Mechanisms linking obesity to hypertension

Obesity-related hypertension is increasingly recognized as a distinct hypertensive phenotype requiring a modified approach to diagnosis and management. In this review rapidly evolving insights into the complex and interdependent mechanisms linking obesity to hypertension are discussed. Overweight and obesity are associated with adipose tissue dysfunction, characterized by enlarged hypertrophied adipocytes, increased infiltration by macrophages and marked changes in secretion of adipokines and free fatty acids. This results in chronic vascular inflammation, oxidative stress, activation of the renin-angiotensin-aldosterone system and sympathetic overdrive, eventually leading to hypertension. These mechanisms may provide novel targets for anti-hypertensive drug treatment. Recognition of obesity-related hypertension as a distinct diagnosis enables tailored therapy in clinical practice. This includes lifestyle modification and accommodated choice of blood pressure-lowering drugs.

The relationship between walking speed and changes in cardiovascular risk factors during a 12-day walking tour to Santiago de Compostela: a cohort study

OBJECTIVES

Physical exercise has beneficial effects on cardiovascular risk factors. Knowledge about the effect of exercise intensity, specifically walking speed, on cardiovascular risk factors is limited. We report the relationship between walking speed and changes in cardiovascular risk factors in participants of a 12-day walking tour to Santiago de Compostela.

DESIGN

Prospective cohort study.

SETTING

Single-centre study with healthy middle-aged volunteers.

PARTICIPANTS

Healthy middle-aged men (n=15) and women (n=14). Subjects using lipid-lowering medication were excluded.

INTERVENTION

Participants walked 281±10 km of the classical route to Santiago de Compostela in 12 days in 2009.

PRIMARY AND SECONDARY OUTCOME MEASURES

Walking speed was recorded and blood pressure, weight, waist circumference, lipids and glucose were measured every other day. Changes in risk factors were compared between gender-pooled groups with faster and slower walking speed. Second, the relationship between walking speed and changes in risk factors was quantified using a linear mixed effects model.

RESULTS

In the faster walking speed (4.6±0.2 km/h) group, high-density lipoprotein cholesterol (HDL-c) increased more than in the slower walking speed (4.1±0.2 km/h) group (difference in change between groups: 0.20; 95% CI -0.02 to 0.42 mmol/l), while low-density lipoprotein cholesterol (LDL-c) and total cholesterol decreased more in the slower walking speed group (differences in changes between groups: LDL-c: -0.50; 95% CI -0.88 to -0.12 mmol/l and total cholesterol: -0.75; 95% CI -1.19 to -0.31 mmol/l). A 1 km/h higher walking speed was related to an increase in HDL-c (0.24; 95% CI 0.12 to 0.30 mmol/l), LDL-c (0.18; 95% CI -0.16 to 0.42 mmol/l) and total cholesterol (0.36; 95% CI 0.12 to 0.60 mmol/l), adjusted for age, gender, smoking, body mass index and heart rate, during the whole walking tour.

CONCLUSIONS

Walking the same distance faster improves HDL-c more, while LDL-c and total cholesterol decrease more with lower walking speed independent of changes in body weight in healthy middle-aged subjects.

Factor VIII deficiency does not protect against atherosclerosis

BACKGROUND

Hemophilia A patients have a lower cardiovascular mortality rate than the general population. Whether this protection is caused by hypocoagulability or decreased atherogenesis is unclear.

OBJECTIVES

To evaluate atherosclerosis and endothelial function in hemophilia A patients with and without obesity as well as in matched, unaffected controls.

METHODS

Fifty-one obese (body mass index [BMI] ≥ 30 kg m(-2)) and 47 non-obese (BMI ≤ 25 kg m(-2)) hemophilia A patients, and 42 obese and 50 matched non-obese male controls were included. Carotid and femoral intima–media thickness [IMT] and brachial flow-mediated dilatation (FMD) were measured as markers of atherogenesis and endothelial function.

RESULTS

The overall population age was 50 ± 13 years. Carotid IMT was increased in obese subjects (0.77 ± 0.22 mm) as compared with non-obese subjects (0.69 ± 0.16 mm) [mean difference 0.07 mm (95% confidence interval [CI] 0.02–0.13, P = 0.008)]. No differences in mean carotid and femoral IMT between obese hemophilic patients and obese controls were found (mean difference of 0.02 mm [95% CI ) 0.07–0.11, P = 0.67], and mean difference of 0.06 mm [95% CI ) 0.13–0.25, P = 0.55], respectively). Thirty-five per cent of the obese hemophilic patients and 29% of the obese controls had an atherosclerotic plaque (P = 0.49), irrespective of the severity of hemophilia. Brachial FMD was comparable between obese hemophilic patients and obese controls (4.84% ± 3.24% and 5.32% ± 2.37%, P = 0.45).

CONCLUSION

Hemophilia A patients with obesity develop atherosclerosis to a similar extent as the general male population. Detection and treatment of cardiovascular risk factors in hemophilic patients is equally necessary.

Insulin resistance increases the occurrence of new cardiovascular events in patients with manifest arterial disease without known diabetes. the SMART study

Background

Insulin resistance is accompanied by a cluster of metabolic changes, often referred to as metabolic syndrome. Metabolic syndrome is associated with an increased cardiovascular risk in patients with manifest arterial disease. We investigated whether insulin resistance is associated with an increased risk for cardiovascular events in patients with manifest arterial disease without known diabetes and whether this can be explained by the components of the metabolic syndrome or by inflammation.

Methods

Prospective cohort study in 2611 patients with manifest arterial disease without known diabetes. Homeostasis model of insulin resistance (HOMA-IR) was used to quantify insulin resistance. The relation of HOMA-IR with cardiovascular events (vascular death, myocardial infarction or stroke) and all cause mortality was assessed with Cox regression analysis. In additional models adjustments were performed for the single components constituting the metabolic syndrome and for inflammation.

Results

HOMA-IR increases with the number of metabolic syndrome components (mean HOMA-IR ± SD in groups with 0, 1, 2, 3, 4 and 5 metabolic syndrome components: 1.4 ± 0.7; 1.8 ± 1.2; 2.4 ± 1.5; 3.1 ± 1.8; 4.0 ± 2.6; and 5.6 ± 3.6 respectively). High HOMA-IR was independently associated with an increased risk of cardiovascular events (tertile 2 vs. 1 HR 1.92; 95%CI 1.20-3.08) (tertile 3 vs.1 HR 1.78; 95%CI 1.10-2.89) and with all cause mortality (tertile 2 vs. 1 HR 1.80; 95%CI 1.04-3.10) (tertile 3 vs.1 HR 1.56; 95%CI 0.88-2.75). These relations were not influenced by the individual components of metabolic syndrome or by inflammation.

