Multicentric investigations of the role in the disease severity of accelerated phospholipid changes in COVID-19 patient airway

CONTEXT

The changes in host membrane phospholipids are crucial in airway infection pathogenesis. Phospholipase A2 hydrolyzes host cell membranes, producing lyso-phospholipids and free fatty acids, including arachidonic acid (AA), which contributes significantly to lung inflammation.

AIM

Follow these changes and their evolution from day 1, day 3 to day 7 in airway aspirates of 89 patients with COVID-19-associated acute respiratory distress syndrome and examine whether they correlate with the severity of the disease. The patients were recruited in three French intensive care units. The analysis was conducted from admission to the intensive care unit until the end of the first week of mechanical ventilation.

RESULTS

In the airway aspirates, we found significant increases in the levels of host cell phospholipids, including phosphatidyl-serine and phosphatidyl-ethanolamine, and their corresponding lyso-phospholipids. This was accompanied by increased levels of AA and its inflammatory metabolite prostaglandin E2 (PGE2). Additionally, enhanced levels of ceramides, sphingomyelin, and free cholesterol were observed in these aspirates. These lipids are known to be involved in cell death and/or apoptosis, whereas free cholesterol plays a role in virus entry and replication in host cells. However, there were no significant changes in the levels of dipalmitoyl-phosphatidylcholine, the major surfactant phospholipid. A correlation analysis revealed an association between mortality risk and levels of AA and PGE2, as well as host cell phospholipids.

CONCLUSION

Our findings indicate a correlation between heightened cellular phospholipid modifications and variations in AA and PGE2 with the severity of the disease in patients. Nevertheless, there is no indication of surfactant alteration in the initial phases of the illness.

Novel insights into causal effects of serum lipids and lipid-modifying targets on cholelithiasis

OBJECTIVE

Different serum lipids and lipid-modifying targets should affect the risk of cholelithiasis differently, however, whether such effects are causal is still controversial and we aimed to answer this question.

DESIGN

We prospectively estimated the associations of four serum lipids with cholelithiasis in UK Biobank using the Cox proportional hazard model, including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG). Furthermore, we estimated the causal associations of the genetically predicted serum lipids with cholelithiasis in Europeans using the Mendelian randomisation (MR) design. Finally, both drug-target MR and colocalisation analyses were performed to estimate the lipid-modifying targets' effects on cholelithiasis, including HMGCR, NPC1L1, PCSK9, APOB, LDLR, ACLY, ANGPTL3, MTTP, PPARA, PPARD and PPARG.

RESULTS

We found that serum levels of LDL-C and HDL-C were inversely associated with cholelithiasis risk and such associations were linear. However, the serum level of TC was non-linearly associated with cholelithiasis risk where lower TC was associated with higher risk of cholelithiasis, and the serum TG should be in an inverted 'U-shaped' relationship with it. The MR analyses supported that lower TC and higher TG levels were two independent causal risk factors. The drug-target MR analysis suggested that HMGCR inhibition should reduce the risk of cholelithiasis, which was corroborated by colocalisation analysis.

CONCLUSION

Lower serum TC can causally increase the risk of cholelithiasis. The cholelithiasis risk would increase with the elevation of serum TG but would decrease when exceeding 2.57 mmol/L. The use of HMGCR inhibitors should prevent its risk.

Calculated LDL-cholesterol: comparability of the extended Martin/Hopkins, Sampson/NIH, Friedewald and four other equations in South African patients

AIMS

The reference method for low-density lipoprotein-cholesterol (LDL-C) is ultracentrifugation. However, this is unsuitable for routine use and therefore direct LDL-C assays and predictive equations are used. In this study, we compared the Friedewald, extended Martin/Hopkins, Sampson/NIH and four other equations to a direct assay.

METHODS

We analysed 44 194 lipid profiles from a mixed South African population. The LDL-C predictive equations were compared with direct LDL-C assay and analysed using non-parametric statistics and error grid analysis.

RESULTS

Both the extended Martin/Hopkins and Sampson/NIH equations displayed the best correlation with direct LDL-C in terms of desirable bias and total allowable error. The direct LDL-C assay classified 13.9% of patients in the low LDL-C (1.0-1.8 mmol/L) category, in comparison to the extended Martin/Hopkins equation (13.4%), the Sampson equation (14.6%) and the Friedewald equation (16.0%). The Sampson/NIH was least biased in the low LDL-C category (<1.8 mmol/L) and produced the least overall clinically relevant errors compared with the extended Martin/Hopkins and Friedewald equations in the low-LDL-C category.

