Association of extremely high levels of high-density lipoprotein cholesterol with cardiovascular mortality in a pooled analysis of 9 cohort studies including 43,407 individuals: The EPOCH-JAPAN study

Impaired Cholesterol Efflux Capacity rather than Low HDL-C Reflects Oxidative Stress under Acute Myocardial Infarction

AIMS

Acute myocardial infarction (AMI) causes irreversible damage to cardiomyocytes due to the discontinuation of oxygen supply and leads to systemic oxidative stress. It has been reported that high-density lipoprotein (HDL) particles have antioxidant capacity, and reduced antioxidant capacity is associated with decreased cholesterol efflux capacity (CEC). The purpose of this study was to clarify the usefulness of CEC measurement in patients with AMI.

METHODS

We investigated the association between CEC and oxidative stress status in a case-control study. This study included 193 AMI cases and 445 age- and sex-matched controls. We examined the associations of CEC with HDL-cholesterol (HDL-C) and oxidized human serum albumin (HSA), an index of systemic oxidative stress status, and the effect of aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which has been reported to affect HDL-C level and risk for MI, on these associations.

RESULTS

Both bivariable and multivariable analyses showed that CEC was positively correlated with HDL-C levels in both AMI cases and controls, with a weaker correlation in AMI cases than in controls. In AMI cases, oxidized HSA levels were associated with CEC in both bivariable and multivariable analyses, but not with HDL-C. These associations did not differ among the ALDH2 genotypes.

CONCLUSIONS

CEC, but not HDL-C level, reflects systemic oxidative stress status in patients with AMI. CEC measurement for patients with AMI may be useful in that it provides information on systemic oxidative stress status as well as atherosclerosis risk.

High levels of high-density lipoprotein cholesterol may increase the risk of diabetic kidney disease in patients with type 2 diabetes

Studies have indicated that low high-density lipoprotein cholesterol (HDL-C) level is an important risk factor for diabetic kidney disease (DKD) in patients with type 2 diabetes (T2D). However, whether higher HDL-C levels decrease the risk of developing DKD remains unclear. This study aimed to clarify the relationship between HDL-C levels and DKD risk in individuals with T2D in China. In total, 936 patients with T2D were divided into DKD and non-DKD groups. The association between HDL-C levels and DKD risk was evaluated using logistic regression analysis and restricted cubic spline curves adjusted for potential confounders. Threshold effect analysis of HDL-C for DKD risk was also performed. Higher HDL-C levels did not consistently decrease the DKD risk. Furthermore, a nonlinear association with threshold interval effects between HDL-C levels and the incidence of DKD was observed. Patients with HDL-C ≤ 0.94 mmol/L or HDL-C > 1.54 mmol/L had significantly higher DKD risk after adjusting for confounding factors. Interestingly, the association between high HDL-C levels and increased DKD risk was more significant in women. A U-shaped association between HDL-C levels and DKD risk was observed; therefore, low and high HDL-C levels may increase the DKD risk in patients with T2D.

High-Fat Diet Augments Myocardial Inflammation and Cardiac Dysfunction in Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is a familial heart disease characterized by cardiac dysfunction, arrhythmias, and myocardial inflammation. Exercise and stress can influence the disease's progression. Thus, an investigation of whether a high-fat diet (HFD) contributes to ACM pathogenesis is warranted. In a robust ACM mouse model, 8-week-old Desmoglein-2 mutant (Dsg2mut/mut) mice were fed either an HFD or rodent chow for 8 weeks. Chow-fed wildtype (WT) mice served as controls. Echo- and electrocardiography images pre- and post-dietary intervention were obtained, and the lipid burden, inflammatory markers, and myocardial fibrosis were assessed at the study endpoint. HFD-fed Dsg2mut/mut mice showed numerous P-wave perturbations, reduced R-amplitude, left ventricle (LV) remodeling, and reduced ejection fraction (%LVEF). Notable elevations in plasma high-density lipoprotein (HDL) were observed, which correlated with the %LVEF. The myocardial inflammatory adipokines, adiponectin (AdipoQ) and fibroblast growth factor-1, were substantially elevated in HFD-fed Dsg2mut/mut mice, albeit no compounding effect was observed in cardiac fibrosis. The HFD not only potentiated cardiac dysfunction but additionally promoted adverse cardiac remodeling. Further investigation is warranted, particularly given elevated AdipoQ levels and the positive correlation of HDL with the %LVEF, which may suggest a protective effect. Altogether, the HFD worsened some, but not all, disease phenotypes in Dsg2mut/mut mice. Notwithstanding, diet may be a modifiable environmental factor in ACM disease progression.

Thin-cap fibroatheroma in acute coronary syndrome: Implication for intravascular imaging assessment

Acute coronary syndrome (ACS), a significant cardiovascular disease threat, has garnered increased focus concerning its etiological mechanisms. Thin-cap fibroatheroma (TCFA) are central to ACS pathogenesis, characterized by lipid-rich plaques, profuse foam cells, cholesterol crystals, and fragile fibrous caps predisposed to rupture. While TCFAs may be latent and asymptomatic, their pivotal role in ACS risk is undeniable. High-resolution imaging techniques like Optical coherence tomography (OCT) and Intravascular ultrasound (IVUS) are instrumental for effective TCFA detection. Therapeutic strategies encompass pharmacological and interventional measures, including antiplatelet agents, statins, and Percutaneous Coronary Intervention (PCI), aiding in plaque stabilization, inflammation reduction, and rupture risk mitigation. Despite the strong correlation between TCFAs and adverse prognoses in ACS patients, early detection and rigorous treatment significantly enhance patient prognosis and diminish cardiovascular events. This review aims to encapsulate recent advancements in TCFA research within ACS, covering formation mechanisms, clinical manifestations, and prognostic implications.

Effect of Reconstituted Human Apolipoprotein A-I on Recurrent Ischemic Events in Survivors of Acute MI

BACKGROUND

The AEGIS-II trial hypothesized that CSL112, an intravenous formulation of human apoA-I, would lower the risk of plaque disruption, decreasing the risk of recurrent events such as myocardial infarction (MI) among high-risk patients with MI.

OBJECTIVES

This exploratory analysis evaluates the effect of CSL112 therapy on the incidence of cardiovascular (CV) death and recurrent MI.

METHODS

The AEGIS-II trial was an international, multicenter, randomized, double-blind, placebo-controlled trial that randomized 18,219 high-risk acute MI patients to 4 weekly infusions of apoA-I (6 g CSL112) or placebo.

RESULTS

The incidence of the composite of CV death and type 1 MI was 11% to 16% lower in the CSL112 group over the study period (HR: 0.84; 95% CI: 0.7-1.0; P = 0.056 at day 90; HR: 0.86; 95% CI: 0.74-0.99; P = 0.048 at day 180; and HR: 0.89; 95% CI: 0.79-1.01; P = 0.07 at day 365). Similarly, the incidence of CV death or any MI was numerically lower in CSL112-treated patients throughout the follow-up period (HR: 0.92; 95% CI: 0.80-1.05 at day 90, HR: 0.89; 95% CI: 0.79-0.996 at day 180, HR: 0.91; 95% CI: 0.83-1.01 at day 365). The effect of CSL112 treatment on MI was predominantly observed for type 1 MI and type 4b (MI due to stent thrombosis).

CONCLUSIONS

Although CSL112 did not significantly reduce the occurrence of the primary study endpoints, patients treated with CSL112 infusions had numerically lower rates of CV death and MI, type-1 MI, and stent thrombosis-related MI compared with placebo. These findings could suggest a role of apoA-I in reducing subsequent plaque disruption events via enhanced cholesterol efflux. Further prospective data would be needed to confirm these observations.

Association of High-Density Lipoprotein Cholesterol with Sarcopenia in Chinese Community-Dwelling Middle-Aged and Older Adults: Evidence from 4-Year Longitudinal Study

INTRODUCTION

There is inconsistent evidence on the associations between high-density lipoprotein cholesterol (HDL-C) and risk of sarcopenia. The aim of the study was to determine the evidence existing between HDL-C and sarcopenia in Chinese middle-aged and older adults.

METHODS

We used a panel study design of the China Health and Retirement Longitudinal Study (CHARLS), with 7,415 participants (mean age 57.5 years) from 2011, 2013, and 2015. HDL-C was measured by colorimetric test of venous serum samples. Sarcopenia was defined as low muscle mass, plus low muscle strength, or low physical performance. Muscle mass was estimated by anthropometric measures. Muscle strength was measured by handgrip strength using dynamometer. Physical performance was measured by 5-time chair stand test, gait speed test, and short physical performance battery.

