HDL-C is associated with mortality from all causes, cardiovascular disease and cancer in a J-shaped dose-response fashion: a pooled analysis of 37 prospective cohort studies

Interaction Analysis of Abnormal Lipid Indices and Hypertension for Ischemic Stroke: A 10-Year Prospective Cohort Study

Background

Dyslipidemia and hypertension are two important independent risk factors for ischemic stroke (IS); however, their combined effect on IS remains uncertain.

Objectives

This present study aimed to evaluate the interaction effect of hypertension and abnormal lipid indices on IS in a 10-year prospective cohort in Chinese adults.

Methods

The cohort study of 4,128 participants was conducted in May 2009 and was followed up to July 2020. All qualified participants received a questionnaire survey, physical examination, and blood sample detection. Cox regression was used to evaluate the association of dyslipidemia and hypertension with IS, and calculate the hazard ratio (HR) and 95% confidence interval (CI). The relative excess risk of interaction (RERI) and the HR (95%CI) of interaction terms were used to examine additive and multiplicative interactions.

Results

In the hypertensive population, Non-HDL-C ≥190 mg/dl, LDL-C/HDL-C ≥2 and HDL-C ≥60 mg/dl were statistically associated with IS, and after adjusting for covariates, HRs (95%CIs) were 1.565 (1.007–2.429), 1.414 (1.034–1.933) and 0.665 (0.450–0.983), respectively. While in the non-hypertension population, no significant association of Non-HDL-C ≥190 mg/dl, LDL-C/HDL-C ≥2, and HDL-C ≥60 was detected with IS (P > 0.05). There was a significant association between TC/HDL-C ≥ 3.6 and the decreased risk of IS in the non-hypertension population, and the HR (95%CI) was 0.479 (0.307–0.750). Whereas, a similar association was not observed in the hypertensive population. HDL-C ≥ 60 mg/dl, Non-HDL-C ≥ 190 mg/dl, TC/HDL-C ≥ 3.6, and TG/HDL-C ≥ 1 have additive and multiplicative interactions with hypertension (P < 0.05). The RERIs (95% CIs) of the additive interaction are −0.93 (−1.882–0.044), 1.394 (0.38–2.407), 0.752 (0.354–1.151) and 0.575 (0.086–1.065), respectively. The HRs (95% CIs) of the multiplicative interaction terms were 0.498 (0.272–0.911), 4.218 (1.230–14.464), 2.423 (1.437–4.086) and 1.701 (1.016–2.848), respectively.

Conclusion

High concentration of HDL-C reduces the impact of hypertension on IS, while the high concentration of Non-HDL-C, TC/HDL-C, and TG/HDL-C positively interact with hypertension affecting the incidence of IS. This study provides useful evidence for the combined effects of dyslipidemia and hypertension in predicting IS.

The value of combining individual and small area sociodemographic data for assessing and handling selective participation in cohort studies: Evidence from the Swedish CardioPulmonary bioImage Study

Objectives

To study the value of combining individual- and neighborhood-level sociodemographic data to predict study participation and assess the effects of baseline selection on the distribution of metabolic risk factors and lifestyle factors in the Swedish CardioPulmonary bioImage Study (SCAPIS).

Methods

We linked sociodemographic register data to SCAPIS participants (n = 30,154, ages: 50–64 years) and a random sample of the study’s target population (n = 59,909). We assessed the classification ability of participation models based on individual-level data, neighborhood-level data, and combinations of both. Standardized mean differences (SMD) were used to examine how reweighting the sample to match the population affected the averages of 32 cardiopulmonary risk factors at baseline. Absolute SMDs >0.10 were considered meaningful.

Results

Combining both individual-level and neighborhood-level data gave rise to a model with better classification ability (AUC: 71.3%) than models with only individual-level (AUC: 66.9%) or neighborhood-level data (AUC: 65.5%). We observed a greater change in the distribution of risk factors when we reweighted the participants using both individual and area data. The only meaningful change was related to the (self-reported) frequency of alcohol consumption, which appears to be higher in the SCAPIS sample than in the population. The remaining risk factors did not change meaningfully.