Conclusions

In patients with manifest arterial disease without known diabetes, insulin resistance increases with the number of metabolic syndrome components, and elevated insulin resistance increases the risk of new cardiovascular events.

Relation between blood pressure and vascular events and mortality in patients with manifest vascular disease: J-curve revisited

Recent studies have challenged the notion that "lower is better" for blood pressure in relation to vascular events and mortality in patients with vascular disease, whereas practice guidelines currently recommend to lower blood pressure to <130/80 mm Hg. We reassessed this J-curved relationship between blood pressure and cardiovascular events and all-cause mortality in patients with various manifestations of vascular disease. For this purpose, 5788 patients with symptomatic vascular disease enrolled in the Secondary Manifestations of Arterial Disease Study were followed-up for the occurrence of new vascular events (ie, myocardial infarction, stroke, or vascular death) and all-cause mortality. During a median of 5.0 years (interquartile range: 2.6-8.1 years), 788 patients experienced a new vascular event, and 779 died. Overall, the covariate-adjusted relationship between mean baseline systolic, diastolic, or pulse pressure and the occurrence of vascular events followed a J-curve with increased event rates above and below the nadir blood pressure of 143/82 mm Hg. A similar nonlinear relationship was found for diastolic pressure and all-cause mortality. Elevated blood pressure was not associated with increased morbidity and mortality in patients with recently diagnosed coronary artery disease, ≥65 years, and having >60 mm Hg pulse pressure. Importantly, especially in these subgroups, low blood pressure could also be a symptom rather than a cause of disease. Blood pressure level below and above 143/82 mm Hg is, thus, an independent risk factor for recurrent events in patients with manifest vascular disease. Uncertainty of whether this association is causal provides a strong rationale for trials evaluating blood pressure treatment targets.

Estimating treatment effects for individual patients based on the results of randomised clinical trials

OBJECTIVES

To predict treatment effects for individual patients based on data from randomised trials, taking rosuvastatin treatment in the primary prevention of cardiovascular disease as an example, and to evaluate the net benefit of making treatment decisions for individual patients based on a predicted absolute treatment effect.

SETTING

As an example, data were used from the Justification for the Use of Statins in Prevention (JUPITER) trial, a randomised controlled trial evaluating the effect of rosuvastatin 20 mg daily versus placebo on the occurrence of cardiovascular events (myocardial infarction, stroke, arterial revascularisation, admission to hospital for unstable angina, or death from cardiovascular causes). Population 17,802 healthy men and women who had low density lipoprotein cholesterol levels of less than 3.4 mmol/L and high sensitivity C reactive protein levels of 2.0 mg/L or more.

METHODS

Data from the Justification for the Use of Statins in Prevention trial were used to predict rosuvastatin treatment effect for individual patients based on existing risk scores (Framingham and Reynolds) and on a newly developed prediction model. We compared the net benefit of prediction based rosuvastatin treatment (selective treatment of patients whose predicted treatment effect exceeds a decision threshold) with the net benefit of treating either everyone or no one.

RESULTS

The median predicted 10 year absolute risk reduction for cardiovascular events was 4.4% (interquartile range 2.6-7.0%) based on the Framingham risk score, 4.2% (2.5-7.1%) based on the Reynolds score, and 3.9% (2.5-6.1%) based on the newly developed model (optimal fit model). Prediction based treatment was associated with more net benefit than treating everyone or no one, provided that the decision threshold was between 2% and 7%, and thus that the number willing to treat (NWT) to prevent one cardiovascular event over 10 years was between 15 and 50.

CONCLUSIONS

Data from randomised trials can be used to predict treatment effect in terms of absolute risk reduction for individual patients, based on a newly developed model or, if available, existing risk scores. The value of such prediction of treatment effect for medical decision making is conditional on the NWT to prevent one outcome event. Trial registration number Clinicaltrials.gov NCT00239681.

Adipose tissue dysfunction and hypertriglyceridemia: mechanisms and management

Elevated plasma triglyceride levels, as often seen in obese subjects, are independently associated with an increased risk of cardiovascular diseases. By secreting adipokines (such as adiponectin and leptin) and other proteins (such as lipoprotein lipase and cholesteryl ester transferase protein), adipose tissue affects triglyceride metabolism. In obesity, adipocyte hypertrophy leads to many changes in adipocyte function and production of anti- and pro-inflammatory cytokines. Furthermore, free fatty acids are released into the circulation contributing to insulin resistance. Adipose tissue dysfunction will eventually lead to abnormalities in lipid metabolism, such as hypertriglyceridemia (due to increased hepatic very-low-density lipoprotein production and decreased triglyceride hydrolysis), small dense low-density lipoprotein particles, remnant lipoproteins and low high-density lipoprotein cholesterol levels, all associated with a higher risk for the development of cardiovascular diseases. The clinical implications of elevated plasma triglycerides are still a matter of debate. Understanding the pathophysiology of adipose tissue dysfunction in obesity, which is becoming a pandemic condition, is essential for designing appropriate therapeutic interventions. Lifestyle changes are important to improve adipose tissue function in obese patients. Pharmacological interventions to improve adipose tissue function need further evaluation. Although statins are not very potent in reducing plasma triglycerides, they remain the mainstay of therapy for cardiovascular risk reduction in high-risk patients.

Differential propensity for major hemorrhagic events in patients with different types of arterial disease

AIMS

Atherosclerosis is the most frequent cause of coronary artery disease (CAD), cerebrovascular disease (CVD), and peripheral arterial obstructive disease (PAD). We previously found that patients with CVD or PAD had a two-fold higher risk of major hemorrhagic complications than patients with CAD. We investigated whether this difference was attributable to baseline risk factors or genetic variants involved in hemostasis.

METHODS AND RESULTS

We included 2622 consecutive patients from a single university hospital who presented with non-disabling CAD, CVD, or PAD. All patients were followed for the occurrence of major hemorrhagic complications for a mean of 6.6 years. Major hemorrhagic events included intracranial hemorrhagic events, fatal hemorrhagic events, and any hemorrhagic complications requiring hospitalization, irrespective of interventions. Major hemorrhagic complications occurred in 122 patients (annual event rate of 0.77%). Patients with CVD or PAD had more hemorrhagic complications than patients with CAD (hazard ratio [HR] 2.05, 95% confidence interval [CI] 1.39-3.01). Hypertension, diabetes, renal failure and use of oral anticoagulants or antiplatelet therapy did not explain the difference (HR adjusted for all characteristics 1.74; 95% CI 1.14-2.61). Additional adjustment for genetic variants did not further change the HR.

