Abstract
BACKGROUND: Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) are two age-related diseases commonly found in the elderly population, and they are associated with severe health consequences. However, it is currently unclear how patients with either one of these diseases or both diseases simultaneously compare to patients without COPD and CVD in terms of the additive impact on overall mortality, CVD-related mortality, and respiratory system disease-related mortality. METHOD: The study included 42,317 participants from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2018. The main objective of the study was to assess the outcomes of all-cause mortality, CVD mortality, and respiratory system disease mortality. We utilized the National Death Index(NDI) Public Access File, up until December 31, 2019, to determine the participants' mortality status and causes of death, with a mean follow-up period of 9.25 years. To ensure the reliability of the results, we employed Cox proportional hazards models to calculate the hazard ratios (HR) and 95% confidence intervals (CI) for mortality rates, along with conducting sensitivity analyses. RESULTS: Among the 42,317 participants, 36,251 individuals (85.7%) had neither COPD nor CVD (COPD-/CVD-). Additionally, 4,252 people (10.0%) had only CVD (COPD-/CVD+), 1,237 people (2.9%) had only COPD (COPD+/CVD-), and 577 people (1.4%) had both COPD and CVD (COPD+/CVD+). Compared to the COPD-/CVD- group, the all-cause mortality rates increased by 1.58-fold (95% CI: 1.46, 1.70), 1.56-fold (95% CI: 1.38, 1.76), and 2.02-fold (95% CI: 1.72, 2.37) in the COPD-/CVD + group, COPD+/CVD- group, and COPD+/CVD + group, respectively, with the COPD+/CVD + group having the highest all-cause mortality risk. Compared to the COPD-/CVD- group, the other three groups showed increased CVD mortality rates, with a HR of 2.35 for the COPD-/CVD + group and COPD+/CVD + group, respectively. Compared to the COPD-/CVD- group, the other three groups had increased respiratory system disease mortality rates, with a HR of 5.00 (95% CI: 3.70, 6.75) for the COPD+/CVD- group and 6.62 (95% CI: 4.56, 9.61) for the COPD+/CVD + group (All trend p-values < 0.0001). CONCLUSION: Patients with COPD or CVD, or those who have both conditions, are at an increased risk of all-cause mortality, CVD-related mortality, and respiratory system disease-related mortality. Individuals with either of these diseases require more stringent management to prevent the progression of the other disease and reduce mortality rates.