RESULTS

With 961 (13.0%) sarcopenia cases, each 1-unit increase (1 SD = 15.4 mg/dL) of HDL-C levels was associated with 42% increased odds of incident sarcopenia (OR = 1.42, 95% confidence interval [CI] = 1.28-1.58) at 4-year follow-up. Females with high HDL-C levels (HDL-C >60 mg/dL) had a higher risk of sarcopenia (OR = 2.49, 95% CI = 1.76-3.52). The restricted cubic spline curves showed a J-shaped association between HDL-C and risk of sarcopenia in females. HDL-C was negatively associated with muscle mass (β = -0.23, 95% CI = -0.27 to -0.20) and hand grip strength (β = -0.05, 95% CI = -0.19 to 0.09).

CONCLUSION

High HDL-C levels were associated with higher risk of sarcopenia among middle-aged and older Chinese adults, and appropriate control of its high levels informs the management of sarcopenia.

The association of the platelet/high-density lipoprotein cholesterol ratio with self-reported stroke and cardiovascular mortality: a population-based observational study

BACKGROUND

Previous studies have shown that the relationship between high-density lipoprotein cholesterol (HDL-C) and stroke is controversial, and the association between the platelet/high-density lipoprotein cholesterol ratio (PHR), a novel marker for inflammation and hypercoagulability states, and stroke has not been established.

METHODS

This study presents an analysis of cross-sectional data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES). Stroke history, HDL-C levels, and platelet counts were obtained during cross-sectional surveys. The PHR was calculated as the ratio of the number of platelets to HDL-C concentration. Weighted logistic regression was used to assess the associations of HDL-C and the PHR with stroke. Nonlinearity of this relationship was determined through restricted cubic splines (RCSs) and two-piecewise linear regression for identifying inflection points. Furthermore, Cox regression was utilized to prospectively analyze the associations of the PHR and HDL-C concentration with cardiovascular disease (CVD) mortality in stroke survivors.

RESULTS

A total of 27,301 eligible participants were included in the study; mean age, 47.28 years and 50.57% were female, among whom 1,040 had a history of stroke. After full adjustment, the odds ratio (OR) of stroke associated with a per standard deviation (SD) increase in the PHR was estimated at 1.13 (95% confidence interval (CI): 1.03 - 1.24, P = 0.01), and the OR of stroke associated with a per SD increase in HDL-C was 0.95 (95% CI: 0.86-1.05, P = 0.30). The RCS indicated a nonlinear relationship for both variables (PPHR = 0.018 and PHDL-C = 0.003), and further piecewise linear regression identified inflection points at PHR = 223.684 and HDL-C = 1.4 mmol/L. Segmental regression indicated that in the PHR ≥ 223.684 segment, the estimated OR of stroke associated with a per-SD increase in the PHR was 1.20 (95% CI: 1.09 - 1.31, P < 0.001), while the association of stroke with HDL-C was not significant before or after the inflection point (P > 0.05). Furthermore, Cox regression and RCS showed that a per-SD increase in the PHR was linearly associated with a greater risk of CVD mortality among stroke survivors (HR: 1.14, 95% CI: 1.06 - 1.22, P < 0.001; nonlinear, P = 0.956), while HDL-C was not significantly associated with CVD mortality.

CONCLUSION

The association between the PHR and stroke incidence exhibited a significant threshold effect, with an inflection point at 223.684. A PHR exceeding 223.684 was positively associated with stroke, while the association between HDL-C and stroke was not significant. Additionally, the PHR was positively and linearly associated with CVD mortality among stroke survivors.

Association between HDL-C and intensive blood pressure control in patients with hypertension: A post-hoc analysis of SPRINT

Previous studies in patients with hypertension have demonstrated that there is a U-shaped association between HDL-C (high-density lipoprotein cholesterol) and the risk of cardiovascular events in male patients with hypertension. However, to the best of our knowledge, the relationship between HDL-C and intensive blood pressure control in specific cardiovascular events has never been investigated. To fill this knowledge gap, the authors analyzed the relationship between HDL-C levels and cardiovascular events in hypertensive patients within the Systolic Blood Pressure Intervention Trial (SPRINT). The SPRINT evaluated the impact of intensive blood pressure control (systolic blood pressure < 120 mm Hg) versus standard blood pressure control (systolic blood pressure < 140 mm Hg). The Cox proportional risk regression was used to investigate the association between different HDL-C status and clinical outcomes. Additional stratified analyzes were performed to evaluate the robustness of sex difference. A total of 9323 participants (6016 [64.53%] males and 3307 [35.47%] females) with hypertension from the SPRINT research were included in the analysis. The median follow-up period was 3.26 years. Our population was divided into five groups based on the HDL-C plasma levels: HDL-C < 30 mg/dL, HDL-C between 30 and 40 mg/dL, HDL-C between 40 and 60 mg/dL, HDL-C between 60 and 80 mg/dL and HDL-C > 80 mg/dL. Sensitivity analyzes showed that in the SPRINT, women in the HDL-C high population had a higher risk of mortality from all causes than men. In this cohort study, results suggest that patients with HDL-C levels higher than 80 mg/dL had lower risk of SPRINT primary outcome, cardiovascular death, and stroke, but this study tested association, not causation. HDL-C levels were associated with composite cardiovascular outcomes in male but not female patients. Our results demonstrated that in patients with hypertension, the association between HDL-C and risk of cardiovascular events is L-shaped.

Characterization of novel truncated apolipoprotein A-I in human high-density lipoprotein generated by sequential treatment with myeloperoxidase and chymase

High-density lipoprotein (HDL) cholesterol is a well-known biomarker, which has been associated with reduction in the risk of cardiovascular diseases (CVD). However, some HDL anti-atherosclerotic functions may be impaired without altered HDL-cholesterol (HDL-C) level via its dysfunctional proteins or other physiological reactions in vivo. We previously showed that activated mast cell-derived chymase could modestly cleave apolipoprotein A-I (apoA-I) in HDL3, and further easily cleave lipid-free apoA-I. In contrast, myeloperoxidase (MPO) secreted by macrophages, the main cell type in atherosclerotic plaques, could oxidize HDL proteins, which might modify their tertiary structures, increasing their susceptibility to other enzymes. Here we focused on the co-modification and impact of chymase and MPO, usually secreted during inflammation from cells with possible co-existence in atheromas, on HDL. Only after sequential treatment with MPO and then chymase, two novel truncated apoA-I fragments were generated from HDL. One fragment was 16.5 kDa, and the cleavage site by chymase after MPO modification was the C-terminal of Tyr100 in apoA-I, cross-validated by three different mass spectrometry methods. This novel apoA-I fragment can be trapped in HDL particles to avoid kidney glomerular filtration and has a specific site for antibody generation for ELISA tests. As such, its quantification can be useful in predicting patients with CVD having normal HDL-C levels.

Moderate-to-Heavy Alcohol Consumption May Cause a Significant Decrease in Serum High-Density Lipoprotein Cholesterol in Middle-Aged Women: A Cohort Study of the National Database Study in the Kanto 7 Prefectures-4

Aims Little is known about the association between habitual alcohol consumption and serum high-density lipoprotein cholesterol (HDL-C) in women. We aimed to investigate this association in middle-aged Japanese women in a community-based cohort study using conventional statistical analyses and explainable artificial intelligence (AI) analysis. Methods We retrospectively investigated the association between alcohol consumption and HDL-C after 10 years in 90,053 women aged 40-64 years whose drinking habits were generally consistent for 10 years. Results After 10 years, 11.3% and 17.9% of subjects had serum HDL-C decreased by ≥10 mg/dL and ≥10%, respectively. In unadjusted analysis, moderate-to-heavy alcohol consumption may both increase and decrease serum HDL-C levels after 10 years. After adjustment for potential confounding factors, moderate (23-45 g/day) and heavy (≥46 g/day) alcohol consumption were each significantly associated with decreases in HDL-C (OR (95% CI): 1.18 and 1.36 (1.11-1.26 and 1.21-1.53) for ≥10 mg/dL, 1.11 and 1.29 (1.05-1.17 and 1.17-1.43) for ≥10%), but not associated with an increase in HDL-C (0.96 and 0.98 (0.91-1.01 and 0.89-1.08) for ≥10 mg/dL, 0.97 and 0.96 (0.93-1.01 and 0.88-1.05) for ≥10%). Further analysis after adjustment for baseline serum HDL-C showed the same results. AI analysis showed that alcohol consumption was the 8th positive contributor to the decrease in HDL-C, following baseline high HDL-C (≥77 mg/dL), high low-density lipoprotein cholesterol (≥133 mg/dL), high body mass index (≥23.1 kg/m2), pharmacotherapy for dyslipidemia, high triglycerides (≥70 mg/dL), age 44-64 years, and smoking. Heavy alcohol consumption was a more positive contributor to decreased HDL-C than were other alcohol consumption levels. Conclusions Habitual moderate-to-heavy alcohol consumption may cause a significant decrease in serum HDL-C in middle-aged women, which may be modified by concomitant factors.

