Relation of hypertriglyceridemia to plasma concentrations of biochemical markers of inflammation and endothelial activation (C-reactive protein, interleukin-6, soluble adhesion molecules, von Willebrand factor, and endothelin-1)

A stronger association of depression with rheumatoid arthritis in presence of obesity and hypertriglyceridemia

Background

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by chronic and systemic inflammation. Recent research underscores the role of chronic inflammation in multiple common RA comorbidities such as depression, obesity, and cardiovascular diseases (CVDs), suggesting a potential overlap of the pathogenic mechanisms for RA. However, it is not well understood how the coexistence of these comorbid conditions impacts the risk of RA and whether any such association relates to body's inflammatory state.

Methods

We used data from the 2007-2010 United States National Health and Nutrition Examination Survey (NHANES) database and compared RA prevalence between subsamples with the presence of any two conditions among depression, obesity, and hypertriglyceridemia (HTG). Each subsample was further divided into three categories based on the serum level of the inflammatory marker C-reactive protein (CRP) and analyzed for statistically significant differences using three-way χ2 tests of independence.

Results

The study was conducted on 4,136 patients who fulfilled the inclusion criteria (representing 163,540,241 individuals after adjustment for sampling weights). Rates of depression, obesity, and HTG were found to be significantly higher (P < 0.001) among the subjects with RA compared with the control population with no arthritis. The presence of depression along with obesity or HTG showed a noticeably higher RA prevalence but such an association was not observed for the combination of obesity and HTG. The synergistic effect of HTG with depression was found to be most prominent at a medium CRP level (1-3 mg/L), while for obesity, the effect was observed across all CRP levels examined. These findings were further confirmed by the three-way χ2 test for independence.

Conclusions

The presence of obesity or HTG in subjects suffering from depression might pose an increased risk of RA. Inflammatory mechanisms potentially play an important underlying role as suggested by the strong dependency of the association to CRP level. Identification of synergistic associations between RA risk conditions could provide useful information to predict the development and progress of RA.

Impact of clinico-biochemical and inflammatory biomarkers on the immunogenicity and efficacy of SARS-CoV-2 adenoviral vaccine: a longitudinal study

Purpose

Due to a lack of effective antiviral treatment, several vaccines have been put forth to curb SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection and to reduce the mortality and morbidity rate by eliciting a protective immune response, primarily through virus-neutralizing antibodies specific for SARS-CoV-2 spike protein. This longitudinal study was designed to evaluate the vaccine effectiveness and immune response following the administration of adenoviral vaccine, COVISHIELD, in Indian population who were previously uninfected with SARS-CoV-2 and to reveal the effect of various sociodemographic, inflammatory and biochemical factors on antibody response.

Methods

Briefly, the total immunoglobulin G (IgG) against SARS-CoV-2 spike and nucleocapsid protein along with the immunological markers were estimated by chemiluminescent microparticle immunoassay (CMIA) technology. Biochemical parameters were estimated by spectrometry.

Results

A total of 348 subjects received two doses of COVISHIELD (224 males, 124 females). The mean age of the study subjects was 42.03 ± 13.54 years. Although both the doses of COVISHIELD against SARS-CoV-2 spike protein induced a robust immune response that lasted for months in all the subjects, the total IgG titer against SARS-CoV-2 spike protein was found significantly higher in subjects ≥50 years of age, and those with obesity, elevated triglycerides and elevated lactate dehydrogenase levels.

Conclusions

There is a definite effect of age and biochemical factors on the immunogenicity of COVISHIELD. An understanding of these factors could not only impact the design of vaccines and help improve vaccine immunogenicity and efficacy but also assist in decisions on vaccination schedules, in order to combat this deadly pandemic.

Lower Baseline Serum Triglyceride Levels Are Associated With Higher Decrease in Body Mass Index After Laparoscopy Sleeve Gastrectomy Among Obese Patients

AIMS

To investigate the predictive value of baseline serum triglyceride (TG) levels for improvements of metabolism after laparoscopic sleeve gastrectomy (LSG).

METHODS

112 obese patients [body mass index (BMI) ≥ 35 kg/m²] underwent LSG and with complete information of anthropometric and metabolic parameters were divided into normal TG group (group A) and high TG group (group B), while group A had TG levels ≤ 1.7 mmol/L, and group B had TG levels > 1.7 mmol/L. The post-operative changes (Δ) in metabolic parameters between the two groups were compared.

RESULTS

In the whole cohort, the metabolic parameters were significantly improved at 6 months after LSG. BMI and waist circumference (WC) decreased significantly in the two groups. The ΔBMI among group A and group B were 11.42±3.23 vs 9.13±2.77 kg/m² (p<0.001), respectively. ΔBMI was positively correlated with ΔWC (r=0.696, p<0.001), Δfasting insulin level (r=0.440, p=0.002), Δfasting serum C peptide level (r=0.453, p=0.002), and Δhomeostasis model assessment insulin resistance index (r=0.418, p=0.004) in group A. Compared with group B, group A had a significantly higher odds ratio (OR) of 2.83 (95% confidence interval [CI]1.25-6.38, p=0.012)and 2.73 (95% CI 1.11-6.72, p=0.029) for ΔBMI and ΔWC after adjustment for age and gender, respectively.

CONCLUSIONS

Obese patients with baseline TG levels under 1.7 mmol/L had greater loss of weight at six months follow-up later LSG. This finding suggests that baseline TG level may have a predictive value for weight loss, at least in the short-term follow-up.

Circulating microparticle concentrations across acute and chronic cardiovascular disease conditions

Concentrations of different circulating microparticles (MPs) may have clinical and physiological relevance to cardiovascular disease pathologies.

PURPOSE

To quantify plasma concentrations of CD31+/CD42b-, CD62E+, and CD34+ MPs across healthy individuals and those with coronary artery disease (CAD) or acute cardiovascular events (non-ST elevation myocardial infarction (NSTEMI)). Fasted blood was obtained from CAD patients (n = 10), NSTEMI patients (n = 13), and healthy older men (n = 15) 60-75 years old.

METHODS

CD31+/CD42b-, CD62E+, and CD34+ MPs were isolated from plasma and quantified using flow cytometry. Relationships between MP subtypes, fasting blood lipids, blood glucose, blood pressure, body mass index, and total number of medications were assessed.

RESULTS

Concentrations of CD31+/CD42b- MPs were significantly lower in CAD and NSTEMI subjects compared with healthy individuals (p = .02 and .003, respectively). No differences between groups were found for CD62E+ or CD34+ MPs (p > .05 for both). Surprisingly, among all variables assessed, only CD62E+ MP concentrations were positively correlated with triglyceride levels (p = .012) and inversely correlated with SBP (p = .03).

CONCLUSIONS

Our findings provide support for the use of different MP subtypes, specifically CD31+/CD42b- MPs, as a potential biomarker of cardiovascular disease. Importantly, results from this study should be looked at in adjunct to previous MP work in CVD conditions as a way of highlighting the complex interactions of variables such as comorbid conditions and medications on MP concentrations.

The Complex Interplay between Lipids, Immune System and Interleukins in Cardio-Metabolic Diseases

Lipids and inflammation regulate each other. Early studies on this topic focused on the systemic effects that the acute inflammatory response—and interleukins—had on lipid metabolism. Today, in the era of the obesity epidemic, whose primary complications are cardio-metabolic diseases, attention has moved to the effects that the nutritional environment and lipid derangements have on peripheral tissues, where lipotoxicity leads to organ damage through an imbalance of chronic inflammatory responses. After an overview of the effects that acute inflammation has on the systemic lipid metabolism, this review will describe the lipid-induced immune responses that take place in peripheral tissues and lead to chronic cardio-metabolic diseases. Moreover, the anti-inflammatory effects of lipid lowering drugs, as well as the possibility of using anti-inflammatory agents against cardio-metabolic diseases, will be discussed.

