Monocyte-to-HDL cholesterol ratio and cardiovascular comorbidity in COPD

Chronic obstructive pulmonary disease (COPD) is frequently complicated by cardiovascular disease (CVD), which significantly increases morbidity and mortality. The monocyte-to-high-density lipoprotein cholesterol ratio (MHR) has emerged as a novel inflammatory biomarker associated with various cardiovascular conditions. However, its relationship with CVD in COPD patients remains understudied. This study aimed to investigate the association between MHR and coexisting CVD in patients with COPD. This cross-sectional investigation analyzed the National Health and Nutrition Examination Survey data from 2007 to 2018, focusing on adults aged ≥40 years with physician-diagnosed COPD. The primary outcome encompassed cardiovascular conditions including congestive heart failure, coronary heart disease, angina pectoris, or myocardial infarction. MHR was analyzed both as a continuous variable and in quartiles. Four sequential logistic regression models were applied: Model 1 was unadjusted; Model 2 adjusted for sex, age, and race/ethnicity; Model 3 further adjusted for education, marital status, smoking, and poverty-income ratio; Model 4 additionally adjusted for hypertension, diabetes, and body mass index. Dose-response relationships were assessed using restricted cubic splines. A total of 1064 COPD patients were included (mean age, 62.8 ± 10.5 years; 56.6% female), of whom 206 (19.4%) had coexisting CVD. Compared with patients without CVD, those with CVD were older (median, 68 vs 61 years; P < .001), more often male (62.1% vs 38.9%; P < .001), and had a higher prevalence of diabetes (43.2% vs 24.4%; P < .001) and hypertension (82.5% vs 54.6%; P < .001). MHR levels were higher in the CVD group than in the non-CVD group (0.542 vs 0.423; P < .001). In the fully adjusted model, each 1-unit increase in MHR was associated with higher odds of CVD (odds ratio, 3.27; 95% confidence interval, 1.59-6.74; P < .001). A graded association was observed across MHR quartiles (P for trend < .001), with the highest quartile showing greater odds of CVD than the lowest (odds ratio, 2.70; 95% confidence interval, 1.57-4.73; P < .001). Restricted cubic spline analysis indicated a nonlinear positive association between MHR and CVD. In COPD patients, higher MHR was independently associated with a greater prevalence of coexisting CVD, with a graded and nonlinear pattern. Given the cross-sectional design, causal inference is not warranted, and prospective studies are needed.