Multimorbidity, lifestyle factors, and risk of reduced cognitive performance among older adults: evidence from the longitudinal ageing study in India (LASI)

This study examined the association between multimorbidity, lifestyle factors, and cognitive performance among older adults in India using data from the Longitudinal Ageing Study in India (LASI) Wave 1. The analysis included 65,562 individuals aged 45 years and above. Cognitive performance was assessed across multiple domains, including orientation, word recall, arithmetic ability, and executive function. Descriptive statistics, bivariate analyses, and multivariable logistic regression were used to evaluate the relationships between socioeconomic characteristics, multimorbidity, lifestyle behaviours, and cognitive performance and to calculate adjusted odds ratios (aORs). Overall, 30.2% of participants had multimorbidity, with the highest prevalence among individuals aged 61–70 years (35.0%) and those aged ≥ 71 years (39.1%). With advancing age, the odds of poor cognitive performance increased substantially; individuals aged ≥ 71 years had more than fourfold higher odds compared with those aged 45–50 years (aOR = 4.19; 95% CI: 4.18–4.20). Females had significantly higher odds of poor cognitive performance than males (aOR = 1.81; 95% CI: 1.81–1.81). Unhealthy lifestyle behaviours, including smokeless tobacco use and alcohol consumption, were also associated with poorer cognitive outcomes, while physical inactivity, frequent sleep problems, and social isolation further increased risk. In contrast, higher education, greater wealth, engagement in physical activity and yoga, and adherence to prescribed medications were protective. These findings indicate that multimorbidity in combination with adverse socioeconomic and lifestyle factors substantially influences cognitive performance in later life. Targeted, integrated interventions focusing on high-risk groups and the promotion of healthy lifestyles are essential to support cognitive health in India’s ageing population.