High-Density Lipoprotein Cholesterol and the Risk of Myocardial Infarction, Stroke, and Cause-Specific Mortality: a Nationwide Cohort Study in Korea

The predictive role of the hs-CRP/HDL-C ratio for long-term mortality in the general population: evidence from a cohort study

BACKGROUND

The high-sensitivity C-reactive protein (hs-CRP) to high-density lipoprotein cholesterol (HDL-C) ratio, a composite marker of low-grade inflammation and lipid metabolism, is reportedly associated with the occurrence of new cardiovascular diseases (CVDs) in certain people. However, the predictive value of the hs-CRP/HDL-C ratio for long-term mortality in the general population remains unclear.

METHODS

This retrospective cohort study included data from 9,492 adults obtained from the National Health and Nutrition Examination Survey (NHANES) (2015-2018) in the United States. Multivariate Cox regression, two-piecewise linear regression, restricted cubic spline (RCS) models and subgroup analysis by age, sex, smoking status and drinking status were applied to evaluate the associations of the hs-CRP/HDL-C ratio with long-term all-cause and cardiovascular mortality.

RESULTS

The overall median age of the cohort was 47.0 years (interquartile range (IQR) 32.0-62.0), and 4,585 (48.30%) patients were male. During a median follow-up period of 37.0 months, 239 (2.52%) all-cause deaths occurred, 59 (0.62%) of which were attributed to cardiovascular events. Participants with all-cause and cardiovascular mortality presented a higher hs-CRP/HDL-C ratio than did those without events [0.56 (0.24-1.38) vs. 0.37 (0.14-0.94) and 0.60 (0.23-1.60) vs. 0.37 (0.14-0.95), P < 0.001 and P = 0.002]. According to multivariate Cox regression models, the hs-CRP/HDL-C ratio was found to be an independent risk factor for both long-term all-cause mortality [hazard ratio (HR) = 1.09, 95% confidence interval (CI): 1.05-1.13] and cardiovascular mortality (HR = 1.11, 95% CI: 1.05-1.19). A two-piecewise linear regression model indicated that the risk of all-cause mortality increased more prominently when the hs-CRP/HDL-C ratio was less than 1.21. In addition, a significant interaction effect with smoking status was discovered (P = 0.006), indicating that the association of the hs-CRP/HDL-C ratio with all-cause mortality was stronger in nonsmokers. The RCS curve revealed a positive linear association of the hs-CRP/HDL-C ratio with long-term mortality after adjustment for potential confounders.

CONCLUSIONS

The hs-CRP/HDL-C ratio is a crucial predictor of long-term mortality in the general population, independent of potential confounding factors.

Healthier Lipid Profiles of Japanese Adults, Especially in Women with Elevated High-Density Lipoprotein Cholesterol (HDL-C), Are Associated with Low HDL-C Peroxide Content

Japanese adults typically have healthier lipid profiles than American and European adults and a lower prevalence and later onset of atherosclerotic cardiovascular disease (ASCVD). Many Japanese also have uniquely elevated levels of high-density lipoprotein cholesterol (HDL-C). The following analysis examined the relationship between HDL-C level and HDL-C peroxide content, a bioindicator of unhealthy lipid metabolism in Japanese adults. Blood samples were collected from 463 participants, 31-84 years of age, who lived in Tokyo. A second blood sample was collected 5 years later from 241 of the participants, allowing us to evaluate the temporal stability of the inverse correlation between HDL-C level and HDL-C peroxide content. Glucoregulation and inflammatory activity were assessed because both can be associated with dyslipidemia and HDL-C dysfunction. Obesity and central adiposity were also considered. Overall, women had healthier HDL-C profiles than men. Elevated HDL-C (>90 mg/dL) was common (16.6%) and found more often in women. Higher HDL-C peroxide content was associated with older age and central adiposity and incremented further when HA1c and CRP were higher. When assessed 5 years later, lower HDL-C peroxide content continued to be evident in adults with higher HDL-C. While similar associations have been described for other populations, most Japanese adults typically had healthier levels of HDL-C with lower HDL-C peroxide content than previously reported for American adults.

Establishment and validation of a nomogram model containing a triglyceride-glucose index and neutrophil-to-high-density lipoprotein ratio for predicting major adverse cardiac events in patients with ST-segment elevation myocardial infarction

OBJECTIVE

To analyze the predictive value of the triglyceride-glucose (TyG) index and neutrophil-to-high-density lipoprotein ratio (NHR) for in-hospital major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI), and to establish an associated nomogram model.

