Arthritis and cognitive impairment in older adults.

Adults aged 65 or older with arthritis may be at increased risk for cognitive impairment [cognitive impairment but not dementia (CIND) or dementia]. Studies have found associations between arthritis and cognition impairments; however, none have examined whether persons with arthritis develop cognitive impairments at higher rates than those without arthritis. Using data from the Health and Retirement Study, we estimated the prevalence of cognitive impairments in older adults with and without arthritis, and examined associations between arthritis status and cognitive impairments. We calculated incidence density ratios (IDRs) using generalized estimating equations to estimate associations between arthritis and cognitive impairments adjusting for age, sex, race/ethnicity, marital status, education, income, depression, obesity, smoking, the number of chronic conditions, physical activity, and birth cohort. The prevalence of CIND and dementia did not significantly differ between those with and without arthritis (CIND: 20.8%, 95% CI 19.7-21.9 vs. 18.3%, 95% CI 16.8-19.8; dementia: 5.2% 95% CI 4.6-5.8 vs. 5.1% 95% CI 4.3-5.9). After covariate control, older adults with arthritis did not differ significantly from those without arthritis for either cognitive outcome (CIND IDR: 1.6, 95% CI = 0.9-2.9; dementia IDR: 1.1, 95% CI = 0.4-3.3) and developed cognitive impairments at a similar rate to those without arthritis. Older adults with arthritis were not significantly more at risk to develop cognitive impairments and developed cognitive impairments at a similar rate as older adults without arthritis over 6 years.