Associations between total cholesterol/high-density lipoprotein cholesterol (HDL), triglyceride/HDL, neutrophil/HDL, lymphocyte/HDL, platelet/HDL, and cognitive function of older adults: An NHANES analysis

Background Dementia affects 50 million globally. Combining hematologic inflammatory parameters with high-density lipoprotein cholesterol (HDL) has shown potential for predicting neurological diseases, but its link to cognitive function in older individuals is unexplored. Objective This study aimed to evaluate the relationships between these novel biomarkers and cognitive impairment in older adults. Methods This retrospective study used data of adults aged ≥60 years from the National Health and Nutrition Examination Survey (NHANES) 2011–2014. The analysis examined associations between cognitive impairment and total cholesterol (TC)/HDL, triglyceride (TG)/HDL, monocyte/HDL, neutrophil/HDL, lymphocyte/HDL, and platelet/HDL ratios, using univariate and multivariable logistic regression. Cognitive function was assessed using CERAD, Animal Fluency Test, and Digit Symbol Substitution Test (DSST). Results Data from 1379 participants (representing 25,173,874 persons in the US) were analyzed. In the multivariable analysis, compared to the lowest quartile, the highest quartile of neutrophil/HDL ratio was significantly associated with increased odds of low cognitive performance (aOR = 1.85) assessed by DSST. In addition, a unit increase in lymphocyte/HDL was significantly associated with higher odds of low cognitive performance (aOR = 1.16). In stratified analyses, neutrophil/HDL was associated with low cognitive performance in participants without CVD (aOR = 2.09), without CKD (aOR = 2.74), and with or without hypertension (aOR = 3.50 and 4.28). Lymphocyte/HDL was significant only among those without hypertension (aOR = 1.93). Conclusions Increased neutrophil/HDL and lymphocyte/HDL ratios were significantly associated with lower cognitive performance in older adults, particularly among those without major comorbidities, suggesting their potential for identifying cognitive risk in healthier populations.