METHODS

In this retrospective study, we collected data from consecutive STEMI patients who underwent PCI from October 2019 to June 2023 at the Second People's Hospital of Hefei and the Second Affiliated Hospital of Anhui Medical University, as training and validation sets. Stepwise regression and multivariate logistic regression analysis were performed to screen independent risk factors, and a nomogram model was constructed and evaluated for its predictive efficacy.

RESULTS

The TyG index, NHR, urea, diastolic blood pressure, hypertension, and left ventricular ejection fraction were independent risk factors for in-hospital MACE after PCI, and were used to construct the nomogram model. The C-index of the training and validation sets were 0.799 and 0.753, respectively, suggesting that the model discriminated well. Calibration and clinical decision curves also demonstrated that the nomogram model had good predictive power.

CONCLUSION

In STEMI patients, increased TyG index and NHR were closely related to the occurrence of in-hospital MACE after PCI. Our constructed nomogram model has some value for predicting the occurrence of in-hospital MACE in STEMI patients.

Association between very high HDL-C levels and mortality: A systematic review and meta-analysis

BACKGROUND

Recent research has raised questions about the assumed cardiovascular (CV) benefits of high-density lipoprotein cholesterol (HDL-C) and the potential for adverse outcomes with extremely high levels.

OBJECTIVE

We conducted a meta-analysis to investigate the association between very high HDL-C levels (≥80 mg/dL) and mortality outcomes in individuals without coronary artery disease (CAD).

METHODS

We systematically searched PubMed, Embase, and Cochrane databases for studies comparing very high HDL-C levels to normal levels (40-60 mg/dL) in CAD-free individuals. We assessed heterogeneity using I2 statistics with a random-effects model.

RESULTS

Our analysis included 1,004,584 individuals from 8 studies, of whom 133,646 (13.3%) had very high HDL-C levels. All-cause mortality did not significantly differ between groups (p = 0.55), nor did cancer mortality (p = 0.45). Cardiovascular mortality showed no change in those with very high HDL-C (hazard ratio [HR] 1.05; 95% confidence interval [CI] 0.94-1.17; p = 0.37). Fatal and non-fatal coronary heart disease events were less frequent in the very high HDL-C group (HR 0.79; 95% CI 0.73-0.86; p < 0.00001). Subgroup dose-response analysis revealed that very high HDL-C levels increased cardiovascular death in women above 116 mg/dL (HR 1.47; 95% CI 1.01-2.15) and in men above 94 mg/dL (HR 1.29; 95% CI 1.01-1.65) (p_nonlinearity <0.01).

CONCLUSIONS

These findings suggest that very high HDL-C levels are not protective against CV mortality and may, in fact, increase CV mortality risk especially in men.

Cuban Policosanol (Raydel®) Exerts Higher Antioxidant and Anti-Glycation Activities than Chinese Policosanol (BOC Sciences) in Reconstituted High-Density Lipoproteins: In Vivo Anti-Inflammatory Activities in Zebrafish and Its Embryos

The present study compares sugarcane-wax purified policosanols sourced from Cuba (Raydel®) and China (BOC Sciences) and utilized following the synthesis of reconstituted high-density lipoproteins (rHDL). The two policosanols exhibited distinctly different ingredient ratios of long-chain aliphatic alcohols, particularly 1-octacosanol (C28) and 1-tetratriacotanol (C34). After synthesizing rHDL with apolipoprotein A-I (apoA-I), the two policosanols bound well with phospholipid and apoA-I to form the discoidal rHDL. Notably, rHDL-1, containing Cuban policosanol, displayed the largest particle diameter at approximately 78 ± 3 nm. In contrast, both control rHDL (rHDL-0) and rHDL containing Chinese policosanol (rHDL-2) exhibited smaller particles, with diameters of approximately 58 ± 3 nm and 61 ± 2 nm, respectively. Furthermore, rHDL-1 demonstrated enhanced anti-glycation activity, safeguarding apoA-I from degradation within HDL, and displayed the antioxidant ability to inhibit LDL oxidation. A microinjection of each rHDL into zebrafish embryos in the presence of carboxymethyllysine (CML) revealed rHDL-1 to have the strongest antioxidant activity with the highest embryo survivability and normal developmental morphology. Dermal application to recover the wound revealed rHDL-1 to have the highest wound-healing activity (75%) and survivability (92%) in the cutaneous wound area in the presence of CML. In adult zebrafish, injecting CML (250 μg) caused acute death and hyperinflammation, marked by heightened neutrophil infiltration and interleukin (IL)-6 production in liver. However, co-administering rHDL-1 notably increased survival (85%) and exhibited strong anti-inflammatory properties, reducing IL-6 production while improving the blood lipid profile. However, a co-injection of rHDL-2 resulted in the lowest survivability (47%) with more hepatic inflammation. In conclusion, Cuban policosanol (Raydel®) has more desirable properties for the in vitro synthesis of rHDL with stronger anti-glycation and antioxidant activities than those of Chinese policosanol (BOC Sciences). Moreover, Raydel-policosanol-integrated rHDL demonstrates a noteworthy effect on accelerated wound healing and robust anti-inflammatory properties, leading to increased survivability in zebrafish embryos and adults by effectively suppressing CML-induced hyperinflammation.