Type 2 diabetes and older age contribute to elevated plasma microparticle concentrations independent of chronic stroke

NEW FINDINGS

What is the central question of this study? What is the effect of chronic stroke on circulating microparticle populations, accounting for potential effects of age and type 2 diabetes? What is the main finding and its importance? Elevated concentrations of CD31⁺ /CD42b^- and CD62E⁺ microparticles appear to be driven by type 2 diabetes but not chronic stroke and are associated with fasting glucose and triglyceride levels. Older age results in elevations in CD62E⁺ and CD34⁺ microparticle concentrations. These microparticles have been proposed as potential targets for diagnosing, treating and identifying the clinical progression and complications of type 2 diabetes.

ABSTRACT

The elevated circulating concentration of endothelial microparticles (MPs) may provide an index of the extent and nature of cellular damage in chronic stroke. The purpose of this study was to determine the circulating concentrations of CD31⁺ /CD42b^- , CD62E⁺ and CD34⁺ MPs in chronic stroke subjects, focusing on the effects of chronic stroke by comparison with both older adults without a history of stroke but with type 2 diabetes mellitus (T2DM) and older and young healthy controls. Plasma from three groups of sedentary older (50-75 years) men and women (chronic stroke, T2DM or older healthy) as well as a group of younger (18-39 years) healthy controls was isolated from fasting blood, and CD31⁺ /CD42b^- , CD62E⁺ and CD34⁺ MPs were quantified using flow cytometry (n = 17/group). Concentrations of CD31⁺ /CD42b^- and CD62E⁺ MPs were higher in the T2DM group (P < 0.05), but not chronic stroke, compared to older and younger healthy adults. CD62E⁺ MP and CD34⁺ MP concentrations were elevated in the older compared to younger adults (P < 0.05 for both). Sub-analyses excluding chronic stroke subjects who were also diagnosed with diabetes [stroke (diabetes^- )] revealed lower CD31⁺ /CD42b^- (P < 0.05) and CD62E⁺ (P = 0.08) MPs in the stroke (diabetes^- ) group compared to the T2DM group. CD31⁺ /CD42b^- MP and CD62E⁺ MP concentrations were each associated with fasting glucose levels and CD31⁺ /CD42b^- MPs also were associated with triglyceride levels. As MPs have been proposed as potential targets for diagnosing, treating and identifying the clinical progression of T2DM, our study provides further support for the use of CD31⁺ /CD42b^- and CD62E⁺ MPs in the clinical progression of T2DM and associated vascular complications.

Postprandial Increase in Blood Plasma Levels of Tissue Factor-Bearing (and Other) Microvesicles Measured by Flow Cytometry: Fact or Artifact?

Tissue factor (TF)–bearing microvesicles (MVs) and exosomes may play a role in hemostasis and thrombosis. MVs may be quantified by flow cytometry (FC)–based detection of phosphatidylserine (PS)-positive submicron particles carrying specific antigens, although interference from lipoproteins complicates this approach. In this study, we evaluated the effect of food intake on blood levels of TF-bearing particles measured by FC and small extracellular vesicles (EVs) measured by a protein microarray–based test termed EV Array. Platelet-free plasma (PFP) was obtained from 20 healthy persons in the fasting state and 75 minutes after consumption of a meal. Postprandial changes in the concentration of PS-positive particles, including subgroups binding labeled antibodies against TF, CD41, CD146, and CD62E, respectively (FC), small EVs (EV Array), and TF antigen and procoagulant phospholipids (PPLs) were measured. Furthermore, we tested the effect on FC results of in vitro addition of lipoproteins to fasting PFP. We found significantly increased plasma concentrations of PS-positive particles and all examined subgroups postprandially, while no changes in small EVs, PPL, or TF antigen levels were found. Levels of all types of particles measured by FC were also elevated by lipoprotein spiking. In conclusion, meal consumption as well as in vitro addition of lipoproteins to fasting plasma induces increased levels of PS-positive particles as measured by FC, including TF-positive subtypes and subtypes exposing other antigens. While the observed postprandial increase may to some extent reflect elevated MV levels, our results indicate a substantial interference from lipoproteins.

Insulin resistance and vascular dysfunction in chronic kidney disease: mechanisms and therapeutic interventions

Insulin resistance (IR) is a novel cardiovascular risk factor that has been implicated in the pathogenesis of cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). Beyond its metabolic effects, insulin can potentially mediate the increased risk for CVD through its vasoactive properties. This review examines key clinical data and potential mechanisms linking IR and cardiovascular risk in CKD. While lifestyle interventions and pharmacotherapies with known insulin-sensitizing properties are promising therapeutic targets to reduce the CVD burden in this population, clinical trial data on the effect of insulin sensitization on vascular function in CKD are either lacking or conflicting and are limited by small sample size and short duration of intervention. Affirming the role of IR in lowering CVD risk in CKD will require prospective randomized controlled studies with sufficient sample size and hard clinical outcomes. Future research efforts should be directed at assessing the efficacy, safety and mechanisms by which novel insulin sensitizers such as bile acid sequestrant, selective and dual peroxisome proliferator-activated receptor modulators and modulators of gut microbiota and uraemic toxins alter vascular function in patients with CKD.

Apolipoprotein CIII Overexpression-Induced Hypertriglyceridemia Increases Nonalcoholic Fatty Liver Disease in Association with Inflammation and Cell Death

Nonalcoholic fatty liver disease (NAFLD) is the principal manifestation of liver disease in obesity and metabolic syndrome. By comparing hypertriglyceridemic transgenic mice expressing apolipoprotein (apo) CIII with control nontransgenic (NTg) littermates, we demonstrated that overexpression of apoCIII, independent of a high-fat diet (HFD), produces NAFLD-like features, including increased liver lipid content; decreased antioxidant power; increased expression of TNFα, TNFα receptor, cleaved caspase-1, and interleukin-1β; decreased expression of adiponectin receptor-2; and increased cell death. This phenotype is aggravated and additional NAFLD features are differentially induced in apoCIII mice fed a HFD. HFD induced glucose intolerance together with increased gluconeogenesis, indicating hepatic insulin resistance. Additionally, the HFD led to marked increases in plasma TNFα (8-fold) and IL-6 (60%) in apoCIII mice. Cell death signaling (Bax/Bcl2), effector (caspase-3), and apoptosis were augmented in apoCIII mice regardless of whether a HFD or a low-fat diet was provided. Fenofibrate treatment reversed several of the effects associated with diet and apoCIII expression but did not normalize inflammatory traits even when liver lipid content was fully corrected. These results indicate that apoCIII and/or hypertriglyceridemia plays a major role in liver inflammation and cell death, which in turn increases susceptibility to and the severity of diet-induced NAFLD.

Microvesicles Correlated with Components of Metabolic Syndrome in Men with Type 2 Diabetes Mellitus and Lowered Testosterone Levels But Were Unaltered by Testosterone Therapy

Aims. To investigate how circulating microvesicle phenotypes correlate with insulin sensitivity, body composition, plasma lipids, and hepatic fat accumulation. We hypothesized that changes elicited by testosterone replacement therapy are reflected in levels of microvesicles. Methods. Thirty-nine type 2 diabetic males with lowered testosterone levels were assigned to either testosterone replacement therapy or placebo and evaluated at baseline and after 24 weeks. Microvesicles were analysed by flow cytometry and defined as lactadherin-binding particles within the 0.1-1.0 μm gate. Microvesicles of platelet, monocyte, and endothelial cell origin were identified by cell-specific markers and their expression of CD36 was investigated. Results. Triglycerides correlated positively with all investigated microvesicle phenotypes in this study (p < 0.05), and indicators of hepatic fat accumulation, alanine aminotransferase, and gamma glutamyltransferase correlated with platelet and endothelial microvesicles and CD36-expressing microvesicles from platelets and monocytes (p < 0.05). BMI, waist circumference, and fat percentage correlated with CD36-expressing monocyte microvesicles (p < 0.05), while insulin sensitivity did not correlate with any microvesicle phenotypes. Microvesicle levels were unaffected by testosterone therapy. Conclusions. Metabolic syndrome components and hepatic fat accumulation correlated with microvesicle phenotypes, supporting the involvement of especially CD36 on monocytes in metabolic syndrome pathogenesis. Although testosterone therapy improved body composition measures, microvesicle phenotype levels were unaffected. This trial was registered at ClinicalTrials.gov (NCT01560546).

