Exploring the relationship between allostatic load and osteoarthritis: A cross-sectional analysis from the North West Adelaide Health Study

Objective: Cumulative stress-response system dysregulation, known as allostatic load (AL), is suggested as a possible mechanism that may connect upstream health determinants with OA. Our objective was to evaluate the cross-sectional association between AL and the presence of OA. Design: This cross-sectional study used Stage Two (2004–2006) data from the North West Adelaide Health Study (NWAHS), a population-based cohort study. Osteoarthritis and joint pain were defined using self-report and medication data. Allostatic load was a composite index of nine equally-weighted biomarkers; systolic and diastolic blood pressures, waist-hip ratio, body mass index, total cholesterol, high-density lipoprotein, glycated haemoglobin, interleukin 6 and tumour necrosis factor alpha. Binary logistic regression models estimated the association between AL and OA, with adjustment for demographic, health behaviour and comorbidity covariates. Results: Overall, 1600 participants were eligible for inclusion in the analysis. The OA group (n ​= ​459) and the group without arthritis (n ​= ​1151) had mean AL scores of 3.96 (SD 2.3) and 2.68 (SD 2.0), respectively. In adjusted analyses, each one-unit increase in AL was associated with a 12 ​% increased odds of OA presence (OR ​= ​1.12, 95 ​% CI 1.04, 1.19, P ​= ​0.002). There was a similar 11 ​% increase in odds of the presence of self-reported joint pain for every one-unit increase in AL score (OR ​= ​1.11, 95 ​% CI 1.04, 1.18, P ​= ​0.001). Conclusions: There is a cross-sectional association between AL and the presence of OA and self-reported joint pain. Further investigations are warranted using longitudinal data.