Conclusions

Both individual- and neighborhood-level characteristics are informative in assessing study selection effects. Future analyses of cardiopulmonary outcomes in the SCAPIS cohort can benefit from our study, though the average impact of selection on risk factor distributions at baseline appears small.

Lipoproteins and cancer: The role of HDL-C, LDL-C, and cholesterol-lowering drugs

Cholesterol is an amphipathic sterol molecule that is vital for maintaining normal physiological homeostasis. It is a relatively complicated molecule with 27 carbons whose synthesis starts with 2-carbon units. This in itself signifies the importance of this molecule. Cholesterol serves as a precursor for vitamin D, bile acids, and hormones, including estrogens, androgens, progestogens, and corticosteroids. Although essential, high cholesterol levels are associated with cardiovascular and kidney diseases and cancer initiation, progression, and metastasis. Although there are some contrary reports, current literature suggests a positive association between serum cholesterol levels and the risk and extent of cancer development. In this review, we first present a brief overview of cholesterol biosynthesis and its transport, then elucidate the role of cholesterol in the progression of some cancers. Suggested mechanisms for cholesterol-mediated cancer progression are plentiful and include the activation of oncogenic signaling pathways and the induction of oxidative stress, among others. The specific roles of the lipoprotein molecules, high-density lipoprotein (HDL) and low-density lipoprotein (LDL), in this pathogenesis, are also reviewed. Finally, we hone on the potential role of some cholesterol-lowering medications in cancer.

High-density lipoproteins and immune response: A review

High-density lipoproteins (HDLs) are heterogeneous lipoproteins that modify their composition and functionality depending on physiological or pathological conditions. The main roles of HDL are cholesterol efflux, and anti-inflammatory and antioxidant functions. These functions can be compromised under pathological conditions. HDLs play a role in the immune system as anti-inflammatory molecules but when inflammation occurs, HDLs change their composition and carry pro-inflammatory cargo. Hence, many molecular intermediates that influence inflammatory microenvironments and cell signaling pathways can modulate HDLs structural modification and function. This review provides a comprehensive assessment of the importance of HDL composition and anti-inflammatory function in the onset and progression of atherosclerotic cardiovascular diseases. On the other hand, immune cell activation during progression of atheroma plaque formation can be influenced by HDLs through HDL-derived cholesterol depletion from lipid rafts and through HDL interaction with HDL receptors expressed on T and B lymphocytes. Cholesterol efflux is mediated by HDL receptors located in lipid rafts in peripheral cells, which undergo membrane structural modifications, and interferes with subsequent molecules interactions or intracellular signaling cascades. Regarding antigen-presentation cells such as macrophages or dendritic cells, HDL function may then modulate lymphocytes activation in immune response. Our review also contributes to the understanding of the effects exerted by HDLs in signal transduction associated to our immune cell population during chronic diseases progression.

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.

Higher Serum Total Cholesterol to High-Density Lipoprotein Cholesterol Ratio Is Associated with Increased Mortality among Incident Peritoneal Dialysis Patients

This study evaluated the association of the serum total cholesterol to high-density lipoprotein cholesterol ratio (TC/HDL-C) with mortality in incident peritoneal dialysis (PD) patients. We performed a multi-center, prospective cohort study of 630 incident PD patients from 2008 to 2015 in Korea. Participants were stratified into quintiles according to baseline TC, HDL-C, LDL-C and TC/HDL-C. The association between mortality and each lipid profile was evaluated using multivariate Cox regression analysis. During a median follow-up period of 70.3 ± 25.2 months, 185 deaths were recorded. The highest TC/HDL-C group had the highest body mass index, percentage of diabetes and serum albumin level. Multivariate analysis demonstrated that the highest quintile of TC/HDL-C was associated with increased risk of all-cause mortality (hazard ratio 1.69, 95% confidence interval 1.04-2.76; p = 0.036), whereas TC, HDL-C and LDL-C were not associated with mortality. Linear regression analysis showed a positive correlation between TC/HDL-C and body mass index. Increased serum TC/HDL-C was an independent risk factor for mortality in the subgroup of old age, female, cardiovascular disease and low HDL-C. The single lipid marker of TC or HDL-C was not able to predict mortality in PD patients. However, increased serum TC/HDL-C was independently associated with all-cause mortality in PD patients.