Association of high-density lipoprotein cholesterol with all-cause and cause-specific mortality in a Chinese population of 3.3 million adults: a prospective cohort study

Background

High-density lipoprotein cholesterol (HDL-C) has been inversely associated with cardiovascular disease (CVD) risk, but recent evidence suggests that extremely high levels of HDL-C are paradoxically related to increased CVD incidence and mortality. This study aimed to comprehensively examine the associations of HDL-C with all-cause and cause-specific mortality in a Chinese population.

Methods

The China Health Evaluation And risk Reduction through nationwide Teamwork (ChinaHEART) project included 3,397,547 participants aged 35-75 years with a median follow-up of 3.9 years. Baseline HDL-C levels were measured, and mortality data was ascertained from the National Mortality Surveillance System and Vital Registration of Chinese Center for Disease Control and Prevention.

Findings

This study found U-shaped associations of HDL-C with all-cause, cardiovascular and cancer mortality. When compared with the groups with the lowest risk, the adjusted hazard ratios (95% CIs) for HDL-C <30 mg/dL was 1.23 (1.17-1.29), 1.33 (1.23-1.45) and 1.18 (1.09-1.28) for all-cause, CVD and cancer mortality, respectively. For HDL-C >90 mg/dL, the corresponding HR (95% CIs) was 1.10 (1.05-1.15), 1.09 (1.01-1.18) and 1.11 (1.03-1.19). Similar U-shaped patterns were also found in associations of HDL-C with ischemic heart disease, ischemic stroke, and liver cancer. About 3.25% of all-cause mortality could be attributed to abnormal levels of HDL-C. The major contributor to mortality was ischemic heart disease (16.06 deaths per 100,000 persons, 95% UI: 10.30-22.67) for HDL-C <40 mg/dL and esophageal cancer (2.29 deaths per 100,000 persons, 95% UI: 0.57-4.77) for HDL-C >70 mg/dL.

Interpretation

Both low and high HDL-C were associated with increased mortality risk. We recommended 50-79 mg/dL as the optimal range of HDL-C among Chinese adults. Individuals with dyslipidemia might benefit from proper management of both low and high HDL-C.

Funding

The CAMS Innovation Fund for Medical Science (2021-1-I2M-011), the National High Level Hospital Clinical Research Funding (2022-GSP-GG-4), the Ministry of Finance of China and National Health Commission of China, and the 111 Project from the Ministry of Education of China (B16005), the Program for Guangdong Introducing Innovative and Enterpreneurial Teams (2019ZT08Y481), Sanming Project of Medicine in Shenzhen (SZSM201811096), the Young Talent Program of the Academician Fund, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen (YS-2022-006) and Guangdong Basic and Applied Basic Research Foundation (2023A1515010076 & 2021A1515220173).

Expanding the therapeutic landscape: ezetimibe as non-statin therapy for dyslipidemia

Dyslipidemia is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD), and statins are the primary therapeutic options for reducing low-density lipoprotein cholesterol (LDL-C) levels. However, it can be challenging to achieve optimal LDL-C goals with statin monotherapy. Ezetimibe, a cholesterol absorption inhibitor, offers a potential non-statin therapy to optimize LDL-C management. Key clinical trials, such as IMPROVE-IT and RACING, have demonstrated that the addition of ezetimibe to statin therapy leads to further decreases in LDL-C or significant decreases in major adverse cardiovascular events (MACEs), particularly in patients with high ASCVD risk. Subsequent meta-analyses and clinical trials have further supported the beneficial effect of ezetimibe, suggesting additive decreases in LDL-C and MACEs, as well as pleiotropic effects. This review provides a comprehensive analysis of the clinical implications of ezetimibe for managing dyslipidemia; it also evaluates the available evidence that supports the role of ezetimibe as an adjunct non-statin therapy for long-term use. However, the long-term pleiotropic effects of ezetimibe remain controversial because of limited clinical data. Therefore, additional research is needed to clarify its potential benefits beyond LDL-C reduction. Nonetheless, an understanding of the role of ezetimibe in dyslipidemia management will help clinicians to develop effective treatment strategies.

