Influence Plasma Lipid Levels Research Articles

Effect of IL-6R blockade on plasma lipids and clinical outcomes among hospitalized patients with COVID-19 infection

Plasma lipid levels are modulated by systemic infection and inflammation; it is unknown whether these changes reflect inflammatory responses or caused directly by pathogen presence. We explored the hypothesis that anti-inflammatory intervention via interleukin 6 receptor (IL-6R) blockade would influence plasma lipid levels during severe infection and evaluated the association of plasma lipid changes with clinical outcomes. Sarilumab (monoclonal antibody blocking IL-6R) efficacy was previously assessed in patients with coronavirus disease 2019 (COVID-19) (NCT04315298). This analysis determined whether strong inflammatory reduction by sarilumab in patients with COVID-19 pneumonia of increasing severity (severe, critical, multisystem organ dysfunction) affected plasma lipid changes between day 1 and day 7 of study therapy. Baseline lipid levels reflected the presence of acute systemic infection, characterized by very low HDL-C, low LDL-C, and moderately elevated triglycerides (TGs). Disease severity was associated with progressively more abnormal lipid levels. At day 7, median lipid levels increased more in the sarilumab versus placebo group (HDL-C +10.3%, LDL-C +54.7%, TG +32% vs. HDL-C +1.7%, LDL-C +15.4%, TG +8.8%, respectively). No significant association between lipid changes and clinical outcomes was observed. In conclusion, severe-to-critical COVID-19 pneumonia causes profound HDL-C depression that is only modestly responsive to strong anti-IL-6R inflammatory intervention. Conversely, LDL-C depression is strongly responsive to IL-6R blockade, with LDL-C levels likely returning to the predisease set point. These results advance our understanding of the complex relationship between serum lipids and infection/inflammation and suggest that HDL-C depression during acute contagious disease is driven by infection and not IL-6–mediated inflammation.

Role of Rare and Low-Frequency Variants in Gene-Alcohol Interactions on Plasma Lipid Levels.

Alcohol intake influences plasma lipid levels, and such effects may be moderated by genetic variants. We aimed to characterize the role of aggregated rare and low-frequency protein-coding variants in gene by alcohol consumption interactions associated with fasting plasma lipid levels. In the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium, fasting plasma triglycerides and high- and low-density lipoprotein cholesterol were measured in 34 153 individuals with European ancestry from 5 discovery studies and 32 277 individuals from 6 replication studies. Rare and low-frequency functional protein-coding variants (minor allele frequency, ≤5%) measured by an exome array were aggregated by genes and evaluated by a gene-environment interaction test and a joint test of genetic main and gene-environment interaction effects. Two dichotomous self-reported alcohol consumption variables, current drinker, defined as any recurrent drinking behavior, and regular drinker, defined as the subset of current drinkers who consume at least 2 drinks per week, were considered. We discovered and replicated 21 gene-lipid associations at 13 known lipid loci through the joint test. Eight loci (PCSK9, LPA, LPL, LIPG, ANGPTL4, APOB, APOC3, and CD300LG) remained significant after conditioning on the common index single-nucleotide polymorphism identified by previous genome-wide association studies, suggesting an independent role for rare and low-frequency variants at these loci. One significant gene-alcohol interaction on triglycerides in a novel locus was significantly discovered (P=6.65×10-6 for the interaction test) and replicated at nominal significance level (P=0.013) in SMC5. In conclusion, this study applied new gene-based statistical approaches and suggested that rare and low-frequency genetic variants interacted with alcohol consumption on lipid levels.

The relationship of high density lipoprotein cholesterol and cholesterol ester transfer protein TaqIB mutation in non-arteritic anterior ischemic optic neuropathy

