Effect of High-Density Lipoprotein Cholesterol Levels on Overall Survival and Major Adverse Cardiovascular and Cerebrovascular Events

Nonlinearity of the inverse relationship between high-density lipoprotein (HDL) cholesterol and incident cardiovascular risk: Is it time to revisit the "HDL hypothesis"?

BACKGROUND

Low levels of high-density lipoprotein cholesterol (HDL-C) are clearly associated with atherosclerotic cardiovascular disease (ASCVD), but the risk curve is not well defined, especially at very high and low HDL-C levels. Current proportional hazards prediction models assume inverse linearity of effect, which may not accurately represent risk at these levels.

SOURCES OF MATERIAL

Clinical inattention to risk associated with low HDL-C may derive from randomized controlled trials (RCTs) aimed at raising HDL-C, though most failed to reduce ASCVD events when combined with statin-based therapy. However, these prior trials enrolled patients with HDL-C levels largely in the 35-45 mg/dL range.

ABSTRACT OF FINDINGS

Mounting post hoc evidence from RCTsß as well as new genetic and observational data suggests that very low HDL-C (less than 30 or 35 mg/dL) may signal a further increase in incident cardiovascular events. Moreover, when HDL-C exceeds 90 mg/dL, monotonic reduction of ASCVD risk appears to reverse. Because a pervasively agnostic view of the importance of both very low and high levels of HDL-C now exists, consideration should be given to incorporating nonlinear effects of HDL-C into future risk prediction models such that very low HDL-C and/or very high HDL-C levels could be considered as new risk-enhancing factors to promote more optimal risk stratification.

CONCLUSION

When revision of the U.S. Cholesterol Guideline recommences, consideration should be directed to whether HDL-associated risk matches the assumptions of current statistical models. Thus, it may be both timely and opportune to revisit the "HDL Hypothesis" based on evolving scientific evidence.

Sex-based association between high-density lipoprotein cholesterol and adverse outcomes after coronary artery bypass grafting

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) is shown to be an independent protective factor against coronary artery diseases (CAD). Yet there are limited studies focusing on the association between HDL-C and coronary artery bypass graft (CABG) surgery outcomes.

HYPOTHESIS

Low levels of HDL-C are associated with higher incidence of adverse outcomes in patients undergoing CABG.

METHODS

This registry-based study included 17,772 patients who underwent elective isolated CABG between 2007 and 2017. Patients were classified into low and desirable HDL-C groups based on their serum HDL-C levels at admission and were followed for one-year post-surgery. The study population included 13,321 patients with low HDL-C and 4,451 with desirable HDL-C. proportional hazard Cox models were performed to evaluate the association between HDL-C levels and incidence of mortality as well as major adverse cardiovascular and cerebrovascular events (MACCE), while adjusting for potential confounders. Moreover, participants were stratified based on sex and the association was also investigated in each subgroup separately.

RESULTS

No significant difference was found between the groups regarding incidence of both mortality and MACCE, after adjusting with Inverse Probability Weighting (IPW) [HR (95%CI): 0.84 (0.46-1.53), p-value:0.575 and HR (95% CI): 0.91 (0.56-1.50), p-value:0.733, respectively]. According to the sex-based subgroup analysis, no significant association was observed after adjustment with IPW analysis. However, as we examined the association between the interaction of HDL-C levels, sex and cardiovascular outcomes, we found a significant association (HR;1.19 (95%CI: 1.04-1.45); p = 0.030).

CONCLUSION

HDL-C level was not associated with either mortality or MACCE during one year after CABG procedure. Sex-based analysis showed that in males, HDL-C is significantly more protective against these outcomes, compared to females. Further studies are necessary to elucidate the exact mechanisms mediating such association.

The impact of dyslipidemia on prognosis of patients after endovascular abdominal aortic aneurysm repair

Introduction

Dyslipidemia is common in patients with abdominal aortic aneurysm (AAA). However, there is insufficient research on the impact of dyslipidemia on the postoperative outcomes of patients with AAA after endovascular aortic aneurysm repair (EVAR). This study aimed to determine the impact of dyslipidemia on the prognosis of patients with AAA treated with EVAR.

Method

We retrospectively reviewed patients with AAA who underwent EVAR at our hospital between 2010 and 2020. The baseline characteristics and prognoses of patients in the dyslipidemia and non-dyslipidemia groups were analyzed.