CONCLUSIONS

Our findings suggest only a marginal difference between the extended Martin/Hopkins equation and the Sampson/NIH equation with the use of the Beckman Coulter DxC800 analyser in this population. The results favour the implementation of the Sampson/NIH equation when the Beckman Coulter DxC analyser is used, but the extended Martin/Hopkins may also be safely implemented. Both of these equations performed significantly better than the Friedewald equation. We recommend that patients be monitored using one of these methods and that each laboratory perform its own validation of either equation to ensure continuation and accuracy, and to prevent between-method variation.

Best practice for LDL-cholesterol: when and how to calculate

The lipid profile is important in the risk assessment for cardiovascular disease. The lipid profile includes total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides (TGs) and low-density lipoprotein (LDL)-cholesterol (LDL-C). LDL-C has traditionally been calculated using the Friedewald equation (invalid with TGs greater than 4.5 mmol/L and is based on the assumption that the ratio of TG to cholesterol in very- low-density lipoprotein (VLDL) is 5 when measured in mg /dL). LDL-C can be quantified with a reference method, beta-quantification involving ultracentrifugation and this is unsuitable for routine use. Direct measurement of LDL-C was expected to provide a solution with high TGs. However, this has some challenges because of a lack of standardisation between the reagents and assays from different manufacturers as well as the additional costs. Furthermore, mild hypertriglyceridaemia also distorts direct LDL-C measurements. With the limitations of the Friedewald equation, alternatives have been derived. Newer equations include the Sampson-National Institutes of Health (NIH) equation 2 and the Martin-Hopkins equation. The Sampson-NIH2 equation was derived using beta-quantification in a population with high TG and multiple least squares regression to calculate VLDL-C, using TGs and non-HDL-C as independent variables. These data were used in a second equation to calculate LDL-C. The Sampson-NIH2 equation can be used with TGs up to 9 mmol/L. The Martin-Hopkins equation uses a 180 cell stratification of TG/non-HDL-C to determine the TG:VLDL-C ratio and can be used with TGs up to 4.5 mmol/L. Recently, an extended Martin-Hopkins equation has become available for TGs up to 9.04 mmol/L.This article discusses the best practice approach to calculating LDL-C based on the available evidence.

Identification of bacterial lipopeptides as key players in IBS

OBJECTIVES

Clinical studies revealed that early-life adverse events contribute to the development of IBS in adulthood. The aim of our study was to investigate the relationship between prenatal stress (PS), gut microbiota and visceral hypersensitivity with a focus on bacterial lipopeptides containing γ-aminobutyric acid (GABA).

DESIGN

We developed a model of PS in mice and evaluated, in adult offspring, visceral hypersensitivity to colorectal distension (CRD), colon inflammation, barrier function and gut microbiota taxonomy. We quantified the production of lipopeptides containing GABA by mass spectrometry in a specific strain of bacteria decreased in PS, in PS mouse colons, and in faeces of patients with IBS and healthy volunteers (HVs). Finally, we assessed their effect on PS-induced visceral hypersensitivity.

RESULTS

Prenatally stressed mice of both sexes presented visceral hypersensitivity, no overt colon inflammation or barrier dysfunction but a gut microbiota dysbiosis. The dysbiosis was distinguished by a decreased abundance of Ligilactobacillus murinus, in both sexes, inversely correlated with visceral hypersensitivity to CRD in mice. An isolate from this bacterial species produced several lipopeptides containing GABA including C14AsnGABA. Interestingly, intracolonic treatment with C14AsnGABA decreased the visceral sensitivity of PS mice to CRD. The concentration of C16LeuGABA, a lipopeptide which inhibited sensory neurons activation, was decreased in faeces of patients with IBS compared with HVs.

CONCLUSION

PS impacts the gut microbiota composition and metabolic function in adulthood. The reduced capacity of the gut microbiota to produce GABA lipopeptides could be one of the mechanisms linking PS and visceral hypersensitivity in adulthood.