The Associations of Lipid Profiles With Cardiovascular Diseases and Death in a 10-Year Prospective Cohort Study

Background: Dyslipidemia is one of the modifiable risk factors for cardiovascular diseases (CVD). Identifying subjects with lipid abnormality facilitates preventative interventions.

Objectives: To evaluate the effects of lipid indices on the risks of ischemic stroke (IS), coronary heart disease (CHD), CVD, all-cause death, and CVD death.

Methods: The cohort study of 4,128 subjects started in May 2009 and followed up to July 2020. Restricted cubic spline (RCS) regression analysis was used to explore the dose-response relationship between lipid indices with outcomes. Cox proportional hazard regression analysis was used to estimate the association with a hazard ratio (HR) and 95% CI.

Results: RCS analysis showed that there were significant linear associations of TG with IS, non-high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (ApoB), and total cholesterol (TC)/HDL-C ratio with all-cause death, non-HDL-C and RC with CVD death, and significant non-linear associations of ApoB with IS and CVD, TC, LDL-C, ApoAI, and TC/HDL-C ratio with CHD, and TC with all-cause death (all P <0.1). Cox regression analysis revealed that subjects with TC <155 mg/dl (vs. 155–184 mg/dl), > 185 mg/dl (vs. 155–184 mg/dl), and ApoB <0.7 g/l (vs. ≥0.7 g/l) had higher risks of CHD (P < 0.05), the adjusted HRs (95% CIs) were 1.933 (1.248–2.993), 1.561 (1.077–2.261), and 1.502 (1.01–2.234), respectively. Subjects with ApoAI > 2.1 g/l (vs. 1.6–2.1 g/l) and TG <80 mg/dl (vs. 80–177 mg/dl) had higher risks of CVD and all-cause death (P < 0.05), the adjusted HRs (95% CIs) were 1.476 (1.031–2.115) and 1.234 (1.002–1.519), respectively.

Conclusions: Lower or higher levels of TC, higher level of ApoAI, and lower level of ApoB were associated with increased risks of CVD, and lower level of TG was associated with increased all-cause death. Maintaining optimal lipid levels would help to prevent CVD and reduce mortality.

High-density lipoprotein cholesterol to apolipoprotein A1 ratio and all-cause mortality among incident peritoneal dialysis patients

BACKGROUND AND AIMS

The ratio of high-density lipoprotein cholesterol to apolipoprotein A1 (HAR) is associated with all-cause mortality in nonchronic kidney disease patients, but its role in predicting all-cause mortality in patients undergoing peritoneal dialysis (PD) is still unclear. The purpose of this study was to investigate the relationship between HAR and all-cause mortality in patients with PD.

METHODS AND RESULTS

The medical records of 1199 patients with PD from November 1, 2005, to August 31, 2019, were collected retrospectively. The main outcome was defined as all-cause mortality. The HAR was divided into three groups by X-tile software. The association between HAR and all-cause mortality was evaluated by Cox models. The Kaplan-Meier method was used for the survival curve. The median follow-up period was 35 months (interquartile range: 20-57 months), with a total of 326 deaths recorded. After multiple adjustments, the risk of all-cause mortality in the high HAR group was 1.96-fold higher than that in the low HAR group (hazard ratio: 1.96; 95% CI, 1.22 to 3.15; P = 0.005). The restricted cubic splines showed that the risk of all-cause mortality increased gradually when HAR was >0.37. In the stratified analysis, a high HAR was linked to a high risk of all-cause mortality in males, patients under 55 years old, and patients without diabetes or cardiovascular disease (CVD).

CONCLUSION

This study suggests that HAR is independently related to all-cause mortality in PD patients, especially in males, patients under 55 years old, and patients without diabetes or CVD.

Predictive value of a reduction in the level of high-density lipoprotein-cholesterol in patients with non-small-cell lung cancer undergoing radical resection and adjuvant chemotherapy: a retrospective observational study

Background

Cancer patients often exhibit chemotherapy-associated changes in serum lipid profiles, however, their prognostic value before and after adjuvant chemotherapy on survival among non-small-cell lung cancer (NSCLC) patients is unknown.