Results

A total of 641 patients were included; the prevalence of dyslipidemia in patients with AAA was 42.3% (271/641), and the mean follow-up time was 63.37 ± 26.49 months. The prevalence of diabetes (10.0% vs. 15.1%, P = 0.050), peripheral arterial disease (17.3% vs. 25.8%, P = 0.018), and chronic kidney disease (3.0% vs. 6.3%, P = 0.043) was higher in the dyslipidemia group. The three-year all-cause mortality rate after EVAR was 9.98% (64/641), and there was no difference in the incidence of all-cause mortality (10.27% vs. 9.59%, P = 0.778) between the two groups. A total of 36 (5.62%) major adverse cardiovascular and cerebrovascular events (MACCEs) were observed within 3 years and were more common in patients with dyslipidemia (2.97% vs. 9.59%, P < 0.001). The incidence of stent-related complications in all patients was 19.97% (128/641), and there was no difference in the incidence of stent-related complications between the two groups (22.16% vs. 16.97%, P = 0.105); however, the incidence of type I endoleak in the dyslipidemia group was lower than that in the non-dyslipidemia group (9.19% vs. 4.06%, P = 0.012). Cox-regression analysis showed that high level of high-density lipoprotein cholesterol (HDL-C) was the protective factor (HR, 0.203, 95% CI, 0.067-0.616, P = 0.005) for MACCES, but it was the risk factor for type I endoleak (HR, 2.317, 95% CI, 1.202-4.466, P = 0.012).

Conclusion

Dyslipidemia did not affect the mortality of patients with AAA who underwent EVAR; however, it may increase the incidence of MACCEs. Dyslipidemia may decrease the incidence of type I endoleaks after EVAR; however, further studies are warranted. We should strengthen the postoperative management of patients with dyslipidemia, prevent the occurrence of MACCEs.

Sex-Specific Relationships between HDL-Cholesterol Levels and 10-Year Mortality in Individuals with Atherosclerotic Cardiovascular Disease: A Nationwide Cohort Study of South Koreans

Large epidemiological studies show U-shaped relationships between high-density lipoprotein cholesterol (HDL-C) levels and all-cause mortality in individuals without atherosclerotic cardiovascular diseases (ASCVD). Association in those with ASCVD by sex is unclear. We examined the association between HDL-C levels and 10-year all-cause mortality in subjects (≥40 years of age) with ASCVD using the 2010 National Health Insurance Service and the National Death Registry of Korea. We categorized HDL-C levels into three groups (low: <40 mg/dL for males, <50 mg/dL for females; high: 40-90 mg/dL for males, 50-90 mg/dL for females; extremely high: >90 mg/dL) and 10 mg/dL intervals. We conducted a sex-stratified and adjusted Cox proportional hazards analysis. Out of 1,711,548 individuals (54% female, mean age 61.4 years), 10-year mortality was observed in 218,252 (12.8%). Males had a higher mortality rate than females (16.2% vs. 9.8%; p < 0.001). When adjusting for age, body mass index, LDL-cholesterol, triglycerides, hypertension, diabetes, smoking, and alcohol consumption, the low and extremely high HDL-C groups had significantly higher hazard ratios for 10-year mortality compared to the high HDL-C group in males [1.183 (1.166-1.199), 1.359 (1.288-1.434)] and in females [1.153 (1.138-1.169), 1.095 (1.029-1.167)]. The frequency distribution bars for the 10-year mortality rate showed sex-specific nadirs of 50-59 mg/dL in males and 70-79 mg/dL in females. In this ASCVD cohort, the extremely high HDL-C (>90 mg/dL) group had 35.9% and 9.5% higher 10-year mortality risks than the high HDL-C group for males and females, respectively. There was a slightly U-shaped relationship between baseline HDL-C levels and a 10-year mortality rate, with earlier inflection in males than in females.