Could both vitamin D and geomagnetic activity impact serum levels of soluble cell adhesion molecules in young men?

Vitamin D might have a role in diminishing endothelial dysfunction (ED). The initial aim was to test the hypothesis of reciprocity between levels of 25-hydroxyvitamin D (25(OH)D) and levels of soluble endothelial cell adhesion molecules (CAMs) that could serve as biomarkers of ED. Randomly selected men of age 20-39 were examined at February or March (cold season) and reexamined at August or September (warm season). Some lifestyle and anthropometrical data were recorded. Laboratory measurements, including those for serum levels of soluble CAMs-sICAM-1, sVCAM-1, sE-selectin and sP-selectin-were also performed. As some of the results were rather unexpected, indices of geomagnetic activity (GMA), obtained from the online database, were included in further analysis as a confounder. In 2012-2013, 130 men were examined in cold season, and 125 of them were reexamined in warm season. 25(OH)D levels were found to be significantly negatively associated with sVCAM-1 levels (β = -0.15, p = 0.043 in warm season; β = -0.19, p = 0.007 for changes). Levels of sVCAM-1 and sICAM-1 from the same seasons were notably different between years and have changed in an opposite manner. Soluble P-selectin levels were higher at warm season in both years. GMA was positively associated with sVCAM-1 (β = 0.17, p = 0.039 in cold season; β = 0.22, p = 0.002 for changes) and negatively with sICAM-1 (β = -0.30. p < 0.001 in cold season) levels. Vitamin D might play a role in diminishing sVCAM-1 levels. Levels of sVCAM-1 and sICAM-1 were associated with the GMA; this implies a need for further research.

Effects of prandial challenge on triglyceridemia, glycemia, and pro-inflammatory activity in persons with chronic paraplegia

CONTEXT/OBJECTIVE

Exaggerated postprandial lipemia has been reported after spinal cord injury (SCI). We examined metabolite and accompanying pro-inflammatory biomarker responses to repeat feeding of typical high-fat meals in individuals with chronic paraplegia.

DESIGN

Descriptive trial.

METHODS

Metabolites (triglycerides, glucose, and insulin) and inflammatory biomarkers (interleukin-6 and high-sensitivity C-reactive protein (hsCRP)) were measured under fasting conditions in 11 recreationally active individuals with chronic (>1 year) paraplegia. Subjects received high-fat meals at time point 0 and again at minute 240. Antecubital venous blood was obtained at time points -30 (fasting), 0 (first meal), 30, 60, 90, 120, 240 (second meal), 360, and 480 minutes. Correlations were examined among the study variables. Exploratory subgroup analysis was performed for subjects with levels of postprandial glucose greater than >200 mg/dl.

RESULTS

Triglycerides showed a significant rise 4 hours after eating. Basal inflammatory markers were elevated, and did not undergo additional change during the testing. Additionally, subjects with excessive postprandial glucose responses showed higher hsCRP levels than those having typical glucose responses both for fasting (11.8 ± 6.5 vs. 2.9 ± 2.7 mg/l, P = 0.064) and postprandial (11.1 ± 4.9 vs. 3.7 ± 3.8 mg/l, P = 0.018) values.

CONCLUSIONS

Despite elevations in metabolic response markers, inflammatory markers did not change significantly after consumption of population-representative (i.e. hypercaloric) mixed-nutrient meals. Levels of fasting CRP in the high-risk range are consistent with other reports in persons with SCI and continue to pose concern for their cardiovascular disease risk. The possible association between postprandial metabolic responses and inflammatory states warrants further investigation to identify individual component risks for this secondary health hazard.

Fibrates protect against vascular endothelial dysfunction induced by paclitaxel and carboplatin chemotherapy for cancer patients: a pilot study

BACKGROUND

Although we previously demonstrated that paclitaxel and carboplatin chemotherapy (TCchem) is associated with vascular toxicities, the underlying mechanisms remain unclear. Cisplatin is known to inhibit PPARα following microvascular damage to the kidneys. The primary aim of this study was to evaluate whether TCchem induces vascular endothelial dysfunction via systemic PPARα deficiency. In addition, human umbilical vein endothelial cells (HUVECs) were used to elucidate the mechanisms responsible for TCchem-induced vascular toxicities.

METHODS

This study enrolled 45 gynecological cancer patients with normal lipid profiles who underwent surgical treatment followed by TCchem. The elevated triglyceride (TG) group included patients (n = 19) who exhibited hypertriglyceridemia during TCchem, and the stable TG group (n = 15) included patients with a normal TG level. Eleven patients exhibiting hypertriglyceridemia during TCchem were administered bezafibrate (fibrate group). Endothelial dysfunction was evaluated based on flow-mediated dilation (FMD) values and serum pentraxin-3 levels measured before TCchem and immediately after the final TCchem. HUVECs were used to elucidate the biological mechanisms underlying the endothelial dysfunction induced by TCchem.

RESULTS

The administration of TCchem induced hypertriglyceridemia in 66 percent of the participants, and bezafibrate reduced the serum TG levels. Meanwhile, the decrease in flow-mediated dilatation (%FMD) induced by TCchem improved following treatment with bezafibrate. The serum pentraxin-3 level increased rapidly after TCchem and decreased following bezafibrate treatment. An in vitro examination demonstrated TCchem attenuated nitric oxide production and PPARα activity in HUVECs, which was partially improved by treatment with bezafibrate.

CONCLUSION

Bezafibrate prevents endothelial dysfunction induced by TCchem via TG-dependent and TG-independent mechanisms.

Serum glycated albumin, but not glycated hemoglobin, is low in relation to glycemia in men with hypertriglyceridemia

Aims/Introduction:  Serum glycated albumin (GA) and glycated hemoglobin (HbA1c) are influenced by plasma glucose levels, and are used for monitoring chronic glycemic control in diabetic patients. Both glycated proteins are known to be influenced by various factors other than plasma glucose levels. In the present study, we examined the effects of hypertriglyceridemia on them.

MATERIALS AND METHODS

  The present study comprised 273 non-diabetic men. They were grouped into men with normotriglyceridemia (serum triglyceride [TG] <150 mg/dL) and those with hypertriglyceridemia (serum TG ≥150 mg/dL).

RESULTS

  Body mass index (BMI) and high sensitivity C-reactive protein (hs-CRP) were significantly higher in the 160 men with hypertriglyceridemia than the 113 men with normotriglyceridemia. In men with hypertriglyceridemia, as compared with those with normotriglyceridemia, fasting plasma glucose, 2-h plasma glucose after 75 g oral glucose tolerance test, and HbA1c were significantly higher. By contrast, serum GA was significantly lower in men with hypertriglyceridemia. BMI-adjusted serum GA was also significantly lower in these men. In a multivariate analysis, serum TG was an inverse explanatory variable for serum GA.

CONCLUSIONS

  Serum GA is low in relation to plasma glucose levels in men with hypertriglyceridemia. This might be caused by increased albumin metabolism associated with hypertriglyceridemic state. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00049.x, 2010).

Association of circulating endothelial microparticles with cardiometabolic risk factors in the Framingham Heart Study

OBJECTIVE

To examine the relation of endothelial microparticles (EMPs) with cardiometabolic risk in the community.

BACKGROUND

Circulating EMPs are small membrane vesicles released after endothelial cell injury. Endothelial microparticles are reportedly increased among individuals with a high burden of cardiovascular risk factors. However, prior investigations have been limited to small, highly selected samples.