Objective To investigate the association of high density lipoprotein cholesterol (HDL-C) and cholesterol ester transfer protein (CETP) TaqIB mutation with non-arteritic anterior ischemic optic neuropathy (NA-AION) in the Shaanxi Han ethnic population. Methods The study cohort consisted of 45 individuals that had been diagnosed with NA-AION and 45 healthy controls (matched for age, gender). None of the cases or controls had a history of diabetes, serious cardio-cerebral vascular diseases, liver and kidney dysfunction that might influence plasma lipid levels. Plasma HDL-C was detected by enzyme-linked immunosorbent one-step, through the Toshiba TBA-40FR automatic biochemical analyzer. CETP TaqIB gene polymorphism was determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques for analysis. B2B2 genotype was only a fluorescence band with 535 bp; B1B1 genotype was 2 fluorescence bands with 361, 174 bp; B1B2 genotype was 3 fluorescence bands with 535, 361, 174 bp. The relative risk of genotype, HDL-C and disease occurrence was analyzed by logistics regression analysis. Results There have no significant difference between NA-AION patients and controls about plasma total cholesterol level and triglyceride level (t=1.907, 1.877; P>0.05). The plasma HDL-C levels were significantly lower in NA-AION patients than in controls (t=2.367, P=0.022). Compared with controls, the prevalence of B1B1 genotype and B1 allele was higher (χ2=17.289, P=0.001), the prevalence of B2 allele (χ2=15.648, P=0.000) was lower in NA-AION patients. The lower concentration of HDL-C was risk factor of NA-AION (odds ratio=6.143, 95% confidence interval 1.262 - 29.895, χ2=27.676; P=0.013). The proportion of B1B1 genotype was significantly higher in NA-AION patients than in controls (odds ratio=2.24, 95% confidence interval 2.427- 36.323, χ2=10.526; P=0.001). Conclusions The low plasma HDL-C is independent risk factor for NA-AION and is associated with the development of NA-AION in the Shaanxi Han ethnic population. CETP TaqIB mutation is associated with low plasma HDL-C in NA-AION in the Shaanxi Han ethnic population. Key words: Optic neuropathy, ischemic/etiology; Cholesterol, HDL/genetics; Cholesterol ester transfer proteins/genetics; Alleles; Gene frequency; Polymorphism, genetic/genetics

Common variants associated with blood lipid levels do not affect carotid plaque composition

IntroductionAlthough plasma lipid levels are known to influence the risk of cardiovascular disease (CVD), little is known about their effect on atherosclerotic plaque composition. To date, large-scale genome-wide association studies have identified 157 common single-nucleotide polymorphisms (SNPs) that influence plasma lipid levels, providing a powerful tool to investigate the effect of plasma lipid levels on atherosclerotic plaque composition. MethodsIn this study, we included 1443 carotid endarterectomy patients from the Athero-Express Biobank Study with genotype data. Plasma concentrations of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and triglycerides (TG) were determined at the time of endarterectomy. Atherosclerotic plaques, obtained during surgery, were histologically examined. For all patients, we calculated weighted genetic burden scores (GBS) for all lipid traits on the basis of the available genotype data. Plasma lipid levels and GBS were tested for association with 7 histological features using linear and logistic regression models. ResultsAll GBS were associated with their respective plasma lipid concentrations (pHDL-C = 2.4 × 10−14, pLDL-C = 0.003, pTC = 2.1 × 10−6, pTG = 3.4 × 10−8). Neither the measured plasma lipids, nor the GBS, were associated with histological features of atherosclerotic plaque composition. In addition, neither the plasma lipids nor the GBS were associated with clinical endpoints within 3 years of follow-up, with the notable exception of a negative association between HDL-C and composite cardiovascular endpoints. ConclusionThis study found no evidence that plasma lipid levels or their genetic determinants influence carotid plaque composition.

The rs2516839 Polymorphism of the USF1 Gene May Modulate Serum Triglyceride Levels in Response to Cigarette Smoking.

Single nucleotide polymorphisms (SNPs) of the USF1 gene (upstream stimulatory factor 1) influence plasma lipid levels. This study aims to determine whether USF1 SNPs interact with traditional risk factors of atherosclerosis to increase coronary artery disease (CAD) risk. In the present study serum lipid levels and USF1 gene polymorphisms (rs2516839 and rs3737787) were determined in 470 subjects: 235 patients with premature CAD and 235 controls. A trend of increasing triglycerides (TG) levels in relation to the C allele dose of rs2516839 SNP was observed. The synergistic effect of cigarette smoking and C allele carrier state on CAD risk was also found (SIM = 2.69, p = 0.015). TG levels differentiated significantly particular genotypes in smokers (1.53 mmol/L for TT, 1.80 mmol/L for CT and 2.27 mmol/L for CC subjects). In contrast, these differences were not observed in the non-smokers subgroup (1.57 mmol/L for TT, 1.46 mmol/L for CT and 1.49 mmol/L for CC subjects). In conclusion, the rs2516839 polymorphism may modulate serum triglyceride levels in response to cigarette smoking. Carriers of the C allele seem to be particularly at risk of CAD, when exposed to cigarette smoking.

