Background The association between chronic lung disease (CLD) and osteoporosis (OP) is well-recognized, but the direction and magnitude of this relationship remain debated, particularly in aging populations. We aimed to quantify the bidirectional association between CLD (including COPD and asthma) and incident OP using a two-stage individual participant data (IPD) meta-analysis of three large longitudinal cohorts.

Methods We harmonized and analyzed individual-level data from the Health and Retirement Study (HRS, USA), the Survey of Health, Ageing and Retirement in Europe (SHARE, Europe), and the English Longitudinal Study of Ageing (ELSA, UK), all comprising adults aged ≥50 years. In the first stage, Cox proportional hazards models were fitted separately in each cohort to estimate hazard ratios (HRs) for the forward (CLD→OP) and reverse (OP→CLD) associations, adjusting for a comprehensive set of confounders (demographics, lifestyle, comorbidities, functional status). In the second stage, cohort-specific log HRs were pooled using fixed-effect meta-analysis. Heterogeneity was assessed with the I2 statistic.

Results A total of 40,050 participants were included across the three cohorts. The pooled HR for incident OP among individuals with baseline CLD was 1.37 (95% confidence interval [CI] 1.24–1.51), with similar estimates for COPD (HR 1.47, 95% CI 1.27–1.69) and asthma (HR 1.35, 95% CI 1.22–1.50). For the reverse association, baseline OP was associated with increased risk of incident CLD (pooled HR 1.16, 95% CI 1.05–1.29), COPD (HR 1.28, 95% CI 1.11–1.47), and asthma (HR 1.17, 95% CI 1.05–1.30). Heterogeneity was low across all analyses (I2 ≤7.5%).

Conclusion This two-stage IPD meta-analysis provides robust evidence of a bidirectional relationship between CLD and OP in older adults. These findings underscore the need for integrated screening and management of both conditions in aging populations.

Mini Abstract This two-stage individual participant data meta-analysis of 40,050 participants from three international longitudinal studies demonstrates a robust bidirectional association between chronic lung disease and incident osteoporosis, supporting integrated clinical management.

The authors have declared no competing interest.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

All original studies (HRS, SHARE, ELSA, and LASI) were conducted in accordance with the Declaration of Helsinki and were approved by their respective institutional review boards or ethics committees. All participants provided written informed consent prior to enrollment. The present study involved secondary analysis of fully anonymized, publicly available data; therefore, no additional ethical approval or informed consent was required. This manuscript does not contain any individual person's data in any form.

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First Author: Jinying Bao, Email: baojinying87126.com

Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conflict of Interest: Daming Jiang and Jinying Bao declare that they have no conflict of interest.