Associations among body mass index, handgrip strength, and cognitive impairment in older men and women in India

Background: This study examined the associations among body mass index (BMI), handgrip strength (HGS) and cognitive impairment among older adults in India. We also assessed whether these associations vary by gender. Methods: We used data from baseline wave of the Longitudinal Aging Study in India (2017-18) with a sample of 31,464 adults age 60 and above. Cognitive impairment was assessed using different domains of cognition, including memory, orientation, arithmetic functioning, and visuospatial and constructional ability. We used multivariable logistic regression and interaction analyses to test the research hypotheses. Results: Older women had 2.25 times the odds of cognitive impairment than older men [AOR: 2.25; CI: 2.01-2.53]. The odds of cognitive impairment were 1.36 times among underweight older adults [AOR: 1.36; CI: 1.23-1.50], 0.72 times among overweight [AOR: 0.72; CI: 0.62-0.83], and 0.66 times among obese older adults [AOR: 0.66; CI: 0.51-0.84] compared to peers with normal BMI. Underweight women had 3.14 times the odds of being cognitively impaired [AOR: 3.14; CI: 2.67-3.68] compared to older men with normal BMI. Further, older men who were underweight and had a weak HGS had higher odds of cognitive impairment than older men with a normal BMI and strong HGS. Conversely, older women who were overweight or obese and had strong HGS reported lower odds of cognitive impairment than older women with normal BMI and strong HGS. Conclusions: That the association between BMI and cognitive impairment differs between men and women and by HGS gives health care providers and practitioners additional information needed to identify groups of older adults most susceptible to cognitive impairment. In particular, gender specific policies and an assessment of HGS may be useful when crafting interventions to minimize the negative consequences of varying body types on later life cognitive function.