQ in the first 2 decades of life have been found to have lower death rates from all causes in mid- to late adulthood, as reported in a systematic review of 9 prospective studies. 1 Associations between childhood cognition and mortality were not caused by confounding, reverse causality, or selection bias; hence, work directed at understanding the association is needed. Knowledge of the specific diseases associated with childhood cognition may yield clues about the likely explanations. Recent studies have investigated relationships between childhood cognition and intermediate risk factors for later cardiovascular disease. For example, higher childhood cognition has been associated with lower systolic and diastolic blood pressure in the Midspan cohorts of Scottish adults, 2 although another Scottish study found no association for self-reported hypertension. 3 Prevalence of self-reported diabetes was reduced in adults with higher childhood cognition in a US but not a Scottish population. 3 , 4 Associations between higher childhood cognition and lower levels of adiposity have been observed, with some studies investigating mediation of factors such as adult education. 5 – 8 Explanations have been proposed for associations between childhood cognition and adult mortality or morbidity: first, there may be common causes of cognition and adult disease, including childhood socioeconomic position; second, childhood cognition predicts later educational and occupational attainment, which in turn influences exposure to hazardous environments that affect risk of adult disease; and third, childhood cognition affects the extent to which individuals acquire or act on knowledge about protective or health-damaging behaviors linked to disease. 9 Few studies have examined explanations in detail, largely because of limited data availability on relevant factors. We, therefore, examined associations between childhood cognition and several risk factors for cardiovascular disease (CVD) in a large population-based sample of men and women. Our primary aim was to establish whether childhood cognition is associated with blood pressure, lipids, glycosylated hemoglobin (HbA1c), and total or central adiposity in midlife. We sought to determine whether associations between childhood cognition and risk factors for CVD are explained by (1) early life factors, such as birthweight and social origins, which could act as common causes of both cognition and CVD risk; (2) adult social position; or (3) health behaviors. We studied a prospective birth cohort, followed to age 45 years, in which we have previously shown lower birthweight and less-advantaged social origins to be associated with poorer childhood cognition. 10 In turn, poorer cognition was found in this cohort to increase the risk of behaviors, such as abstaining from alcohol and binge drinking 11 and smoking, 12 linked to adverse health outcomes.