Association between extremely high-density lipoprotein cholesterol and adverse cardiovascular outcomes: a systematic review and meta-analysis

Background

The association between high-density lipoprotein cholesterol (HDL-C) and adverse cardiovascular outcomes is understudied. Based on cohort studies, the current study aimed to investigate the association of extremely high HDL-C with all-cause, atherosclerotic cardiovascular disease (CVD) mortality, and stroke risk.

Methods

A systematic literature search in Embase, PubMed, Cochrane Library, and Web of Science was performed to collect relevant cohort studies published before August 20, 2022. A random-effects model was used to pool relative risks (RRs) and 95% confidence intervals (CIs).

Results

A total of 17 cohort studies involving 19,630,829 participants were included, encompassing 18,547,132 total deaths (1,328,036 CVD deaths). All-cause mortality, CVD mortality, and stroke risk in the extremely high HDL-C group were increased by 15% (RR = 1.15, 95% CI:1.05-1.25), 14% (RR = 1.14, 95% CI:0.96-1.35) and 14% (RR = 1.14, 95% CI:0.82-1.58), compared to the normal HDL-C group. In subgroup analyses, extremely high HDL-C was associated with a reduced risk of CVD mortality in women and a lower risk of stroke in men compared to normal HDL-C levels.

Conclusions

The extremely high levels of HDL-C were associated with elevated risks of all-cause mortality, CVD mortality, and stroke. More well-designed studies are needed to confirm our findings.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=370201, identifier: CRD42022370201.

Hepatic Cdkal1 deletion regulates HDL catabolism and promotes reverse cholesterol transport

BACKGROUND AND AIMS

Associations between CDKAL1 variants and cholesterol efflux capacity (CEC) have been reported. This study aimed to investigate the effects of Cdkal1 deficiency on high-density lipoprotein (HDL) metabolism, atherosclerosis, and related pathways.

METHODS

Lipid and glucose metabolic profiles, CEC, and in vivo reverse cholesterol transport (RCT) were compared in liver-specific Alb-Cre:Cdkal1fl/fl and Cdkal1fl/fl mice. Aortic atherosclerosis was compared in Apoe-/-Alb-Cre:Cdkal1fl/fl and Apoe-/- mice fed high-fat diets. HDL subclasses and mediators of HDL metabolism from Alb-Cre:Cdkal1fl/fl mice were examined.

RESULTS

HDL-cholesterol level tended to be higher in the Alb-Cre:Cdkal1fl/fl mice (p = 0.050). Glucose and other lipid profiles were similar in the two groups of mice, irrespective of diet. The mean CEC was 27% higher (p = 0.007) in the Alb-Cre:Cdkal1fl/fl mice, as were the radioactivities of bile acids (mean difference 17%; p = 0.035) and cholesterol (mean difference 42%; p = 0.036) from faeces. The radioactivity tendency was largely similar in mice fed a high-fat diet. Atherosclerotic lesion area tended to be smaller in the Apoe-/-Alb-Cre:Cdkal1fl/fl mice than in the Apoe-/- mice (p = 0.067). Cholesterol concentrations in large HDLs were higher in the Alb-Cre:Cdkal1fl/fl mice (p = 0.024), whereas in small HDLs, they were lower (p = 0.024). Endothelial lipase (mean difference 39%; p = 0.002) and hepatic lipase expression levels (mean difference 34%; p < 0.001) were reduced in the Alb-Cre:Cdkal1fl/fl mice, whereas SR-B1 expression was elevated (mean difference 35%; p = 0.007).

CONCLUSIONS

The promotion of CEC and RCT in Alb-Cre:Cdkal1fl/fl mice verified the effect of CDKAL1 seen in human genetic data. These phenotypes were related to regulation of HDL catabolism. This study suggests that CDKAL1 and associated molecules could be targets for improving RCT and vascular pathology.

