The negative association between serum albumin levels and coronary heart disease risk in adults over 45 years old: a cross-sectional survey

This study aimed to assess the correlation between serum albumin levels and coronary heart disease (CHD) risk in adults aged over 45 years. This cross-sectional study used the non-institutionalized US population from the National Health and Nutrition Examination Survey (NHANES 2011–2018) as the sample source. Multiple logistic regression was performed to evaluate the association between serum albumin levels and CHD risk. Smooth curve fitting was performed to explore potential nonlinear relationships. When nonlinear relationships were found, a recursive algorithm was used to calculate inflection points. Additionally, a piecewise logistic regression model was constructed. After adjusting for confounders, multiple logistic regression and smooth curve fitting indicated an inverse association between serum albumin levels and CHD risk [OR = 0.970, 95% CI = (0.948, 0.992)]. Subgroup analysis revealed that the negative correlation was statistically significant in the population of female patients, over 60 years, with hypertension, without diabetes. There was a correlation between serum albumin levels and CHD risk. Lower serum albumin levels were associated with a higher CHD risk.