CONCLUSION

Patients with CVD or PAD are at higher risk for major hemorrhagic events than patients with CAD. This difference could not be explained by known risk factors, use of antithrombotic agents, or genetic variants involved in hemostasis. Further research to find the reason for this difference and possible differences in pathogenesis is warranted.

Waist circumference and metabolic risk factors have separate and additive effects on the risk of future Type 2 diabetes in patients with vascular diseases. A cohort study

AIMS

To assess the effect of various measures of adiposity and of metabolic risk factors, both separately and in combination, on the risk of future Type 2 diabetes in patients with manifest vascular diseases.

METHODS

This was a prospective cohort study in 2924 patients (mean age 59 ± 12 years) with manifest atherosclerosis. Metabolic risk factors were defined according to National Cholesterol Education Program criteria for the metabolic syndrome. Incidence of Type 2 diabetes was assessed by questionnaire and subsequent verification.

RESULTS

During a median follow-up of 4.9 years (range 3.0-7.6 years) there were 178 cases (6.1%) of incident Type 2 diabetes. An increase with 1 sd waist circumference showed a strong association with incident Type 2 diabetes in both men (hazard ratio 2.45, 95% CI 1.97-3.04) and women (hazard ratio 1.77, 95% CI 1.38-2.26). Compared with patients with normal (i.e. below the National Cholesterol Education Program criteria for abdominal adiposity) waist circumference and < 3 metabolic risk factors, both patients with normal waist circumference and ≥ 3 metabolic risk factors and patients with high (i.e. above the National Cholesterol Education Program criteria for abdominal adiposity) waist circumference and < 3 metabolic risk factors had an increased risk of Type 2 diabetes (hazard ratio 2.44, 95% CI 1.37-4.36 and hazard ratio 3.61, 95% CI 2.23-5.85, respectively). Patients with both high waist circumference and ≥ 3 metabolic risk factors had the highest risk of developing Type 2 diabetes (hazard ratio 10.76, 95% CI 6.95-16.64).

CONCLUSIONS

In patients with manifest atherosclerosis, both presence of ≥ 3 metabolic risk factors and presence of a high waist circumference alone are associated with increased risk for developing Type 2 diabetes. The combined presence of ≥ 3 metabolic risk factors and high waist circumference, which is present in 15% of patients, is associated with a 10-fold increased risk of future Type 2 diabetes. To identify patients with manifest atherosclerosis at the highest risk of developing Type 2 diabetes, fat distribution in combination with metabolic risk factors should be considered.

The association between breastfeeding and the cardiovascular system in early childhood

BACKGROUND

Breastfeeding is suggested to have beneficial effects on children's health and future health status. However, its cardiovascular effects in childhood and possibly later in life remain largely unclear.

OBJECTIVE

The aim of the present study was to determine the cardiovascular effects of exclusive breastfeeding in early childhood.

DESIGN

We used the ongoing WHeezing Illnesses STudy LEidsche Rijn (WHISTLER) birth cohort to obtain data on infant feeding. In the first 306 children who were 5 y of age, ultrasonographic measurements of the carotid artery were performed to obtain carotid intima-media thickness (CIMT), distensibility, and elastic modulus.

RESULTS

At 5 y of age, children who had been exclusively breastfed in infancy for 3 to 6 mo had a CIMT that was 21.1 μm greater than that of exclusively formula-fed children (95% CI: 5.0, 37.2 μm; P = 0.01, adjusted for confounders). CIMT was not significantly different between children exclusively breastfed for either <3 or >6 mo and formula-fed children. In addition, no significant differences in carotid stiffness were observed between groups.

CONCLUSIONS

The duration of exclusive breastfeeding in infancy is related to properties of the carotid arterial wall at the age of 5 y, as shown by the greater CIMT in children who were exclusively breastfed for 3 to 6 mo. This relation was independent of early growth in infancy and current cardiovascular disease risk factors. The choice of infant feeding appears to have an effect on the vascular system already in early childhood.

Statin treatment for primary prevention of vascular disease: whom to treat? Cost-effectiveness analysis

OBJECTIVE

To assess the cost-effectiveness of low dose statins for primary prevention of vascular disease, incorporating current prices, non-adherence (reduced clinical efficacy while maintaining healthcare costs), and the results of the recently published JUPITER trial.

DESIGN

Cost-effectiveness analysis using a Markov model. Sensitivity analyses and Monte Carlo simulation evaluated the robustness of the results.

SETTING

Primary care in The Netherlands.

PARTICIPANTS

Hypothetical populations of men and women aged 45 to 75 years without a history of vascular disease at different levels of risk for vascular disease (myocardial infarction and stroke) over 10 years.

INTERVENTIONS

Low dose statin treatment daily versus no treatment for 10 years.

MAIN OUTCOME MEASURES

Number of fatal and nonfatal vascular events prevented, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios over 10 years.

RESULTS

Over a 10-year period, statin treatment cost €35 000 (£30 000, $49 000) per QALY gained for men aged 55 years with a 10-year vascular risk of 10%. The incremental cost-effectiveness ratio improved as risk for vascular disease increased. The cost per QALY ranged from approximately €5000 to €125 000 when the 10-year vascular risk for men aged 55 years was varied from 25% to 5%. The incremental cost-effectiveness ratio slightly decreased with age after the level of vascular risk was specified. Results were sensitive to the costs of statin treatment, statin effectiveness, non-adherence, disutility of taking medication daily, and the time horizon of the model.

CONCLUSIONS

In daily practice, statin treatment seemed not to be cost-effective for primary prevention in populations at low risk of vascular disease, despite low costs of generic drug pills. Adherence to statin treatment needs to be improved to enhance the cost-effectiveness of the use of statins for primary prevention.

The relation between thyroid-stimulating hormone and measures of adiposity in patients with manifest vascular disease

BACKGROUND

Visceral adiposity is associated with cardiovascular risk factors and increased cardiovascular risk. Thyroid-stimulating hormone (TSH) levels in the normal range are associated with a higher risk of fatal coronary artery disease. We hypothesize that TSH levels in the normal range are associated with an increase in visceral adipose tissue (VAT) in patients with vascular diseases.

DESIGN

In 2419 patients with vascular diseases, visceral fat thickness was analysed with ultrasonography. The association between TSH and VAT was quantified using linear regression analysis. Results are expressed as beta (β) regression coefficients with 95% confidence intervals. Adjustments were made for age, sex, current smoking and weight. Separate analyses were performed per quartile of age.

