The burden of stroke, ischaemic heart disease, and dementia in Africa, 1990-2021: an ecological analysis of the Global Burden of Disease 2021.

BACKGROUND

Stroke, ischaemic heart disease, and dementia share risk factors and influence one another, substantially affecting brain health. Limited health-care resources in Africa might exacerbate the burden of these diseases, with serious brain health consequences. We analysed trends from 1990 to 2021 to inform optimised prevention strategies.

METHODS

Using The Global Burden of Diseases, Injuries, and Risk Factors Study 2021 data, we assessed the burden of these conditions, measured by disability-adjusted life-years (DALYs) lost attributed to 12 risk factors, and their changes from 1990 to 2021. Bayesian modelling generated means and 95% uncertainty intervals (UIs) based on the 2·5th and 97·5th percentiles of 500 posterior distribution draws.

FINDINGS: In Africa in 2021, 17·3 (95% UI 15·5-19·2) million DALYs were lost due to strokes, 17·6 (15·5-19·6) million were lost due to ischaemic heart diseases, and 1·8 (0·8-4·0) million were lost due to dementia. New and prevalent cases doubled from 1990 to 2021, with two-thirds of DALYs occurring before age 70 years. Among five continents, Africa had the highest age-standardised DALY rates per 100 000 population for stroke (2628·1 [2367·4-2893·0]) and ischaemic heart disease (2743·5 [2451·8-3033·6]), and the lowest for dementia (423·4 [190·6-934·6]). Regionally, central and southern Africa showed higher stroke DALY rates, northern Africa had the highest rates for ischaemic heart disease, and central and northern Africa had the highest rates for dementia. Among 12 modifiable risk factors, high systolic blood pressure, unhealthy diet, and air pollution contributed most to DALYs. Stroke DALYs rose prominently due to high BMI, high fasting plasma glucose, high LDL cholesterol, low physical activity, and high systolic blood pressure.

INTERPRETATION: Africa faces substantial challenges from stroke, heart disease, and dementia, including the highest DALY rates globally, with worsening trends over the past three decades, including younger ages of onset. These patterns, coupled with limited health resources, necessitate urgent and targeted strategies to protect, preserve, and promote brain health in Africa.

FUNDING: Weston Family Foundation.