Relationship between biomarkers and pain and falls in middle aged and older adults – An analysis of the Canadian Longitudinal Study on Aging

BACKGROUND: Pain is highly prevalent in older adults, and is associated with an increased risk of falls. There has been growing attention on the role of biomarkers. However, most studies have focused on a smaller number of biomarkers, and few have investigated the interrelationship with other biopsychosocial outcomes and the interrelationship between pain and falls simultaneously. Therefore, we aimed to evaluate the association of biomarkers with pain and falls, including the interrelationship with socio-demographics, biopsychosocial factors, function and mobility. METHODS: This was a secondary analysis of data from the Canadian Longitudinal Study on Aging (CLSA). We included adults aged 45 to 85 years old. Dependent variables were pain and falls at baseline and 3 years. Independent variables were socio-demographic characteristics, inflammation, biological markers, body composition, lifestyle and behavior, mobility, functional assessment, and psychosocial variables at baseline. Structural equation modelling was used to test direct and indirect effects. RESULTS: We included 30,087 adults with a mean age of 62.9 (Standard Deviation: 10.2) years. Most of the biomarkers showed direct effects on pain and not on falls. Inflammation showed a direct effect on pain, but nutritional risk had a higher proportion of indirect effects on pain and falls through inflammation. CONCLUSION: Pain and falls in older adults are a complex phenomenon. Most of the biomarkers are associated with both pain and falls. Inflammation demonstrated a total effect on pain but not on falls, suggesting that the influence of inflammation is higher for pain and more complex with respect to falls.