B. Klop

Understanding Postprandial Inflammation and Its Relationship to Lifestyle Behaviour and Metabolic Diseases

Postprandial hyperlipidemia with accumulation of remnant lipoproteins is a common metabolic disturbance associated with atherosclerosis and vascular dysfunction, particularly during chronic disease states such as obesity, the metabolic syndrome and, diabetes. Remnant lipoproteins become attached to the vascular wall, where they can penetrate intact endothelium causing foam cell formation. Postprandial remnant lipoproteins can activate circulating leukocytes, upregulate the expression of endothelial adhesion molecules, facilitate adhesion and migration of inflammatory cells into the subendothelial space, and activate the complement system. Since humans are postprandial most of the day, the continuous generation of remnants after each meal may be one of the triggers for the development of atherosclerosis. Modulation of postprandial lipemia by lifestyle changes and pharmacological interventions could result in a further decrease of cardiovascular mortality and morbidity. This paper will provide an update on current concepts concerning the relationship between postprandial lipemia, inflammation, vascular function, and therapeutic options.

Cardiovascular risk in rheumatoid arthritis: how to lower the risk?

Patients with rheumatoid arthritis (RA) carry an excess risk for cardiovascular disease, which is comparable to the risk in patients with type 2 diabetes mellitus. The mechanisms involved are partly related to traditional cardiovascular risk factors, disease-associated inflammation and undertreatment of traditional cardiovascular disease (CVD) risk factors. Since atherosclerosis is an inflammatory disease, the auto-immune mediated inflammation observed in RA patients contributes to increased endothelial dysfunction, oxidative stress and activation and vascular migration of leukocytes. This concept is underscored by the CVD risk reduction that is seen by anti-inflammatory disease modifying anti-rheumatic drugs such as methotrexate and TNFα inhibitors. The evidence for underdiagnosis and undertreatment of traditional CVD risk factors in RA strengthens the potential benefit of structured CVD risk management in these patients. Current cardiovascular guidelines recommend screening and treatment of CVD risk factors in RA patients, without well defined treatment targets. At present, there is a lack of scientific evidence to establish treatment targets for CVD risk factors in RA. Therefore, expanding research regarding screening and treatment of traditional CVD risk factors in RA patients is needed.

Marked underdiagnosis and undertreatment of hypertension and hypercholesterolaemia in rheumatoid arthritis

OBJECTIVEnTo investigate the prevalence of underdiagnosis and undertreatment of traditional cardiovascular risk factors in RA patients.nnnMETHODSnRA patients ⩽70 years of age without cardiovascular disease (CVD) or diabetes mellitus were included. Systolic blood pressure and a fasting lipid profile were measured. The 10-year CVD risk was estimated using the Dutch Cardiovascular Risk Management (CVRM) guideline and EULAR modifications of the Systemic Coronary Risk Evaluation tables.nnnRESULTSnA total of 327 patients were included (female gender: 68%). The mean age was 53 (11) years [mean (s.d.)]. The median disease duration was 7 years (inter quartile range: 2-14 years). According to the CVRM guideline, 52% of the patients had a CVD risk ⩾20% and according to the EULAR guidelines, 18% of the patients had a CVD risk ≥ 20%. Low-density lipoprotein cholesterol (LDL-C) >2.5 mmol/l was found in >80% of the patients with a CVD risk ⩾10% as estimated by both the CVRM and EULAR guidelines, and 32-42% of the patients with a CVD risk ⩾10% had a systolic blood pressure >140 mmHg, depending on the risk model used. Statins were used in 6% and antihypertensives in 23-25%, and 50-86% of these patients did not reach the recommended treatment targets.nnnCONCLUSIONnRegardless of the adapted risk assessment model used, untreated hypertension and hypercholesterolaemia were frequently found in RA patients with increased CVD risk. Treatment of these cardiovascular risk factors deserves more attention in RA.nnnTRIAL REGISTRATIONnThe Dutch Trial Register, www.trialregister.nl, NTR3873.

Leukocyte cell population data (volume conductivity scatter) in postprandial leukocyte activation

Changes in leukocyte cell population data have been reported in various infectious diseases, but little is known in other inflammatory conditions such as the postprandial state. We investigated whether leukocyte cell population data change during postprandial leukocyte activation.

