In a groundbreaking study that has immense effect on developing countries, presented at the American Stroke Association's International Stroke Conference in Phoenix, USA, researchers reveal a startling connection between strokes and the heightened risk of developing dementia.
Dr Raed Joundi, an assistant professor at McMaster University in Hamilton, Ontario, Canada, and an investigator at the Population Health Research Institute, led the study, which highlighted the nearly tripled risk of developing dementia in the first year after a stroke. While the risk diminishes after the first 12 months, it can stay high for up to two decades.
"Our findings show that stroke survivors are uniquely susceptible to dementia," Dr. Raed Joundi said in a statement.
The study analysed data from hospital admissions, emergency department visits, and pharmacies prescribing medications for dementia across Ontario, identifying 180,940 people, who recently experienced either an ischemic stroke or an intracerebral haemorrhage. The risk of dementia was found to be 80% higher among those who had a stroke, with a staggering 150% higher risk for those who experienced a bleeding stroke.
Connecting these findings to the situation in developing countries, where healthcare resources are limited, the study underscores the need for targeted interventions to address the increased risk of post-stroke dementia. In such countries, where approximately 610,000 people experience a first stroke each year and 185,000 have recurrent strokes, the impact on public health is significant.
It should be noted that a 2019 study published in the Journal of Neurological Sciences revealed that the worldwide population of people aged 60 and up is anticipated to grow dramatically, from 900 million in 2015 to 2 billion by 2050. This indicates a change from 12% to 22% of the global population. Notably, this ageing tendency is progressing faster than in prior years. By 2050, a staggering 80% of the elderly population will live in low- and middle-income countries.
In 2016, the average global life expectancy at birth was 72.0 years, with differences by location. Females had a life expectancy of 74.2 years, while males had a slightly lower one of 69.8 years. Life expectancy ranged from 61.2 years in the WHO African Region to 77.5 years in the WHO European Region, they said.
Pointing out that the prevalence of dementia is a growing concern on a global scale, researchers said that in 2015, an estimated 47.47 million people were living with dementia, a number projected to increase to 75.63 million by 2030 and a striking 135.46 million by 2050. In 2010, 58% of individuals with dementia were in low- or middle-income countries, a proportion expected to rise to 63% by 2030 and 71% by 2050.
In Latin America, the number of people with dementia is predicted to quadruple from 2015 to 2050. By 2020, an estimated 89.28 million people with dementia will reside in low- and lower-middle-income countries. Meanwhile, in the Asia-Pacific region, the number of individuals with dementia is anticipated to surge from 23 million in 2015 to 71 million by 2050.
Dementia prevalence in Sub-Saharan Africa exhibits wide variability, ranging from 2.29% to 21.60%. Alzheimer's disease emerges as the most prevalent type of dementia. In Egypt, the prevalence of dementia among individuals aged 65 years and older was found to be 5.9%. These statistics highlight the urgent need for global attention and resources to address the escalating challenges associated with an ageing population and the increasing prevalence of dementia in various regions.
The study further highlights that, during the first year after a stroke, individuals face a nearly threefold increased risk for dementia compared to their peers who did not have strokes. Even after 20 years, the risk remains higher for stroke survivors than for those who have not experienced a stroke.
Dr. Joundi emphasised the importance of monitoring stroke survivors for cognitive decline, implementing appropriate treatments to address vascular risk factors, and preventing recurrent strokes. He also called for further research to understand why some stroke survivors develop dementia while others do not.
The study reinforces the critical importance of addressing the unique challenges faced by developing countries in managing post-stroke dementia, urging governments and healthcare organisations to prioritise preventive measures, research initiatives, and collaborative care strategies to mitigate the impact of this concerning health issue.