Methods

NSCLC patients undergoing radical resection and subsequent adjuvant chemotherapy from 2013 to 2017 at Sun Yat-sen University Cancer Center were retrospectively reviewed. Fasted serum lipid levels were measured before and after chemotherapy. The optimal lipid cut-off values at baseline and fluctuation were determined using X-tile™. The fluctuations in serum lipid levels and disease-free survival (DFS) were assessed.

Results

Serum cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglyceride, apolipoprotein (Apo) A-I, and ApoB all significantly increased after adjuvant chemotherapy. X-tile determined 1.52 mmol/L of HDL-C and 0.74 g/L of ApoB as the optimal cut-off values before chemotherapy. Patients with HDL-C ≥ 1.52 mmol/L (median DFS: not reached vs. 26.30 months, P = 0.0005) and a decreased HDL-C level after adjuvant chemotherapy (median DFS: 80.43 vs. 26.12 months, P = 0.0204) had a longer DFS. An HDL-C level that increased by ≥ 0.32 mmol/L after chemotherapy indicated a worse DFS. A high baseline ApoB level were associated with a superior DFS. In the univariate analysis and the multivariate Cox analyses, a high baseline HDL-C level and a HDL-C reduction after adjuvant chemotherapy were independent indicators for superior DFS. High baseline HDL-C was related to N0-1 stage (χ² = 6.413, P = 0.011), and HDL-C fluctuation was significantly correlated with specific chemotherapy regimens (χ² = 5.002, P = 0.025).

Conclusions

Adjuvant chemotherapy increased various lipid levels in resected NSCLC patients. A higher HDL-C level before chemotherapy and a reduced HDL-C level after adjuvant chemotherapy were independent predictors of longer DFS in patients with curable NSCLC.

HDL-C, longitudinal change and risk of mortality in a Chinese cohort study

BACKGROUND AND AIMS

High-density lipoprotein cholesterol (HDL-C) concentration and variability are both important factors of cardiovascular disease (CVD) and mortality. We aimed to explore the associations of HDL-C and longitudinal change in HDL-C with risk of mortality.

METHODS AND RESULTS

We recruited a total of 69,163 participants aged ≥40 years and had medical examination records of HDL-C during 2010-2014 from the Yinzhou District, Ningbo, China. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models. We observed a non-linear association of HDL-C with risks of non-accidental and CVD mortality. Compared with the moderate concentration group (1.4-1.6 mmol/L), HDL-C <1 mmol/L was associated with a higher risk of non-accidental mortality (HR: 1.13 (95% CI: 1.01-1.27)) and both HDL-C <1 mmol/L and ≥2 mmol/L were associated with a higher risk of CVD mortality (HRs: 1.23 (95% CI: 1.01-1.50) and 1.37 (95% CI: 1.03-1.82), respectively). Compared with the stable group ([-0.1, +0.1 mmol/L]), a large decrease ([-0.5, -0.3 mmol/L]) and very large decrease (<-0.5 mmol/L) in HDL-C were associated with a higher risk of non-accidental mortality (HRs: 1.40 (95% CI: 1.21-1.63) and 1.78 (95% CI: 1.44-2.20), respectively). Similar results were observed for CVD mortality and cancer mortality.

CONCLUSION

Extremely low or high HDL-C and a large decrease or very large decrease in HDL-C were associated with a higher risk of cause-specific mortality. Monitoring of HDL-C may have utility in identifying individuals at higher risk of mortality.