Differential complement activation pathways promote C3b deposition on native and acetylated LDL thereby inducing lipoprotein binding to the complement receptor 1.

Background: LDL and modified LDL may be cleared via the adherence receptor CR1. Results: LDL bound C1q, whereas acLDL bound IgM, C1q and properdin. Both became opsonized by C3b. Conclusion: Binding of opsonized LDL and acLDL to CR1 is mediated via different complement pathways. Significance: CR1 is a novel receptor for cell-bound lipoproteins. Lipoproteins can induce complement activation resulting in opsonization and binding of these complexes to complement receptors. We investigated the binding of opsonized native LDL and acetylated LDL (acLDL) to the complement receptor 1 (CR1). Binding of complement factors C3b, IgM, C1q, mannose-binding lectin (MBL), and properdin to LDL and acLDL were investigated by ELISA. Subsequent binding of opsonized LDL and acLDL to CR1 on CR1-transfected Chinese Hamster Ovarian cells (CHO-CR1) was tested by flow cytometry. Both native LDL and acLDL induced complement activation with subsequent C3b opsonization upon incubation with normal human serum. Opsonized LDL and acLDL bound to CR1. Binding to CHO-CR1 was reduced by EDTA, whereas MgEGTA only reduced the binding of opsonized LDL, but not of acLDL suggesting involvement of the alternative pathway in the binding of acLDL to CR1. In vitro incubations showed that LDL bound C1q, whereas acLDL bound to C1q, IgM, and properdin. MBL did neither bind to LDL nor to acLDL. The relevance of these findings was demonstrated by the fact that ex vivo up-regulation of CR1 on leukocytes was accompanied by a concomitant increased binding of apolipoprotein B-containing lipoproteins to leukocytes without changes in LDL-receptor expression. In conclusion, CR1 is able to bind opsonized native LDL and acLDL. Binding of LDL to CR1 is mediated via the classical pathway, whereas binding of acLDL is mediated via both the classical and alternative pathways. Binding of lipoproteins to CR1 may be of clinical relevance due to the ubiquitous cellular distribution of CR1.

Association of Cardiovascular Risk Factors with Carotid Intima Media Thickness in Patients with Rheumatoid Arthritis with Low Disease Activity Compared to Controls: A Cross-Sectional Study

Objectives Rheumatoid arthritis (RA) has been identified as an independent cardiovascular risk factor. The importance of risk factors such as hypertension and hyperlipidemia in the generation of atherosclerosis in RA patients is unclear. This study analyzed clinical parameters associated with carotid intima media thickness (cIMT) in patients with RA. Methods Subjects with RA and healthy controls without RA, both without known cardiovascular disease, were included. Participants underwent a standard physical examination and laboratory measurements including a lipid profile. cIMT was measured semi-automatically by ultrasound. Results In total 243 RA patients and 117 controls were included. The median RA disease duration was 7 years (IQR 2–14 years). The median DAS28 was 2.4 (IQR 1.6–3.2) and 114 (50.4%) of the RA patients were in remission. The presence of RA and cIMT were not associated (univariate analysis). Multivariable regression analysis showed that cIMT in RA patients was associated with age (B = 0.006, P<0.001) and systolic blood pressure (B = 0.003, P = 0.003). In controls, cIMT was associated with age (B = 0.006, P<0.001) and smoking (B = 0.097, P = 0.001). Conclusion cIMT values were similar between RA patients and controls. Hypertension was strongly associated with cIMT in RA patients. After adjustment, no association between cIMT and specific RA disease characteristics was found in this well treated RA cohort.

Vitamin D3 mediated effects on postprandial leukocyte activation and arterial stiffness in men and women

Postprandial inflammation is considered to be pro-atherogenic. Vitamin D can reduce inflammation and arterial stiffness. We hypothesized that vitamin D3 improves postprandial arterial elasticity by the modulation of leukocyte activation. Healthy volunteers underwent two oral fat-loading tests (OFLTs). The augmentation index (AIx) and flow cytometric quantification of leukocyte activation markers were measured. After the first OFLT, 100u2009000u2009IU of vitamin D3 was administered and a second OFLT was carried out 7 days later. Six men and six women were included. A favorable reduction in AIx was found after vitamin D3 supplementation (P=0.042) in both genders. After vitamin D3, exclusively in women a reduction in the area under the postprandial curve for monocytes CD11b and CD35 by 10.5% (P=0.016) and 12.5% (P=0.04) and neutrophil CD11b by 17.0% (P=0.014) was observed. In conclusion, vitamin D3 probably increased postprandial arterial elasticity in men and women, but reduced postprandial leukocyte activation exclusively in women.

