Depression, Not Osteoarthritis, Linked to Cognitive Impairments Among Older Adults

Osteoarthritis (OA) is not directly correlated with cognitive decline, but depression may play a mediating role in linking OA to cognitive performance impairments, according to study results published in Therapeutic Advances in Musculoskeletal Disease.

Previous studies have hinted at a potential connection between OA and dementia, but findings were often constrained by small sample sizes, confounding factors, and the possibility of reverse causality. Researchers used data from the United States National Health and Nutrition Examination Survey (NHANES; 2011-2014 cycles) to evaluate the association between OA and cognitive function among adults aged 60 years or older.

Included participants received cognitive function testing during the NHANES cycles in the form of word learning and recall challenges. Multiple regression models were adjusted for demographic, health, and socioeconomic covariates. Causality was further investigated using 2-sample Mendelian randomization (MR) with genetic data from large genome-wide association studies focusing on OA and dementia subtypes.

A total of 2199 participants (mean age, 68.94 years) were included in the study, among whom 709 had OA, 53.61% were women, and 81.56% were White. Patients with vs without OA more often had depression (9.78 vs 3.68; P =.002).

Osteoarthritis was not significantly linked to low cognitive performance across measures such as delayed word recall (β = 0.29; 95% CI, -0.01 to 0.59; P =.06) and total word recall (β = 0.48; 95% CI, -0.39 to 1.34; P =.22). Results of stratified analyses showed no meaningful interactions between OA and most variables. However, depression was strongly associated with impaired total word recall (odds ratio [OR], 4.74; 95% CI, 1.09-20.63; P =.04).

Results of MR analyses revealed no causal association between OA and dementia (OR, 1.12; 95% CI, 0.96-1.32; P =.16) or its subtypes, such as Alzheimer disease (OR, 0.95; 95% CI, 0.68-1.31; P =.74) and vascular dementia (OR, 1.32; 95% CI, 0.82-2.13; P =.25). Depression was found to mediate the relationship between OA and vascular dementia (β = 0.044; 95% CI, -0.391 to 0.479; P <.05).

Study limitations include reliance on self-reported OA diagnoses in the NHANES dataset and potential misclassification of depression based on questionnaire data. Additionally, the population-specific nature of NHANES may limit generalizability to other demographics.

“[W]e observed a higher proportion of individuals with depression within the OA group, highlighting the potential impact of pain and emotional strain on mental health,” the study authors concluded.

This article originally appeared on Rheumatology Advisor