Rethinking HDL-C: An In-Depth Narrative Review of Its Role in Cardiovascular Health

The interplay between HDL-C and LDL levels are closely intertwined with the cardiovascular system. High-Density Lipoprotein Cholesterol (HDL-C) is a well-known biomarker traditionally being interpreted as higher the HDL-C levels, minimal the risk of adverse cardiovascular disease (CVD) outcomes. However, recent research has unveiled a more complex relationship between HDL-C levels and cardiovascular outcomes, including genetic influences and potential risks associated with extremely high HDL-C levels. Intriguingly, extremely high HDL-C levels have been linked to unexpected cardiovascular risks. Up To date research suggests that individuals with genetically linked ultra-high HDL-C levels may depict an increased susceptibility to CVD, challenging the conventional realm that higher HDL-C is always beneficial. The mechanisms underlying this mystery are not fully understood but may involve HDL particle functionality and composition. In a nutshell, the relationship between HDL-C levels and cardiovascular outcomes is multifactorial. While low HDL-C remains a recognized risk factor for CVD, the genetic determinants of HDL-C levels add complexity to this association. Furthermore, extremely high HDL-C levels may not exhibit the expected protective benefits and may even pose unprecedented cardiovascular risks. A comprehensive understanding of these dynamics is essential for advancing our knowledge of CVD risk assessment and developing targeted therapeutic interventions. Further studies are needed to unravel the intricacies of HDL-C's role in cardiovascular health and disease.

Does Elevated High-Density Lipoprotein Cholesterol Protect Against Cardiovascular Disease?

High-density lipoprotein (HDL) contributes to reverse cholesterol transport, which is 1 of the main explanations for the described inverse association between HDL-cholesterol (HDL-C) and atherosclerotic cardiovascular disease (ASCVD) risk. However, efforts to therapeutically raise HDL-C levels with niacin, fibrates, or cholesteryl ester transfer protein inhibitors have not demonstrated a reduction in ASCVD events when compared with placebo among individuals treated with statins. Furthermore, mendelian randomization studies suggest that HDL-C is unlikely to be a direct biologic variable impacting ASCVD risk. More recently, observations from well-conducted epidemiologic studies have indicated a nonlinear U-shaped relationship between HDL-C and subclinical atherosclerosis, and that very high HDL-C (≥80 mg/dL in men, ≥100 mg/dL in women) is paradoxically associated with higher all-cause and ASCVD-related mortality. These observations suggest that HDL-C is not a universal protective factor for atherosclerosis. Thus, there are several opportunities for reframing the contribution of HDL-C to ASCVD risk and related clinical calculators. Here, we examine our growing understanding of HDL-C and its role in ASCVD risk assessment, treatment, and prevention. We discuss the biological functions of HDL-C and its normative values in relation to demographics and lifestyle markers. We then summarize original studies that observed a protective association between HDL-C and ASCVD risk and more recent evidence indicating an elevated ASCVD risk at very high HDL-C levels. Through this process, we advance the discussion regarding the future role of HDL-C in ASCVD risk assessment and identify knowledge gaps pertaining to the precise role of HDL-C in atherosclerosis and clinical ASCVD.

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).

High-Density Lipoprotein Cholesterol in Atherosclerotic Cardiovascular Disease Risk Assessment: Exploring and Explaining the "U"-Shaped Curve

PURPOSE OF REVIEW

Review updates for the association of HDL-cholesterol with atherosclerotic cardiovascular disease (ASCVD) and discuss the approach to incorporating HDL-cholesterol within risk assessment.

RECENT FINDINGS

There is a U-shaped relationship between HDL-cholesterol and ASCVD. Both low HDL-cholesterol (< 40 mg/dL in men, < 50 mg/dL in women) and very-high HDL-cholesterol (≥ 80 mg/dL in men) are associated with a higher risk of all-cause and ASCVD mortality, independent from traditional risk factors. There has been inconsistency for the association between very-high HDL-cholesterol and mortality outcomes in women. It is uncertain whether HDL-cholesterol is a causal ASCVD risk factor, especially due to mixed results from Mendelian randomization studies and the collinearity of HDL-cholesterol with established risk factors, lifestyle behaviors, and socioeconomic status. HDL-cholesterol is a risk factor or risk enhancer in primary prevention and high-risk condition in secondary prevention when either low (men and women) or very-high (men). The contribution of HDL-cholesterol to ASCVD risk calculators should reflect its observed U-shaped association with all-cause and ASCVD mortality.

Relationship of serum lipid parameters with kidney function decline accompanied by systemic arterial stiffness: a retrospective cohort study

Background

Dyslipidemia is associated with kidney function decline (KFD), although the non-linear relationship of lipid parameters to KFD has not been fully elucidated. We aimed to determine the detailed relationship of baseline lipid parameters with KFD, considering the mediation of arterial stiffness.

Methods

A total of 27 864 urban residents with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 at baseline, who participated in a median of three (range two to eight) consecutive annual health examinations were studied. Arterial stiffness was assessed by cardio-ankle vascular index (CAVI). KFD was defined as development of eGFR <60 mL/min/1.73 m2.

Results

During the study period, 1837 participants (6.6%) developed KFD. Receiver operating characteristic analysis determined that the cutoff values independently associated with KFD are 123 mg/dL for low-density lipoprotein cholesterol (LDL-C) [area under the curve (95% confidence interval) 0.570 (0.557-0.583)], 65 mg/dL for high-density lipoprotein cholesterol (HDL-C) [0.552 (0.539-0.566)], 82 mg/dL for triglycerides (TG) [0.606 (0.593-0.618)] and 1.28 for TG/HDL-C ratio [0.600 (0.587-0.612)]. These cut-offs were independently associated with KFD in Cox analysis. Regarding the contribution of each lipid parameter to KFD, a linear relationship was observed for both TG and TG/HDL-C, and a U-shaped relationship for HDL-C. A adjusted mediating effect of CAVI on the relationship of TG or TG/HDL-C ratio with KFD was observed (mediating rate: 2.9% in TG, 2.5% in TG/HDL-C ratio). Regarding the association to KFD, a linear relationship was observed for both TG and TG/HDL-C, and a U-shaped relationship for HDL-C. A mediating effect of CAVI on the relationship of TG or TG/HDL-C ratio with KFD was observed after adjustment for confounders.

Conclusions

TG and TG/HDL-C ratio related linearly to KFD and this was partially mediated by CAVI. A U-shaped relationship was observed between HDL-C and KFD risk. LDL-C showed no significant association. Further study should investigate whether intensive TG-lowering treatment prevents KFD via decreasing CAVI.

Relationship Between Time-Varying Achieved High-Density Lipoprotein Cholesterol and Risk of Coronary Events Depends on Haptoglobin Phenotype Within the ACCORD Lipid Study

Background The Hp (haptoglobin)2-2 phenotype (~40% of people) is associated with dysfunctional high-density lipoprotein (HDL) that is heavily oxidized in hyperglycemia, which may explain why raising HDL-cholesterol (HDL-C) does not reliably prevent coronary artery disease (CAD) in diabetes. Methods and Results In this observational study using longitudinal data from the ACCORD (Action to Control Cardiovascular Risk in Diabetes) lipid trial, time-varying (achieved) HDL-C updated at 4, 8, and 12 months, and annually thereafter over a mean of 4.7 years, was analyzed in relation to risk of CAD and secondary outcomes using Cox proportional hazards regression with time-varying covariables among participants with (n=1781) and without (n=3191) the Hp2-2 phenotype. HDL-C did not differ between the phenotypes throughout the study. Having low HDL-C (<40 mg/dL for male participants and <50 mg/dL for female participants) was associated with a greater risk of CAD compared with non-low HDL-C among participants with the non-Hp2-2 phenotype (hazard ratio [HR], 1.48 [95% CI, 1.18-1.87]) but not among the Hp2-2 phenotype (HR, 0.97 [95% CI, 0.70-1.35]; P interaction=0.03). Similarly, an inverse relationship was observed between HDL-C quintiles and CAD risk among participants without the Hp2-2 phenotype, whereas no significant inverse relationship was observed among participants with the Hp2-2 phenotype (P interaction=0.38). Among the Hp2-2 phenotype group, having low HDL-C was associated with higher risk of CVD mortality (HR, 2.09 [95% CI, 1.05-4.13]), and compared with the lowest HDL-C quintile, higher quintiles were associated with lower risk of CVD mortality and congestive heart failure. Conclusions Hp phenotype modified the association between HDL-C and risk of CAD in the ACCORD lipid study, suggesting that HDL dysfunction in the Hp2-2 phenotype may hinder CAD-protective properties of HDL-C.

