Project description:The focus of this study was to explore the association between the non-HDL-cholesterol to HDL-cholesterol (non-HDLc/HDLc) ratio and mortality in septic patients. This was a retrospective cohort study of patients with sepsis in the eICU Collaborative Research Database (eICU-CRD) from 208 distinct ICUs across the United States between 2014 and 2015 that explored. All-cause mortality within 28 days after ICU admission. A multivariable logistic regression model was used to estimate the risk of death. Of the 724 patients with a median age of 68 years, 43 (5.94%) died within 28 days after ICU admission. When the non-HDLc/HDLc ratio was < 3.3, the mortality rate decreased with an adjusted odds ratio (OR) of 0.60 (95% CI 0.37-0.99, P = 0.043) for every 1 increment in the non-HDLc/HDLc ratio. When the non-HDLc/HDLc ratio was ≥ 3.3, the mortality rate increased with an adjusted OR of 1.28 (95% CI 1.01-1.62, P = 0.039) for every one increment in the non-HDLc/HDLc ratio. For patients with sepsis, the association between the non-HDLc/HDLc ratio and the 28-day mortality risk was a U-shaped curve. A higher or lower non-HDLc/HDLc ratio was associated with an increased risk of 28-day mortality.
Project description:ObjectiveIt is well established that patients with systemic sclerosis (SSc) have a disrupted lipid profile and an increased cardiovascular risk. Cholesterol efflux capacity (CEC), the ability of high-density lipoprotein (HDL)-cholesterol to accept cholesterol from macrophages, has been linked to cardiovascular events. The aim of this study was to establish whether CEC and lipid profile were impaired in SSc patients with respect to controls and whether these changes were associated with disease-related data.MethodsCross-sectional study encompassed 188 individuals: 73 SSc patients and 115 controls. CEC, using an in vitro assay, and lipoprotein serum concentrations were assessed in patients and controls. A multivariable analysis was performed to study the differences in CEC between patients and controls, and if SSc-related data could explain such differences.ResultsThe multivariable analysis adjusted for demographic characteristics, cardiovascular risk factors, and lipid-related molecules showed that total cholesterol (beta coefficient: -?22 [95%CI - 37 to - 7], p?=?0.004), triglycerides (beta coefficient: 24 [95%CI 2-47], p?=?0.033), lipoprotein A (beta coefficient: 22 [95%CI 2-43], p?=?0.033), and CEC (beta coefficient: - 6 [95%CI -?10 to - 2]%,p?=?0.002) were significantly different between patients and controls. Skin thickness, as assessed by modified Rodnan skin score, was independently associated with a lower CEC (beta coefficient: - 0.21 [95%CI - 0.37 to - 0.05]%, p?=?0.011) after multivariable adjustment.ConclusionSSc patients show an abnormal lipid profile with respect to controls including CEC. Skin thickness is independent and inversely associated with CEC in SSc patients.
Project description:A low level of high density lipoprotein cholesterol (HDL-C) is a powerful risk factor for cardiovascular disease. However, despite the reported key role of apolipo-proteins, specifically, apoA-I, in HDL metabolism, lipid molecular composition of HDL particles in subjects with high and low HDL-C levels is currently unknown. Here lipidomics was used to study HDL derived from well-characterized high and low HDL-C subjects. Low HDL-C subjects had elevated triacylglycerols and diminished lysophosphatidylcholines and sphingomyelins. Using information about the lipid composition of HDL particles in these two groups, we reconstituted HDL particles in silico by performing large-scale molecular dynamics simulations. In addition to confirming the measured change in particle size, we found that the changes in lipid composition also induced specific spatial distributions of lipids within the HDL particles, including a higher amount of triacylglycerols at the surface of HDL particles in low HDL-C subjects. Our findings have important implications for understanding HDL metabolism and function. For the first time we demonstrate the power of combining molecular profiling of lipoproteins with dynamic modeling of lipoprotein structure.
Project description:Purpose of the reviewTo evaluate recent studies related to the paradox of high HDL-C with mortality and atherosclerotic cardiovascular disease (ASCVD) risk.Recent findingsTwo observational studies (Cardiovascular Health in Ambulatory Care Research Team [CANHEART] and Copenhagen City Heart Study and the Copenhagen General Population Study [Copenhagen Heart Studies]) of adults without pre-existing ASCVD have shown a significant U-shaped association of HDL-C with all-cause and cause-specific mortality. Both studies showed that low HDL-C levels consistently increased hazard risk (HR) for all-cause and cause-specific mortality. In the CANHEART study, high HDL-C levels, HDL-C >?90 mg/dL, were associated with increased HR for non-CVD/non-cancer mortality. In the Copenhagen Heart Studies, women with HDL-C ??135 mg/dL showed increased HR for all-cause and CVD mortality, while men with HDL-C?>?97 mg/dL showed increased HR for all-cause and CVD mortality. Genetic association studies failed to show that genetic etiologies of high HDL-C significantly reduced risk for myocardial infarction (MI), while hepatocyte nuclear factor-4 (HNF4A) was significantly associated with high HDL-C and increased MI risk. Candidate gene studies have identified scavenger receptor B class I (SCARB1) and lymphocyte activation gene-3 (LAG3) as genes significantly associated with high HDL-C and increased MI risk. Low HDL-C remains as a significant factor for increased disease risk while high HDL-C levels are not associated with cardioprotection. Clinical CVD risk calculators need revision.