RESULTS

β-coefficients for the relation between TSH and VAT (change per SD of 2·55 cm) was 0·085 (95% CI 0·012-0·157) in the highest quartile of age (range 67-80 years) when adjusted for age, gender and current smoking and remained statistical significant after further adjustment for weight (β 0·096 95% CI 0·034-0·157). Per SD change, the β-coefficient for TSH and VAT tissue was larger than for other measures of adiposity.

CONCLUSIONS

In conclusion, higher TSH plasma levels in the normal range are associated with more VAT in patients with manifest vascular disease above the age of 66 years. No association was found between plasma TSH levels and weight or BMI. The relation between TSH levels and VAT may provide an explanation for the increased cardiovascular risk associated with elevated TSH plasma concentrations within the normal range.

Pharmacological and non-pharmacological interventions to influence adipose tissue function

Obesity is associated with metabolic derangements such as insulin resistance, inflammation and hypercoagulobility which can all be understood as consequences of adipose tissue dysfunction. The potential role for adipose tissue derived cytokines and adipokines in the development of vascular disease and diabetes may produce a clinical need to influence adipose tissue function. Various pharmacological and non-pharmacological interventions affect plasma cytokine and adipokine levels. The effects of these interventions depend on weight loss per se, changes in fat distribution without weight loss and/or direct effects on adipose tissue inflammation.

Weight loss, as a result of diet, pharmacology and surgery, positively influences plasma adipokines and systemic inflammation. Several classes of drugs influence systemic inflammation directly through their anti-inflammatory actions. PPAR-γ agonism positively influences adipose tissue inflammation in several classes of intervention such as the thiazolidinediones and perhaps salicylates, CB1-antagonists and angiotensin II receptor blockers. Furthermore, within drug classes there are differential effects of individual pharmacologic agents on adipose tissue function.

It can be concluded that several commonly used pharmacological and non-pharmacological interventions have unintended influences on adipose tissue function. Improving adipose tissue function may contribute to reducing the risk of vascular diseases and the development of type 2 diabetes.

[Cardiovascular polypill in high risk patients]

The initial theoretical concept of a polypill was a fixed-dosed combination pill containing an antiplatelet agent, a cholesterol-lowering agent and multiple blood pressure-lowering agents aimed at the prevention of atherosclerotic vascular disease in the population aged 55 years and up. The reduction in the risk of cardiovascular disease does not depend on the cholesterol level and blood pressure at the start of treatment. The pharmacological reduction in risk factors in individuals with a high risk of atherosclerotic vascular disease is often suboptimal, partly due to the complexity of the guidelines and low adherence to the therapy. A polypill may offer opportunities for improvement. Research has shown that the use of combination products leads to a greater reduction in risk factors than the use of separate substances, possibly through improved adherence to the therapy. The use of a polypill in the prevention of vascular disease in high-risk patients may lead to a more effective reduction in risk, a decrease in costs and a reduction in pharmacological expenditure.

[Obesity-related hypertension]

Hypertension occurs in more than 40% of obese adults and leads to increased risk for cardiovascular disease and death. In practice, obesity-related hypertension is often difficult to control with pharmacological treatment. The association of obesity and hypertension can partly be explained by mutual risk factors, but there is also an etiological relation. Increasing obesity may lead to dysfunctional adipose tissue, characterised e.g. by deranged production of hormones and cytokines (adipokines). This results in sympathoactivation, upregulation of the renin-angiotensin-aldosterone system (RAAS) and systemic low grade inflammation and oxidative stress. The common result of these deregulations is increased resistance of the peripheral vasculature due to endothelial dysfunction, vasoconstriction and vascular wall hypertrophy, and increased circulating volume due to impaired pressure natriuresis. This leads to the development of hypertension that is relatively resistant to drug therapy. Lifestyle modifications by means of weight reduction and salt restricted diet are the cornerstones of obesity-related hypertension treatment. Pharmacological treatment with beta-blockers or diuretics is not self-evident, since this increases the risk of developing de novo diabetes mellitus.

Effectiveness of a hospital-based vascular screening programme (SMART) for risk factor management in patients with established vascular disease or type 2 diabetes: a parallel-group comparative study

AIMS

Modification of vascular risk factors is effective in reducing mortality and morbidity in patients with symptomatic atherosclerosis; however, it is difficult to achieve and maintain. The aim of the Risk management in Utrecht and Leiden Evaluation (RULE) study was to assess risk factor status after referral in patients with established vascular disease or type 2 diabetes who took part in the multidisciplinary hospital-based vascular screening programme, Second Manifestations of ARTerial disease, compared with a group who did not participate in such a programme.

METHODS AND RESULTS

Patients with type 2 diabetes, coronary artery disease, cerebrovascular disease or peripheral arterial disease referred by general practitioners to the medical specialist at the University Medical Center (UMC) Utrecht (a setting with a vascular screening programme of systematic screening of risk factors followed by treatment advice) and the Leiden UMC (a setting without such a screening programme), were enrolled in the study. Blood pressure, levels of lipids, glucose and creatinine, weight, waist circumference and smoking status were measured in patients 12-18 months after referral to the two hospitals. A total of 604 patients were treated in the setting with a vascular screening programme and 566 in the setting without such a programme; 70% of all patients were male, with a mean age of 61 +/- 10 years. Amongst screened patients, systolic blood pressure [2.5 mmHg, 95% confidence interval (CI) 0.3-4.6] and the level of LDL cholesterol (0.3 mmol L(-1), 95% CI 0.2-0.4) were lower compared with the group that received usual care, after a median of 16 months from referral.

CONCLUSION

Systematic screening of risk factors, followed by evidence-based, tailored treatment advice contributed to slightly better risk factor reduction in patients with established vascular disease or type 2 diabetes. However, a large proportion of patients did not reach the treatment goals according to (inter)national guidelines. Systematic screening of vascular risk factors alone is not enough for adequate risk factor management in high-risk patients.

Perivascular adipose tissue as a cause of atherosclerosis

Perivascular adipose tissue surrounds (coronary) arteries and may be involved in local stimulation of atherosclerotic plaque formation. Epicardial adipose tissue, the adipose tissue within the pericardium, is a frequently used measure of coronary perivascular adipose tissue and can be quantified with echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI). The quantity of (coronary) perivascular adipose tissue is correlated with parameters of the metabolic syndrome, such as increased waist circumference, hypertriglyceridemia and hyperglycemia, and with coronary atherosclerosis. Coronary artery segments covered by myocardium are not exposed to coronary perivascular adipose tissue and interestingly, atherosclerosis is absent in these intra-myocardial segments. Pro-inflammatory cytokines and adipokines are expressed and secreted at a higher level in epicardial adipose tissue of patients with coronary artery disease compared to patients without coronary artery disease. Furthermore, in vitro and ex vivo perivascular adipose tissue induces inflammation of the artery wall by secretion of pro-inflammatory proteins. Atherogenesis in the vascular wall is thus stimulated from 'outside to inside'. Based on the results of clinical, ex vivo and in vitro studies, it can be argued that perivascular adipose tissue may be involved in the process of atherosclerosis.