Cell-free, high-density lipoprotein-specific phospholipid efflux assay predicts incident cardiovascular disease

BACKGROUNDCellular cholesterol efflux capacity (CEC) is a better predictor of cardiovascular disease (CVD) events than HDL-cholesterol (HDL-C) but is not suitable as a routine clinical assay.METHODSWe developed an HDL-specific phospholipid efflux (HDL-SPE) assay to assess HDL functionality based on whole plasma HDL apolipoprotein-mediated solubilization of fluorescent phosphatidylethanolamine from artificial lipid donor particles. We first assessed the association of HDL-SPE with prevalent coronary artery disease (CAD): study I included NIH severe-CAD (n = 50) and non-CAD (n = 50) participants, who were frequency matched for sex, BMI, type 2 diabetes mellitus, and smoking; study II included Japanese CAD (n = 70) and non-CAD (n = 154) participants. We also examined the association of HDL-SPE with incident CVD events in the Prevention of Renal and Vascular End-stage Disease (PREVEND) study comparing 340 patients with 340 controls individually matched for age, sex, smoking, and HDL-C levels.RESULTSReceiver operating characteristic curves revealed stronger associations of HDL-SPE with prevalent CAD. The AUCs in study I were as follows: HDL-SPE, 0.68; apolipoprotein A-I (apoA-I), 0.62; HDL-C, 0.63; and CEC, 0.52. The AUCs in study II were as follows: HDL-SPE, 0.83; apoA-I, 0.64; and HDL-C, 0.53. Also longitudinally, HDL-SPE was significantly associated with incident CVD events independent of traditional risk factors with ORs below 0.2 per SD increment in the PREVEND study (P < 0.001).CONCLUSIONHDL-SPE could serve as a routine clinical assay for improving CVD risk assessment and drug discovery.TRIAL REGISTRATIONClinicalTrials.gov NCT01621594.FUNDINGNHLBI Intramural Research Program, NIH (HL006095-06).

Pre-diagnosis lipid levels and mortality after obesity-related cancer diagnosis in the Women's Health Initiative cardiovascular disease biomarker cohort

BACKGROUND

Published studies have demonstrated inconclusive relationships between serum lipid levels and mortality after cancer.

METHODS

The primary objective was to evaluate the relationship between fasting lipid levels and mortality after cancer. Data were obtained on baseline lipids and outcomes after cancer from 1263 postmenopausal women diagnosed with 13 obesity-related cancers who were part of the Women's Health Initiative (WHI) lipid biomarkers cohort. Obesity-related cancers included incident invasive cancers of the breast, colorectum, endometrium, esophagus (adenocarcinoma), kidney, liver, gallbladder, pancreas, ovaries, small intestine, thyroid, stomach, as well as multiple myeloma. Baseline lipid measurements included high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and non-HDL-cholesterol. Outcomes were all cause, cancer-specific, and CVD mortality. Multivariable Cox proportional hazards models were used to measure associations between lipid levels and mortality (all cause, cancer, and CVD) after a cancer diagnosis, with lipids analyzed as continuous variables.

RESULTS

Among women with obesity-related cancer, there were 707 deaths, of which 379 (54%) were due to cancer and 113 (16%) were due to CVD. Mean time from blood draw to cancer diagnosis was 5.1 years (range: 0.05-10 years). LDL-C values above the 95th percentile were associated with higher risk of all-cause mortality (p < 0.001), and cancer-specific mortality (p < 0.001), but not mortality due to CVD. Non-HDL-C values above the 65th percentile were associated with higher risk of all-cause mortality (p = 0.01) and mortality due to CVD (p = 0.003), but not cancer-specific mortality (p = 0.37). HDL-C values above the 95th percentile were associated with lower all-cause mortality (p = 0.002), and above the 65th percentile with lower cancer-specific mortality (p = 0.003), but no significant relationship with mortality due to CVD was observed.

CONCLUSIONS

The relationship between pre-diagnosis fasting lipid levels and mortality after cancer diagnosis is complex. These results suggest that improved lipid control through lifestyle and anti-lipid medications could have a meaningful impact on outcomes after cancer.

Continuous and Marked Increase of Japanese HDL Associates Paradoxically with their Nutritional Shift

AIMS

Plasma HDL has evidently increased for decades among Japanese, exclusively in HDL particles containing apoA-I but not A-II. Its metabolic background is yet to be elucidated.

METHODS

Trends in plasma lipoproteins were analyzed by examining data on total cholesterol, triglyceride and HDL-cholesterol, which are available in the public database of the National Health and Nutrition Examination Survey of Japan (NHNESJ) and in the clinical data of SRL Co., from 1989 to 2019, estimating cholesterol (C) in non-HDL, VLDL, LDL, and sub-fractions of LDL using the equations by Sampson et al. Food intake and supply data in NHNSJ and in the UN Food and Agriculture Organization were also analyzed in relation to the lipoprotein analysis.

RESULTS

HDL-C levels showed a steady increase in men and women throughout the period as per the data retrieved in NHNSJ and SRL data. It is noted to be higher in women than men (from 46.8 to 52.7, and from 58.4 to 68.3 in mg/dl, respectively). Triglyceride and VLDL-C were higher in men but sex difference was not apparent in non-HDL-C and LDL-C levels, while these parameters slightly decreased in both sexes. The increase in HDL was most prominent in women in the age of 50 - 59 (from 57.0 to 73.4). The age-dependent HDL trend was reversed among women during the study period, as increasing instead of decreasing. This increase in HDL was found to coincide with lowered fish/meat ratio in food intake among Japanese.

CONCLUSION

Marked increase in plasma HDL among Japanese is age- and sex-dependent and exhibited an apparent paradoxical association with lowered fish/meat ratio in their diet. Further investigation is required to elucidate the background for these findings.

Achieved low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio predicts the pathophysiological evolution of lipid-rich plaques in acute coronary syndromes: an optical coherence tomography study

Background

As a novel lipoprotein ratio, baseline low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (LHR) is closely related to the clinical outcomes of acute coronary syndromes (ACS) after percutaneous coronary intervention. However, the pathophysiological impact of achieved LHR (aLHR) on the evolution of non-culprit lipid-rich plaques has not been systematically explored.

Methods

Between September 2013 and December 2018, ACS patients with both baseline and 1-year follow-up optical coherence tomography (OCT) examinations were included in current study. They were divided into two groups according to the median value of aLHR at 1 year.

Results

Overall, 132 patients with 215 lipid-rich plaques were enrolled, with a median aLHR: 1.62. There were thinner fibrous cap thickness (FCT) (133.3 [70.0-180.0] µm vs. 160.0 [100.0-208.3] µm, p = 0.025) and higher prevalence of thin-cap fibroatheroma (TCFA) (24 [22.4%] vs. 13 [12.0%], p = 0.044) and CLIMA-defined high-risk plaques (12 [11.2%] vs. 3[2.8%], p = 0.015) in the high aLHR group at 1 year. Compared with other serum lipid indexes, aLHR showed the best robust correlation with the evolution of plaque vulnerability in both unadjusted and adjusted analyses. Cut-off value of aLHR to predict the progression of maximal lipid arc and FCT was 1.51. In the adjusted model, aLHR ≥1.51 was an independent predictor of TCFA [odds ratio (OR): 3.008, 95% CI: 1.370 to 6.605, p = 0.006] at 1 year.

Conclusions

aLHR correlates well with the evolution of lipid-rich plaques and vulnerable phenotypes at 1-year follow-up, which might be an important and convenient serum indicator in the secondary prevention of ACS.

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.

