Combined Impact of Mean and Variability of Non-HDL Cholesterol on Myocardial Infarction in Hemodialysis Patients

Objectives: The aim of this study was to stratify cardiovascular risk based on the mean and variability of non-high-density lipoprotein cholesterol (non-HDL-C) in patients undergoing hemodialysis. Methods: Data were analyzed for 453 hemodialysis patients without a history of myocardial infarction (MI) or stroke, who underwent at least five lipid profile measurements at any one of seven university hospitals in the Republic of Korea between March 2009 and December 2020. Visit-to-visit non-HDL-C variability was calculated using the coefficient of variation. The endpoints of the study were newly diagnosed MI, stroke, or all-cause death. Patients were divided into four groups according to quartiles of the mean and variability of non-HDL-C. Results: During a median follow-up of 97.0 months, there were 39 cases of MI, 99 cases of stroke, and 96 deaths. The cumulative incidence rate of MI was significantly highest in the low mean/high variability group (log-rank p = 0.0296). However, there were no significant differences between groups in the incidence rates of stroke (log-rank p = 0.9939) or all-cause mortality (log-rank p = 0.9373). In the multivariable Cox regression analysis, age and low mean/high variability (HR: 3.311, 95% CI: 1.380-7.944) were identified as independent risk factors for MI. However, for stroke and all-cause mortality, age was the only independent risk factor. Moreover, neither the mean nor the variability of non-HDL-C alone was associated with MI, stroke, or all-cause mortality. Conclusions: Our results suggest that the coexistence of low mean non-HDL-C and high variability is associated with an elevated risk of MI in hemodialysis patients.