Increased visceral adipose tissue mass is associated with increased C-reactive protein in patients with manifest vascular diseases

BACKGROUND

Obesity is related to the development of vascular diseases and metabolic complications. Low grade inflammation is a key feature of central obesity, characterized by elevated plasma levels of C-reactive protein (CRP). We hypothesize that visceral adipose tissue contributes to systemic concentrations of CRP.

METHODS

In 2410 patients (1729 men and 681 women) with vascular diseases, subcutaneous and visceral fat masses were analyzed with ultrasonography. Metabolic parameters and CRP were measured in a fasting state. The association between fat measurements and plasma CRP was quantified using linear regression analysis. CRP levels were logarithmically transformed. Adjustments were made for age, smoking, type 2 diabetes mellitus, insulin resistance (HOMA-IR) and medication use.

RESULTS

Visceral fat was categorized into quartiles (Q) ranging from 3.2 to 7.8 cm in Q1 (reference) to 11.0-19.8 cm in Q4 in men and 2.7-6.0 cm in Q1 (reference) to 9.0-17.4 cm in Q4 in women. beta-coefficients gradually increased across the quartiles from 0.07 (0.01-0.13) in Q2 to 0.25 (0.19-0.31) in Q4 in men and 0.17 (0.07-0.26) in Q2 to 0.42 (0.32-0.52) in Q4 in women, indicating 0.25 and 0.42 mg/l higher logarithmically transformed (log)CRP levels in Q4 compared to Q1 in respectively men and women. Per standard deviation increase of visceral fat, logCRP levels increased with 0.10 mg/l (0.07-0.12) in men and with 0.11 (0.15-0.19) in women. Likewise, in separate analyses waist circumference and body mass index showed a positive, but weaker association with logCRP levels across quartiles (in men: beta 0.21 (0.15-0.27) in Q4 for waist circumference and beta 0.23 (0.17-0.30) in Q4 for body mass index; in women: beta 0.32 (0.22-0.42) in Q4 for waist circumference and beta 0.32 (0.22-0.42) in Q4 for body mass index). In men subcutaneous fat was not associated with logCRP (beta-coefficients relative to Q1: -0.01 (-0.07 to -0.05), -0.01 (-0.07 to -0.05) and 0.05 (-0.01 to -0.11) in Q2 to Q4 respectively).

CONCLUSIONS

In conclusion, visceral fat thickness is the strongest contributor to the systemic CRP concentrations in patients with vascular diseases.

Alcohol consumption and risk of recurrent cardiovascular events and mortality in patients with clinically manifest vascular disease and diabetes mellitus: the Second Manifestations of ARTerial (SMART) disease study

OBJECTIVE

This study investigated the relation between alcohol consumption and specific vascular events and mortality in a high risk population of patients with clinical manifestations of vascular disease and diabetes.

METHODS

Patients with clinically manifest vascular disease or diabetes (n=5447) from the SMART study were followed for cardiovascular events and mortality. Alcohol consumption was assessed with a baseline questionnaire and analysed in relation with coronary heart disease (CHD), amputations, stroke, and all-cause and vascular death.

RESULTS

After a follow up of 4.7 years, we documented 363 cases of CHD, 187 cases of stroke, 79 amputations and 641 cases of all-cause death, of which 382 were vascular. In multivariate-adjusted models, alcohol consumption was inversely associated with CHD (p(linear trend)=0.007) and stroke (p(linear trend)=0.051) with respective hazard ratios of 0.39 (95%CI: 0.20-0.76) and 0.67 (0.31-1.46) for consuming 10-20 drinks/week compared with abstainers. We observed significant U-shaped associations between alcohol consumption and amputations (p(quadratic trend)=0.001), all-cause death (p(quadratic trend)=0.001) and vascular death (p(quadratic trend)=0.013). Hazard ratios for consuming 10-20 drinks/week were 0.29 (0.07-1.30) for amputations, 0.40 (0.24-0.69) for all-cause death and 0.34 (0.16-0.71) for vascular death compared with abstainers. Similar associations were observed for red wine consumption only.

CONCLUSION

Moderate alcohol consumption (1-2 drinks/day) is not only associated with a reduced risk of vascular and all-cause death in a high risk patients with clinical manifestations of vascular disease, but also with reduced risks of non-fatal events like CHD, stroke and possibly amputations.

Leisure-time physical activity and risk of type 2 diabetes in patients with established vascular disease or poorly controlled vascular risk factors

AIM

To investigate the effect of leisure-time physical activity on the incidence of type 2 diabetes (T2DM) in patients with manifest arterial disease, or poorly controlled risk factors.

METHODS

We examined 3940 patients with manifest arterial disease, hypertension or hyperlipidemia, aged 55.2+/-12.2 years. Leisure-time physical activity was measured by a questionnaire and metabolic equivalent (MET) hours per week (h/wk) were calculated. Incident T2DM was evaluated by a specific diabetes questionnaire.

RESULTS

Most patients (65%) were physically inactive (0METh/wk), 12% were insufficiently physically active (0-10.5METh/wk) and 23% were sufficiently physically active (>or=10.5METh/wk). During a mean follow-up of 4.7 years, 194 (5%) incident cases of T2DM occurred. Sufficiently physically active patients had a lower incidence of diabetes (hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.37-0.83). Patients who were physically active and not-obese (BMI<30kg/m(2)) were at the lowest risk for developing T2DM (HR 0.18, 95% CI 0.12-0.28) compared with patients who were physically inactive and obese.

CONCLUSIONS

Leisure-time physical activity is associated with a decreased risk of T2DM in patients with manifest arterial disease, or poorly controlled risk factors. The combination of physical activity and non-obesity is associated with an even lower risk of the development of type 2 diabetes than the sum of their independent, protective effect.

[Muscle problems due to statins: underestimated]

Statin-associated muscle problems are more common than the 1-5% prevalence reported in large clinical trials. Observational studies show a prevalence of about 10%. Muscle problems can occur anytime during statin treatment, but usually occur in the first 6 months. The occurrence of rhabdomyolysis is rare. Depletion of isoprenoids due to HMG-CoA reductase inhibition is probably the main cause of the myopathy. Statin-associated myopathy is treated by prevention and treatment of risk factors. The main risk factors are multiple drug treatment, alcohol abuse, hypothyroidism and a family history of muscle problems due to statin therapy. The first step in the treatment of muscle problems or of elevated creatine kinase levels is lowering or stopping the statin. The chance of another type of statin not having the same muscular effects is about 40%.The benefit of Q10 or other supplements is unproven thus far. In the presence of recurrent creatine kinase elevation or muscle problems, other cholesterol-lowering agents can be considered.