A Metabolic Screen in Adolescents Reveals an Association Between Circulating Citrate and Cortical Bone Mineral Density

Observations that insulin and adiponectin levels are related to cortical bone size in adolescents, independently of body composition, suggest factors related to fat metabolism directly influence skeletal development. To explore this question, we examined associations between a metabolic screen focusing on fat metabolism, and peripheral quantitative computed tomography (pQCT) measures of the mid-tibia, in 15-year-olds from the Avon Longitudinal Study of Parents and Children. Metabolic profiles were generated by proton nuclear magnetic resonance spectroscopy, from blood samples obtained at the same time as pQCT scans. Ordinary least squares linear regression was used to investigate relationships between metabolic measures and periosteal circumference (PC), cortical thickness (CT), and cortical bone mineral density (BMDC ). Metabolic profiles yielded 22 independent components following principal component analysis (PCA), giving a Bonferroni-adjusted threshold for statistical significance of p = 0.002. Data were available in 1121 subjects (487 males), mean age 15 years. Several metabolites related to lipid and cholesterol metabolism were associated with PC, CT, and BMDC after adjustment for age, sex, and Tanner stage. After additional adjustment for height, fat, and lean mass, only the association between citrate and BMDC remained below the Bonferroni-significant threshold (β = -0.14 [-0.18, -0.09]) (β represents a standardized coefficient). Citrate also showed evidence of association with PC (β = 0.06 [0.03, 0.10]) and strength strain index (SSI; β = 0.04 [0.01, 0.08]). Subsequently, we investigated whether these relationships were explained by increased bone resorption. Citrate was strongly related to serum β-C-telopeptides of type I collagen (β-CTX) (β = 0.20 [0.16, 0.23]). After additional adjustment for β-CTX the above associations between citrate and BMDC (β = -0.04 [-0.08, 0.01]), PC (β = 0.03 [-0.01, 0.07]) and SSI (β = 0.03 [-0.01, 0.07]) were no longer observed. We conclude that in adolescents, circulating levels of citrate are inversely related to BMDC and positively related to PC, reflecting associations with higher bone turnover. Further studies are justified to elucidate possible contributions of citrate, a constituent of bone matrix, to bone resorption and cortical density. © 2019 American Society for Bone and Mineral Research.

Niche Extracellular Matrix Components and Their Influence on HSC

Maintenance of hematopoietic stem cells (HSC) takes place in a highly specialized microenvironment within the bone marrow. Technological improvements, especially in the field of in vivo imaging, have helped unravel the complexity of the niche microenvironment and have completely changed the classical concept from what was previously believed to be a static supportive platform, to a dynamic microenvironment tightly regulating HSC homeostasis through the complex interplay between diverse cell types, secreted factors, extracellular matrix molecules, and the expression of different transmembrane receptors. To add to the complexity, non-protein based metabolites have also been recognized as a component of the bone marrow niche. The objective of this review is to discuss the current understanding on how the different extracellular matrix components of the niche regulate HSC fate, both during embryonic development and in adulthood. Special attention will be provided to the description of non-protein metabolites, such as lipids and metal ions, which contribute to the regulation of HSC behavior. J. Cell. Biochem. 118: 1984-1993, 2017. © 2017 Wiley Periodicals, Inc.

Human Milk MicroRNA and Total RNA Differ Depending on Milk Fractionation

MicroRNA have been recently discovered in human milk signifying potentially important functions for both the lactating breast and the infant. Whilst human milk microRNA have started to be explored, little data exist on the evaluation of sample processing, and analysis to ensure that a full spectrum of microRNA can be obtained. Human milk comprises three main fractions: cells, skim milk, and lipids. Typically, the skim milk fraction has been measured in isolation despite evidence that the lipid fraction may contain more microRNA. This study aimed to standardize isolation of microRNA and total RNA from all three fractions of human milk to determine the most appropriate sampling and analysis procedure for future studies. Three different methods from eight commercially available kits were tested for their efficacy in extracting total RNA and microRNA from the lipid, skim, and cell fractions of human milk. Each fraction yielded different concentrations of RNA and microRNA, with the highest quantities found in the cell and lipid fractions, and the lowest in skim milk. The column‐based phenol‐free method was the most efficient extraction method for all three milk fractions. Two microRNAs were expressed and validated in the three milk fractions by qPCR using the three recommended extraction kits for each fraction. High expression levels were identified in the skim and lipid milk factions for these microRNAs. These results suggest that careful consideration of both the human milk sample preparation and extraction protocols should be made prior to embarking upon research in this area. J. Cell. Biochem. 116: 2397–2407, 2015. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

Statins, antidiabetic medications and liver histology in patients with diabetes with non-alcoholic fatty liver disease

Background

Type-2 diabetes mellitus (T2DM) is a risk factor for progressive non-alcoholic fatty liver disease (NAFLD). Drugs commonly prescribed in patients with T2DM may affect liver histology by interfering with lipid metabolism and insulin resistance/secretion.