Favorable Effect of High-Density Lipoprotein Cholesterol on Gastric Cancer Mortality by Sex and Treatment Modality

Studies on the effects of high-density lipoprotein cholesterol (HDL-C) on gastric cancer mortality are few, and the results are inconsistent. In this study, we investigated the effects of HDL-C on gastric cancer mortality and conducted sub-group analysis by sex and treatment modality. Newly diagnosed patients with gastric cancer (n = 22,468) who underwent gastric cancer screening between January 2011 and December 2013 were included and followed up until 2018. A validation cohort (n = 3379) that had newly diagnosed gastric cancer from 2005 to 2013 at a university hospital, was followed up until 2017. HDL-C was inversely related with mortality; adjusted hazard ratio (aHR) 0.90 (95% confidence interval [CI], 0.83-0.98) for HDL-C of 40-49 mg/dL, 0.86 (0.79-0.93) for HDL-C of 50-59 mg/dL, 0.82 (0.74-0.90) for HDL-C of 60-69 mg/dL, and 0.78 (0.69-0.87) for HDL-C ≥ 70 mg/dL compared to HDL-C < 40 mg/dL. In the validation cohort, HDL-C was also inversely associated with mortality; aHR 0.81 (0.65-0.99) for HDL-C of 40-49 mg/dL, 0.64 (0.50-0.82) for HDL-C of 50-59 mg/dL, and 0.46 (0.34-0.62) for HDL-C ≥ 60 mg/dL compared to HDL-C < 40 mg/dL. The two cohorts demonstrated that higher HDL-C was associated with a low risk of mortality in both sexes. In validation cohort, this association was observed in both gastrectomy and endoscopic resection (p for trend < 0.001) as more remarkable in endoscopic resection group. In this study, we explored that an increased HDL-C reduced mortality in both sexes and curative resection group.

Lean or diabetic subtypes predict increased all-cause and disease-specific mortality in metabolic-associated fatty liver disease

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) encompasses diverse disease groups with potentially heterogeneous clinical outcomes. We investigated the risk of all-cause and disease-specific mortality in MAFLD subgroups.

METHODS

Using the Korean National Health Insurance Service database, participants were divided into four subgroups: no MAFLD, MAFLD-diabetes, MAFLD-overweight/obese, and MAFLD-lean. Hazard ratios (HRs) and 95% confidence interval (CI) values for all-cause and disease-specific mortality according to MAFLD subgroups were analyzed using Cox proportional hazards models.

RESULTS

Among 9,935,314 participants, those with MAFLD-diabetes showed the highest risk of all-cause and disease-specific mortality. The HRs (95% CI) for all-cause mortality were 1.61 (1.59-1.63), 1.36 (1.34-1.38), and 1.19 (1.18-1.20) in the MAFLD-diabetes, MAFLD-lean, and MAFLD-overweight/obese groups, respectively. The magnitude of cardiovascular disease and cancer-related risk showed the same pattern. The risk of liver-related mortality in the MAFLD-lean group (HR: 2.84, 95% CI: 2.72-2.97) was comparable with that in the MAFLD-diabetes group (HR: 2.85, 95% CI: 2.75-2.95). When stratified by body mass index, liver-related mortality was the highest in MAFLD-lean individuals in the underweight group (HR, 5.03, 95% CI: 4.23-5.97).

CONCLUSIONS

The MAFLD-lean and MAFLD-diabetes groups had a higher risk of all-cause and disease-specific mortality than did the MAFLD-overweight/obese group. Classifying MAFLD subgroups based on metabolic phenotypes might help risk stratification of patients with MAFLD.

Remnant cholesterol is associated with cardiovascular mortality

BACKGROUND

Genetic, observational, and clinical intervention studies indicate that circulating levels of remnant cholesterol (RC) are associated with cardiovascular diseases. However, the predictive value of RC for cardiovascular mortality in the general population remains unclear.

METHODS

Our study population comprised 19,650 adults in the United States from the National Health and Nutrition Examination Survey (NHANES) (1999-2014). RC was calculated from non-high-density lipoprotein cholesterol (non-HDL-C) minus low-density lipoprotein cholesterol (LDL-C) determined by the Sampson formula. Multivariate Cox regression, restricted cubic spline analysis, and subgroup analysis were applied to explore the relationship of RC with cardiovascular mortality.

RESULTS

The mean age of the study cohort was 46.4 ± 19.2 years, and 48.7% of participants were male. During a median follow-up of 93 months, 382 (1.9%) cardiovascular deaths occurred. In a fully adjusted Cox regression model, log RC was significantly associated with cardiovascular mortality [hazard ratio (HR) 2.82; 95% confidence interval (CI) 1.17-6.81]. The restricted cubic spline curve indicated that log RC had a linear association with cardiovascular mortality (p for non-linearity = 0.899). People with higher LDL-C (≥130 mg/dL), higher RC [≥25.7/23.7 mg/dL in males/females corresponding to the LDL-C clinical cutoff point (130 mg/dL)] and abnormal HDL-C (<40/50 mg/dL in males/females) levels had a higher risk of cardiovascular mortality (HR 2.18; 95% CI 1.13-4.21 in males and HR 2.19; 95% CI 1.24-3.88 in females) than the reference group (lower LDL-C, lower RC and normal HDL-C levels).