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 Lipoproteins and Diabetes

Epidemiological studies have established that a high plasma high density lipoprotein cholesterol (HDL-C) level is associated with reduced cardiovascular risk. However, recent randomised clinical trials of interventions that increase HDL-C levels have failed to establish a causal basis for this relationship. This has led to a shift in HDL research efforts towards developing strategies that improve the cardioprotective functions of HDLs, rather than simply increasing HDL-C levels. These efforts are also leading to the discovery of novel HDL functions that are unrelated to cardiovascular disease. One of the most recently identified functions of HDLs is their potent antidiabetic properties. The antidiabetic functions of HDLs, and recent key advances in this area are the subject of this review. Given that all forms of diabetes are increasing at an alarming rate globally, there is a clear unmet need to identify and develop new approaches that will complement existing therapies and reduce disease progression as well as reverse established disease. Exploration of a potential role for HDLs and their constituent lipids and apolipoproteins in this area is clearly warranted. This review highlights focus areas that have yet to be investigated and potential strategies for exploiting the antidiabetic functions of HDLs.

A Non-Linear Association of High-Density Lipoprotein Cholesterol with All-Cause and Cause-Specific Mortality in Diabetic Patients

BACKGROUND

The association between high-density lipoprotein cholesterol (HDL-C) and the risk of death among people with diabetes remains to be verified.

METHODS

This was a nationwide, population-based cohort study in United States. A total of 6549 diabetes patients were included from the National Health and Nutrition Examination Surveys (NHANES). HDL-C concentration was divided into quintiles, and the lowest risk group (Q4: 1.32 to 1.53 mmol/L) was used as reference. Multivariate Cox proportional hazards models and restrictive cubic curves were performed to estimate hazard ratios (HRs) with 95% confidence interval (CI) for all-cause and cause-specific mortality.

RESULTS

During a median follow-up of 82.36 ± 50.11 months, 1546 (23.61%) cases of all-cause, 389 (5.94%) cardiovascular and 262 (4.00%) cancer mortality have occurred, respectively. After adjusting for potential covariates, a U-shaped association was found between HDL-C and all-cause mortality (minimum mortality risk at 1.37 mmol/L); the risk for all-cause mortality was significantly higher in the groups with HDL-C concentration <0.96 mmol/L (HR: 1.30; 95% CI: 1.09, 1.56; P=0.0046) and with HDL-C concentration ≥1.55 mmol/L (HR: 1.20; 95% CI: 1.00, 1.44; P=0.0481) than participants with HDL-C concentrations ranging from 1.32 to 1.53mmol/L. Nonlinear associations of HDL-C levels with both cardiovascular and cancer mortality were also observed.

CONCLUSION

A non-linear association was observed association of HDL-C with all-cause, cardiovascular and cancer mortality among diabetic patients.

Cardiovascular risk factors during cancer treatment. Prevalence and prognostic relevance: insights from the CARDIOTOX registry

Aims

The actual usefulness of cardiovascular (CV) risk factor assessment in the prognostic evaluation of cancer patients treated with cardiotoxic treatment remains largely unknown. Prospective multicentre study in patients scheduled to receive anticancer therapy related with moderate/high cardiotoxic risk.

Methods and results

A total of 1324 patients underwent follow-up in a dedicated cardio-oncology clinic from April 2012 to October 2017. Special care was given to the identification and control of CV risk factors. Clinical data, blood samples, and echocardiographic parameters were prospectively collected according to protocol, at baseline before cancer therapy and then at 3 weeks, 3 months, 6 months, 1 year, 1.5 years, and 2 years after initiation of cancer therapy. At baseline, 893 patients (67.4%) presented at least one risk factor, with a significant number of patients newly diagnosed during follow-up. Individual risk factors were not related with worse prognosis during a 2-year follow-up. However, a higher Systemic Coronary Risk Estimation (SCORE) was significantly associated with higher rates of severe cardiotoxicity (CTox) and all-cause mortality [hazard ratio (HR) 1.79 (95% confidence interval, CI 1.16–2.76) for SCORE 5–9 and HR 4.90 (95% CI 2.44–9.82) for SCORE ≥10 when compared with patients with lower SCORE (0–4)].

Conclusions

This large cohort of patients treated with a potentially cardiotoxic regimen showed a significant prevalence of CV risk factors at baseline and significant incidence during follow-up. Baseline CV risk assessment using SCORE predicted severe CTox and all-cause mortality. Therefore, its use should be considered in the evaluation of cancer patients.