Aim

We studied if statins or antidiabetic agents were associated with non-alcoholic steatohepatitis (NASH) and significant fibrosis (SF).

Methods

We performed a cross-sectional study of 346 diabetics with biopsy-proven NAFLD. T2DM was defined as fasting glucose ≥7 mmol/L or glycated haemoglobin ≥6.5% and/or use of antidiabetics. NASH was defined according to the FLIP algorithm and SF as F2–4 Kleiner's stages.

Results

84% of patients were on antidiabetic therapy and 45% on statins. NASH and SF were present in 57% and 48% of patients. Statin-treated patients were older, more frequently male and with poorer glycaemic control despite more frequent antidiabetic therapy than those without statins; however, the prevalence of NASH (57%vs56%, p=0.868) and SF (48%vs48%, p=0.943) was not different between statin users and non-users. NASH was more common in patients on metformin or insulin than in those not treated with these drugs (60%vs47%, p=0.026; 68%vs53%, p=0.017). SF was more common in those treated with sulfonylureas (57%vs44%, p=0.030). Multivariate analyses confirmed that use of statins was independently and negatively associated with both NASH (OR (95% CI) 0.57 (0.32 to 1.01), p=0.055) and SF (OR (95% CI) 0.47 (0.26 to 0.84), p=0.011). Moreover, we found independent associations between insulin use and NASH (OR (95% CI) 2.24 (1.11 to 4.54), p=0.025) and sulfonylureas use and SF (OR (95% CI) 2.04 (1.11 to 3.74), p=0.022).

Conclusions

Several medications used in patients with diabetes are differently associated with NAFLD histology. Statin use is negatively associated, while insulin and sulfonylureas are positively associated with NASH and SF. A wider use of statins may be warranted in this high-risk population.

Distribution of lifespan gain from primary prevention intervention

Objective

When advising patients about possible initiation of primary prevention treatment, clinicians currently do not have information on expected impact on lifespan, nor how much this increment differs between individuals.

Methods

First, UK cardiovascular and non-cardiovascular mortality data were used to calculate the mean lifespan gain from an intervention (such as a statin) that reduces cardiovascular mortality by 30%. Second, a new method was developed to calculate the probability distribution of lifespan gain. Third, we performed a survey in three UK cities on 11 days between May–June 2014 involving 396 participants (mean age 40 years, 55% male) to assess how individuals evaluate potential benefit from primary prevention therapies.

Results

Among numerous identical patients, the lifespan gain, from an intervention that reduces cardiovascular mortality by 30%, is concentrated within an unpredictable minority. For example, men aged 50 years with national average cardiovascular risk have mean lifespan gain of 7 months. However, 93% of these identical individuals gain no lifespan, while the remaining 7% gain a mean of 99 months. Many survey respondents preferred a chance of large lifespan gain to the equivalent life expectancy gain given as certainty. Indeed, 33% preferred a 2% probability of 10 years to fivefold more gain, expressed as certainty of 1 year.

Conclusions

People who gain lifespan from preventative therapy gain far more than the average for their risk stratum, even if perfectly defined. This may be important in patient decision-making. Looking beyond mortality reduction alone from preventative therapy, the benefits are likely to be even larger.

Clinical trial: free fatty acid suppositories compared with enema as bowel preparation for flexible sigmoidoscopy

OBJECTIVES

The purpose of this trial was to evaluate the efficacy and safety of recently developed suppositories containing free fatty acids as a bowel-cleansing agent prior to flexible sigmoidoscopy and compare them with Klyx (docusate sodium/sorbitol).

DESIGN

A controlled, non-inferiority, single-blind, randomised study on outpatients undergoing flexible sigmoidoscopy.

SETTING

Department of Gastroenterology, Landspitali-University Hospital and endoscopic clinic.

PATIENTS

53 outpatients undergoing flexible sigmoidoscopy.