A Regulator of Secretory Vesicle Size, Kelch-Like Protein 12, Facilitates the Secretion of Apolipoprotein B100 and Very-Low-Density Lipoproteins—Brief Report

One of the major risk factors for atherosclerosis is the plasma level of low-density lipoprotein (LDL), which is a product of very-low-density lipoprotein (VLDL). Hepatic apolipoprotein B100 (apoB100) is the essential component that provides structural stability to VLDL particles. Newly translated apoB100 is partially lipidated in the endoplasmic reticulum (ER), forming nascent apoB100-VLDL particles. These particles are further modified to form fully mature VLDLs in the Golgi apparatus. Therefore, the transport of nascent VLDL from the ER to the Golgi represents a critical step during VLDL maturation and secretion and in regulating serum LDL cholesterol levels. Our previous studies showed that apoB100 exits the ER in coat complex II vesicles (COPII), but the cohort of related factors that control trafficking is poorly defined. Expression levels of Kelch-like protein 12 (KLHL12), an adaptor protein known to assist COPII-dependent transport of procollagen, were manipulated by using a KLHL12-specific small interfering RNA and a KLHL12 expression plasmid in the rat hepatoma cell line, McArdle RH7777. KLHL12 knockdown decreased the secreted and intracellular pools of apoB100, an effect that was attenuated in the presence of an autophagy inhibitor. KLHL12 knockdown also significantly reduced secretion of the most lipidated apoB100-VLDL species and led to the accumulation of apoB100 in the ER. Consistent with these data, KLHL12 overexpression increased apoB100 recovery and apoB100-VLDL secretion. Images obtained from confocal microscopy revealed colocalization of apoB100 and KLHL12, further supporting a direct link between KLHL12 function and VLDL trafficking from the ER. KLHL12 plays a critical role in facilitating the ER exit and secretion of apoB100-VLDL particles, suggesting that KLHL12 modulation would influence plasma lipid levels.

The association of apolipoprotein E polymorphism and lipid levels in children with a family history of premature coronary artery disease

Polymorphisms in the apolipoprotein E (apoE) gene may modulate lipoprotein metabolism and influence plasma lipid levels. Thus, they have been associated with relative risk of coronary artery disease (CAD). To evaluate the association of apolipoprotein E polymorphism and lipid levels in children with family history of premature coronary artery disease. The apoE genotypes, allele frequencie,s and plasma lipid levels were analyzed in 137children. Among these children, 70 (study group) had and 67 (control group) did not have a parental history of premature CAD RESULTS: Total cholesterol (Tc) levels were greater in the study group (P= .04). The frequencies of ɛ3ɛ4 genotype and ɛ4 allele were significantly greater in the study group (P= 005 for both), Thɛ ɛ2 allele correlated negatively with Tc and low-density lipoprotein cholesterol levels, and ɛ4 had a positive correlation with Tc and low-density lipoprotein cholesterol levels. Tc levels are influenced by apoE genotypes in childhood. Also, the frequency of the ɛ4 allele is greater in children with family history of premature CAD. The ɛ4 allele may be associated with an increased risk for development of atherosclerosis by elevated levels of Tc in children with family history of CAD. The evaluation of apoE gene polymorhisms may contribute to the assessment of cardiovascular risk in children with a family history of CAD.

Beneficial Effects of Periodontal Treatment on Metabolic Control of Hypercholesterolemia

The authors aimed to evaluate whether local periodontal therapy may influence plasma lipid levels in patients with periodontitis. Fifty patients (31 females and 19 males, age 36-66 yr) were randomly assigned to the treatment and control groups. Lipid profile and dental variables were measured at baseline and at the end of the study in both groups. In the third month, there was a significant decrease in total and low density lipoprotein (LDL) cholesterol levels of the treatment group compared with baseline values. Also, the reduction in bleeding on probing, pocket depth, attachment loss, plaque index and gingival index were statistically significant in the treatment group. The present study indicates that periodontitis causes changes in total and LDL cholesterol levels and local periodontal treatment resulted in a significant decrease in these markers. These results suggest a potential effect of periodontitis-driven systemic inflammation on lipid metabolism.

Site-specific influence of polyunsaturated fatty acids on atherosclerosis in immune incompetent LDL receptor deficient mice

Polyunsaturated fatty acids (PUFA) are thought to influence plasma lipid levels, atherosclerosis, and the immune system. In this study, we fed male LDL receptor deficient (LDLR −/−) mice and immune incompetent LDLR −/− RAG2 −/− mice diets containing predominantly saturated fats (milk fat) or PUFA (safflower oil) to determine if the response to diet was influenced by immune status. Relative to milk fat diet, plasma lipid and VLDL levels in both the LDLR −/− and LDLR −/− RAG2 −/− mice fed safflower oil diet were lower, suggesting that the primary effect of PUFA on plasma lipids was not due to its inhibition of the immune system. Neither diet nor immune status influenced hepatic triglyceride production and post-heparin lipase activity, suggesting that the differences in triglyceride levels are due to differences in rates of catabolism of triglyceride-rich lipoproteins. While both diets promoted atherogenesis, both aortic root and innominate artery atherosclerosis in LDLR −/− mice was less in safflower oil fed animals. In contrast, a site-specific effect of PUFA was observed in the immune incompetent LDLR −/− RAG2 −/−. In these mice, aortic root atherosclerosis, but not innominate artery atherosclerosis, was less in PUFA fed animal. These results suggest that PUFA and the immune system may influence innominate artery atherosclerosis by some overlapping mechanisms.