Metabolic syndrome and cognition in patients with manifest atherosclerotic disease: the SMART study

BACKGROUND

It is unclear whether the metabolic syndrome (MetS) increases risk of cognitive dysfunction beyond the level expected from its individual components. We examined the association of MetS with cognitive dysfunction and assessed whether MetS increased risk of cognitive dysfunction more than that of the sum of its individual components.

METHODS

Data on 823 participants were used from the SMART-study, a cohort study among patients with atherosclerotic disease. MetS was defined according to the NCEP-ATPIII-criteria. Neuropsychological tests assessing memory, executive, and visuospatial functioning were performed. Regression analyses were performed to assess the association of MetS and its individual components with cognitive dysfunction. To examine whether MetS increased risk of cognitive dysfunction beyond its individual components we tested whether there was interaction on an additive scale by calculating the relative excess risk due to interaction (RERI).

RESULTS

MetS was associated with increased risk of memory (OR 2.0, 95% CI 1.1-3.3) and visuospatial dysfunction (OR 2.3, 95% CI 1.4-2.7) but not with executive dysfunction. However, risk of memory and visuospatial dysfunction for having all MetS components was not greater than that of the sum of the individual components (RERI 0.2 and -0.9).

CONCLUSIONS

In this population, MetS is related to increased risk of cognitive dysfunction but not more than that of the sum of its individual components.

Obesity and cancer: the role of dysfunctional adipose tissue

Overweight and obesity are health problems of epidemic proportions, increasing the risk not only of cardiovascular disease and type 2 diabetes mellitus but also of various types of cancer. Obesity is strongly associated with changes in the physiological function of adipose tissue, leading to insulin resistance, chronic inflammation, and altered secretion of adipokines. Several of these factors, such as insulin resistance, increased levels of leptin, plasminogen activator inhibitor-1, and endogenous sex steroids, decreased levels of adiponectin, and chronic inflammation, are involved in carcinogenesis and cancer progression. This article reviews these mechanisms, focusing on adipose tissue dysfunction as a unifying causal factor. Although understanding of the link between obesity and cancer might provide therapeutic targets, preventing overweight and obesity still remains number one priority.

Role of adipose tissue in haemostasis, coagulation and fibrinolysis

Obesity is associated with an increased incidence of insulin resistance (IR), type 2 diabetes mellitus and cardiovascular diseases. The increased risk for cardiovascular diseases could partly be caused by a prothrombotic state that exists because of abdominal obesity. Adipose tissue induces thrombocyte activation by the production of adipose tissue-derived hormones, often called adipokines, of which some such as leptin and adiponectin have been shown to directly interfere with platelet function. Increased adipose tissue mass induces IR and systemic low-grade inflammation, also affecting platelet function. It has been demonstrated that adipose tissue directly impairs fibrinolysis by the production of plasminogen activator inhibitor-1 and possibly thrombin-activatable fibrinolysis inhibitor. Adipose tissue may contribute to enhanced coagulation by direct tissue factor production, but hypercoagulability is likely to be primarily caused by affecting hepatic synthesis of the coagulation factors fibrinogen, factor VII, factor VIII and tissue factor, by releasing free fatty acids and pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukin-1beta and interleukin-6) into the portal circulation and by inducing hepatic IR. Adipose tissue dysfunction could thus play a causal role in the prothrombotic state observed in obesity, by directly and indirectly affecting haemostasis, coagulation and fibrinolysis.

Low plasma HDL-c, a vascular risk factor in high risk patients independent of LDL-c

BACKGROUND

High concentrations of high density lipoprotein-cholesterol (HDL-c) are associated with lower cardiovascular risk, but it is not known whether this is also the case in the presence of intensive low density lipoprotein-cholesterol (LDL-C) therapy. In this study, we determined the relationship between HDL-c and new non-fatal or fatal vascular events in patients with various manifestations of clinical evident vascular disease and evaluated whether this relationship is modified by LDL-c levels.

MATERIALS AND METHODS

Prospective single centre, cohort study of 3837 patients with a history or recent diagnosis of clinical manifest vascular disease (coronary, cerebrovascular, peripheral arterial disease or abdominal aortic aneurysm) The relationship between HDL-c quintiles and time to a new event (myocardial infarction, ischaemic stroke, vascular death) was quantified with Cox-regression models and adjusted for potential confounders (age, gender, body mass index, type 2 diabetes, triglycerides, smoking, use of alcohol and lipid-lowering therapy). Effect modification of LDL-c was assessed with interaction terms.

RESULTS

During a median follow up of 3.3 (range 0.1-9.5) years, a total of 465 first new events occurred. Compared with the lowest quintile, the upper quintile of HDL-c levels was associated with a lower risk for new events; Hazard Ratio 0.61 (95% CI 0.43-0.86) irrespective of the localisation of vascular disease and use of lipid-lowering medication. Higher HDL-c levels were associated with comparably lower risks for vascular events in patients with LDL-c levels above and below 2.5 mmol L(-1) (P-values for interaction > 0.05).

CONCLUSIONS

Patients with various clinical manifestations of vascular diseases in the highest HDL-c quintile have a lower risk for vascular events compared with patients in the lowest HDL-c quintile. Further, the current results expand the evidence by showing that also in a cohort of patients with various localisations of clinical evident vascular disease, in which statins were widely used, higher HDL-c levels confer a lower risk for developing new vascular events, irrespective of the localisation of vascular disease, use of lipid-lowering medication and plasma LDL-c concentration.

[Cardiovascular prevention: begin young]

Atherosclerotic vascular disease is rare in the young. Nevertheless, the foundations for atherosclerotic disease in later life are laid early by a harmful lifestyle including overweight and smoking. Adolescents who are overweight or have the metabolic syndrome are at increased cardiovascular risk later in life.

Lipid-lowering therapy does not affect the postprandial drop in high density lipoprotein-cholesterol (HDL-c) plasma levels in obese men with metabolic syndrome: a randomized double blind crossover trial

INTRODUCTION

The postprandial lipid metabolism in metabolic syndrome patients is disturbed and may add to the increased cardiovascular risk in these patients. It is not known whether postprandial high density lipoprotein-cholesterol (HDL-c) metabolism is also affected and whether this can be influenced by statin and/or ezetimibe treatment.