INTERVENTION

Participants were randomised to receive either free fatty acid suppositories (28) or a standard bowel preparation with Klyx enema (25). In the study group, two suppositories were administered the evening before as well as 2 h prior to the sigmoidoscopy. In the control group, Klyx enema (120 mL) was administered the evening before and repeated 2 h prior to the procedure.

MAIN OUTCOME MEASUREMENTS

Quality of the bowel cleansing, height of scope insertion and safety.

RESULTS

The mean height of scope insertion and bowel cleansing was 43 cm (SD=13.4) in the study group and 48 cm (SD=10.4) in the control group (NS). The investigating physicians were less satisfied with the bowel preparation in the study group compared with the control group with a difference of 20% (p<0.016). The amount of faeces noted in the rectum was similar in both groups with no significant difference (p<0.56). No serious side effects, toxic reaction or irritation were observed.

CONCLUSIONS

The suppositories are well tolerated with no significant side effects. The suppositories had distinct bowel emptying effect and as effective as Klyx in rectal cleansing. Although physician's satisfaction was slightly lower, the height of scope insertion was similar.

TRIAL REGISTRATION NUMBER

EudraCT nr.: 2010-018761-35.

Statin therapy in patients with cirrhosis

Cardiovascular disease is one of the leading causes of death among patients with cirrhosis and following liver transplantation. Although 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors ('statins') reduce the risk of cardiovascular events, fears about hepatotoxicity have historically led to underuse in patients with liver disease. In addition, the pharmacokinetics of statins can be significantly altered in cirrhosis, creating challenges with their use in liver disease. However, emerging data from randomised controlled trials and observational studies suggest that statin therapy appears to be safe and effective in patients with chronic liver disease and compensated cirrhosis. The cardiovascular risk benefits as well as the potential pleiotropic benefits of statins warrants strong consideration of use of statin therapy in patients with cirrhosis.

Reduction of Inflammation Drives Lipid Changes in Ankylosing Spondylitis

OBJECTIVE

To investigate the effects of changing inflammation on lipid levels in ankylosing spondylitis.

METHODS

In a cohort of 230 patients, lipid levels were measured at baseline and after 52 weeks of treatment with tumor necrosis factor-α-blocking agents (anti-TNF).

RESULTS

Total cholesterol (TC; +4.6%), low-density lipoprotein cholesterol (+4.3%), and high-density lipoprotein cholesterol (HDL-C; +3.7%) increased upon treatment. Changes were most evident in patients with substantial reduction in inflammatory levels (TC +8.2% vs +1.6% and HDL-C +8.3% vs +2.2% in patients with C-reactive protein ≥ 10 mg/l normalizing upon treatment vs CRP < 10 mg/l throughout treatment period).

CONCLUSION

Anti-TNF therapy results in lipid changes mostly when inflammation is appreciably modified.

AGXT2L1 is down-regulated in heptocellular carcinoma and associated with abnormal lipogenesis

AIMS

To clarify the clinical implications and functional role of the alanine-glyoxylate aminotransferase 2-like 1 (AGXT2L1) gene in hepatocellular carcinoma (HCC).

METHODS AND RESULTS

We confirmed that AGXT2L1 was down-regulated in liver cancer samples by immunohistochemical (IHC) staining. We also demonstrated that this down-regulation was associated with several clinicopathological features such as alpha fetoprotein (AFP) serum level and T stage. Furthermore, we showed with Kaplan-Meier analysis that expression of AGXT2L1 in tumour samples was significantly correlated with patient prognosis. The bioinformatic tool indicated that AGXT2L1 plays a role in the lipid metabolic process of HCC tissue, while siRNA silenced the expression of AGXT2L1 in HCC 97H and LM3 cells, confirming that down-regulation of AGXT2L1 promotes the lipogenesis of cancer cells.

CONCLUSIONS

For the first time, we have shown that AGXT2L1 is down-regulated in HCC and its low expression indicates a poor prognosis. Our findings also demonstrated that AGXT2L1 is a crucial gene in the abnormal lipogenesis of HCC tissue.

Metabolic syndrome is associated with and predicted by resting heart rate: a cross-sectional and longitudinal study

OBJECTIVE

Although higher resting heart rate (RHR) has emerged as a predictor for lifespan, the underlying mechanisms remain obscure. The present study investigates whether a positive relationship exists between RHR and metabolic syndrome (MetS) and whether RHR predicts future MetS.