METHODS

We studied 844 individuals without a history of cardiovascular disease in the Framingham Offspring cohort (mean age 66 ± 9 years, 57% women). We used standardized flow cytometry methods to identify and quantify circulating CD144+ and CD31+/CD41- EMPs. We then used multivariable regression analyses to investigate the relations of EMP phenotypes with cardiovascular and metabolic risk factors.

RESULTS

In multivariable analyses, the following cardiovascular risk factors were associated with one or more of the circulating EMP populations: hypertension (P = 0.025 for CD144+,), elevated triglycerides (P = 0.002 for CD144+, P < 0.0001 for CD31+/CD41-), and metabolic syndrome (P < 0.0001 for CD144+,). Overall, each tertile increase in the Framingham risk score corresponded to a 9% increase in log-CD31+/CD41- EMPs (P = 0.022). Furthermore, the presence of hypertriglyceridaemic waist status was associated with 38% higher levels of CD144+ EMPs (P < 0.0001) and 46% higher levels of CD31+/CD41- EMPs (P < 0.0001).

CONCLUSION

In a large community-based sample, circulating EMP levels were associated with the presence of cardiometabolic risk factors, particularly dyslipidaemia. These data underscore the potential influence of high-risk metabolic profiles on endothelial integrity.

Acute hypertriglyceridemia induces platelet hyperactivity that is not attenuated by insulin in polycystic ovary syndrome

Background

Atherothrombosis is associated with platelet hyperactivity. Hypertriglyceridemia and insulin resistance (IR) are features of polycystic ovary syndrome (PCOS). The effect of induced hypertriglyceridemia on IR and platelet function was examined in young women with PCOS.

Methods and Results

Following overnight fasting, 13 PCOS and 12 healthy women were infused with saline or 20% intralipid for 5 hours on separate days. Insulin sensitivity was measured using a hyperinsulinemic euglycaemic clamp in the final 2 hours of each infusion. Platelet responses to adenosine diphosphate (ADP) and prostacyclin (PGI₂) were measured by flow cytometric analysis of platelet fibrinogen binding and P‐selectin expression using whole blood taken during each infusion (at 2 hours) and at the end of each clamp. Lipid infusion increased triglycerides and reduced insulin sensitivity in both controls (median, interquartile range ) (5.25 [3.3, 6.48] versus 2.60 [0.88, 3.88] mg kg⁻¹ min⁻¹, P<0.001) and PCOS (3.15 [2.94, 3.85] versus 1.06 [0.72, 1.43] mg kg⁻¹ min⁻¹, P<0.001). Platelet activation by ADP was enhanced and ability to suppress platelet activation by PGI₂ diminished during lipid infusion in both groups when compared to saline. Importantly, insulin infusion decreased lipid‐induced platelet hyperactivity by decreasing their response to 1 μmol/L ADP (78.7% [67.9, 82.3] versus 62.8% [51.8, 73.3], P=0.02) and increasing sensitivity to 0.01 μmol/L PGI₂ (67.6% [39.5, 83.8] versus 40.9% [23.8, 60.9], P=0.01) in controls, but not in PCOS.

Conclusion

Acute hypertriglyceridemia induced IR, and increased platelet activation in both groups that was not reversed by insulin in PCOS subjects compared to controls. This suggests that platelet hyperactivity induced by acute hypertriglyceridemia and IR could contribute athero‐thrombotic risk.

Clinical Trial Registration

URL: www.isrctn.org. Unique Identifier: ISRCTN42448814.

Different gene expression profiles in normo- and dyslipidemic men after fish oil supplementation: results from a randomized controlled trial

Background

Epidemiological studies have suggested the benefits of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on cardiovascular health, but only limited data are available describing n-3 PUFA regulated pathways in humans. The aim of this study was to investigate the effects of n-3 PUFA administration on whole genome expression profiles in the blood of normo- and dyslipidemic subjects.

Methods

Differentially expressed genes were detected after four hours, one week and twelve weeks of supplementation with either fish oil (FO) or corn oil in normo- and dyslipidemic men using whole genome microarrays.

Results

Independent of the oil, a significantly higher number of genes was regulated in dyslipidemic subjects compared to normolipidemic subjects. Pathway analyses discovered metabolisms dominantly affected by FO after twelve weeks of supplementation, including the lipid metabolism, immune system and cardiovascular diseases. Several pro-inflammatory genes, in particular, were down-regulated in dyslipidemic subjects, indicating the immune-modulatory and anti-inflammatory capability of FO and its bioactive FAs, eicosapentaenoic acid and docosahexaenoic acid.

Conclusions

This is the first study showing significant differences in gene expression profiles between normo- and dyslipidemic men after FO supplementation. Further studies need to clarify the exact role of n-3 PUFAs in pathways and metabolisms which were identified as being regulated after FO supplementation in this study.

Trial registration

ClinicalTrials.gov (ID: NCT01089231)

Effect of weight reduction on cardiovascular risk factors and CD34-positive cells in circulation

Being overweight or obese is associated with an increased risk for the development of non-insulin-dependent diabetes mellitus, hypertension, and cardiovascular disease. Dyslipidemia of obesity is characterized by elevated fasting triglycerides and decreased high-density lipoprotein-cholesterol concentrations. Endothelial damage and dysfunction is considered to be a major underlying mechanism for the elevated cardiovascular risk associated with increased adiposity. Alterations in endothelial cells and stem/endothelial progenitor cell function associated with overweight and obesity predispose to atherosclerosis and thrombosis. In our study, we analyzed the effect of a low calorie diet in combination with oral supplementation by vitamins, minerals, probiotics and human chorionic gonadotropin (hCG, 125-180 IUs) on the body composition, lipid profile and CD34-positive cells in circulation. During this dieting program, the following parameters were assessed weekly for all participants: fat free mass, body fat, BMI, extracellular/intracellular water, total body water and basal metabolic rate. For part of participants blood chemistry parameters and circulating CD34-positive cells were determined before and after dieting. The data indicated that the treatments not only reduced body fat mass and total mass but also improved the lipid profile. The changes in body composition correlated with the level of lipoproteins responsible for the increased cardiovascular risk factors. These changes in body composition and lipid profile parameters coincided with the improvement of circulatory progenitor cell numbers. As the result of our study, we concluded that the improvement of body composition affects the number of stem/progenitor cells in circulation.

Examination of adhesion molecules, homocysteine and hs-CRP in patients with polygenic hypercholesterolemia and isolated hypertriglyceridemia

BACKGROUND

Increased levels of selectins, adhesion molecules, hs-CRP and homocysteine are considered important as indicators of atherosclerosis. There is a significant amount of evidence that high LDL-C levels are a risk factor for coronary artery disease, whereas the relevance of isolated triglycerides is controversial. The present study aims to compare the levels of homocysteine, hs-CRP, E-selectin, sP-selectin, VCAM-1, ICAM-1 in patients with isolated hypertriglyceridemia and polygenic hypercholesterolemia.

METHODS

The following three groups were formed: polygenic hypercholesterolemia group (n=30), isolated hypertriglyceridemia group (n=30) and control group (n=30). These three groups were matched in terms of BMI, waist circumference and gender. Plasma high sensitive CRP, homocysteine, sVCAM-1, sICAM-1, sP-selectin, sE-Selectin levels of patients in these three groups were measured.

RESULTS

In the present study, mean values for sE-selectin, sVCAM-1 and sICAM-1 in the polygenic hypercholesterolemia group were significantly higher than in the other two groups (p<0.001). Homocysteine and hs-CRP levels were higher in the polygenic hypercholesterolemia group, compared to the isolated hypertriglyceridemia group (p=0.019, p<0.001; respectively) and the control group (p<0.001, p<0.001; respectively). Comparison of patients with hypertriglyceridemia to individuals in the control group did not yield a significant difference in terms of sE-selectin, sP-selectin, sVCAM-1, sICAM and homocysteine (p>0.05), where as the hs-CRP value was significantly higher in patients with isolated hypertriglyceridemia compared to the control group (p=0.001).