METHODS

Prospective, randomized, double blind, crossover trial comparing simvastatin 80 mg with simvastatin/ezetimibe 10 mg/10 mg treatment for 6 weeks on postprandial HDL-c metabolism in 15, nonsmoking, male, obese metabolic syndrome patients (Adult Treatment Panel III, ATPIII). Only study medication was allowed. HDL-c concentrations, cholesteryl ester transfer (CET), CET protein (CETP) mass and adiponectin were measured before and after oral fat loading. ClinicalTrials.gov NCT00189085.

RESULTS

Plasma HDL-c levels remained stable during continuous fasting following an overnight fast. Pre-fat load HDL-c concentrations without treatment, after simvastatin and simvastatin/ezetimibe treatment were 1.15 +/- 0.04, 1.16 +/- 0.05 and 1.11 +/- 0.04 mmol/l. Fat load induced a 11% drop in HDL-c plasma levels; 1.02 +/- 0.05 mmol/l (P < 0.001) which was not affected by either therapy. Triglyceride levels during fat load were similar after both treatments. Total CET increased from 9.73 +/- 0.70 to 12.20 +/- 0.67 nmol/ml/h (P = 0.004). Four hours after fat loading CETP mass was increased while adiponectin levels were decreased, irrespective of treatment.

DISCUSSION

HDL-c levels decrease as CET increases after fat loading in obese metabolic syndrome patients. This is not influenced by either simvastatin or simvastatin/ezetimibe treatment. After fat loading, CETP mass and CET increased, and adiponectin decreased pointing towards a potential role for intra-abdominal fat. Decreased postprandial HDL-c levels may contribute to the increased cardiovascular risk in metabolic syndrome patients on top of already low HDL-c levels.

A pilot-study to identify the feasibility of an Internet-based coaching programme for changing the vascular risk profile of high-risk patients

OBJECTIVE

To evaluate the feasibility of a web-based coaching programme for vascular risk factor treatment, to describe the patterns of use and to measure changes in risk factors.

METHODS

Patients with a clinical manifestation of arterial disease and Internet access were asked to participate in the nurse-led Internet-based risk factor management programme. At the first clinic visit, a personalized action plan was made for the treatment of risk factors. Patients were instructed on communication with a specialized nurse through Internet and encouraged to enter self-measured risk factor levels at their personalized website. The nurse practitioner replied on working days and gave feedback, support, and recommendations on lifestyle and medical treatment. After 6 months, risk factors were re-measured.

RESULTS

Fifty patients participated, 70% were overweight, 64% had hypertension, 42% hyperlipidemia, and 24% smoked at baseline. During 6 months, the log-in average at the individual website was 35 times per patient (1.3 log-ins/week); while the nurse practitioner logged-in at the overall website 23 times/week. The website was hardly used by five patients. Most e-mail messages were sent by patients for hypertension (211 times) and obesity (203 times), whereas the nurse practitioner sent nearly twice as many e-mail messages for hypertension (400 times) and obesity (455 times). The level of most risk factors decreased and the fraction of achieved treatment goals increased (blood pressure from 36 to 58%, LDL-cholesterol from 58 to 64%, glucose from 64 to 82%).

CONCLUSIONS

A web-based vascular risk factor intervention programme is feasible; it is frequently used by patients and suitable to decrease the level of several risk factors. It has the promise of being an efficacious intervention for risk factor sanitation in patients with symptomatic vascular disease.

PRACTICE IMPLICATIONS

An Internet-based individualised risk management programme could make patients aware of their self-management capability and may contribute to risk factor reduction.

Cardiovascular events and all-cause mortality by albuminuria and decreased glomerular filtration rate in patients with vascular disease

OBJECTIVES

Albuminuria and decreased estimated glomerular filtration rate (eGFR) are associated with increased cardiovascular risk, but do not necessarily coexist and have different pathophysiological mechanisms. This study aims to evaluate separate and combined effects of decreased eGFR and albuminuria on the occurrence of vascular diseases and mortality in patients with vascular disease.

DESIGN

Prospective cohort study.

SETTING

University Medical Center Utrecht, the Netherlands.

SUBJECTS AND MAIN OUTCOME MEASURES

2600 patients with vascular disease were followed for vascular events, vascular and all-cause mortality. Cox regression analysis was used to calculate hazard ratios (HRs) according to eGFR (MDRD) and albuminuria (albumin-to-creatinine ratio >3 mg mmol(-1)).

RESULTS

In this population, 14.0% had albuminuria, 15.6% had eGFR <60 ml min(-1) 1.73 m(-2) and 5.2% had both. Nonalbuminuric decreased eGFR and albuminuria with normal eGFR generated moderately increased risks on all outcomes. eGFR <60 ml min(-1) 1.73 m(-2) without albuminuria mainly influenced the risk of vascular events (HR 1.50; 1.05-2.15) whilst albuminuria with eGFR >or=60 ml min(-1) 1.73 m(-2) principally affected all-cause mortality (HR 1.53; 1.04-2.26). The combination of eGFR <60 ml min(-1) 1.73 m(-2) and albuminuria was associated with an increased risk for vascular events (HR 2.27; 1.54-3.34), vascular mortality (HR 2.22; 1.40-3.52) and all-cause mortality (HR 1.84; 1.25-2.69). Comparable results were found in additional analyses amongst 759 diabetic patients.

CONCLUSIONS

The combination of decreased eGFR with albuminuria is associated with the highest risks of vascular events, vascular and all-cause mortality in patients with vascular diseases. To adequately estimate vascular risk associated with impaired renal function, both eGFR and urinary albumin should be considered.

Adipose tissue dysfunction in obesity, diabetes, and vascular diseases

The classical perception of adipose tissue as a storage place of fatty acids has been replaced over the last years by the notion that adipose tissue has a central role in lipid and glucose metabolism and produces a large number of hormones and cytokines, e.g. tumour necrosis factor-alpha, interleukin-6, adiponectin, leptin, and plasminogen activator inhibitor-1. The increased prevalence of excessive visceral obesity and obesity-related cardiovascular risk factors is closely associated with the rising incidence of cardiovascular diseases and type 2 diabetes mellitus. This clustering of vascular risk factors in (visceral) obesity is often referred to as metabolic syndrome. The close relationship between an increased quantity of visceral fat, metabolic disturbances, including low-grade inflammation, and cardiovascular diseases and the unique anatomical relation to the hepatic portal circulation has led to an intense endeavour to unravel the specific endocrine functions of this visceral fat depot. The objective of this paper is to describe adipose tissue dysfunction, delineate the relation between adipose tissue dysfunction and obesity and to describe how adipose tissue dysfunction is involved in the development of diabetes mellitus type 2 and atherosclerotic vascular diseases. First, normal physiology of adipocytes and adipose tissue will be described.

