History of coronary heart disease and cognitive performance in midlife: the Whitehall II study

Aims Some studies show coronary heart disease (CHD) to be a risk factor for cognitive function while others report no association between the two. We examined the effect of CHD history and duration on cognition in a middle-aged population. Methods and results Data come from the Whitehall II study of 10 308 participants (33% women), aged 35-55 years at baseline (Phase 1; 1985-88). CHD events were assessed up to Phase 7 (2002-04) when 5837 participants (28.4% women) undertook six cognitive tests: reasoning, vocabulary, phonemic and semantic fluency, memory and the mini-mental-state-examination (MMSE); standardized to T-scores (mean = 50, standard deviation = 10). Analysis of covariance was used first to model the association between CHD history and cognition and then to examine the effect of time since first CHD event (in the last 5 years, 5-10 years ago, > 10 years ago). Among men, in analyses adjusted for age, education, marital status and medication for cardiovascular disease, CHD history was associated with lower T-scores on reasoning [-1.16; 95% confidence interval (CI) = -2.07, -0.25], vocabulary (-2.11; 95% CI = -3.01, -1.21), and the MMSE (-1.45; 95% CI = -2.42, -0.49). In women, these effects were also evident for phonemic and semantic fluency. Among men, the trend within CHD cases suggested progressively lower scores on reasoning, vocabulary and semantic fluency among those with longer duration of CHD. Conclusion Our findings go some way towards suggesting an association between CHD history and cognitive performance in middle-aged adults.