Is LDL cholesterol associated with long-term mortality among primary prevention adults? A retrospective cohort study from a large healthcare system

Is Targeting LDL-C Levels Below 70 mg/dL Beneficial for Cardiovascular and Overall Health? A Critical Examination of the Evidence

Over the past two decades, cardiovascular disease (CVD) prevention guidelines have progressively lowered LDL-C targets to <70 mg/dL for high-risk individuals based on the assumption of a linear relationship between LDL-C levels and CVD risk. However, the available evidence challenges this premise. Multiple studies demonstrate a weak or inconsistent association between LDL-C levels and atherosclerosis progression at the individual patient-level. Systematic reviews supporting the linearity assumption have notable limitations, including extrapolation beyond observed LDL-C ranges and potential ecological fallacy, as meta-regression analyses rely on study-level data, while patient-level data within the same trials often show no association between LDL-C reduction and CVD outcomes. Moreover, randomized controlled trials explicitly designed to assess LDL-C targets have yielded inconclusive and biased results. LDL-C itself is a heterogeneous marker, with particle size and composition influencing its atherogenicity. The cardiovascular benefits of lipid-lowering therapies may arise in part from pleiotropic effects unrelated to LDL-C lowering. Additionally, several studies indicate that higher LDL-C levels are paradoxically associated with longevity in elderly populations that is equal to or even greater than that of the general population. Collectively, this body of evidence raises questions about the validity of current LDL-C targets < 70 mg/dL in high-risk patients.

Analysis of 26 Studies of the Impact of Coconut Oil on Lipid Parameters: Beyond Total and LDL Cholesterol

Coconut oil (CNO) is often characterized as an "artery-clogging fat" because it is a predominantly saturated fat that ostensibly raises total cholesterol (TChol) and LDL cholesterol (LDL-C). Whereas previous analyses assessed CNO based on the relative effects on lipid parameters against other fats and oils, this analysis focuses on the effects of CNO itself. Here, we review the literature on CNO and analyze 984 lipid profile data sets from 26 CNO studies conducted over the past 40 years. This analysis shows considerable heterogeneity among CNO studies regarding participant selection, the amount consumed, and the study duration. The analysis reveals that, overall, CNO consumption gives variable TChol and LDL-C values, but that the HDL-cholesterol (HDL-C) values increase and triglycerides (TG) decrease. This holistic lipid assessment, together with the consideration of lipid ratios, shows that CNO does not pose a health risk for heart disease. Because the predominantly medium-chain fatty acid profile of CNO is significantly different from that of lard and palm oil, studies using these as reference materials do not apply to CNO. This paper concludes that the recommendation to avoid consuming coconut oil due to the risk of heart disease is not justified.

Independent Association of Individual Lipid Abnormalities with Cardiovascular All-cause Mortality: A Prospective Cohort Study

INTRODUCTION

Abnormalities in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) are each associated with increased cardiovascular risk, after adjusting for non-lipid risk factors. However, whether and to what extent the association for each lipid measure is confounded by other lipid measures is less understood.

AIM

This study aims to investigate the association of each lipid measure with cardiovascular and all-cause mortality while precluding the confounding caused by abnormalities in other lipid measures.

METHODS

The study utilized data from the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994) and ten cycles of continuous NHANES (1999-2018). The study cohort included 23,761 participants who were 20 years or older, not pregnant, not receiving lipid-lowering treatment, and had complete data on all four lipid measures and mortality status. Participants were categorized into seven subgroups based on their lipid profiles. Kaplan-Meier survival curves and Cox proportional hazards models were used to examine the association between lipid abnormalities and mortality.

RESULTS

During a median follow-up of 140 months, 5,003 participants (14.1%) died, with 1,665 deaths (4.2%) attributable to cardiovascular causes. Compared with the reference group in which the four lipid measures were all normal, the subgroups with isolated high TC, two to three lipid abnormalities, and four lipid abnormalities were associated with increased risks for both cardiovascular and all-cause mortality in univariate analysis. However, only those with isolated high TC (for cardiovascular mortality, HR 1.52, 95% CI 1.13-2.06) and four lipid abnormalities (for all-cause mortality, HR 1.34, 95% CI 1.04-1.72) remained statistically significant after adjusting for non-lipid risk factors. Of note, compared with the reference group, the profile of non-lipid risk factors was apparently less favorable in the subgroup with two to three lipid abnormalities but similar (and some factors even more favorable) in the subgroup with isolated high TC. When the lipid measures were analyzed as continuous variables, a U-shaped relationship between HDL-C and mortality risk was observed for both cardiovascular and all-cause mortality, and very low LDL-C level was associated with increased mortality risk. No statistically significant association was found between TG levels and mortality risk.

CONCLUSION

Isolated high TC, very low LDL-C, and concurrent abnormalities in all four lipid measures were associated with increased mortality risk, whereas isolated high TG was not. A U-shaped relationship may exist between HDL-C level and mortality. Overall, these findings underscore the need for integrated management of dyslipidemia that takes all four lipid measures as well as non-lipid cardiovascular risk factors into account, particularly for those with concurrent abnormalities in two or more lipid measures.

Iterative random forest-based identification of a novel population with high risk of complications post non-cardiac surgery

Assessing the risk of postoperative cardiovascular events before performing non-cardiac surgery is clinically important. The current risk score systems for preoperative evaluation may not adequately represent a small subset of high-risk populations. Accordingly, this study aimed at applying iterative random forest to analyze combinations of factors that could potentially be clinically valuable in identifying these high-risk populations. To this end, we used the Japan Medical Data Center database, which includes claims data from Japan between January 2005 and April 2021, and employed iterative random forests to extract factor combinations that influence outcomes. The analysis demonstrated that a combination of a prior history of stroke and extremely low LDL-C levels was associated with a high non-cardiac postoperative risk. The incidence of major adverse cardiovascular events in the population characterized by the incidence of previous stroke and extremely low LDL-C levels was 15.43 events per 100 person-30 days [95% confidence interval, 6.66-30.41] in the test data. At this stage, the results only show correlation rather than causation; however, these findings may offer valuable insights for preoperative risk assessment in non-cardiac surgery.