HDL and cancer - causality still needs to be confirmed? Update 2020

An inverse correlation between high-density lipoprotein cholesterol (HDL-C) and cancer risk has been shown by several epidemiological studies. Some studies have even suggested that HDL-C can be used as a prognostic marker in patients with certain types of cancer. However, whether reduced HDL-C level is a consequential or causal factor in the development and progression of cancer remains a controversial issue. In this review, we update and summarize recent advances that highlight the role of HDL and some of its components in prognosis, diagnosis and treatment of cancer.

U-Shaped Association of High-Density Lipoprotein Cholesterol with All-Cause and Cardiovascular Mortality in Hypertensive Population

Purpose

Whether the paradox of high-density lipoprotein cholesterol (HDL-C) and elevated mortality risk extends to hypertensive patients is unclear. We aimed to investigate the association between HDL-C and all-cause and cardiovascular disease mortality in adults with hypertension.

Methods

In the National Health and Nutrition Examination Surveys, 11,497 hypertensive participants aged ≥18years old and examined at baseline between 1999 and 2014 were followed up until December 2015. We categorized the HDL-C concentration as ≤30, 31–40, 41–50, 51–60 (reference), 61–70, >70 mg/dL and examined their associations with all-cause and cardiovascular mortality, respectively. Multivariate Cox regression was used to calculated hazard ratio (HR) and 95% confidence interval (CI) for mortality risk.

Results

During follow-up (median: 9.2 ± 3.8 years), 3012 deaths and 713 cardiovascular deaths were observed. In the restrictive cubic curves, associations of HDL-C levels and all-cause and cardiovascular mortality were detected to be U-shaped. After multivariable adjustment, HRs for all-cause mortality were for the lowest HDL-C concentration (≤30 mg/dL) 1.29 (95% CI, 1.07–1.56) and the highest (>70 mg/dL) 1.20 (1.06–1.37), comparing with the reference group. For cardiovascular mortality, HRs were 1.31 (0.83–1.48) and 1.09 (0.83–1.43), respectively. Similar results were obtained in subgroups stratified by age, gender, race, and taking lipid-lowering drugs. The lowest all-cause mortality risk was observed at HDL-C 66 mg/dL (concentration) and 51–60 mg/dL (range).

Conclusion

Both lower and higher HDL-C concentration appeared to be associated with higher mortality in hypertensive population. Further investigation is warranted to clarify the underlying mechanisms.

Microarray analysis of long non-coding RNA expression profiles in low high-density lipoprotein cholesterol disease

Background

Low high-density lipoprotein cholesterol (HDL-C) disease with unknown etiology has a high prevalence in the Xinjiang Kazak population. In this study, long noncoding RNAs (lncRNAs) that might play a role in low HDL-C disease were identified.

Methods

Plasma samples from 10 eligible individuals with low HDL disease and 10 individuals with normal HDL-C levels were collected. The lncRNA profiles for 20 Xinjiang Kazak individuals were measured using microarray analysis.

Results

Differentially expressed lncRNAs and mRNAs with fold-change values not less than 1.5 and FDR-adjusted P-values less than 0.05 were screened. Bioinformatic analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and network analyses, were used to determine relevant signaling pathways and predict potential target genes. In total, 381 lncRNAs and 370 mRNAs were differentially expressed based on microarray analysis. Compared with those in healthy individuals, several lncRNAs were upregulated or downregulated in patients with low HDL-C disease, among which TCONS_00006679 was most significantly upregulated and TCONS_00011823 was most significantly downregulated. GO and KEGG pathway analyses as well as co-expression networks of lncRNAs and mRNAs revealed that the platelet activation pathway and cardiovascular disease were associated with low HDL-C disease.

Conclusions

Potential target genes integrin beta-3 (ITGB3) and thromboxane A2 receptor (TBXA2R) were regulated by the lncRNAs AP001033.3–201 and AC068234.2–202, respectively. Both genes were associated with cardiovascular disease and were involved in the platelet activation pathway. AP001033.3–201 and AC068234.2–202 were associated with low HDL-C disease and could play a role in platelet activation in cardiovascular disease. These results reveal the potential etiology of dyslipidemia in the Xinjiang Kazakh population and lay the foundation for further validation using large sample sizes.