Project description:Clear cell renal cell carcinoma (ccRCC), which accounts for the majority of kidney cancer, is known to accumulate excess cholesterol. However, the mechanism and functional significance of the lipid accumulation for development of the cancer remains obscure. In this study, we analyzed 42 primary ccRCC samples, and determined that cholesterol levels of ~ 70% of the tumors were at least two-fold higher than that of benign kidney tissues. Compared to tumors without cholesterol accumulation, those containing excess cholesterol expressed higher levels of scavenger receptor BI (SR-B1), a receptor for uptake of HDL-associated cholesterol, but not genes involved in cholesterol synthesis and uptake of LDL-associated cholesterol. To further determine the roles of sterol accumulation for cancer development, we implanted ccRCC from patients into mouse kidneys using a mouse ccRCC xenograft model. Feeding mice with probucol, a compound lowing HDL-cholesterol, markedly reduced levels of cholesterol in tumors containing excess cholesterol. This treatment, however, did not affect growth of these tumors. Our study suggests that cholesterol overaccumulation in ccRCC is the consequence of increased uptake of HDL-cholesterol as a result of SR-B1 overexpression, but the lipid accumulation by itself may not play a significant role in progression of the cancer.
Project description:OBJECTIVE:To characterize the fate of protein and lipid in nascent HDL (high-density lipoprotein) in plasma and explore the role of interaction between nascent HDL and mature HDL in promoting ABCA1 (ATP-binding cassette transporter 1)-dependent cholesterol efflux. Approach and Results: Two discoidal species, nascent HDL produced by RAW264.7 cells expressing ABCA1 (LpA-I [apo AI containing particles formed by incubating ABCA1-expressing cells with apo AI]), and CSL112, human apo AI (apolipoprotein AI) reconstituted with phospholipids, were used for in vitro incubations with human plasma or purified spherical plasma HDL. Fluorescent labeling and biotinylation of HDL were employed to follow the redistribution of cholesterol and apo AI, cholesterol efflux was measured using cholesterol-loaded cells. We show that both nascent LpA-I and CSL112 can rapidly fuse with spherical HDL. Redistribution of the apo AI molecules and cholesterol after particle fusion leads to the formation of (1) enlarged, remodeled, lipid-rich HDL particles carrying lipid and apo AI from LpA-I and (2) lipid-poor apo AI particles carrying apo AI from both discs and spheres. The interaction of discs and spheres led to a greater than additive elevation of ABCA1-dependent cholesterol efflux. CONCLUSIONS:These data demonstrate that although newly formed discs are relatively poor substrates for ABCA1, they can interact with spheres to produce lipid-poor apo AI, a much better substrate for ABCA1. Because the lipid-poor apo AI generated in this interaction can itself become discoid by the action of ABCA1, cycles of cholesterol efflux and disc-sphere fusion may result in net ABCA1-dependent transfer of cholesterol from cells to HDL spheres. This process may be of particular importance in atherosclerotic plaque where cholesterol acceptors may be limiting.
Project description:BackgroundThe discordance of the low-density lipoprotein cholesterol-to-high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio with alterative lipid parameters may explain the inconsistent association of CIMT with the LDL-C/HDL-C ratio. Therefore, this study aimed to explore the associations between LDL-C/HDL-C ratio discordance with alternative lipid parameters and elevated carotid intima-media thickness (CIMT) risk in a large cohort in Beijing, China.MethodsIn total, 13,612 adults who didn't have elevated CIMT at baseline and who participated in at least one follow-up of annual examination between 2009 and 2016 were included in this cohort study. A multivariable Cox regression model was utilized to evaluate the associations of discordance of the LDL-C/HDL-C ratio with TC, TGs, LDL-C and HDL-C with elevated CIMT risk.ResultsDuring 37,999 person-years of follow-up, 2004 individuals (1274 men and 730 women) developed elevated CIMT. Among individuals with normal TC and TGs, 16.6 and 15.2% individuals had a discordantly high LDL-C/HDL-C ratio, respectively, and the risk of elevated CIMT increased by 1.54 (95% CI 1.33, 1.77) and 1.53 (95% CI 1.33, 1.76), respectively, comparing to individuals with a concordantly low LDL-C/HDL-C ratio. A high LDL-C/HDL-C ratio could significantly increase elevated CIMT risk regardless of discordance/concordance with LDL-C and HDL-C (P < 0.001). A low LDL-C/HDL-C ratio with discordantly normal HDL-C and high LDL-C (13.2% of individuals) had a 32% (HR = 1.32, 95% CI 1.11, 1.57) higher risk of elevated CIMT than concordantly low LDL-C and normal HDL-C. Sensitivity analysis by excluding CIMT developed in the first 2 years follow-up further confirmed the above results.ConclusionsA high LDL-C/HDL-C ratio could significantly increase elevated CIMT risk regardless of discordance/concordance with TC, TGs, LDL-C and HDL-C Even a low LDL-C/HDL-C ratio with discordantly high LDL-C and normal HDL-C could also significantly increase CIMT risk. Individuals should maintain both the LDL-C/HDL-C ratio and LDL-C at normal levels to prevent elevated CIMT.