Diurnal Triglyceridemia in Relation to Alcohol Intake in Men

Fasting and postprandial triglyceride concentrations largely depend on dietary and lifestyle factors. Alcohol intake is associated with triglycerides, but the effect of alcohol on diurnal triglyceridemia in a free living situation is unknown. During three days, 139 men (range: 18–80 years) measured their own capillary triglyceride (cTG) concentrations daily on six fixed time-points before and after meals, and the total daily alcohol intake was recorded. The impact of daily alcohol intake (none; low, <10 g/day; moderate, 10–30 g/day; high, >30 g/day) on diurnal triglyceridemia was analyzed by the incremental area under the cTG curve (∆cTG-AUC) reflecting the mean of the six different time-points. Fasting cTG were similar between the alcohol groups, but a trend of increased cTG was observed in men with moderate and high alcohol intake after dinner and at bedtime (p for trend <0.001) which persisted after adjustment for age, smoking and body mass index. The ∆cTG-AUC was significantly lower in males with low alcohol intake (3.0 ± 1.9 mmol·h/L) (n = 27) compared to males with no (7.0 ± 1.8 mmol·h/L) (n = 34), moderate (6.5 ± 1.8 mmol·h/L) (n = 54) or high alcohol intake (7.2 ± 2.2 mmol·h/L) (n = 24), when adjusted for age, smoking and body mass index (adjusted p value < 0.05). In males, low alcohol intake was associated with decreased diurnal triglyceridemia, whereas moderate and high alcohol intake was associated with increased triglycerides after dinner and at bed time.

Adherence to cardiovascular prevention strategies in patients with rheumatoid arthritis

Objectives: Patients with rheumatoid arthritis (RA) have a high risk of cardiovascular disease (CVD). Recent national and international guidelines suggest strict treatment of CVD risk factors in RA. The aim of this study was to evaluate the self-reported adherence to CV prevention strategies in patients with RA. Method: RA patients visiting an outpatient clinic for strict CVD risk management received a validated questionnaire to evaluate adherence to CV prevention strategies. Strict treatment targets were defined and lifestyle recommendations were given following a prespecified protocol. CVD risk was assessed using the SCORE algorithm. Results: In total, 111 questionnaires were returned (response rate of 82%). A high 10-year CVD risk (≥ 20%) was present in 53%, but only 3% thought they had an increased CVD risk. A total of 53% of patients reported that they ‘follow the doctors’ suggestions exactly’ and 75% reported finding it ‘easy to follow the suggestions’. Of the 69% of patients who were prescribed lipid- and/or blood pressure-lowering drugs, 90% reported taking all prescribed tablets. The advice to follow a diet was given to 42%, of whom 68% said they followed the advised diet. Physical exercise was advised to 67%, of whom 62% said they performed specific physical exercise on at least 3 days a week. The adherence to lifestyle recommendations was not significantly different across the CVD risk groups. Conclusions: RA patients tend to underestimate their CVD risk. The self-reported adherence of RA patients to CVD risk management was high concerning pharmaceutical interventions and moderate in the case of lifestyle interventions.

Dyslipidemias in clinical practice

Most dyslipidemic conditions have been linked to an increased risk of cardiovascular disease. Over the past few years major advances have been made regarding the genetic and metabolic basis of dyslipidemias. Detailed characterization of the genetic basis of familial lipid disorders and knowledge concerning the effects of environmental factors on the expression of dyslipidemias have increased substantially, contributing to a better diagnosis in individual patients. In addition to these developments, therapeutic options to lower cholesterol levels in clinical practice have expanded even further in patients with familial hypercholesterolemia and in subjects with cardiovascular disease. Finally, promising upcoming therapeutic lipid lowering strategies will be reviewed. All these advances will be discussed in relation to current clinical practice with special focus on common lipid disorders including familial dyslipidemias.