South Asian, Black and White ethnicity and the effect of potentially modifiable risk factors for dementia: A study in English electronic health records.

Introduction: We aimed to investigate ethnic differences in the associations of potentially modifiable risk factors with dementia.

Methods: We used anonymised data from English electronic primary care records for adults aged 65 and older between 1997 and 2018. We used Cox regression to investigate main effects for each risk factor and interaction effects between each risk factor and ethnicity.

Results: We included 865,674 people with 8,479,973 person years of follow up. Hypertension, dyslipidaemia, obesity and diabetes were more common in people from minority ethnic groups than White people. The impact of hypertension, obesity, diabetes, low HDL and sleep disorders on dementia risk was increased in South Asian people compared to White people. The impact of hypertension was greater in Black compared to White people.

Discussion: Dementia prevention efforts should be targeted towards people from minority ethnic groups and tailored to risk factors of particular importance.