Endothelial Function in Dyslipidemia: Roles of LDL-Cholesterol, HDL-Cholesterol and Triglycerides

Dyslipidemia is associated with endothelial dysfunction. Endothelial dysfunction is the initial step for atherosclerosis, resulting in cardiovascular complications. It is clinically important to break the process of endothelial dysfunction to cardiovascular complications in patients with dyslipidemia. Lipid-lowering therapy enables the improvement of endothelial function in patients with dyslipidemia. It is likely that the relationships of components of a lipid profile such as low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides with endothelial function are not simple. In this review, we focus on the roles of components of a lipid profile in endothelial function.

The association between HDL-C and stroke in the middle-aged and elderly: A cross-sectional study

BACKGROUND

Previous epidemiological studies have indicated that high-density lipoprotein cholesterol (HDL-C) is inversely associated with the risk of cardiovascular disease. However, this issue has aroused controversy in recent years. Besides, the relationship between HDL-C and the risk of total stroke in sex and race is less clear. Thus, we aimed to examine the association between different ranges of HDL-C and the risk of total stroke in adults over 40 years old.

METHODS

This cross-sectional study was conducted on a sample of 8643 participants (4222 men and 4421 women) aged ≥40 years old from the National Health and Nutrition Examination Survey 2007-2016. HDL-C was an independent variable and stroke was a dependent variable in this study, with the other variables as potential effect modifiers. To examine the associations between them, we used multivariate logistical regression models and smooth curve fittings, as well as subgroup analyses.

RESULTS

HDL-C was inversely associated with stroke when HDL-C was less than 1.55 mmol/L (odds ratio [OR] = 0.36, 95% confidence interval [CI] :0.21-0.62, p < .05). However, above 1.55 mmol/L, the incidence of stroke was not significant (OR = 1.29, 95% CI: 0.79-2.09, p>.05). Stratified by race/ethnicity and sex, the subgroup analyses demonstrated that HDL-C was inversely associated with stroke in men and Whites, but no significant differences among women, Mexicans, blacks, and other races.

CONCLUSION

We found a nonlinear relationship between HDL-C and total stroke. Our study reveals a range of inverse associations between HDL-C and stroke (HDL-C<1.55 mmol/L), especially among men and Whites. This finding suggested that maintaining an appropriate HDL-C range may be beneficial in reducing the incidence of stroke.

HDL Functions-Current Status and Future Perspectives

Cardiovascular disease (CVD) is the leading cause of death in Western countries. A low HDL-C is associated with the development of CVD. However, recent epidemiology studies have shown U-shaped curves between HDL-C and CVD mortality, with paradoxically increased CVD mortality in patients with extremely high HDL-C levels. Furthermore, HDL-C raising therapy using nicotinic acids or CETP inhibitors mostly failed to reduce CVD events. Based on this background, HDL functions rather than HDL-C could be a novel biomarker; research on the clinical utility of HDL functionality is ongoing. In this review, we summarize the current status of HDL functions and their future perspectives from the findings of basic research and clinical trials.

Development and validation of ischemic heart disease and stroke prognostic models using large-scale real-world data from Japan

BACKGROUND

Previous cardiovascular risk prediction models in Japan have utilized prospective cohort studies with concise data. As the health information including health check-up records and administrative claims becomes digitalized and publicly available, application of large datasets based on such real-world data can achieve prediction accuracy and support social implementation of cardiovascular disease risk prediction models in preventive and clinical practice. In this study, classical regression and machine learning methods were explored to develop ischemic heart disease (IHD) and stroke prognostic models using real-world data.

METHODS

IQVIA Japan Claims Database was searched to include 691,160 individuals (predominantly corporate employees and their families working in secondary and tertiary industries) with at least one annual health check-up record during the identification period (April 2013-December 2018). The primary outcome of the study was the first recorded IHD or stroke event. Predictors were annual health check-up records at the index year-month, comprising demographic characteristics, laboratory tests, and questionnaire features. Four prediction models (Cox, Elnet-Cox, XGBoost, and Ensemble) were assessed in the present study to develop a cardiovascular disease risk prediction model for Japan.

RESULTS

The analysis cohort consisted of 572,971 invididuals. All prediction models showed similarly good performance. The Harrell's C-index was close to 0.9 for all IHD models, and above 0.7 for stroke models. In IHD models, age, sex, high-density lipoprotein, low-density lipoprotein, cholesterol, and systolic blood pressure had higher importance, while in stroke models systolic blood pressure and age had higher importance.

CONCLUSION

Our study analyzed classical regression and machine learning algorithms to develop cardiovascular disease risk prediction models for IHD and stroke in Japan that can be applied to practical use in a large population with predictive accuracy.

Additive Effects of Drinking Habits and a Susceptible Genetic Polymorphism on Cholesterol Efflux Capacity

AIMS

High levels of high-density lipoprotein cholesterol (HDL-C) are not necessarily effective in preventing atherosclerotic cardiovascular disease, and cholesterol efflux capacity (CEC) has attracted attention regarding HDL functionality. We aimed to elucidate whether drinking habits are associated with CEC levels, while also paying careful attention to confounding factors including serum HDL-C levels, other life style factors, and rs671 (^＊2), a genetic polymorphism of the aldehyde dehydrogenase 2 (ALDH2) gene determining alcohol consumption habit.

METHODS

A cross-sectional study was performed in 505 Japanese male subjects who were recruited from a health screening program. Associations of HDL-C and CEC levels with drinking habits and ALDH2 genotypes were examined.

RESULTS

The genotype frequencies of ALDH2 ^＊1/^＊1 (homozygous wild-type genotype), ^＊1/^＊2 and ^＊2/^＊2 (homozygous mutant genotype) were 55%, 37% and 8%, respectively. Both HDL-C and CEC levels were higher in ALDH2 ^＊1/^＊1 genotype carriers than in ^＊2 allele carriers. Although HDL-C levels were higher in subjects who had a drinking habit than in non-drinkers, CEC levels tended to be lower in subjects with ≥ 46 g/day of alcohol consumption than in non-drinkers. Furthermore, CEC levels tended to be lower in ALDH2 ^＊1/^＊1 genotype carriers with a drinking habit of ≥ 46 g/day than non-drinkers, while for ^＊2 allele carriers, CEC levels tended to be lower with a drinking habit of 23-45.9 g/day compared to no drinking habit.

CONCLUSIONS

Our results suggest that heavy drinking habits may tend to decrease CEC levels, and in the ALDH2 ^＊2 allele carriers, even moderate drinking habits may tend to decrease CEC levels.

Longitudinal effects of lipid indices on incident cardiovascular diseases adjusting for time-varying confounding using marginal structural models: 25 years follow-up of two US cohort studies

Background

This study assesses the effect of blood lipid indices and lipid ratios on cardiovascular diseases (CVDs) using inverse probability-of-exposure weighted estimation of marginal structural models (MSMs).

Methods

A pooled dataset of two US representative cohort studies, including 16736 participants aged 42-84 years with complete information at baseline, was used. The effect of each lipid index, including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), ratios of TC/HDL-C, LDL-C/HDL-C, and TG/HDL-C on coronary heart disease (CHD) and stroke were estimated using weighted Cox regression.

Results

There were 1638 cases of CHD and 1017 cases of stroke during a median follow-up of 17.1 years (interquartile range: 8.5 to 25.7). Compared to optimal levels, the risk of CVD outcomes increased substantially in high levels of TC, LDL-C, TC/HDL-C, and LDL-C/HDL-C. If everyone had always had high levels of TC (≥240 mg/dL), risk of CHD would have been 2.15 times higher, and risk of stroke 1.35 times higher than if they had always had optimal levels (<200 mg/dL). Moreover, if all participants had been kept at very high (≥190 mg/dL) levels of LDL-C, risk of CHD would have been 2.62 times higher and risk of stroke would have been 1.92 times higher than if all participants had been kept at optimal levels, respectively. Our results suggest that high levels of HDL-C may be protective for CHD, but not for stroke. There was also no evidence of an adverse effect of high triglyceride levels on stroke.

Conclusions

Using MSM, this study highlights the effect of TC and LDL-C on CVD, with a stronger effect on CHD than on stroke. There was no evidence for a protective effect of high levels of HDL-C on stroke. Besides, triglyceride was not found to affect stroke.

BMI modifies HDL-C effects on coronary artery bypass grafting outcomes

BACKGROUND

Despite the recognized implications of high-density lipoprotein cholesterol (HDL-C) in cardiovascular diseases, the role of body mass index (BMI) in HDL-C association with cardiovascular outcomes remains unclear. This study investigated the possible modifying implications of BMI on the correlation between HDL-C and coronary artery bypass grafting (CABG) outcomes.