CONCLUSION

The increase of adhesion molecules, homocysteine and hs-CRP in polygenic hypercholesterolemia subjects compared to the isolated hypertriglyceridemia group reflects their high cardiovascular risk.

Endothelial inflammation correlates with subject triglycerides and waist size after a high-fat meal

A rise in postprandial serum triglycerides (PP-sTG) can potentiate inflammatory responses in vascular endothelial cells (ECs) and thus serves as an independent risk factor for predicting increased cardiovascular morbidity. We examined postprandial triglyceride-rich lipoproteins (PP-TGRLs) in subjects ranging from normal to hypertriglyceridemic for their capacity to alter EC acute inflammatory responses. Cultured human aortic ECs (HAECs) were conditioned with PP-TGRLs isolated from human serum at the peak after a moderately high-fat meal. VLDL particle size increased postprandially and varied directly with the subject's PP-sTG level and waist circumference. PP-TGRL particles bound to HAECs and were internalized via LDL receptor-mediated endocytosis. PP-TGRL alone did not induce an inflammatory response over the range of individuals studied. However, combined with low-dose TNF-α stimulation (0.3 ng/ml), it elicited a net 10-15% increase above cytokine alone in the membrane expression of VCAM-1, ICAM-1, and E-selectin, which was not observed with fasting TGRLs. In contrast to upregulation of ICAM-1 and E-selectin, VCAM-1 transcription and expression varied in direct proportion with individual PP-sTG and waist circumference. The extent of monocyte arrest on inflamed HAECs under shear stress also correlated closely with VCAM-1 expression induced by conditioning with PP-TGRL and TNF-α stimulation. This ex vivo approach provides a quantitative means to assess an individual's inflammatory potential, revealing a greater propensity for endothelial inflammation in hypertriglyceridemic individuals with abdominal obesity.

Adiposity is associated with endothelial activation in healthy 2-3 year-old children

Adiposity is associated with C-reactive protein level in healthy 2-3 year-old children and with other markers of endothelial activation in adults, but data are lacking in very young children. Data from 491 healthy Hispanic children were analyzed. Mean age was 2.7 years (SD 0.5, range 2-3 years); mean body mass index (BMI) was 17.2 kg/m2 (SD 1.9) among boys and 17.1 kg/m2 (SD 2.1) among girls. E-selectin level was associated with BMI (R = 0.11; p < 0.02), ponderal index (p < 0.02), waist circumference (p = 0.02), fasting insulin (p < 0.02), and insulin resistance (p < or = 0.05); these associations remained significant after adjustment for age, sex and fasting glucose. sVCAM was also associated with BMI (R = 0.12; p < 0.05). These observations indicate that adiposity is associated with inflammation and endothelial activation in very early childhood.

The Effect of Ciprofibrate on Flow-Mediated Dilation and Inflammatory Markers in Patients with Combined Hyperlipidemia

Impairment of flow-mediated dilation (FMD) has been shown to be associated with hypercholesterolemia and hypertriglyceridemia and reduction of cholesterol and/or triglyceride levels can improve FMD. In hyperlipidemia the role of inflammatory substances on endothelial function requires further clarification. In patients with combined hyperlipidemia (n = 29), the capacity of FMD was weaker whereas the levels of interleukin (IL)-lalpha, tumor necrosis factor alpha (TNFalpha), soluble intercellular adhesion molecule (sICAM), and fibrinogen were higher compared to normolipemic controls with normal FMD adjusted for age and sex. Patients were randomized to a diet-only or to a ciprofibrate treatment group. After 8 weeks FMD levels rose significantly both in the diet-only (10.2%) and the ciprofibrate treatment (79.4%) groups. In the diet-only group improvement of FMD was significantly associated with the reduction of triglyceride (by 15.9%) and cholesterol (6.9%) levels. The much larger improvement of FMD due to ciprofibrate therapy was accompanied by significant reductions of cholesterol (by 14.4%), fibrinogen, IL-1alpha, and sICAM levels and by significant increase of high-density lipoprotein (HDL) cholesterol concentration, but the change in FMD correlated only with the reduction of the cholesterol level. In line with previous data the authors emphasize that improvement of FMD in patients with combined hyperlipidemia treated with diet and/or ciprofibrate is linked directly to the reduction of cholesterol and triglyceride concentrations rather than to changes in the level of the investigated inflammatory markers.

Increased levels of C‐reactive protein and interleukin‐6 in hyperhomocysteinemic subjects

OBJECTIVE

Elevated plasma homocysteine concentration is considered to be an independent risk factor for cardiovascular disease. However, the mechanisms by which hyperhomocysteinemia are related to vascular disease are unclear. High-sensitivity C-reactive protein (CRP), a marker of inflammation, has been reported to be an independent predictor of future myocardial infarction among clinically healthy individuals. Interleukin (IL)-6 is a regulator of CRP and has a key role in initiation of inflammation. The aim of this study was to investigate whether individuals with increased plasma homocysteine concentrations have altered levels of serum CRP and IL-6.

MATERIAL AND METHODS

Serum concentrations of CRP and IL-6 were measured in 39 individuals with hyperhomocysteinemia and in 39 control subjects matched for gender, age and body mass index (BMI). In addition, the inflammatory effect of IL-6 on peripheral blood mononuclear cells was measured.

RESULTS

Compared to controls, hyperhomocysteinemic subjects have elevated serum levels of CRP and IL-6 (p < or =0.001 and p < 0.005, respectively). Importantly, this raised level of IL-6 was also seen in hyperhomocysteinemic individuals without accompanying hypercholesterolemia or cardiovascular disease. IL-6 increased the release of monocyte chemoattractant protein-1 from peripheral blood mononuclear cells, with particularly enhancing effects in cells from patients with hyperhomocysteinemia.

CONCLUSIONS

These data suggest that enhanced inflammation may be associated with homocysteine-related cardiovascular disease, possibly involving IL-6-related mechanisms.

Possible risk factor for postmenopausal women: postprandial hypertriglyceridemia

AIM

To explore the clinical implications of postprandial hypertriglyceridemia in postmenopausal Japanese women.

METHODS

Postprandial blood samples were collected from 91 women at their initial visit, with fasting blood samples collected within the following month to examine their lipid profiles. These women were grouped into normotriglyceridemia (fasting/postprandial triglycerides [TG] < 150; n = 36), mild postprandial hypertriglyceridemia (fasting TG < 150, postprandial TG > or = 150, < 225; n = 27), moderate postprandial hypertriglyceridemia (fasting TG < 150, postprandial TG > or = 225; n = 19) and hypertriglyceridemia (fasting TG > or = 150; n = 9) by using 225 mg/dL as the cut-off value for postprandial hypertriglyceridemia.

RESULTS

The subjects were 54.1 +/- 7.8 years old; their duration of menopause, 6.0 +/- 7.7 years; body mass index, 21.4 +/- 4.0 kg/m(2); postprandial TG concentration, 189 +/- 110 mg/dL; and fasting TG concentration, 109 +/- 50 mg/dL. Approximately 50% (n = 46) of the women had normal fasting TG (fasting TG < 150), but high postprandial TG (postprandial TG > or = 150). Approximately 10% (n = 9) of the women had hypertriglyceridemia (fasting TG > or = 150 mg/dL). In those with postprandial hypertriglyceridemia (n = 46), postprandial TG negatively correlated with high-density lipoprotein cholesterol (HDL-C), while fasting TG showed no such correlation with HDL-C.

CONCLUSION

Postprandial TG may provide a better understanding of lipid metabolism in postmenopausal women.

Acute hypertriglyceridaemia in humans increases the triglyceride content and decreases the anti-inflammatory capacity of high density lipoproteins

INTRODUCTION

Post-prandial hypertriglyceridaemia is a risk factor for cardiovascular disease, although the underlying mechanisms remain unclear. High density lipoproteins (HDL) have been shown to be atheroprotective, in part through attenuation of vascular inflammation. In this study, the influence of acute hypertriglyceridaemia on the composition and anti-inflammatory properties of HDL was investigated.