METHODS

A cohort of 89,860 participants were surveyed during 2006-2007 in Kailuan/Tangshan, China. MetS was diagnosed when a participant presented at least three of the following: abdominal adiposity, low high density lipoprotein-cholesterol, high triglycerides, hypertension or impaired fasting glucose. RHR was derived from ECG recordings and subjects were stratified based on RHR. Some participants without MetS at baseline were followed-up for 4 years.

RESULTS

At baseline, 23,150 participants (25.76%) had MetS. There was a positive association between RHR and MetS. The OR of having MetS was 1.49 (95% CI 1.32 to 1.69) in subjects with RHR at 95-104 compared with those at 55-64 beats per minute (bpm) (reference), after adjusting for variables including age, sex, education, cigarette smoking, alcohol drinking, physical activities, body mass index, hypertension, diabetes, hyperlipidaemia, inflammatory biomarkers and renal function. More importantly, when 43,725 individuals from the original study without MetS at baseline were followed-up, higher RHR was found to predict greater risk of MetS incidence. The OR of developing MetS 4 years later was 1.41 (95% CI 1.21 to 1.65) in subjects with RHR at 95-104 bpm compared with reference, after all adjustments.

CONCLUSIONS

Our cross-sectional and longitudinal findings provide evidence that RHR is an independent risk factor for existing MetS and a powerful predictor for future incidence of MetS.

Associations of maternal 25-hydroxyvitamin D in pregnancy with offspring cardiovascular risk factors in childhood and adolescence: findings from the Avon Longitudinal Study of Parents and Children

Objective

Lower maternal vitamin D status in pregnancy may be associated with increased offspring cardiovascular risk in later life, but evidence for this is scant. We examined associations of maternal total 25-hydroxyvitamin D (25(OH)D) in pregnancy with offspring cardiovascular risk factors assessed in childhood and adolescence.

Design

A longitudinal, prospective study.

Setting

The study was based on data from mother–offspring pairs in the Avon Longitudinal Study of Parents and Children (ALSPAC), a UK prospective population-based birth cohort (N=4109).

Outcome measures

Offspring cardiovascular risk factors were measured in childhood (mean age 9.9 years) and in adolescence (mean age 15.4 years): blood pressure, lipids, apolipoproteins (at 9.9 years only), glucose and insulin (at 15.4 years only), C reactive protein (CRP), and interleukin 6 (at 9.9 years only) were measured.

Results

After adjustments for potential confounders (maternal age, education, body mass index (BMI), smoking, physical activity, parity, socioeconomic position, ethnicity, and offspring gestational age at 25(OH)D sampling; gender, age, and BMI at outcome assessment), maternal 25(OH)D was inversely associated with systolic blood pressure (−0.48 mm Hg difference per 50 nmol/L increase in 25(OH)D; 95% CI −0.95 to −0.01), Apo-B (−0.01 mg/dL difference; 95% CI −0.02 to −0.001), and CRP (−6.1% difference; 95% CI −11.5% to −0.3%) at age 9.9 years. These associations were not present for risk factors measured at 15.4 years, with the exception of a weak inverse association with CRP (−5.5% difference; 95% CI −11.4% to 0.8%). There was no strong evidence of associations with offspring triglycerides, glucose or insulin.

Conclusions

Our findings suggest that fetal exposure to 25(OH)D is unlikely to influence cardiovascular risk factors of individuals later in life.

MRI-measured regression of carotid atherosclerosis induced by statins with and without niacin in a randomised controlled trial: the NIA plaque study

OBJECTIVE

To evaluate the benefit of niacin in addition to statin therapy on plaque regression among older individuals with established atherosclerosis.

DESIGN

Randomised, controlled, double-blind clinical trial.

SETTING

University outpatient center.

PATIENTS

145 patients older than 65 years, half of them older than 75 years of age, with established atherosclerosis were enrolled.

INTERVENTIONS

Participants received either extended release niacin (1500 mg daily) or placebo in addition to statin therapy to reach their National Cholesterol Education Program-defined low density lipoprotein (LDL) cholesterol target.

MAIN OUTCOME MEASURES

The primary endpoint was reduction in the wall volume of the internal carotid artery (ICA) measured by MRI.

