Objectives: Dementia is rising globally, particularly in low-and-middle-income countries. India has almost four million people living with dementia, set to double by 2050. Targeting nine potentially modifiable risk factors (less education, hearing impairment, depression, physical inactivity, hypertension, obesity, smoking, diabetes, and social isolation) could possibly prevent or delay many dementias. We aimed for the first time to examine risk factors for dementia in India and their link with cognitive status and dementia, to inform prioritisation of public health interventions that could prevent or delay dementia.
Methods: We conducted a cross-sectional analysis using three studies: 10/66 Dementia Study (n = 2004), Longitudinal Aging Study of India (n = 386), and Study of Global Ageing (n = 2441). Our exposures were the nine risk factors above. We calculated a cognitive z-score within each study and used dementia diagnosis in 10/66. We adjusted for socioeconomic factors, age, and sex using multivariable linear for cognition and logistic regression for dementia.
Results: Less education, hearing impairment, depression, and physical inactivity were associated with lower z-scores and increased odds of dementia. Obesity was associated with higher z-score and lower odds of dementia. Social isolation was associated with lower z-scores and decreased odds of dementia. Results for smoking, diabetes, and hypertension were inconsistent.
Conclusion: Our risk estimates were larger for less education, hearing impairment and physical inactivity compared to global estimates and should be intervention priorities. This study highlights the need for longitudinal studies to clarify the relationship between these potentially modifiable risk factors and dementia in India.
Keywords: India; cognition; dementia prevention; epidemiology; public health.
© 2021 John Wiley & Sons Ltd.