METHODS

Eight fasting healthy male subjects (34+/-2 years) received 20% Intralipid (15 mg/kg/h) or saline, on separate occasions in random order. At baseline and 60 min post-infusion, the total HDL fraction was isolated and its chemical composition determined. HDL were added to TNF-alpha stimulated human coronary artery endothelial cells and VCAM-1 and ICAM-1 expression was determined by flow cytometry.

RESULTS

Serum triglyceride (97.4+/-8.5mg/dL baseline, 283.2+/-35.4 mg/dL post-infusion, p<0.001) and HDL triglyceride content (3.8+/-0.5% HDL mass baseline, 5.3+/-0.9% HDL mass post-infusion, p<0.05) increased significantly after Intralipid infusion. HDL post-Intralipid were significantly less anti-inflammatory compared with control (e.g. at 8 microM apoA-I, %VCAM-1 expression 54+/-5 post-saline, 73+/-4 post-Intralipid, p=0.01; %ICAM-1 expression 94+/-1 post-saline, 99.4+/-0.6 post-Intralipid, p<0.01). There was also a significant correlation between HDL triglyceride content and VCAM-1 expression (R=0.70, p=0.005); as well as between plasma triglyceride levels and both VCAM-1 (R=0.71, p<0.005) and ICAM-1 expression (R=0.80, p<0.005).

CONCLUSION

Acute hypertriglyceridaemia, simulating the post-prandial state, results in triglyceride-rich HDL with impaired anti-inflammatory capacity.

Supplements of l-arginine attenuate the effects of high-fat meal on endothelial function and oxidative stress

BACKGROUND

Postprandial hypertriglyceridemia is known to cause endothelial dysfunction and increased oxidative stress. Oral supplements of l-arginine have been found to improve endothelial function. However, the effects of supplements of l-arginine on the influences of postprandial hypertriglyceridemia were not studied before.

METHODS

Forty young healthy men without any risk factors were equally divided into two groups. l-arginine group (age 22+/-1 years, body mass index 23.5+/-1.2 kg/m(2)) received a standard high-fat meal with 15 g oral l-arginine. Control group (age 22+/-1 years, body mass index 23.8+/-0.9 kg/m(2)) received a standard high-fat meal with placebo. A standard high-fat meal consisted of 900 kcal and 50 g of fat. Flow-mediated vasodilation (FMD), von Willebrand factor (vWF), p-Selectin, and glutathione peroxidase (GSH-Px) were measured before and 2 h after the high-fat meal.

RESULTS

Serum triglyceride levels were significantly increased 2 h after the high-fat meal in both groups. In the control group, FMD (10.5+/-1.2% vs. 6.8+/-1.4%, p<0.001) and GSH-Px (23.5+/-6.2 vs. 21.9+/-5.0 mug/ml, p=0.029) were significantly decreased after the high-fat meal. P-Selectin (20.0+/-7.7 vs. 25.9+/-10.5 mg/l, p=0.025) and vWF (731.2+/-131.5 vs. 934.9+/-133.8 mU/ml, p<0.001) were significantly increased after the high-fat meal. In the l-arginine group, FMD (10.3+/-1.3 vs. 9.3+/-0.9%, p<0.001) was slightly but significantly decreased after the high-fat meal but not GSH-Px (23.6+/-3.6 vs. 23.0+/-4.8%, p=0.468). P-Selectin (20.1+/-5.9 vs. 25.7+/-10.2 mg/l, p=0.001) and vWF (793.2+/-146.0 vs. 944.4+/-136.8 mU/ml, p<0.001) were significantly increased after the high-fat meal. Degree of FMD attenuation following the high-fat meal was significantly less in the l-arginine group (1.0+/-0.9 vs. 3.8+/-1.5%, p<0.001).

CONCLUSIONS

Concomitant supplements of l-arginine improved endothelial dysfunction and oxidative stress induced by postprandial hypertriglyceridemia. However, changes of p-Selectin and vWF were not affected by supplements of l-arginine with the high-fat meal.

Post-prandial endothelial dysfunction in hypertriglyceridemic subjects: Molecular mechanisms and gene expression studies

OBJECTIVE

Triglyceride-rich lipoproteins (TGRLs) are a cardiovascular risk factor and induce endothelial dysfunction. In the present study, we investigated the effects of post-prandial TGRLs from type IV hyperlipidemic subjects on endothelial activation addressing the effects of the lipoproteins on intracellular pathways and gene expression.

METHODS

Thirty fasted hypertriglyceridemic patients were given an oral fat load (OFL) and blood samples were collected before the OFL (T0) and 2, 4, 6 and 8h thereafter. Endothelial function, determined as flow-mediated dilatation of the brachial artery, was assessed at the same time points. TGRLs were isolated at T0 and T4 (PP-TGRL) for in vitro studies.

RESULTS

Compared with TGRLs, PP-TGRLs induced to a larger extent phosphorylation of p38 MAPK, CREB and IKB-alpha in human endothelial cells and increased the DNA binding activity of CREB, NFAT and NF-kappaB. Furthermore, PP-TRGLs upregulated the expression of several pro-inflammatory genes including vascular cell adhesion molecule-1 (VCAM-1), PECAM-1, ELAM-1, intercellular adhesion molecule-1 (ICAM-1), P-selectin, MCP-1, interleukin-6 (IL-6), TLR-4, CD40, ADAMTS1 and PAI-1.

CONCLUSION

These effects may relate to the severe impairment of endothelial function seen during the post-prandial phase in hypertriglyceridemic patients.

Endothelial and leukocyte adhesion molecules in primary hypertriglyceridemia

Hypertriglyceridemia is known to be associated to functional impairment of the endothelium and, consequently, to higher risk of atherosclerosis. Nevertheless, some crucial steps in the development of the atherosclerotic plaque are still unknown in primary hypertriglyceridemia. The aim of the present study was to explore the expression of soluble and leukocyte-associated cell adhesion molecules in a group of patients with primary hypertriglyceridemia, both including (n=50) and excluding (n=24) subjects with metabolic syndrome, in comparison with control normotriglyceridemic individuals (n=30). Lipid profile, CETP activity, HDL and VLDL chemical composition were evaluated. Soluble (VCAM-1, ICAM-1 and E-selectin) and leukocyte cell adhesion molecules (CD18, CD49d and CD54) were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Patients with primary hypertriglyceridemia as compared with control subjects showed significantly higher VCAM-1 (15.6+/-4.5 ng/ml versus 13.9+/-3.8 ng/ml, respectively; p<0.05) and ICAM-1 (16.9+/-3.1 ng/ml versus 15.2+/-3.2 ng/ml, respectively; p<0.05). Regarding leukocyte cell adhesion molecules, significant increases were also detected in monocyte CD18 (398+/-180 versus 332+/-136 arbitrary units, respectively; p<0.05) and CD54 (49+/-14 versus 42+/-12 arbitrary units, respectively; p<0.05), and lymphocyte CD18 (122+/-53 versus 101+/-33 arbitrary units, respectively; p<0.05). ICAM-1 plasma levels, as well as monocyte CD18 and CD54, and lymphocyte CD18 persisted elevated even if patients with metabolic syndrome were discarded among those with hypertriglyceridemia. The increase in circulating and leukocyte cell adhesion molecules in primary hypertriglyceridemic patients would highlight the inflammatory process which is a key event in atherogenesis.

A high-fat meal is accompanied by increased plasma interleukin-6 concentrations

BACKGROUND AND AIM

Enhanced and prolonged postprandial lipaemia is associated with coronary heart disease (CHD). However, the mechanisms linking postprandial lipaemia to the increased risk of atherosclerosis and CHD remain to be determined. The aim of the present study was to examine the effects of a high-fat meal on plasma levels of the pro-inflammatory cytokine interleukin-6 (IL-6) and cellular adhesion molecules in CHD patients and control subjects.

