ASSOCIATIONS OF ALLOSTATIC LOAD WITH CORONARY HEART DISEASE AND DEMENTIA IN THE ENGLISH LONGITUDINAL STUDY OF AGEING

We evaluated the associations between allostatic load (AL), with subsequent coronary heart disease (CHD) and dementia during 12-year follow-up in the English Longitudinal Study of Ageing. Participants (N= 4,335) were aged ≥50 years at baseline. The AL index included five biomarker risk groups covering neuroendocrine (Insulin growth factor 1), cardiovascular (systolic and diastolic blood pressure, resting pulse rate, medication), metabolic (total cholesterol-to-HDL ratio, HbA1c, triglycerides), immune (C-reactive protein, fibrinogen) and anthropometric systems (waist-to-height ratio, obese) as measured at baseline. Except for obesity, the highest gender-specific quartile of the distribution for each biomarker was scored with 1, while the remaining groups with 0. The sum ranged from 0 to 12, with higher scores signifying higher AL, was grouped into three categories: 0 (reference group), 1–3 and 4+. CHD events were defined as myocardial infarction and angina. Dementia was determined by doctor-diagnosis combined with a positive score on the Informant Questionnaire on Cognitive Decline in the Elderly. After adjustment for a range of covariates such as age, sex, socioeconomic status and health behaviours, we found that those with a higher AL index of 4+ had a 56% increased risk of CHD (Incidence Rate Ratio (IRR) 1.56 (95% Confidence Intervals (CI) 1.08–2.24), with a significant trend p=0.01), whereas the results for dementia were inconclusive (IRR=1.16 (95% CI) 0.68–1.97)). Our results showed that a high physiological burden was related to subsequent CHD, supporting the hypothesis that a cumulative index of “biological dysregulation” could act as an early determinant of CHD.