Changing demography and the challenge of dementia in India

• Published in: Nature reviews. Neurology Vol. 17; no. 12; pp. 747 - 758
• Main Authors: Ravindranath, Vijayalakshmi, Sundarakumar, Jonas S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.12.2021; Nature Publishing Group
• Subjects: 631/378/1689/132; 692/699/375/132; Aged; Aged, 80 and over; Aging; Dementia; Dementia - epidemiology; Demographic aspects; Humans; India - epidemiology; Longitudinal studies; Medicine; Medicine & Public Health; Middle Aged; Neurology; Population; Prevalence; Prevention; Public Health; Review; Review Article; Risk factors; India
• DOI: 10.1038/s41582-021-00565-x
• ISSN: 1759-4758; 1759-4766

In India, increasing lifespan and decreasing fertility rates have resulted in a growing number of older persons. By 2050, people over 60 years of age are predicted to constitute 19.1% of the total population. This ageing of the population is expected to be accompanied by a dramatic increase in the prevalence of dementia. The aetiopathogenesis of dementia has been the subject of a number of prospective longitudinal studies in North America and Europe; however, the findings from these studies cannot simply be translated to the Indian population. The population of India is extremely diverse in terms of socio-economic, cultural, linguistic, geographical, lifestyle-related and genetic factors. Indeed, preliminary data from recently initiated longitudinal studies in India indicate that the prevalence of vascular and metabolic risk factors, as well as white matter hyperintensities, differs between urban and rural cohorts. More information on the complex role of vascular risk factors, gender and genetic influences on dementia prevalence and progression in Indian populations is urgently needed. Low-cost, culturally appropriate and scalable interventions need to be developed expeditiously and implemented through public health measures to reduce the growing burden of dementia. Here, we review the literature concerning dementia epidemiology and risk factors in the Indian population and discuss the future work that needs to be performed to put in place public health interventions to mitigate the burden of dementia. The prevalence of dementia in India is expected to increase. Here, the authors review the existing data on dementia in India, discuss areas for future research and highlight the importance of developing appropriate public health strategies to tackle the growing dementia burden. Key points Increasing lifespan means that the incidence and prevalence of dementia in India is growing and is expected to rise dramatically in the coming decades. The Indian population currently has a very high burden of vascular risk factors, such as diabetes, hypertension and obesity, which can adversely impact the onset and progression of dementia. To identify risk and protective factors that contribute to dementia in India, longitudinal cohort studies need to be performed in urban and rural settings. These studies should include brain imaging, detailed genetic analysis and measurement of blood biomarkers, in addition to the use of well-adapted clinical and cognitive assessments. Evidence from studies performed outside of India indicate that dementia burden can be reduced through community-based, multimodal, early interventions, including dietary changes, increased physical activity and control of vascular risks; however, to be effective in India, interventions need to be adapted to the specific sociocultural milieu. Tools and data must be shared, both internationally and within the resource-constrained low-income and middle-income countries, to drive research towards better interventions to reduce the burden of dementia.