Association between blood cell ratios and coronary heart disease: A 10-year nationwide study (NHANES 2009-2018)

Blood cell ratios are a standard clinical index for the assessment of inflammation. Although a large number of epidemiological investigations have shown that inflammation is a potential risk factor for the development of coronary heart disease (CHD), there is not sufficient and direct evidence to confirm the relationship between blood cell ratios and CHD. Therefore, this study aimed to elucidate the effect of blood cell ratios on the incidence of coronary heart disease. This 10-year national study included data from 24,924 participants. The independent variable was blood cell ratios, and the dependent variable was coronary heart diseases (yes or no). The relationship between blood cell ratios and coronary heart disease was verified using baseline characteristic analysis, multivariate logistic regression analysis, smoothed fitted curves, and subgroup analysis. This study found that in multiple logistic regression analysis showed significant positive correlation between monocyte counts x meutrophil counts/lymphocyte counts (SIRI) (OR = 1.495; 95% CI = 1.154-1.938), monocyte-lymphocyte ratio (MLR) (OR = 3.081; 95% CI = 1.476-6.433) and the incidence of CHD; lymphocyte-monocyte ratio (LMR) (OR = 0.928;95% CI = 0.873-0.987), monocyte-lymphocyte ratio (PLR) (OR = 0.997;95% CI = 0.994-1.000) showed negative correlation with CHD. The smoothed curve fitting shows a nonlinear relationship between SIRI, LMR, PLR, and CHD, with an inverted U-shaped curve between SIRI and CHD, an L-shaped angle between LMR and CHD, and a U-shaped curve between PLR and CHD, respectively. Their inflection points are 1.462, 3.75, and 185.714, respectively. SIRI has an inverted U-shaped curve with coronary heart disease, suggesting that low levels of SIRI increase the risk of CHD; LMR with an L-shaped curve with CHD, and PLR with a U-shaped curve with CHD, suggesting that the risk of CHD can be prevented when LMR and PLR are reduced to a certain level. This has positive implications for the prevention and treatment of CHD.