METHODS AND RESULTS

Forty-one middle-aged men with premature CHD and 26 healthy male controls were investigated. The plasma triglyceride response to the high-fat meal was significantly greater among cases than controls. The oral fat load induced a twofold increase in plasma concentrations of IL-6, an increase that was similar in CHD patients and control subjects. No changes could be detected in plasma concentrations of cellular adhesion molecules in response to postprandial lipaemia in either CHD patients or control subjects.

CONCLUSION

The results of the present study suggest that a high-fat meal affects mechanisms that induce increased inflammatory activity, which is recognised as a key modulator in the development of atherosclerosis and CHD. However, the increased levels of plasma IL-6 appear not to be determined by the magnitude of the postprandial triglyceridaemia.

Inflammatory effects of very low-density lipoprotein and fatty acids

High plasma triacylglycerol (triglyceride, TG) levels is a risk factor for atherosclerosis. Very large lipoproteins, such as chylomicrons, alone are not considered atherogenic, but TG-rich remnant lipoproteins can penetrate into the vascular wall. Importantly, accumulating evidence suggests that all TG-rich lipoproteins stimulate cytokine expression in circulating monocytes. Very low-density lipoprotein (VLDL) stimulates monocyte adhesion to endothelial cells and expression of inflammatory genes in macrophages. Furthermore, fatty acids released from large lipoproteins can stimulate both vascular cells and circulating monocytes. It is likely that fatty acids released from TG-rich lipoproteins contribute to atherogenesis, but the role of fatty acids in ischemic heart disease is not as direct as that of cholesterol. Fatty acids influence plasma lipoprotein levels and either stimulate or suppress numerous cellular functions relevant to atherogenesis. While certain n-3 fatty acids are good for health, most other medium- to long-chain fatty acids appear to promote inflammation in cell culture studies and need to be studied further. Nevertheless, the existing evidence supports the general conclusion that TG-rich lipoproteins and fatty acids greatly accelerate the progression of atherosclerosis. This may be because of their inflammatory effects.

Dietary diacylglycerol reduces postprandial hyperlipidemia and ameliorates glucose intolerance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats

OBJECTIVE

The aim of the present study was to determine the effects of dietary diacylglycerol (DG) on the metabolism of lipids and glucose in type II diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

METHODS

In experiment 1, the rats were orally administered 10 mL/kg of a triacylglycerol (TG) or DG emulsion (15% [w/v] oil), and the subsequent changes in the serum lipid levels were compared. In experiment 2, the rats were fed diets containing 15% DG or TG oil. After 22 weeks, the serum levels of lipids, glucose, and cytokines were determined. In addition, an oral glucose tolerance test (OGTT) was performed on the rats.

RESULTS

Administration of an oral fat load caused marked hypertriglyceridemia with a peak at 2 h. Oral DG loading reduced the serum TG increase; the difference between the groups was significant at 4 and 6 h (P < 0.05). Diacylglycerol also markedly reduced the serum free fatty acid concentration increase due to the fat load. After 22 weeks of feeding, dietary DG reduced serum TG levels in the non-fasting state. Moreover, an OGTT revealed enhanced glucose disposal in the DG-fed rats compared with the TG-fed rats. Serum levels of adiponectin, an important insulin-sensitizing adipocytokine, were higher in the DG-fed rats than in the TG-fed rats (P < 0.05). In addition, DG-feeding reduced serum levels of C-reactive protein, a cardiovascular risk factor (P < 0.05).

CONCLUSION

These results suggested that dietary DG improves lipid metabolism and glucose tolerance, and retards the progress of diabetes mellitus in OLETF rats.

Metabolic syndrome aggravates the increased endothelial activation and low-grade inflammation in subjects with familial low HDL

BACKGROUND

Inhibition of cytokine-induced expression of adhesion molecules is one of the atheroprotective mechanisms of high-density lipoprotein (HDL).

AIM

We investigated whether increased endothelial activation and low-grade inflammation are present in Finnish subjects with familial low HDL, and which factors contribute to the inflammatory parameters.

METHOD

High-sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), and sE-selectin were measured in 91 subjects with low HDL-cholesterol from 41 low-HDL families and in 112 normolipidemic controls with comparable age- and gender distribution. Presence of the features of the metabolic syndrome (MetS) was recorded.

RESULTS

sVCAM-1, sICAM-1, sE-selectin, and hsCRP were significantly higher in low-HDL subjects than in the controls (sVCAM-1: 560+/-147 ng/mL versus 496+/-95 ng/mL, P = 0.001; sICAM-1: 247+/-60 ng/mL versus 215+/-47 ng/mL, P<0.001; sE-selectin: 52+/-20 ng/mL versus 44+/-16 ng/mL, P = 0.022; and hsCRP: 1.73+/-2.05 mg/L versus 0.85+/-1.10 mg/L, P<0.001). Low-HDL subjects had increased body mass index (BMI) and waist, and elevated insulin and triglyceride levels. Adhesion molecules and hsCRP increased according to the number of the features of the MetS.

CONCLUSIONS

The presence of the MetS in subjects with familial low HDL-cholesterol aggravates the low-grade inflammation and endothelial activation, and ultimately may add to the higher susceptibility for atherosclerotic disease in these individuals.

High-fat meal impairs vascular compliance in a subgroup of young healthy subjects

Postprandial hypertriglyceridemia impairs endothelial function and may possibly worsen vascular compliance by increasing oxidative stress. Large (C1) and small (C2) artery compliance, glucose, insulin, and triglycerides (TGs) were measured hourly for 6 hours in 18 young healthy volunteers after a low-fat meal and a high-fat meal, with and without antioxidant vitamins. C1 and C2 declined significantly for 6 hours after fat ingestion in 8 subjects ("fat reactors") and increased in 10 ("nonreactors"). Fat reactors had higher fasting and peak serum TGs after fat loading and increased baseline glucose and insulin levels and homeostasis model assessment of insulin resistance (HOMA(IR)). Fasting insulin correlated with C1 and C2 only in fat reactors. After fat intake, plasma nitric oxide metabolites decreased more in fat reactors than in nonreactors (17.0% +/- 5.1% vs 4.8% +/- 2.1%; P < .05). In fat reactors, pretreatment with antioxidant vitamins before the high-fat meal blunted the fall in C1 but not in C2. Compliance was unchanged after the low-fat meal. Normal weight young subjects with an insulin resistance phenotype show significantly decreased vascular compliance, increased postprandial TG peaks, and markedly reduced plasma nitric oxide metabolites after a high-fat meal.

Effects of bezafibrate on lipoprotein subclasses and inflammatory markers in patients with hypertriglyceridemia--a nuclear magnetic resonance study

BACKGROUND

Hypertriglyceridemia is often associated with elevated remnants, small dense LDL and decreased HDL-cholesterol (C). The objective of this study was to investigate the efficacy of bezafibrate on lipoprotein subfractions profile and inflammation markers in patients with hypertriglyceridemia.

METHODS

Twenty-four hypertriglyceridemic subjects took bezafibrate, 400 mg daily, for 4 weeks. Lipoprotein subclasses were measured by nuclear magnetic resonance (NMR) spectroscopy. Inflammation markers including C-reactive protein (CRP), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) were also determined.

RESULTS

Bezafibrate lowered triglyceride (TG) by 59% and increased HDL-C by 20%. NMR analysis revealed that bezafibrate lowered large TG-rich lipoproteins and IDL by 81% and 46%, respectively. Small LDL was selectively decreased by 53% with increase in large to intermediate LDL, thus altering the LDL distribution towards the larger particles (mean diameter 19.9 to 20.7 nm, p = 0.0001). Small (HDL1) and intermediate (HDL3) HDL significantly increased by 168% and 70%, whereby resulting in a significant reduction of the mean HDL particle size from 9.0 to 8.7 nm (p = 0.026). None of inflammation makers showed significant change by bezafibrate.