METHODS

The present cohort included isolated CABG patients (median follow-up: 76.58 [75.79-77.38] months). The participants were classified into three groups: 18.5 ≤ BMI < 25 (normal), 25 ≤ BMI < 30 (overweight), and 30 ≤ BMI < 35 (obese) kg/m². Cox proportional hazard models (CPHs) and restricted cubic splines (RCSs) were applied to evaluate the relationship between HDL-C and all-cause mortality as well as major adverse cardio-cerebrovascular events (MACCEs) in different BMI categories.

RESULTS

This study enrolled a total of 15,639 patients. Considering the final Cox analysis among the normal and overweight groups, HDL-C ≥ 60 was a significant protective factor compared to 40 < HDL-C < 60 for all-cause mortality (adjusted hazard ratio (aHR): 0.47, P: 0.027; and aHR: 0.64, P: 0.007, respectively). However, the protective effect of HDL-C ≥ 60 was no longer observed among patients with 30 ≤ BMI < 35 (aHR: 1.16, P = 0.668). RCS trend analyses recapitulated these findings; among 30 ≤ BMI < 35, no uniform inverse linear association was observed; after approximately HDL-C≈55, its increase was no longer associated with reduced mortality risk. RCS analyses on MACCE revealed a plateau effect followed by a modest rise in overweight and obese patients from HDL-C = 40 onward (nonlinear association).

CONCLUSIONS

Very high HDL-C (≥ 60 mg/dL) was not related to better outcomes among obese CABG patients. Furthermore, HDL-C was related to the post-CABG outcomes in a nonlinear manner, and the magnitude of its effects also differed across BMI subgroups.

High HDL (High-Density Lipoprotein) Cholesterol Increases Cardiovascular Risk in Hypertensive Patients

BACKGROUND

Emerging evidence suggests that elevated circulating levels of HDL-C (high-density lipoprotein cholesterol) could be linked to an increased mortality risk. However, to the best of our knowledge, the relationship between HDL-C and specific cardiovascular events has never been investigated in patients with hypertension.

METHODS

To fill this knowledge gap, we analyzed the relationship between HDL-C levels and cardiovascular events in hypertensive patients within the Campania Salute Network in Southern Italy.

RESULTS

We studied 11 987 patients with hypertension, who were followed for 25 534 person-years. Our population was divided in 3 groups according to the HDL-C plasma levels: HDL-C<40 mg/dL (low HDL-C); HDL-C between 40 and 80 mg/dL (medium HDL-C); and HDL-C>80 mg/dL (high HDL-C). At the follow-up analysis, adjusting for potential confounders, we observed a total of 245 cardiovascular events with a significantly increased risk of cardiovascular events in the low HDL-C group and in the high HDL-C arm compared with the medium HDL-C group. The spline analysis revealed a nonlinear U-shaped association between HDL-C levels and cardiovascular outcomes. Interestingly, the increased cardiovascular risk associated with high HDL-C was not confirmed in female patients.

CONCLUSIONS

Our data demonstrate that there is a U-shaped association between HDL-C and the risk of cardiovascular events in male patients with hypertension.

Integrating Health Data-Driven Machine Learning Algorithms to Evaluate Risk Factors of Early Stage Hypertension at Different Levels of HDL and LDL Cholesterol

Purpose: Cardiovascular disease (CVD) is a major worldwide health burden. As the risk factors of CVD, hypertension, and hyperlipidemia are most mentioned. Early stage hypertension in the population with dyslipidemia is an important public health hazard. This study was the application of data-driven machine learning (ML), demonstrating complex relationships between risk factors and outcomes and promising predictive performance with vast amounts of medical data, aimed to investigate the association between dyslipidemia and the incidence of early stage hypertension in a large cohort with normal blood pressure at baseline. Methods: This study analyzed annual health screening data for 71,108 people from 2005 to 2017, including data for 27 risk-related indicators, sourced from the MJ Group, a major health screening center in Taiwan. We used five machine learning (ML) methods—stochastic gradient boosting (SGB), multivariate adaptive regression splines (MARS), least absolute shrinkage and selection operator regression (Lasso), ridge regression (Ridge), and gradient boosting with categorical features support (CatBoost)—to develop a multi-stage ML algorithm-based prediction scheme and then evaluate important risk factors at the early stage of hypertension, especially for groups with high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels within or out of the reference range. Results: Age, body mass index, waist circumference, waist-to-hip ratio, fasting plasma glucose, and C-reactive protein (CRP) were associated with hypertension. The hemoglobin level was also a positive contributor to blood pressure elevation and it appeared among the top three important risk factors in all LDL-C/HDL-C groups; therefore, these variables may be important in affecting blood pressure in the early stage of hypertension. A residual contribution to blood pressure elevation was found in groups with increased LDL-C. This suggests that LDL-C levels are associated with CPR levels, and that the LDL-C level may be an important factor for predicting the development of hypertension. Conclusion: The five prediction models provided similar classifications of risk factors. The results of this study show that an increase in LDL-C is more important than the start of a drop in HDL-C in health screening of sub-healthy adults. The findings of this study should be of value to health awareness raising about hypertension and further discussion and follow-up research.

Serum Cholesterol Levels and Risk of Cardiovascular Death: A Systematic Review and a Dose-Response Meta-Analysis of Prospective Cohort Studies

Introduction: Numerous studies have demonstrated that abnormal levels of cholesterol are associated with a high attributable risk for the occurrence of cardiovascular disease (CVD). However, there has been no comprehensive study to investigate the relationship between serum cholesterol levels and cardiovascular mortality. Therefore, we conducted a systematic review and dose-response meta-analysis. Methods: A systematic literature search of key databases, including EMBASE and MEDLINE, was conducted and included all the published epidemiological studies that contained estimates of the hazard ratios (HR) of serum cholesterol of CVD mortality. Data extraction, eligibility, and assessment of the risk of bias were assessed by two reviewers independently. All published risk estimates were hazard ratios and analyzed by quantitative meta-analysis using a random-effects model and dose-response relationships of serum cholesterol with CVD mortality. Results: A total of 14 independent reports, including 1,055,309 subjects and 9457 events, were analyzed. The pooled HR (95% CI) was 1.27 (95% CI, 1.19–1.36) for total cholesterol, 1.21 (95% CI, 1.09–1.35) for low-density lipoprotein cholesterol (LDL-C), and 0.60 (95% CI, 0.50–0.72) for high-density lipoprotein cholesterol (HDL-C). We observed a linear association between serum cholesterol (TC, HDL-C) levels and CVD mortality in this meta-analysis. Conclusions: Serum total cholesterol and LDL-C level is associated with increased CVD mortality, but HDL-C level is inversely associated with CVD mortality.

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.

HDL and Cholesterol Ester Transfer Protein (CETP)

Cholesterol ester transfer protein (CETP) is important clinically and is one of the major targets in cardiovascular disease studies. With high conformational flexibility, its tunnel structure allows unforced movement of high-density lipoproteins (HDLs), VLDLs, and LDLs. Research in reverse cholesterol transports (RCT) reveals that the regulation of CETP activity can change the concentration of cholesteryl esters (CE) in HDLs, VLDLs, and LDLs. These molecular insights demonstrate the mechanisms of CETP activities and manifest the correlation between CETP and HDL. However, animal and cell experiments focused on CETP give controversial results. Inhibiting CETP is found to be beneficial to anti-atherosclerosis in terms of increasing plasma HDL-C, while it is also claimed that CETP weakens atherosclerosis formation by promoting RCT. Currently, the CETP-related drugs are still immature. Research on CETP inhibitors is targeted at improving efficacy and minimizing adverse reactions. As for CETP agonists, research has proved that they also can be used to resist atherosclerosis.

