Novel association between chronic obstructive pulmonary disease and osteoporosis: A prospective cross-sectional study.

Background: Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition often associated with a high incidence of osteoporosis. Studies indicate that patients with COPD present with a significant decrease in bone mineral density (BMD), potentially related to inflammation and corticosteroid use.

Aim: To investigate the relationship between BMD and lung function, mainly the forced expiratory volume in the forced expiratory volume in 1 second (FEV1)/ forced vital capacity percentage (FVC%), in patients with COPD using quantitative computed tomography (QCT).

Methods: This prospective cross-sectional study included 85 patients with COPD treated at Gansu Provincial People's Hospital. Exposure variables included lung function parameter (FEV1/FVC%), age, sex, body mass index, smoking status, tea-drinking habits, and physical activity. BMD was measured using QCT. Linear regression and generalized additive models were employed to analyze the relationship between exposure variables and BMD.

Results: Linear regression analysis revealed a significant positive relationship between BMD and FEV1/FVC% (β = 0.1, 95% confidence interval [CI]: 0.1-0.1; P < 0.0001). Non-linear analysis identified a unique BMD breakpoint of 128.08 mg/cm³. Before the breakpoint, BMD was significantly positively correlated with FEV1/FVC% (β = 0.245; P = 0.0019); while after the breakpoint, the relationship was negative and showed no statistical significance (β = -0.136; P = 0.0753). This finding underscores the critical role of BMD in COPD management and highlights the importance of individualized clinical interventions in improvement of lung function and overall health status in patients.

Conclusion: There is a complex non-linear relationship between BMD and lung function in patients with COPD, highlighting the importance of monitoring change in bone density during the management of COPD.