CONCLUSIONS

Elevated RC levels were associated with cardiovascular mortality independent of traditional risk factors.

Crocins for Ischemic Stroke: A Review of Current Evidence

Crocins (CRs) and the related active constituents derived from Crocus sativus L. (Saffron) have demonstrated protective effects against cerebral ischemia and ischemic stroke, with various bioactivities including neuroprotection, anti-neuroinflammation, antioxidant, and cardiovascular protection. Among CRs, crocin (CR) has been shown to act on multiple mechanisms and signaling pathways involved in ischemic stroke, including mitochondrial apoptosis, nuclear factor kappa light chain enhancer of B cells pathway, S100 calcium-binding protein B, interleukin-6 and vascular endothelial growth factor-A. CR is generally safe and well-tolerated. Pharmacokinetic studies indicate that CR has poor bioavailability and needs to convert to crocetin (CC) in order to cross the blood-brain barrier. Clinical studies have shown the efficacy of saffron and CR in treating various conditions, including metabolic syndrome, depression, Alzheimer’s disease, and coronary artery disease. There is evidence supporting CR as a treatment for ischemic stroke, although further studies are needed to confirm their efficacy and safety in clinical settings.

Lipid cutoffs for increased cardiovascular disease risk in nondiabetic young people

AIMS

The relevance of blood lipid abnormalities to cardiovascular disease (CVD) risk in young populations is unclear. Here, we aimed to identify the cutoff levels of lipid parameters for increased risk of CVD among nondiabetic young adults aged 20-39 years.

METHODS

Using data from a nationally representative Korean National Health Insurance System database, we followed up 6,204,153 subjects who underwent health examinations between 2009 and 2012 until the end of 2018. The primary outcome was incident CVD, defined as a composite of myocardial infarction and stroke. We assessed the associations between pre-specified lipid levels and CVD risk. Subgroup analysis of the number of cardiovascular risk factors (obesity, hypertension, and current smoking) was also conducted.

RESULTS

During a median follow-up of 7.7 years, there were 14,569 (0.23%) cases of myocardial infarction, 9,459 (0.15%) cases of stroke, and 23,680 (0.38%) cases of composite CVD. Using total cholesterol (TC) level of <140 mg/dL, triglyceride (TG) level of <60 mg/dL, LDL-cholesterol level of <100 mg/dL, and non-HDL-cholesterol level of <130 mg/dL as reference groups, a significantly higher risk of CVD was observed in subjects with a TC level of ≥200 mg/dL, TG level of ≥60 mg/dL, LDL-cholesterol level of ≥130 mg/dL, or non-HDL-cholesterol level of ≥140 mg/dL. The cutoff levels of TC that had statistical significance for increased risk of CVD were 240, 220, and 200 mg/dL in subjects with 0, 1, or 2-3 risk factors, respectively.

CONCLUSIONS

Even modest increases in lipid levels were associated with increased risk of CVD in this nondiabetic young population. Our data provide potential criteria for stratifying CVD risk based on real-world evidence.

Sex-Specific U-Shaped Relationships Between High-Density Lipoprotein Cholesterol Levels and 10-year Major Adverse Cardiovascular Events: A Nationwide Cohort Study of 5.7 Million South Koreans

Background

High-density lipoprotein cholesterol (HDL-C) is a well-known predictor of atherosclerotic cardiovascular diseases (ASCVD). We explored the relationships between HDL-C levels and 10-year major adverse cardiovascular events (MACE) and provided sex-specific upper reference limits for HDL-C levels.

Methods

Based on the Korean National Health Insurance Sharing Service, we identified 5,703,897 subjects (women, 48%) with age ≥40 years, eligible HDL-C results, and no prior ASCVD in 2009. We investigated the distribution of 10-year MACE according to HDL-C levels in 10 mg/dL (0.26 mmol/L) intervals and in three HDL-C groups (low: men <40 mg/dL [1.03 mmol/L], women <50 mg/dL [1.29 mmol/L]; high: between low and extremely high levels; and extremely high: >90 mg/dL [2.33 mmol/L]).