High-Density Lipoprotein Is Associated with Leukoaraiosis Severity in Patients with Acute Ischemic Stroke

Many patients with acute ischemic stroke (AIS) are found to accompany with leukoaraiosis (LA) in brain imaging. The risk factors of LA in patients with AIS were examined in this study. Patients with AIS were recruited and underwent head magnetic resonance imaging. According to Fazekas scores, patients were divided into LA group and non-LA group. We compared demographic and laboratory characteristics in two groups. Multivariate logistic regression analysis demonstrated that high-density lipoprotein (HDL), age, stroke history, admission SBP, and homocysteine were independent risk factors for LA in patients with AIS (P < 0.05). Multinomial logistic regression analysis demonstrated that HDL was an independent risk factor for moderate LA (OR 4.151, 95% CI 1.898-9.078, P < 0.001) and severe LA (OR 3.151, 95% CI 1.350-7.358, P = 0.008). In order to further explore the correlation between HDL level and the severity of LA, HDL was categorized in quartiles and multinomial logistic regression analysis was presented. Regression analysis showed that HDL ≥ 1.34 mmol/L was correlated with moderate and severe LA after adjusting for corresponding confounding factors in different models. After 1-year follow-up, patients were divided into regular statin therapy group and irregular statin therapy group. There was no significant difference in HDL level between two groups; however, the proportion of patients with increased Fazekas scores in regular statin therapy group was significantly less than that in the irregular statin therapy group (P < 0.05). In conclusion, HDL was an independent risk factor for LA and associated with the severity of LA in patients with AIS; regular statin therapy may be negatively related with the progress of LA. These results provide more evidences for controlling risk factors and severity of LA in patient with AIS.

A dose-response meta-analysis to evaluate the relationship between high-density lipoprotein cholesterol and all-cause and cardiovascular disease mortality

PURPOSE

Previous studies have not fully described the relationship between high-density lipoprotein cholesterol (HDL-C) and death risks from all cause and cardiovascular disease (CVD). This study quantitatively evaluates HDL-C-mortality associations.

METHODS

Embase and PubMed databases were searched for relevant articles published up to 1 June 2019. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs). We used restricted cubic splines to model the dose-response association.

RESULTS

We identified 32 prospective cohort studies including 369,904 participants and 33,473 total deaths (9426 CVD deaths). Compared to the lowest HDL-C levels, all cause and CVD mortality risks were reduced by 18% (RR 0.82; 95% CI, 0.73-0.93) and 36% (0.64, 0.46-0.89), respectively, for the highest HDL-C levels. All cause and CVD mortality risks were reduced by 15% (0.85, 0.79-0.92) and 23% (0.77, 0.69-0.87), respectively, with each 1 mmol/L increment of HDL-C. We found evidence of nonlinear and negative dose-response associations of HDL-C with all cause and CVD mortality (P_nonlinearity < 0.001), and the lowest death risks from all cause and CVD were observed at approximately 1.34 and 1.55 mmol/L, respectively.

CONCLUSION

HDL-C is inversely associated with all cause and CVD mortality risks under approximately 2.05 and 2.33 mmol/L, respectively. Optimal doses require investigation via clinical practice or high-quality research.

U-Shaped Relationship of High-Density Lipoprotein Cholesterol and Incidence of Total, Ischemic and Hemorrhagic Stroke: A Prospective Cohort Study

BACKGROUND

We aimed to investigate the association between serially measured HDL-C (high-density lipoprotein cholesterol) levels and stroke risk in a prospective cohort study.

METHODS

We included 96 258 individuals (79.6% men, mean age 51.5 years) without a history of stroke, myocardial infarction, or cancer at baseline from the Kailuan Study, with repeated measurements of HDL-C in 2006, 2008, 2010, 2012, 2014, and 2016. Cumulatively, averaged HDL-C concentrations were calculated using all available HDL-C measurements before incidence stroke or end of follow-up (December 31, 2017). Incident stroke cases were confirmed by review of medical records and further subclassified into ischemic or hemorrhagic stroke. Cox proportional hazards regression and restricted cubic splines were used to examine these associations.

RESULTS

During a median follow-up of 10.7 years, 5012 incident stroke cases occurred. Restricted cubic splines analysis suggested a U-shaped association between concentrations of cumulatively averaged HDL-C and risk of stroke (P_nonlinearity <0.001), with the nadir of risk at 1.29 mmol/L. After adjustment for cardiovascular risk factors, individuals with cumulatively averaged HDL-C ≤1.06 mmol/L or ≥2.05 mmol/L had hazard ratios for total stroke of 1.31 (95% CI, 1.15-1.49) and 1.85 (1.63-2.09) compared with those with HDL-C of 1.26 to 1.39 mmol/L. Corresponding hazard ratios were 1.29 (1.11-1.48) and 1.84 (1.60-2.11) for ischemic stroke and 1.54 (1.12-2.12) and 2.29 (1.73-3.04) for hemorrhagic stroke, respectively.

CONCLUSIONS

Both low and high cumulatively averaged HDL-C were associated with an increased risk of ischemic and hemorrhagic strokes.

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.

Prediction of Lifetime Risk of Cardiovascular Disease Deaths Stratified by Sex in the Japanese Population

Background

Lifetime risk is an informative estimate for driving lifestyle and behavioral changes especially for young adults. The impact of composite risk factors for cardiovascular disease on lifetime risk stratified by sex has not been investigated in the Japanese population, which has a much lower mortality of coronary heart disease compared with the Western population. We aimed to estimate lifetime risk of death from cardiovascular disease attributable to traditional risk factors.

Methods and Results

We analyzed pooled individual data from the Evidence for Cardiovascular Prevention from Observational Cohorts in a Japanese cohort study. A modified Kaplan–Meier approach was used to estimate the remaining lifetime risk of cardiovascular death. In total, 41 002 Japanese men and women with 537 126 person‐years of follow‐up were included. The lifetime risk at the index‐age of 45 years for those with optimal risk factors (total cholesterol <4.65 mmol/L, systolic blood pressure <120 mm Hg, diastolic blood pressure <80 mm Hg, absence of diabetes, and absence of smoking habit) was lower compared with the highest risk profile of ≥2 risk factors (6.8% [95% CI, 0%–11.9%] versus 19.4% [16.7%–21.4%] for men and 6.9% [1.2%–11.5%] versus 15.4% [12.6%–18.1%] for women).

Conclusions

The magnitude and the number of risk factors were progressively associated with increased lifetime risk even in individuals in early adulthood who tend to have low short‐term risk. The degree of established cardiovascular risk factors can be converted into lifetime risk. Our findings may be useful for risk communication in the early detection of future cardiovascular disease risk.

Novel cholesterol efflux assay using immobilized liposome-bound gel beads: Confirmation and improvement for application in clinical laboratory

OBJECTIVES

Cholesterol efflux capacity (CEC), an atheroprotective function of high-density lipoprotein, is expected to be a potential biomarker for cardiovascular disease. However, CEC has not been widely introduced for application in clinical laboratories because of the complexity of the conventional CEC assay using cells and radioactive materials. Previously, we developed a novel CEC assay using immobilized liposome-bound gel beads (ILG), which solves these issues. We aimed to confirm the validation and further improve the ILG method for application in the clinical setting.

METHODS

Cholesterol efflux capacity values by the ILG method assayed for shorter incubation time (4 h) were compared to those assayed for 16 h (our previous ILG method). To investigate a reference material that can correct the variation between ILG manufacturing lots, bovine serum albumin, human gamma-globulins, and globulin complexes were evaluated. CEC values were also estimated in plasmas obtained with different anticoagulants, serum treated with freeze-thaw cycles, and serum mixed with several interference substances.

RESULTS

The CEC of 4- and 16-h incubation times were well correlated. Globulin complexes may be used as a reference material. Plasma can be used as the specimen. The serum and stored temperature of the specimen did not largely affect CEC. Hemoglobin and chyle did not have an effect on CEC, whereas high-bilirubin serum showed elevated CEC. The effect of bilirubin was nearly canceled by subtracting basal fluorescence intensity.

CONCLUSIONS

Present ILG method further fulfills some requirements for application in clinical laboratory. Using this reliable simple method, evaluation for clinical significance of CEC is expected.

Association of Serum High-Density Lipoprotein Cholesterol with High Blood Pressures at Checkup: Results of Kanagawa Investigation of Total Checkup Data from the National Database-9 (KITCHEN-9)

BACKGROUND

although high-density lipoprotein has cardioprotective effects, the association between serum high-density lipoprotein cholesterol (HDL-C) and hypertension is poorly understood. Therefore, we investigated whether high and low concentrations of HDL-C are associated with high blood pressure (HBP) using a large healthcare dataset.

METHODS

in a community-based cross-sectional study of 1,493,152 Japanese people (830,669 men and 662,483 women) aged 40-74 years who underwent a health checkup, blood pressures automatically measured at healthcare center were investigated in nine HDL-C groups (20-110 mg/dL or over).