CONCLUSIONS

Bezafibrate effectively ameliorates atherogenic dyslipidemia by reducing remnants and small LDL as well as by increasing HDL particles in hypertriglyceridemic subjects.

Metabolic syndrome and endothelial dysfunction

The incidence of metabolic syndrome is rapidly increasing in the United States. Metabolic syndrome is associated with increased cardiovascular morbidity and mortality, and endothelial dysfunction is an early pathogenetic event in the metabolic syndrome. Endothelial dysfunction of either the coronary, the peripheral, or the cerebral vasculature is a predictor of vascular events and appears to be a marker of uncontrolled atherosclerotic risk that adds to the burden of the genetic predisposition to cardiovascular disease. Clinically and experimentally, endothelial dysfunction can be restored by several agents, including blockers/inhibitors of the renin-angiotensin-aldosterone system, as well as statins. Nevertheless, it would be premature, and most likely inappropriate, to use improvement of endothelial function as a surrogate end point to predict reduction in cardiovascular morbidity and mortality. However, a clear understanding of the mechanisms of endothelial dysfunction in the metabolic syndrome may allow the development of preventive and early therapeutic measures targeting cardiovascular disease.

Severe hypertriglyceridaemia in idiopathic (non-HCV-related) mixed cryoglobulinaemia

We describe a 28-year-old male patient in whom the development of idiopathic mixed cryoglobulinaemia (MC) with typical clinical manifestations such as polyarthralgia, weakness, purpura, and Raynaud's phenomenon was associated with a remarkable increase in serum triglycerides (TG). Prednisone administration was effective in classical cryoglobulinaemia symptoms and also in dyslipidaemia. Infective, autoimmune, and haematological disorders are often related to cryoglobulinaemia and it has been analysed that some of them also show an increase in TG.

Relationship between C-reactive protein and features of the metabolic syndrome in military pilots in the Serbia and Montenegro

Background/Aim. C-reactive protein is an independent predictor of the risk of cardiovascular events and diabetes mellitus in apparently healthy men. The relationship between C-reactive protein and the features of metabolic syndrome has not been fully elucidated. To assess the cross-sectional relationship between C-reactive protein and the features of metabolic syndrome in healthy people. Methods. We studied 161 military pilots (agee, 40?6 years) free of cardiovascular disease, diabetes mellitus and active inflammation on their regular annual medical control. Age, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, fasting glucose, glycosylated hemoglobin, blood pressure, smoking habit, waist circumference and body mass index were evaluated. Plasma C-reactive protein was measured by the immunonephelometry (Dade Behring) method. Metabolic syndrome was defined according to the National Cholesterol Education Program Expert Panel. Results. The mean C-reactive protein concentrations in the subjects grouped according to the presence of 0, 1, 2 and 3 or more features of the metabolic syndrome were 1.11, 1.89, 1.72 and 2.22 mg/L, respectively (p = 0.023) with a statistically, significant difference between those with 3, and without metabolic syndrome (p = 0.01). In the simple regression analyses C-reactive protein did not correlate with the total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, body mass index and blood pressure (p > 0.05). In the multiple regression analysis, waist circumference (? = 0.411, p = 0.000), triglycerides to high density lipoprotein cholesterol ratio (? = 0.774, p = 0.000), smoking habit (? = 0.236, p = 0.003) and triglycerides (? = 0.471, p = 0.027) were independent predictors of C-reactive protein. Conclusions. Our results suggested a cross-sectional independent correlation between the examined cardiovascular risk factors as the predominant features of metabolic syndrome and C-reactive protein in the group of apparently healthy subjects. The lack of correlation of C-reactive protein with the total cholesterol and low density lipoprotein cholesterol in our study may suggest their different role in the process of atherosclerosis and the possibility to determine C-reactive protein in order to identify high-risk subjects not identified with cholesterol screening.

Postprandial Hypertriglyceridemia Increases Circulating Levels of Endothelial Cell Microparticles

Background— This study evaluated a possible relationship between levels of endothelial microparticles (EMPs), known to be a sensitive indicator of endothelial disturbance, and changes in postprandial lipid levels in healthy volunteers after a low- or high-fat meal.

Methods and Results— Eighteen healthy subjects without known cardiovascular risk factors were evaluated. Lipid and EMP levels were measured before and 1 and 3 hours after a single low- or high-fat isocaloric meal. The low-fat meal had no significant postprandial effect on EMPs or lipids compared with fasting levels. In contrast, a single high-fat meal significantly increased EMP levels after 1 and 3 hours, from 389±54 (thousands per milliliter) when fasting to 541±139 ( P =0.0002) and 677±159 ( P <0.0001), respectively, and correlated with a postprandial elevation in serum triglycerides.

Conclusions— A single high-fat meal led to a significant elevation of plasma EMP levels in healthy, normolipidemic subjects and correlated with a postprandial elevation of serum triglycerides. EMPs may be an indirect marker of endothelial dysfunction or injury induced by postprandial triglyceride-rich lipoproteins.

The pattern of inflammation and a potential new clinical meaning and usefulness of C-reactive protein in end-stage renal failure patients

Inflammatory indexes are frequently elevated in end-stage renal failure (ESRF) patients. It seems that the pattern of inflammation is particular in this population. In the presence of a higher than normal microinflammatory background (CRP, C-reactive protein, values between 0.1 and 10-15 mg/l) that varies with time, waves of 'true' inflammation (CRP > 10-15 mg/l), mainly due to infections, are added periodically. To accurately assess the average microinflammation in these patients, multiple CRP measurements are required. As recent experimental studies showed that inflammation and particularly elevated CRP levels may be risk factors and not just a risk index for atherosclerosis, in this case, the characteristic inflammation pattern might be of importance in the evolution of this disease in ESRF patients. The causes of the inflammatory state in ESRF patients are multiple: renal insufficiency per se and its complications, coexisting diseases, established atherosclerosis, the consequences of renal replacement treatment, and frequent infections are potentially the main ones. The fluctuating inflammatory pattern is probably due to destabilization or changes in time of the above-mentioned parameters. Thus, the clinical meaning of the average microinflammation in these patients, as assessed by CRP measurements, seems to be that of an index indicative of the grade of their health aggravation by the multiple factors implicated in the inflammation formation. CRP is a sensitive, but not specific, risk index of the overall morbidity and mortality in these patients. The manipulation of the inflammation in ESRF patients should include follow-up and treatment of all the factors that contribute to this state and probably medications such as the statins. If inflammation and CRP in particular definitely prove to be risk factors for atherosclerosis, intensification of this treatment will be necessary.

Endothelial dysfunction in obesity and insulin resistance: a road to diabetes and heart disease

Obesity, insulin resistance, and endothelial dysfunction closely coexist throughout the natural history of type 2 diabetes. They all can be identified not only in people with type 2 diabetes, but also in various groups at risk for the disease, such as individuals with impaired glucose tolerance, family history of type 2 diabetes, hypertension, dyslipidemia, prior gestational diabetes, or polycystic ovary syndrome. Whereas their evident association cannot fully establish a cause-effect relationship, fascinating mechanisms that bring them closer together than ever before are rapidly emerging. Central or abdominal obesity leads to insulin resistance and endothelial dysfunction through fat-derived metabolic products, hormones, and cytokines. Insulin resistance leads to endothelial dysfunction through the frequent association with traditional cardiovascular risk factors and through some more direct novel mechanisms. Some specific and shared insulin signaling abnormalities in muscle, fat, and endothelial cells, as well as some new genetic and nontraditional factors, may contribute to this interesting association. Some recent clinical studies demonstrate that nonpharmacological and pharmacological strategies targeting obesity and/or insulin resistance ameliorate endothelial function and low-grade inflammation. All these findings have added a new dimension to the association of obesity, insulin resistance, and endothelial dysfunction that may become a key target in the prevention of type 2 diabetes and cardiovascular disease.