Cognitive function in childhood and cardiovascular disease risk factors up to 6 decades later: Pooled data from two...

Higher childhood (pre-morbid) cognitive function (IQ) appears to confer a lower risk of cardiovascular disease (CVD) episodes in adulthood, however, the underpinning mechanisms are uncertain. We tested the association between childhood cognitive ability and later CVD risk factors that may underpin this gradient.

We used data from two well-characterized prospective birth cohort studies initiated in the United Kingdom in 1958 (N=10870) and 1970 (N=9278). Cognitive function was quantified using validated written tests at around 10 years of age. A total of 16 biological, psychosocial, and behavioral risk factors were collected at 46-48 (1970 cohort) and 61-65 (1958 cohort) years of age in both studies. Associations were summarized using linear and logistic regression.

After pooling the data and controlling for early life confounding factors, higher childhood cognitive ability was related to more favorable levels of 4/4 psychosocial, 3/3 behavioral, and 6/9 biological risk factors in middle/older age. The magnitude of these relationships increased from biological, to behavioral then psychosocial risk factors. For example, a one standard deviation higher cognitive test score was related to protective levels of body mass index (beta coefficient [95% confidence interval]: -0.58 [-0.70, -0.45]; p-value <0.001), triglycerides (-0.03 [-0.04, -0.01]; <0.001), cigarette smoking (odds ratio [95% confidence interval]: 0.72 [0.67, 0.76] <0.001), depressive symptoms (0.79 [0.74, 0.84]; <0.001), and a high prestige occupation (2.27 [2.21, 2.35]; <0.001). There was some evidence of mediation via educational attainment.

The present correlations implicate a series of mechanistic pathways which may connect cognition with subsequent CVD events. The greater burden of unfavorable risk factors at the lower end of the cognition spectrum suggests that compliance with preventive health advice may be sub-optimal.