Project description:Cardiovascular disease, with atherosclerosis as the major underlying factor, remains the leading cause of death worldwide. It is well established that cholesterol ester-enriched foam cells are the hallmark of atherosclerotic plaques. Multiple lines of evidence support that enhancing foam cell cholesterol efflux by HDL (high-density lipoprotein) particles, the first step of reverse cholesterol transport (RCT), is a promising antiatherogenic strategy. Yet, excitement towards the therapeutic potential of manipulating RCT for the treatment of cardiovascular disease has faded because of the lack of the association between cardiovascular disease risk and what was typically measured in intervention trials, namely HDL cholesterol, which has an inconsistent relationship to HDL function and RCT. In this review, we will summarize some of the potential reasons for this inconsistency, update the mechanisms of RCT, and highlight conditions in which impaired HDL function or RCT contributes to vascular disease. On balance, the evidence still argues for further research to better understand how HDL functionality contributes to RCT to develop prevention and treatment strategies to reduce the risk of cardiovascular disease.
Project description:Levels of high-density lipoprotein cholesterol (HDL-C) are inversely associated with the incidence of coronary artery disease (CAD). However, the underlying mechanism of CAD in the context of elevated HDL-C levels is unclear. Our study aimed to explore the lipid signatures in patients with CAD and elevated HDL-C levels and to identify potential diagnostic biomarkers for these conditions. We measured the plasma lipidomes of forty participants with elevated HDL-C levels (men with >50 mg/dL and women with >60 mg/dL), with or without CAD, using liquid chromatography-tandem mass spectrometry. We analyzed four hundred fifty-eight lipid species and identified an altered lipidomic profile in subjects with CAD and high HDL-C levels. In addition, we identified eighteen distinct lipid species, including eight sphingolipids and ten glycerophospholipids; all of these, except sphingosine-1-phosphate (d20:1), were higher in the CAD group. Pathways for sphingolipid and glycerophospholipid metabolism were the most significantly altered. Moreover, our data led to a diagnostic model with an area under the curve of 0.935, in which monosialo-dihexosyl ganglioside (GM3) (d18:1/22:0), GM3 (d18:0/22:0), and phosphatidylserine (38:4) were combined. We found that a characteristic lipidome signature is associated with CAD in individuals with elevated HDL-C levels. Additionally, the disorders of sphingolipid as well as glycerophospholipid metabolism may underlie CAD.
Project description:BackgroundProper functioning of high-density lipoprotein (HDL) is necessary for protection against sepsis. However, previous work has demonstrated that HDL becomes oxidized and dysfunctional (Dys-HDL) during sepsis. Older (aged >65 years) patients are at particularly high risk of sepsis and poor outcomes from sepsis.Study objectiveThe aim of the study was to compare functional properties of HDL (cholesterol efflux capacity and paraoxonase enzyme 1 [PON-1] activity) and Dys-HDL between older (aged >65 years) sepsis patients and older healthy volunteers.MethodsThis was a subanalysis of a prospective study in which patients with sepsis were prospectively enrolled from the emergency department within the first 24 h. Serum and plasma samples were drawn from septic patients and age- and sex-matched control subjects. Percent cholesterol efflux, HDL inflammatory index, and PON1 activity were measured. Data were analyzed using Student t test or Wilcoxon rank-sum test.ResultsTen sepsis and 10 healthy controls were analyzed. Mean age of sepsis patients (80 ± 2 years [SD]) and control subjects (77 ± 2 years) was similar (P = 0.31). Mean systolic blood pressures were significantly different in sepsis patients (113 ± 8 mmHg) compared with controls (133 ± 6 mmHg) (P = 0.049). Median SOFA scores for sepsis patients were 5.5 (interquartile range [IQR] 4-9). Mean percent cholesterol efflux was significantly reduced in sepsis (24.1 ± 1.2%) compared with controls (31.5 ± 1.0%) (P < 0.001). HDL inflammatory index was also significantly elevated in septic patients (1.63, IQR 1.3-2.34) compared with controls (0.62, IQR 0.56-0.67) (P < 0.001). However, PON1 activity was not significantly different between septic patients (70.3 ± 16.3 nmol/min/mL) and control subjects (88.8 ± 18.3 nmol/min/mL).ConclusionsCholesterol efflux capacity seems to be significantly impaired in sepsis patients who also exhibited a higher index of Dys-HDL. The findings suggest that HDL function may be impaired in older individuals with sepsis.