Long-term, in vivo therapeutic effects of a single dose of miR-145 micelles for atherosclerosis

Atherosclerosis is a chronic inflammatory disease that is characterized by the build-up of lipid-rich plaques in the arterial walls. The standard treatment for patients with atherosclerosis is statin therapy aimed to lower serum lipid levels. Despite its widespread use, many patients taking statins continue to experience acute events. Thus, to develop improved and alternative therapies, we previously reported on microRNA-145 (miR-145 micelles) and its ability to inhibit atherosclerosis by targeting vascular smooth muscle cells (VSMCs). Importantly, one dose of miR-145 micelles significantly abrogated disease progression when evaluated two weeks post-administration. Thus, in this study, to evaluate how long the sustained effects of miR-145 micelles can be maintained and towards identifying a dosing regimen that is practical for patients with chronic disease, the therapeutic effects of a single dose of miR-145 micelles were evaluated for up to two months in vivo. After one and two months post-treatment, miR-145 micelles were found to reduce plaque size and overall lesion area compared to all other controls including statins without causing adverse effects. Furthermore, a single dose of miR-145 micelle treatment inhibited VSMC transdifferentiation into pathogenic macrophage-like and osteogenic cells in plaques. Together, our data shows the long-term efficacy and sustained effects of miR-145 micelles that is amenable using a dosing frequency relevant to chronic disease patients.

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.

The relationship between high-density lipoprotein cholesterol (HDL-C) and glycosylated hemoglobin in diabetic patients aged 20 or above: a cross-sectional study

AIM

The incidence rate of diabetes is increasing year by year, seriously threatening human health. As a predictor of glycemic control, glycated hemoglobin is reported to be related to various complications and prognoses of diabetes. Besides, HDL-C dyslipidemia is a component of metabolic syndrome and may be related to various cardiovascular and cerebrovascular diseases. The principal objective of this project was to investigate the relationship between HDL-C and glycosylated hemoglobin in adult diabetic patients.

METHODS

A total of 3171 adult diabetic patients aged 20 years and above were included in the present study from the National Health and Nutrition Examination Survey (NHANES). HDL-C and glycosylated hemoglobin were regarded as independent and dependent variables, respectively. EmpowerStats software and R (version 3.4.3) were used to examine the association between HDL-C and glycosylated hemoglobin.

RESULTS

HDL-C was inversely associated with glycohemoglobin after adjusting for other covariates (β = - 0.004, 95% CI:- 0.008 to - 0.000, p = 0.044). Race/ethnicity and age were considered the most prominent interactive factors that affect the relationship between HDL and glycosylated hemoglobin by the interaction analysis. A U-shaped association was detected between HDL-C and glycosylated hemoglobin for people of other race/ethnicity or aged 60 and above, which had an inflection point of HDL-C at 60 mg/dL. In contrast, we observed an inverted U-shaped distribution between HDL-C and glycosylated hemoglobin in people under 40 with point of inflection located at 60 mg/dL as well.

CONCLUSIONS

HDL-C in diabetic patients is inversely associated with glycosylated hemoglobin and may be relevant to glycemic control. However, a U-shaped relationship was also observed in a certain kind of people, which implied that, though HDL-C is considered as metabolism and anti-atherogenic property, for diabetics, it is not the higher, the better.

Associations between High-Density Lipoprotein Functionality and Major Adverse Cardiovascular Events in Patients Who Have Undergone Coronary Computed Tomography Angiography

The present study aimed to investigate the associations between high-density lipoprotein (HDL) functionality and major adverse cardiovascular events (MACE) in patients who have undergone coronary computed tomography angiography (CCTA). We performed a prospective cohort study and enrolled 151 patients who underwent CCTA and had a follow-up of up to 5 years. We measured cholesterol efflux capacity (CEC), caspase-3/7 activity and monocyte chemoattractant protein-1 (MCP-1) secretion as bioassays of HDL functionality. The patients were divided into MACE(−) (n = 138) and MACE(+) (n = 13) groups. While there was no significant difference in %CEC, caspase-3/7 activity or MCP-1 secretion between the MACE(−) and MACE(+) groups, total CEC and HDL cholesterol (HDL-C) in the MACE(+) group were significantly lower than those in the MACE(−) group. Total CEC was correlated with HDL-C. A receiver-operating characteristic curve analysis showed that there was no significant difference between the areas under the curves for total CEC and HDL-C. In conclusion, total CEC in addition to HDL-C, but not %CEC, was associated with the presence of MACE. On the other hand, HDL functionality with regard to anti-inflammatory and anti-apoptosis effects was not associated with MACE.