RESULTS

crude U-shaped relationship were observed between the nine HDL-C and blood pressures in both men and women. Logistic regression analysis showed left-to-right inverted J-shaped relationships between HDL-C and odds ratios for HBP (≥140/90 mmHg and/or pharmacotherapy), with lower limits of 90-99 mg/dL in both sexes, which were unchanged after adjusting for confounding factors. However, further adjustment for body mass index and serum triglyceride concentration revealed positive linear associations between HDL-C and HBP, although blunt U-shaped associations remained in nonalcohol drinkers.

CONCLUSION

both low and extremely high HDL-C concentrations are associated with HBP. The former association might be dependent on excess fat mass concomitant with low HDL-C, whereas the latter association may be largely dependent on frequent alcohol consumption.

High-density lipoproteins (HDL): Novel function and therapeutic applications

The failure of high-density lipoprotein (HDL)-raising agents to reduce cardiovascular disease (CVD) together with recent findings of increased cardiovascular mortality in subjects with extremely high HDL-cholesterol levels provide new opportunities to revisit our view of HDL. The concept of HDL function developed to explain these contradictory findings has recently been expanded by a role played by HDL in the lipolysis of triglyceride-rich lipoproteins (TGRLs) by lipoprotein lipase. According to the reverse remnant-cholesterol transport (RRT) hypothesis, HDL critically contributes to TGRL lipolysis via acquirement of surface lipids, including free cholesterol, released from TGRL. Ensuing cholesterol transport to the liver with excretion into the bile may reduce cholesterol influx in the arterial wall by accelerating removal from circulation of atherogenic, cholesterol-rich TGRL remnants. Such novel function of HDL opens wide therapeutic applications to reduce CVD in statin-treated patients, which primarily involve activation of cholesterol flux upon lipolysis.

ANGPTL3 and ANGPTL8 in Thai subjects with hyperalphalipoproteinemia and severe hypertriglyceridemia

BACKGROUND

The role of ANGPTL3 and ANGPTL8 in lipid regulation in patients with very high levels of HDL-cholesterol and triglyceride is unknown.

OBJECTIVE

We examined plasma levels of ANGPTL3 and ANGPTL8 in subjects with hyperalphalipoproteinemia (HALP) and in those with severe hypertriglyceridemia (HTG).

METHODS

Plasma ANGPTL3 and ANGPTL8 levels were measured by ELISA in 320 subjects, consisting of HALP subjects with HDL-cholesterol ≥100 mg/dl (n=90) and healthy controls (n=90) and subjects with triglyceride ≥886 mg/dl (n=89) and control subjects (n=51).

RESULTS

The mean plasma ANGPTL3 level was significantly higher in the HALP group compared to that of the controls (297 ± 112 ng/mL vs. 230 ± 100 ng/mL, p<0.001). Similarly, the mean plasma ANGPTL8 level was also higher in the HALP group (30 ± 11 ng/mL vs. 20 ± 8 ng/mL, p<0.001). Both ANGPTL3 and ANGPTL8 levels positively correlated with HDL-cholesterol levels. In the severe HTG group, plasma ANGPTL3 level was significantly higher than those in the control group (223 ± 105 ng/mL vs. 151 ± 60 ng/mL, p<0.001), but not ANGPTL8 (23 ± 20 ng/mL vs. 31 ± 23 ng/mL in controls, p=0.028). Only ANGPTL3, but not ANGPTL8, levels positively correlated with triglyceride levels.

CONCLUSION

Plasma level of ANGPTL3 was increased in both HALP and severe HTG whereas an increase in plasma level of ANGPTL8 was found only in HALP, and not in severe HTG, suggesting that both ANGPTL3 and ANGPTL8 might play distinct roles in lipid regulation on these two extremes of dyslipidemia.

Different associations between HDL cholesterol and cardiovascular diseases in people with diabetes mellitus and people without diabetes mellitus: a prospective community-based study

BACKGROUND

Experimental studies have found that the functionality of HDL cholesterol may be lost in the presence of diabetes mellitus (DM).

OBJECTIVES

We aimed to elucidate whether DM modified the association between HDL-cholesterol concentrations and cardiovascular disease (CVD) outcomes.

METHODS

Included were 91,354 Chinese adults (8244 participants with DM and 83,110 participants without DM) free of CVD or cancer at baseline (2006) and without use of lipid-lowering drugs at baseline and during follow-up. The primary endpoint of interest was a composite of CVDs (myocardial infarction, ischemic stroke, and hemorrhagic stroke). Cumulative average HDL-cholesterol concentrations were calculated from all available HDL-cholesterol measures at baseline (2006) and during the follow-up period (2008, 2010, 2012, and 2014).

RESULTS

During a mean of 10.4 y of follow-up, there were 5076 CVD events identified. There was a significant interaction between DM and HDL-cholesterol concentrations on CVD risk (Pinteraction = 0.003). The association between HDL-cholesterol concentrations and CVD followed a U-shaped curve in individuals without DM (Pnonlinearity < 0.001). The adjusted HR of CVD was 1.26 (95% CI: 1.07, 1.48) for HDL-cholesterol concentrations < 1.04 mmol/L and 1.76 (95% CI: 1.53, 2.03) for HDL-cholesterol concentrations > 2.07 mmol/L, relative to the lowest-risk group (HDL-cholesterol concentrations of 1.30-1.42 mmol/L). In participants with DM, higher HDL-cholesterol concentrations were associated with a higher risk of CVD, in a dose-response manner (Pnonlinearity = 0.44; Ptrend < 0.001). The adjusted HR of CVD was 1.62 (95% CI: 1.19, 2.20) for HDL-cholesterol concentrations >2.07 mmol/L, relative to HDL-cholesterol concentrations of 1.30-1.42 mmol/L.

CONCLUSIONS

High HDL-cholesterol concentrations were paradoxically associated with high risk of composite CVD outcomes in individuals with or without DM. However, low HDL-cholesterol concentrations failed to predict future CVD risk in individuals with DM.

Is a High HDL-Cholesterol Level Always Beneficial?

The specific interest concerning HDL cholesterol (HDL-C) is related to its ability to uptake and return surplus cholesterol from peripheral tissues back to the liver and, therefore, to its role in the prevention of cardiovascular diseases, such as atherosclerosis and myocardial infarction, but also transient ischemic attack and stroke. Previous epidemiological studies have indicated that HDL-C concentration is inversely associated with the risk of cardiovascular disease and that it can be used for risk prediction. Some genetic disorders are characterized by markedly elevated levels of HDL-C; however, they do not translate into diminished cardiovascular risk. The search of the potential causative relationship between HDL-C and adverse events has shifted the attention of researchers towards the composition and function of the HDL molecule/subfractions. HDL possesses various cardioprotective properties. However, currently, it appears that higher HDL-C is not necessarily protective against cardiovascular disease, but it can even be harmful in extremely high quantities.

High-density lipoprotein cholesterol and all-cause mortality by sex and age: a prospective cohort study among 15.8 million adults

BACKGROUND

The associations between high-density lipoprotein cholesterol (HDL-C) levels and all-cause mortality are unclear in young adults (<45 years) and in Asian populations.

METHODS

In total, 15 860 253 Korean adults underwent routine health examinations during 2009-10 and were followed until June 2018 for all-cause mortality. Hazard ratios (HRs) were calculated using Cox proportional hazard models.

RESULTS

During a mean 8.4 years of follow-up, 555 802 individuals died. U-curve associations were found between HDL-C levels and mortality, irrespective of sex or age. The HDL-C ranges associated with the lowest mortality were 40-59 and 50-69 mg/dL (1.03-1.54 and 1.29-1.80 mmol/L) in men aged <65 and ≥65 years, respectively, and the corresponding ranges were 40-69 and 50-79 mg/dL (1.03-1.80 and 1.29-2.06 mmol/L) in women aged <45 and ≥45 years, respectively. For HDL-C ranges of 60-149 mg/dL (1.55-3.86 mmol/L), each 39 mg/dL (1 mmol/L) increase in HDL-C was associated with higher mortality [men: HR = 1.39; 95% confidence interval (CI) = 1.36-1.42; women: HR = 1.15, 95% CI = 1.11-1.18], adjusting for age. These positive associations were generally stronger at younger than older ages, whereas inverse associations for HDL-C ranges <60 mg/dL (1.55 mmol/L) were strongest in middle age (45-64 years). The U-curve associations were generally unchanged after adjustment for various confounders.

CONCLUSIONS

Korean adults showed U-curve associations of HDL-C with mortality, regardless of sex, and age. Younger adults had a lower optimal range and a stronger positive association with mortality than older adults in the high HDL-C range. Even moderately high HDL-C levels are not necessarily a sign of good health, especially in young adults.