Changes in Plasma Lipid and Antioxidant Activity in Rats as a Result of Naringin and Red Grapefruit Supplementation

The aim of this investigation was to compare the influence of naringin versus red grapefruit juice on plasma lipid levels and plasma antioxidant activity in rats fed cholesterol-containing and cholesterol-free diets. The antioxidant activity of a correlated quantity of red grapefruit juice was higher than that of naringin. Forty-two male Wistar rats were randomly divided into six groups of 7 named control, naringin, grapefruit, Chol, Chol/naringin, and Chol/grapefruit. The rats of the control group were fed basal diet (BD) and 1-2 mL of distilled water. To the BD of the other five groups were added 0.46-0.92 mg of naringin dissolved in 1-2 mL of distilled water (naringin), 1-2 mL of red grapefruit juice (grapefruit), 1% of nonoxidized cholesterol (NOC) and 1-2 mL of distilled water (Chol), 1% of NOC and 0.46-0.92 mg of naringin in 1-2 mL of water (Chol/naringin), and 1% of NOC and 1-2 mL of red grapefruit juice (Chol/grapefruit). After 30 days of different feeding, it was found that diets supplemented with red grapefruit juice and to a lesser degree with naringin improved the plasma lipid levels mainly in rats fed cholesterol and increased the plasma antioxidant activity. In conclusion, naringin is a powerful plasma lipid lowering and plasma antioxidant activity increasing flavonone. However, fresh red grapefruit is preferable than naringin: it more effectively influences plasma lipid levels and plasma antioxidant activity and, therefore, could be used as a valuable supplement for disease-preventing diets.

Plasma circulating fibrinogen stability and moderate beer consumption

Moderate beer consumption (MBC) is cardioprotective: it positively influences plasma lipid levels and plasma antioxidant activity in beer-consuming individuals. The connection between MBC and blood coagulation is not clearly defined. Forty-two volunteers were equally divided into experimental (EG) and control (CG) groups following coronary bypass surgery. For 30 consecutive days, only patients of the EG consumed 330 mL of beer per day (about 20 g of alcohol). A comprehensive clinical investigation of 42 patients was done. Blood samples were collected before and after the investigation for a wide range of laboratory tests. The plasma fibrinogen was denatured with 8 M urea and intrinsic fluorescence (IF), hydrophobicity and differential scanning calorimetry (DSC) were used to reveal possible qualitative changes. After 30 days of moderate beer consumption, positive changes in the plasma lipid levels, plasma anticoagulant and plasma antioxidant activities were registered in patients of the EG group. In 17 out of 21 patients of the same group, differences in plasma circulating fibrinogen's (PCF), secondary and tertiary structures were found. The stability of fibrinogen, expressed in thermodynamic parameters, has shown that the loosening of the structure takes place under ethanol and urea denaturation. Also fluorescence stability of PCF was decreased. No changes in the lipid levels, anticoagulant and antioxidant activity or changes in PCF were detected in patients of CG. In conclusion, for the first time after a short term of moderate beer consumption some qualitative changes in the plasma circulating fibrinogen were detected: differences in the emission peak response, fluorescence intensity and all thermodynamic data. Together, with the decrease in the PCF concentration it may lead to an elevation of the blood anticoagulant activity.

Polymorphisms in the gene for hepatic triglyceride lipase influence plasma lipid levels but are weak predictors for the occurrence and severity of coronary heart disease — the luric study

Polymorphisms in the gene for hepatic triglyceride lipase influence plasma lipid levels but are weak predictors for the occurrence and severity of coronary heart disease — the luric study

Common genetic variation in ABCA1 is associated with altered lipoprotein levels and a modified risk for coronary artery disease.

