Investigating the association between angina and osteoporosis: a 20-year longitudinal cohort study of ELSA

Osteoporosis (OP) is recognized as a major global health threat. Although an association between angina and osteoporosis was established, the underlying mechanisms connecting the two conditions were not clearly elucidated. Therefore, this study aims to systematically investigate the association between angina and OP of the English Longitudinal Study of Ageing (ELSA) database.

This longitudinal cohort study utilized data from Wave 1 to Wave 11 of the ELSA database. Participants free of angina and OP at baseline were included. Time-dependent Cox proportional hazards regression models were employed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident OP. Multiple imputation and rigorous sensitivity analyses (e.g., E-value, bootstrap) were performed to ensure robustness. Additionally, a random forest model was utilized to evaluate the relative importance of covariates, and the overall classification performance of the multivariable model was assessed using the area under the Receiver Operating Characteristic curve (AUC). OP was defined as a self-reported physician diagnosis with persistent confirmation, and angina was defined as a self-reported physician diagnosis.

A total of 6509 eligible participants were enrolled. During the follow-up, new-onset angina was significantly associated with an increased hazard of subsequent OP across all models. In the fully adjusted model, incident angina increased the risk of OP (HR = 1.621, 95% CI: 1.081-2.430, P = 0.02). Kaplan-Meier analysis demonstrated significantly lower OP-free survival probability in the new-onset angina group. Machine learning analysis confirmed time-dependent angina as a top predictor for incident OP. The AUC of the multivariable model was 0.793, indicating that the collective classification ability of all included variables was good.

Among middle-aged and older adults initially free of these conditions, new-onset angina is an independent prognostic risk factor for subsequent osteoporosis. This longitudinal evidence clarifies the temporal relationship and highlights the need for OP surveillance in patients developing angina.