RESULTS

After 18 months, high density lipoprotein cholesterol was higher with statins plus niacin compared with statins alone (1.6 ± 0.4 vs 1.4 ± 0.4 mmol/L p<0.001). Both groups had significant decreases in the main outcome measure of ICA wall volume, which regressed at 0.5%/month (SEM 0.2, p=0.004) in the statins plus placebo group and at 0.7%/month in the statins plus niacin group (SEM 0.2, p<0.001). There was no difference in the rate of regression between groups (p=0.49).

CONCLUSIONS

Treatment with statin therapy to presently recommended LDL levels, with or without niacin, resulted in significant atherosclerosis reduction.

Use of lipid-lowering agents in rheumatoid arthritis: a population-based cohort study

OBJECTIVE

Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease and mortality. Lipid-lowering therapy is reportedly underused in patients with RA. Longitudinal cohort studies comparing use of lipid-lowering medications in patients with RA versus the general population are lacking.

METHODS

Cardiovascular risk factors, lipid measures, and use of lipid-lowering agents were assessed in a population-based inception cohort of patients with RA and a cohort of non-RA subjects followed from January 1, 1988, to December 31, 2008. The National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATPIII) guidelines were assessed at the time of each lipid measure throughout followup. Time from meeting guidelines to initiation of lipid-lowering agents was assessed using Kaplan-Meier methods.

RESULTS

The study population included 412 RA and 438 non-RA patients with ≥ 1 lipid measure during followup and no prior use of lipid-lowering agents. Rates of lipid testing were lower among patients with RA compared to non-RA subjects. Among patients who met NCEP ATPIII criteria for lipid-lowering therapy (n = 106 RA; n = 120 non-RA), only 27% of RA and 26% of non-RA subjects initiated lipid-lowering agents within 2 years of meeting the guidelines for initiation.

CONCLUSION

There was substantial undertreatment in both the RA and the non-RA cohorts who met NCEP ATPIII criteria for initiation of lipid-lowering agents. Patients with RA did not have as frequent lipid testing as individuals in the general population.

The fate of bacteria within phagocytic cells. I. The degradation of isotopically labeled bacteria by polymorphonuclear leucocytes and macrophages

The intraleucocytic fate of a variety of P³²- and C¹⁴-labeled bacteria has been studied in both polymorphonuclear leucocytes and macrophages. Both cell types brought about extensive degradation of bacterial lipids, nucleic acids, and proteins. Intracellular breakdown was primarily dependant upon the composition of the ingested particle rather than on the type or source of the phagocyte. Evidence is presented for the reincorporation of bacterial constituents into leucocyte lipid. More than 50 per cent of the acid-soluble degradation products of P³²-labeled bacteria appear as inorganic phosphate. Bacterial RNA is degraded more readily than DNA. Following phagocytosis, labeled bacteria lose their pool of small molecular weight intermediates. This is followed by the degradation of acid-insoluble constituents. The majority of bacterial breakdown products are then excreted by the leucocyte and appear in the medium. Heat-killed bacteria were more readily broken down than viable organisms. Only small amounts of C¹⁴-labeled bacteria were completely oxidized by leucocytic enzymes to C¹⁴O₂. Acid extracts of polymorphonuclear leucocyte granules, which were highly bactericidal, liberated the acid-soluble constituents of labeled bacteria but did not significantly degrade bacterial macromolecules.

Pancreatectomy in rats: onset of metabolic changes in liver, adipose, and diaphragm

The time of onset of metabolic alterations in utilization of C14-labeled glucose and acetate by liver and adipose tissue, and in uptake of glucose by diaphragm was studied in "totally" depancreatized rats, a preparation in which severe manifestations of diabetes develop rapidly. The earliest changes were observed in glucose utilization by liver and adipose tissue. Two hours after pancreatectomy, conversion of glucose carbon to a) fatty acids, glycogen, and CO2 by liver slices and b) fatty acids and CO2 by adipose tissue was depressed. Defective utilization of acetate appeared earlier in adipose tissue than in liver. A decrease in the liver's capacity to convert acetate carbon to fatty acids developed some time between 4 and 14 hr after pancreatectomy. In adipose tissue this occurred between 2 and 4 hr. Defective uptake of glucose by diaphragm was observed later after pancreatectomy, some time between 4 and 14 hr. The results are discussed from the standpoint of the nature of metabolic lesions in the diabetic liver and of whether insulin has a direct or indirect action on hepatic tissue.