Study Finds Sex-Based Differences in Comorbidities Among Patients With COPD

A study published in Scientific Reports found different patterns of comorbidities in men and women who had chronic obstructive pulmonary disease (COPD), which has implications for COPD risk assessment.

Participants were found through the prospective COPD cohort “COPD and Systemic Consequences-Comorbidities Network” (COSYCONET). There were 2741 patients that were enrolled in this cohort from 2010 to 2013. Patients with a previous history of cancer, including lung cancer, were excluded from this study. This study required complete spirometry data (used for COPD grading), comorbidities, and laboratory parameters for creatinine, hemoglobin, and uric acid (used to define comorbidities).

All comorbidities were recorded in structured interviews based on physician-based diagnoses or defined based on disease-specific biomarkers.

There were 2575 patients included in this study, with 1531 men and 1044 women participating. There were significant differences in age, body mass index, smoking status, and lung function parameters between men and women. There were also significant differences in hemoglobin and uric acid.

Men had more comorbidities than women did overall, and the percentage of participants with a Charlson Comorbidity Index (CCI) sore greater than 2 was higher in men. A CCI score (excluding age) greater than 2 vs less than or equal to 2 was linked to mortality rates of 12.7% vs 9.5% in men and 11.6% vs 4.1% in women.

Women reported extrapulmonary comorbidities that included cachexia, mental disorders, and osteoporosis. Comorbidities among men included arterial hypertension, coronary artery disease without infarction, myocardial infarction (MI), hyperuricemia, diabetes with or without insulin, alcoholism, peripheral artery disease, or anemia. Women had asthma and severe hyperinflation more often, whereas men had sleep apnea, emphysema, or airway obstruction more often.

There were 159 (10.4%) men and 59 (5.7%) women who died during the median follow-up period of 3.7 years. Only kidney disease (men: HR, 1.6; 95% CI, 1.0-2.4; women: HR, 2.6; 95% CI, 1.4-5.1) and increased heart rate (men: HR, 1.4; 95% CI, 1.0-2.0; women: HR, 1.9; 95% CI, 1.1-3.2) had a mortality risk for both.

Arterial hypertension (HR, 1.5; 95% CI, 1.1-2.2), coronary artery disease without MI (HR, 1.6; 95% CI, 1.1-2.5), liver cirrhosis (HR, 2.6; 95% CI, 1.0-6.5), and osteoporosis (HR, 1.6; 95% CI, 1.0-2.5) were associated with increased mortality risk in men. Heart failure (HR, 4.7; 95% CI, 2.0-11.1), mental disorders (HR, 2.6; 95% CI, 1.5-4.5), and hyperuricemia (HR, 2.2; 95% CI, 1.1-4.3) were independent risk factors for mortality in women.

Sever hyperinflation was a risk factor of mortality for both men and women (men: HR, 1.5; 95% CI, 1.0-2.3; women: HR, 1.9; 95% CI, 1.0-3.4). Impaired diffusion capacity of the lungs for carbon monoxide was a risk factor in men (HR, 2.9; 95% CI, 1.9-4.5) whereas presence of asthma (HR, 2.4; 95% CI, 1.3-4.3) and sleep apnea (HR, 2.4; 95% CI, 1.0-5.7) were risk factors in women.

There were some limitations to this study. Direct causal relationships could not be inferred based on the cross-sectional design of the study. There was also a lack of information on cause of death, which meant that all mortality was determined as all-cause mortality. Presence of malignant diseases was an exclusion criterion of the COSYCONET and could not be studied in this study. Comorbidities could not be validated by an independent assessment and were based on physician diagnoses, which could allow gender bias of systemic under- or overdiagnosis.

Patients with COPD have significant differences in comorbidities based on sex, according to the researchers. The data demonstrate that the prevalence and impact of mortality could differ between the sexes.

“It has to be explored to which extent this can lead to more individually tailored strategies for the treatment and surveillance of COPD patients,” the authors wrote.

Reference

Trudzinski FC, Jorres RA, Alter P, et al. Sex-specific associations of comorbidome and pulmorbidome with mortality in chronic obstructive pulmonary disease: results from COSYCONET. Sci Rep. 2022;12:8790. doi:10.1038/s41598-022-12828-8