Results

There were U-shaped relationships between HDL-C levels and 10-year MACE with later inflection in women than in men (nadir: 80-99 mg/dL [2.07-2.56 mmol/L] and 50-59 mg/dL [1.29-1.53 mmol/L], respectively). In men, the extremely high HDL-C group showed significantly higher 10-year MACE than the high group (28.1% vs. 24.6%, P< 0.0001). In women, the extremely high group showed the lowest 10-year MACE; if the extremely high starting point was raised to 130 mg/dL, it became similar to that in men and showed higher 10-year MACE than the high group (25.6% vs. 20.1%, P<0.0001).

Conclusions

The 10-year MACE showed U-shaped relationships with HDL-C levels, and extremely high HDL-C level at 90 mg/dL (2.33 mmol/L) in men was corresponding in risk to 130 mg/dL (3.36 mmol/L) in women.

Cardiovascular Risk and Treatment Outcomes in Severe Hypercholesterolemia: A Nationwide Cohort Study

Background

This study aimed to evaluate the cardiovascular risk and outcomes after lipid reduction in patients with severe hypercholesterolemia using a nationwide cohort.

Methods and Results

This study used the database from the National Health Insurance Service of Korea. Among individuals who underwent regular health examination and follow‐up, 2 377 918 were enrolled and categorized into 3 groups with severe hypercholesterolemia according to low‐density lipoprotein cholesterol (LDL‐C) levels, namely, ≥260, 225 to 259, and 190 to 224 mg/dL groups, and a control group (<160 mg/dL). Risks of composite cardiovascular events (myocardial infarction, coronary revascularization, and ischemic stroke) and total mortality were compared. In statin new users, the outcomes after statin use were further analyzed according to posttreatment LDL‐C levels. The prevalence of individuals with LDL‐C≥190 mg/dL was 1 of 106. Adjusted hazard ratios of composite events and total mortality (median follow‐up, 6.1 years) in the groups ranged up to 2.4 (log‐rank P<0.0001) and 2.3 (log‐rank P=0.0002), respectively, and were dependent on LDL‐C levels. The risks of each event were up to 4.1‐, 3.8‐, and 1.9‐fold higher, respectively, in these groups. The risk of composite events (median follow‐up, 6.2 years) was lower after lipid lowering; particularly, the risk was lowest in the group showing LDL‐C<100 mg/dL after treatment (hazard ratio, 0.56, log‐rank P=0.043).

Conclusions

Using large Korean cohort data, our study proved incrementally elevated cardiovascular risk and clinical benefit associated with LDL‐C<100 mg/dL in individuals with severe hypercholesterolemia. These results support aggressive lipid lowering and provide evidence for the LDL‐C target in this population.

Prognostic Role of Neutrophil to High-Density Lipoprotein Cholesterol Ratio for All-Cause and Cardiovascular Mortality in the General Population

Background

Neutrophil counts to high-density lipoprotein cholesterol ratio (NHR), a composite marker of inflammation and lipid metabolism, has been considered as a predictor of clinical outcomes in patients with acute ischemic stroke and acute myocardial infarction. However, the predictive value of NHR for all-cause and cardiovascular mortality in the general population remains unclear.

Methods

Our study population comprised 34,335 adults in the United States obtained from the National Health and Nutrition Examination Survey (NHANES) (1999–2014) and were grouped in accordance with tertiles of NHR. Kaplan–Meier curves and log-rank test were used to investigate the differences of survival among groups. Multivariate Cox regression, restricted cubic spline analysis, and subgroup analysis were applied to explore the relationship of NHR with all-cause and cardiovascular mortality.

Results

The mean age of the study cohort was 49.6 ± 18.2 years and 48.4% were men. During a median follow-up of 82 months, 4,310 (12.6%) all-cause deaths and 754 (2.2%) cardiovascular deaths occurred. In a fully-adjusted Cox regression model, participants in the highest tertile had 29% higher hazard of all-cause mortality than those in the lowest tertile [hazard ratio (HR) = 1.29, 95% CI: 1.19–1.41]. For cardiovascular mortality, the continuously increased HR with 95% CIs among participants in the middle and highest tertile were 1.30 (1.06–1.59) and 1.44 (1.17–1.78), respectively. The restricted cubic spline curve indicated that NHR had a non-linear association with all-cause mortality (p for non-linearity < 0.001) and a linear association with cardiovascular mortality (p for non-linearity = 0.553).

Conclusion

Increased NHR was a strong and independent predictor of all-cause and cardiovascular mortality in the general population.

