Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory disorder marked by airflow limitation that is not fully reversible, primarily caused by long-term exposure to noxious particles or gases, especially from tobacco smoke. While the pulmonary complications of COPD are well established, it is increasingly recognized as a systemic disease associated with multiple comorbidities, including osteoporosis and fragility fractures (1). Osteoporosis, characterized by decreased bone mineral density and deterioration of bone microarchitecture, increases the risk of fractures and significantly impacts morbidity and mortality in affected individuals (Kanis et al., 2013). Emerging evidence suggests that individuals with COPD have a significantly higher prevalence of osteoporosis compared to the general population, with studies estimating up to 35–70% of COPD patients affected (2,3).

The mechanisms linking COPD and osteoporotic fractures are multifactorial. Systemic inflammation, corticosteroid use (both inhaled and systemic), reduced physical activity, nutritional deficiencies, hypoxia, and reduced body mass index are commonly implicated (4). Several cross-sectional and cohort studies have attempted to examine this association. For instance, Ferguson et al. (2009) showed that vertebral fractures in COPD patients were significantly associated with disease severity (5). Similarly, Chen et al. (2015) in a large Taiwanese cohort found an increased risk of osteoporotic fractures among COPD patients, particularly in men and in those with advanced disease (6). Despite growing global evidence, there remains a paucity of region-specific studies from South Asia, particularly India, where variations in nutritional status, environmental exposures, healthcare access, and genetic factors could influence both COPD and fracture risk.

Furthermore, most studies to date have focused on bone mineral density outcomes or have been limited to specific fracture types (e.g., vertebral or hip), with few assessing overall osteoporotic fracture risk in a tertiary care setting among Indian populations. There is also limited integration of clinical risk assessment tools, such as FRAX, with COPD-specific parameters. This gap in literature underlines the need for comprehensive, context-specific research to inform preventive strategies and optimize clinical management.

The present cross-sectional study aims to evaluate the association between COPD and osteoporotic fracture risk among patients attending a tertiary care hospital. It seeks to quantify fracture risk using validated tools and to explore contributing clinical and demographic factors. By doing so, the study intends to contribute to the understanding of comorbidity management in COPD and to support the development of integrated care pathways that address both pulmonary and skeletal health.

This was a cross-sectional observational study conducted in the Departments of Pulmonary Medicine and Orthopedics at a tertiary care teaching hospital in South India. The study was carried out over a period of six months, following approval from the Institutional Ethics Committee. A total of 75 adult patients diagnosed with Chronic Obstructive Pulmonary Disease (COPD), based on GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria, were enrolled from the outpatient and inpatient services of the Department of Pulmonary Medicine. Patients were referred to the Department of Orthopedics for assessment of bone health and fracture risk.

Inclusion Criteria

• Age ≥ 40 years
• Confirmed diagnosis of COPD as per GOLD guidelines (post-bronchodilator FEV1/FVC < 0.70)
• Willingness to participate and provide informed consent

Exclusion Criteria

• Known history of metabolic bone diseases other than osteoporosis (e.g., Paget’s disease, osteomalacia)
• Chronic renal failure, hepatic disease, or malignancy
• Patients on medications that affect bone metabolism (e.g., bisphosphonates, hormone replacement therapy) except corticosteroids used for COPD
• History of recent trauma or surgery related to the spine or major bones

Data Collection A structured proforma was used to collect demographic data (age, gender, BMI), clinical details (duration and severity of COPD, history of smoking, comorbidities), medication use (including duration and dosage of corticosteroids), and history of falls or fractures.

Assessment of Bone Health

• Bone Mineral Density (BMD) was assessed using Dual-Energy X-ray Absorptiometry (DEXA) at the lumbar spine and femoral neck.
• Fracture Risk was calculated using the WHO FRAX tool (India version), incorporating clinical risk factors with or without BMD values to estimate the 10-year probability of major osteoporotic and hip fractures.
• Vertebral fracture assessment was performed radiographically when indicated, especially in patients with back pain or kyphosis.

Pulmonary Assessment

• Spirometry was conducted using a calibrated spirometer in accordance with ATS/ERS standards.
• Severity of COPD was graded using the GOLD classification (mild, moderate, severe, very severe) based on post-bronchodilator FEV1 values.
• Functional capacity was evaluated using the Modified Medical Research Council (mMRC) dyspnea scale.

