Abstract
Introduction: There is mixed evidence for an association between cardiometabolic risk factors with dementia incidence. This study aimed to determine whether different latent classes of cardiometabolic risk factors were associated with the risk of dementia in older adults across England, the USA and China. Methods: Data were used from three nationally representative studies, the English Longitudinal Study of Ageing (n= 4511), Health and Retirement Study (n=5112) and China Health and Retirement Longitudinal Study (n=9022). Latent class analyses were across each dataset utilising seven baseline cardiometabolic indicators: obesity, low high‐density lipoprotein cholesterol, systolic and diastolic blood pressure, hyperglycaemia, diabetes, and inflammation. Confounder-adjusted Cox proportional hazards regressions were conducted to examine the association between cardiometabolic latent classes with dementia incidence. Results: Three similar cardiometabolic latent classes were identified across all countries: 1) 'relatively healthy/healthy obesity', 2) 'obesity-hypertension' and 3) 'complex cardiometabolic' class. Across the three samples a total of 1,230 individuals developed dementia over a median of 6.8 to 12.2 years. Among English and American participants those people in the 'complex cardiometabolic' group had a higher dementia risk when compared to people in the 'healthy obesity' groups (England: AdjHR=1.62: 95%CI [1.11 - 2.37]; USA: AdjHR=1.31: 95%CI [1.02 - 1.68]). However, in Chinese participants the 'obesity-hypertension' group had a significantly higher risk of developing dementia when compared to the 'relatively healthy' group (AdjHR=1.28: 95%CI [1.04 - 1.57]). Conclusion: This study provides evidence that in Western populations, complex cardiometabolic clusters are associated with a greater risk of dementia, whereas in a Chinese sample, a different cardiometabolic profile seems to be linked to a greater risk of dementia.