Relationship between continuity of care and clinical outcomes in patients with dyslipidemia in Korea: a real world claims database study

Dyslipidemia is a risk factor for atherosclerotic cardiovascular disease and requires proactive management. This study aimed to investigate the association between care continuity and the outcomes of patients with dyslipidemia. We conducted a retrospective cohort study on patients with dyslipidemia by employing the Korea National Health Insurance claims database during the period 2007-2018. The Continuity of Care Index (COCI) was used to measure continuity of care. We considered incidence of atherosclerotic cardiovascular disease as a primary outcome. A Cox's proportional hazards regression model was used to quantify risks of primary outcome. There were 236,486 patients newly diagnosed with dyslipidemia in 2008 who were categorized into the high and low COC groups depending on their COCI. The adjusted hazard ratio for the primary outcome was 1.09 times higher (95% confidence interval: 1.06-1.12) in the low COC group than in the high COC group. The study shows that improved continuity of care for newly-diagnosed dyslipidemic patients might reduce the risk of atherosclerotic cardiovascular disease.

HDL Is Not Dead Yet

High-density lipoprotein cholesterol (HDL-C) levels are inversely correlated with coronary heart disease (CHD) in multiple epidemiological studies, but whether HDL is causal or merely associated with CHD is unclear. Recent trials for HDL-raising drugs were either not effective in reducing CHD events or, if beneficial in reducing CHD events, were not conclusive as the findings could be attributed to the drugs’ LDL-reducing activity. Furthermore, the first large Mendelian randomization study did not causally relate HDL-C levels to decreased CHD. Thus, the hypothesis that HDL is protective against CHD has been rightfully challenged. However, subsequent Mendelian randomization studies found HDL characteristics that are causally related to decreased CHD. Many aspects of HDL structure and function, especially in reverse cholesterol transport, may be better indicators of HDL’s protective activity than simply measuring HDL-C. Cholesterol efflux capacity is associated with lower levels of prevalent and incident CHD, even after adjustment for HDL-C and apolipoprotein A-1 levels. Also, subjects with very high levels of HDL-C, including those with rare mutations that disrupt hepatic HDL uptake and reverse cholesterol transport, may be at higher risk for CHD than those with moderate levels. We describe here several cell-based and cell-free in vitro assays of HDL structure and function that may be used in clinical studies to determine which of HDL’s functions are best associated with protection against CHD. We conclude that the HDL hypothesis may need revision based on studies of HDL structure and function, but that the HDL hypothesis is not dead yet.

High-density lipoprotein cholesterol and cardiovascular mortality: a prospective cohort study among 15.8 million adults

AIMS

We aimed to investigate whether the associations between high-density lipoprotein cholesterol (HDL-C) and cardiovascular disease (CVD) mortality and the optimal range differ by age and CVD subtypes.

METHODS AND RESULTS

Korean adults (n = 15,859,501) with no CVD/cancer who received routine health examinations during 2009-2010 were followed until 2018 for CVD mortality. During a mean 8.8 years of follow-up, 108,123 individuals died from CVD. U-curve associations were found between HDL-C and CVD mortality, regardless of sex, age, and CVD subtype. The optimal range was 50-79 mg/dL (1.29-2.06 mmol/L), while it was 40-69 (1.03-1.80), 50-79 (1.29-2.06), and 60-89 (1.55-2.32) mg/dL (mmol/L) in adults aged <45 years, 45-64 years, and 65-99 years, respectively. Assuming linear associations <60 mg/dL, the multivariable-adjusted hazard ratios (HRs) per 39 mg/dL (1 mmol/L) higher level were 0.58 (95% CI = 0.56-0.60), and they were 0.61 (0.52-0.72), 0.58 (0.54-0.62), and 0.59 (0.56-0.61) in individuals aged 18-44, 45-64, and 65-99 years, respectively (P  interaction[age]=0.845). Assuming linear associations in the 60-150 mg/dL range, HDL-C was positively associated with CVD mortality (HR = 1.09, 1.04-1.14). The strongest association was for sudden cardiac death (HR = 1.37), followed by heart failure (HR = 1.20) and intracerebral hemorrhage (HR = 1.13). The HRs were 1.47 (1.23-1.76), 1.17 (1.08-1.28), and 1.03 (0.97-1.08) in individuals aged 18-44, 45-64, and 65-99 years, respectively (P  interaction[age]<0.001).

CONCLUSIONS

Both low and high levels of HDL-C were associated with increased mortality from CVD in the general population, especially sudden cardiac death, heart failure, and intracerebral hemorrhage. High HDL-C levels are not necessarily a sign of good cardiovascular health, especially in younger adults.