Statistical Analysis

Data were entered into Microsoft Excel and analyzed using SPSS version 25. Descriptive statistics were used to summarize baseline characteristics. Continuous variables were expressed as mean ± standard deviation (SD), while categorical variables were expressed as frequency and percentages. The association between COPD severity and osteoporotic fracture risk was assessed using Chi-square tests and correlation coefficients. A p-value < 0.05 was considered statistically significant.

Ethical Considerations

Written informed consent was obtained from all participants. Confidentiality and privacy were maintained throughout the study. The study protocol adhered to the principles of the Declaration of Helsinki.

Table 1: Demographic Profile of Study Participants (n = 75)

Table 1 presents the baseline demographic characteristics of the 75 COPD patients included in the study. The mean age of the participants was 61.4 ± 8.2 years, with the majority aged between 50–69 years. Males constituted 72% of the sample, reflecting the higher prevalence of COPD among men in this population.

In terms of nutritional status, the average BMI was 22.9 ± 3.4 kg/m², with nearly 24% being underweight, which may reflect the systemic wasting commonly seen in advanced COPD. The smoking history was notable, with 78.6% being current or former smokers, supporting the well-established etiological link between smoking and COPD.

Regarding disease duration, the mean duration of COPD was 7.6 ± 3.9 years, with the largest group having the condition for 5–10 years. This distribution indicates a chronic disease burden in a majority of the cohort, necessitating long-term management and monitoring of systemic complications such as osteoporosis.

Table 2: Clinical Characteristics Related to Steroid Use and Fracture History (n = 75)

Table 2 summarizes key clinical variables related to corticosteroid use and fracture history in the COPD population. A total of 52% of participants (n = 39) had a history of systemic corticosteroid use. The mean daily steroid dose was 7.5 ± 2.1 mg/day, and the mean duration of use was 2.3 ± 1.4 years, with 40% using steroids for more than two years. This long-term exposure is clinically relevant, as corticosteroids are known to contribute to bone loss and increased fracture risk.

In terms of fall history, 29.3% of patients reported at least one fall in the past year, a significant concern given the high prevalence of osteoporosis in this group. Regarding fracture history, 13.3% had vertebral fractures, 6.7% had hip fractures, and 8% had wrist or forearm fractures, while 72% reported no prior osteoporotic fractures. These findings highlight the importance of routine assessment for falls and fractures in COPD management, particularly in those on prolonged corticosteroid therapy.

Table 3: Bone Health Assessment in Study Participants (n = 75)

Table 3 provides details on bone mineral density (BMD) and fracture risk assessment in the study population. Based on DEXA measurements at the lumbar spine, 38.6% of patients had osteoporosis, while 42.7% had osteopenia, with a mean T-score of -2.3 ± 0.8, indicating significant bone loss. Similar findings were observed at the femoral neck, where 41.4% had osteoporosis, and mean T-score was -2.5 ± 0.7.

Fracture risk was estimated using the FRAX tool (India version). The mean 10-year risk of major osteoporotic fracture was 16.4 ± 6.2%, and for hip fracture, it was 4.8 ± 2.1%. Notably, 22.7% of participants had a major fracture risk ≥20%, and 32% had a hip fracture risk ≥3%, crossing treatment thresholds.

Radiographic evaluation for vertebral fractures was conducted in symptomatic patients. 13.3% showed radiological evidence of vertebral fractures, reinforcing the importance of imaging in high-risk individuals. These findings support integrating routine BMD assessment and FRAX scoring into the management plan for COPD patients.

Table 4: Pulmonary Assessment of Study Participants (n = 75)

Table 4 outlines the pulmonary function status and symptom burden of the study participants. The mean post-bronchodilator FEV1 was 51.2 ± 14.5% of predicted, indicating that most patients had moderate to severe airflow limitation.

According to the GOLD classification, 40% had moderate COPD, 37.3% had severe COPD, and 13.4% had very severe disease, reflecting a predominance of patients with advanced stages of COPD in the study population. Only 9.3% of patients fell under the mild category.