Low plasma HDL cholesterol (HDL-C) is associated with an increased risk of coronary artery disease (CAD). We recently identified the ATP-binding cassette transporter 1 (ABCA1) as the major gene underlying the HDL deficiency associated with reduced cholesterol efflux. Mutations within the ABCA1 gene are associated with decreased HDL-C, increased triglycerides, and an increased risk of CAD. However, the extent to which common variation within this gene influences plasma lipid levels and CAD in the general population is unknown. We examined the phenotypic effects of single nucleotide polymorphisms in the coding region of ABCA1. The R219K variant has a carrier frequency of 46% in Europeans. Carriers have a reduced severity of CAD, decreased focal (minimum obstruction diameter 1.81+/-0.35 versus 1.73+/-0.35 mm in noncarriers, P:=0.001) and diffuse atherosclerosis (mean segment diameter 2.77+/-0.37 versus 2.70+/-0.37 mm, P:=0.005), and fewer coronary events (50% versus 59%, P:=0.02). Atherosclerosis progresses more slowly in carriers of R219K than in noncarriers. Carriers have decreased triglyceride levels (1.42+/-0.49 versus 1.84+/-0.77 mmol/L, P:=0.001) and a trend toward increased HDL-C (0.91+/-0.22 versus 0.88+/-0.20 mmol/L, P:=0.12). Other single nucleotide polymorphisms in the coding region had milder effects on plasma lipids and atherosclerosis. These data suggest that common variation in ABCA1 significantly influences plasma lipid levels and the severity of CAD.

Influence of the apolipoprotein E polymorphism on plasma lipoproteins in a Mexican population.

The influence of apolipoprotein E (APOE) genotypes on plasma lipid levels was determined in 278 Mexican individuals. The most frequent genotype was E3/3 (80.5%) followed by E3/4 (12.5%), E2/3 (5.0%), E2/4 (1.4%), and E4/4 (0.3%). Our data are similar to those previously described for Mexican-American and American Indian populations, which show the highest frequency worldwide of the APOE*3 and the E3/3 genotype. Compared to female carriers of the E3/3 genotype, women with the E3/4 genotype presented increased low-density lipoprotein cholesterol (117 +/- 28.0 mg/dL vs. 134.0 +/- 31.7 mg/dL, p < 0.05), and total cholesterol (179.4 +/- 33.4 mg/dL vs. 197.5 +/- 35.4 mg/dL, p < 0.01). Also, we detected increased high-density lipoprotein concentrations in women with the E2/3 genotype (53.7 +/- 19.5 mg/dL) when compared to women with the E3/3 genotype (45.2 +/- 12.0 mg/dL) (p < 0.032). Our data suggest that genetic variation at the APOE locus in the Mexican population is a genetic factor that influences plasma lipid levels. This effect was observed only in the female population. Additional studies attempting to correlate APOE polymorphism with plasma lipid profile in a large number of individuals would be helpful in establishing the true significance of this polymorphism in the Mexican population.

Hydrogenated fat consumption affects cholesterol synthesis in moderately hypercholesterolemic women

To determine mechanisms by which hydrogenated fat influences plasma lipid levels, 14 women (65–71 yrs with LDL-C ≥ 130 mg·dl−1) consumed, for 5-week periods each, a baseline (BL) diet (39% kcal fat, 164 mg chol·1000 kcal−1) and reduced fat diets (30% kcal) where two-thirds of the fat was either soybean oil (SO), low trans squeeze (SQM), medium trans tub (TM), or high trans stick (SM) margarines, or butter (BT). Plasma lipid levels were analyzed at the end of each phase. Fractional synthesis rates (FSR) in pools/day (p·d−1) and absolute synthesis rates (ASR) in grams/day (g·d−1) of free cholesterol (FC) were measured using the deuterium incorporation methodology. Plasma total (P < 0.01) and low density lipoprotein (P < 0.05) cholesterol levels increased with increasing degree of hydrogenation or saturated fat intake. High density lipoprotein cholesterol levels (P < 0.05) were lowest on the SM diet when compared to the BT diet. Low trans SQM (0.081 ± 0.019 p·d−1) and medium trans TM (0.086 ± 0.029 p·d−1) diets elicited responses similar to the SO (0.078 ± 0.024 p·d−1) diet, whereas high trans SM (0.053 ± 0.029 p·d−1) diet mimicked the BT (0.062 ± 0.017 p·d−1) and high fat BL (0.053 ± 0.023 p·d−1) diet in its suppression (P < 0.05) of FSR-FC. ASR-FC, which is an approximation of the daily production of newly synthesized cholesterol, showed a trend similar to the FSR-FC data. These results indicate that reduced synthesis is not responsible for the higher plasma TC levels seen with consumption of the SM, BT, and BL diets, and suggest that another mechanism, possibly impairment of the catabolic pathway of cholesterol, is involved.—Matthan, N. R., L. M. Ausman, A. H. Lichtenstein, and P. J. H. Jones. Hydrogenated fat consumption affects cholesterol synthesis in moderately hypercholesterolemic women. J. Lipid Res. 2000. 41: 834–839.