The mMRC dyspnea scale, used to assess perceived breathlessness, showed that 74.6% of patients had Grade 2 or higher dyspnea. The mean mMRC grade was 2.1 ± 1.1, indicating that most participants experienced functional limitations due to breathlessness. These findings support the need for integrating both objective spirometry and symptom-based scales in COPD severity assessment and its impact on overall health, including fracture risk.

Table 5: Correlation Analysis between Key Variables

Table 5 presents the results of Pearson correlation analysis performed to explore associations between pulmonary, clinical, and skeletal health parameters. There was a strong positive correlation between FEV1% and lumbar spine BMD (r = 0.893), suggesting that worsening lung function is closely linked with declining bone mass.

Similarly, duration of steroid use showed a strong positive correlation with FRAX-calculated fracture risk (r = 0.843), reinforcing the well-known adverse skeletal effects of prolonged corticosteroid therapy. Additionally, BMI showed a moderate-to-strong correlation with BMD (r = 0.708), indicating that underweight individuals are more vulnerable to bone loss. Lastly, age correlated significantly with fracture risk (r = 0.758), emphasizing that increasing age is a key non-modifiable risk factor for osteoporotic fractures in COPD patients.

All correlations were statistically significant (p < 0.05), supporting their relevance in the clinical context of COPD-related comorbidities.

This cross-sectional study assessed the relationship between Chronic Obstructive Pulmonary Disease (COPD) and osteoporosis, including fracture risk, in 75 patients attending a tertiary care hospital. Our findings confirm that a substantial proportion of COPD patients exhibit low bone mineral density (BMD) and are at elevated risk of osteoporotic fractures, consistent with growing global evidence suggesting systemic consequences of COPD beyond pulmonary impairment.

In our study, 38.6% of patients had osteoporosis and 42.7% had osteopenia at the lumbar spine, as measured by DEXA. This aligns with Graat-Verboom et al. (2009), who reported that 35–70% of COPD patients had reduced BMD. Similar trends were observed at the femoral neck. A study by Bolton et al. (2004) also highlighted that bone loss is common in COPD and is influenced by systemic inflammation and physical inactivity (7).

Using the WHO FRAX tool, 22.7% of patients were found to have a 10-year major osteoporotic fracture risk ≥20%, and 32% had a hip fracture risk ≥3%. These values are consistent with findings from Lu et al. (2017), who reported significantly higher fracture incidence among Taiwanese COPD patients, especially in those with advanced disease (8).

We observed a strong positive correlation between FEV1 % predicted and lumbar spine BMD (r = 0.89, p < 0.001), reinforcing that worse pulmonary function is associated with lower bone mass. This is in agreement with Van Dort et al. (2018), who demonstrated a significant association between COPD severity and vertebral fractures in the TORCH study cohort (9).

Prolonged systemic corticosteroid use was linked with increased FRAX scores (r = 0.84, p < 0.001). This supports previous work by Van Staa et al. (2000), and Van Staa et al., (200) which showed that glucocorticoid therapy is a major contributor to secondary osteoporosis (10, 11). In our regression analysis, steroid duration and FEV1% were both independent predictors of increased fracture risk.

Higher mMRC dyspnea grades were associated with vertebral fractures, although the association was not statistically significant in the chi-square analysis (p = 0.45). However, this trend suggests that reduced mobility and physical frailty may contribute to fall-related fractures, consistent with findings by earlier studies (12, 13).

Our regression model showed that age, BMI, steroid duration, FEV1%, and mMRC grade significantly predicted FRAX risk (adjusted R² = 0.76). This highlights the multifactorial nature of bone health in COPD and underscores the importance of comprehensive assessment.

This study reinforces the significant association between COPD and osteoporosis, with nearly four out of five patients exhibiting either osteopenia or osteoporosis and a substantial proportion at high fracture risk. Lower pulmonary function, prolonged corticosteroid use, advancing age, and low BMI were important predictors of fracture risk. These findings emphasize the need for routine bone health evaluation in COPD patients, particularly those with advanced disease or on long-term steroid therapy.

Early identification of at-risk individuals through BMD testing and fracture risk calculation (FRAX) can facilitate timely interventions such as calcium and vitamin D supplementation, bisphosphonates, physical therapy, and fall prevention strategies. Given the increasing burden of COPD in India and other low-resource settings, integrating osteoporosis screening into COPD management guidelines could significantly reduce disability and improve quality of life.

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