The role of self-efficacy in vascular risk factor management: a randomized controlled trial

OBJECTIVE

Given the large number of patients at high risk of vascular events, new strategies are needed to reduce vascular risk. We investigated whether self-efficacy promotion could change self-efficacy levels in patients with vascular diseases and whether baseline self-efficacy and changes in self-efficacy were related to changes in vascular risk factors.

METHODS

One hundred fifty-three recently referred patients with symptomatic vascular diseases (cerebrovascular, abdominal, or peripheral arterial) participated in a randomized trial investigating the effect of nursing care, as compared with usual care, on vascular risk factors. Nursing care consisted of self-efficacy promotion and medical treatment of vascular risk factors. Self-efficacy and vascular risk factors (smoking, BMI, waist, blood pressure, lipid, and glucose levels) were measured at baseline and after 1 year.

RESULTS

While total self-efficacy did not change over the 1-year intervention period in either treatment group, self-efficacy in choosing healthy food (mean +0.4+/-1.4, p-value 0.01) and in doing extra exercise (mean +0.3+/-1.3, p-value 0.03) increased in the intervention group. No relation was seen between baseline total self-efficacy or change in composite self-efficacy and change in vascular risk factors.

CONCLUSION

The nursing intervention did not influence total self-efficacy but did improve self-efficacy in choosing healthy food and doing extra exercise. Change in composite self-efficacy was not related to change in vascular risk factors in patients at high risk of developing (new) cardiovascular diseases.

PRACTICE IMPLICATIONS

Influencing self-efficacy in choosing healthy food and doing extra exercise could be incorporated in vascular risk reduction programs in addition to medical treatment of vascular risk factors.

Simvastatin with or without ezetimibe in familial hypercholesterolemia

BACKGROUND

Ezetimibe, a cholesterol-absorption inhibitor, reduces levels of low-density lipoprotein (LDL) cholesterol when added to statin treatment. However, the effect of ezetimibe on the progression of atherosclerosis remains unknown.

METHODS

We conducted a double-blind, randomized, 24-month trial comparing the effects of daily therapy with 80 mg of simvastatin either with placebo or with 10 mg of ezetimibe in 720 patients with familial hypercholesterolemia. Patients underwent B-mode ultrasonography to assess the intima-media thickness of the walls of the carotid and femoral arteries. The primary outcome measure was the change in the mean carotid-artery intima-media thickness, which was defined as the average of the means of the far-wall intima-media thickness of the right and left common carotid arteries, carotid bulbs, and internal carotid arteries.

RESULTS

The primary outcome, the mean (+/-SE) change in the carotid-artery intima-media thickness, was 0.0058+/-0.0037 mm in the simvastatin-only group and 0.0111+/-0.0038 mm in the simvastatin-plus-ezetimibe (combined-therapy) group (P=0.29). Secondary outcomes (consisting of other variables regarding the intima-media thickness of the carotid and femoral arteries) did not differ significantly between the two groups. At the end of the study, the mean (+/-SD) LDL cholesterol level was 192.7+/-60.3 mg per deciliter (4.98+/-1.56 mmol per liter) in the simvastatin group and 141.3+/-52.6 mg per deciliter (3.65+/-1.36 mmol per liter) in the combined-therapy group (a between-group difference of 16.5%, P<0.01). The differences between the two groups in reductions in levels of triglycerides and C-reactive protein were 6.6% and 25.7%, respectively, with greater reductions in the combined-therapy group (P<0.01 for both comparisons). Side-effect and safety profiles were similar in the two groups.

CONCLUSIONS

In patients with familial hypercholesterolemia, combined therapy with ezetimibe and simvastatin did not result in a significant difference in changes in intima-media thickness, as compared with simvastatin alone, despite decreases in levels of LDL cholesterol and C-reactive protein. (ClinicalTrials.gov number, NCT00552097 [ClinicalTrials.gov].).

Determinants of CRP level in statin-treated patients

OBJECTIVE

All factors of the metabolic syndrome (MetS) are reported to be associated with elevated C-reactive protein (CRP) levels. As CRP levels have been found to decrease as a result of statin treatment, the present study was intended to explore the relationship between CRP and the MetS in statin treated patients.

METHODS

In this study, the relationship between the components of the MetS and CRP level were analysed and factors determining CRP were identified in patients with longstanding intensive lipid lowering therapy with known cardiovascular disease.

RESULTS

In this population CRP levels are still associated with the MetS, with waist circumference, fasting glucose level and smoking being the most important determinants of CRP levels.

CONCLUSIONS

CRP levels are still associated with the MetS in patients treated with intensive lipid lowering therapy.

Infection-induced inflammatory response of adipocytes in vitro

BACKGROUND

Abdominal obesity plays an important role in the development of insulin resistance, diabetes mellitus and atherosclerosis. The exact pathophysiological mechanisms are unclear but adipocyte dysfunction is thought to be crucial. Infections are associated with the development of atherosclerosis as well as diabetes. In this study we investigated whether adipocytes can be infected and whether this results in production of inflammatory cytokines relevant for the development of atherosclerosis and diabetes.

METHODS

Pre-adipocytes were cultured and differentiated into mature adipocytes in vitro. Adipocytes and pre-adipocytes were incubated with infective and heat-inactivated Chlamydia pneumoniae, cytomegalovirus (CMV), adenovirus (Ad) subtypes 2 and 36, influenza A and respiratory syncitial virus (RSV). After 48 h, adiponectin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and plasminogen activator inhibitor-1 (PAI-1) were measured in supernatants.

RESULTS

Infection of adipocytes with Ad-36, CMV and RSV resulted in increased IL-6 production from 192+/-22 pg ml(-1) (uninfected) to 1030+/-86 pg ml(-1), 838+/-59 pg ml(-1) and 1241+/-191 pg ml(-1), respectively (all P<0.01 vs control). In addition, Ad-36 infection slightly reduced PAI production in adipocytes (285+/-26.8 ng ml(-1) vs uninfected: 477+/-71.2 ng ml(-1); P=0.05) and pre-adipocytes (709+/-43.3 ng ml(-1) vs uninfected: 1071+/-71.8 ng ml(-1); P<0.01). In contrast, human Ad type 2 did not exert any effect on IL-6 or PAI production. None of the microorganisms induced significant changes in adiponectin and/or TNF-alpha production.

CONCLUSIONS

Adipocytes can be infected with several microorganisms in vitro. Infection of adipocytes with Ad-36, but not Ad-2 leads to increased production of IL-6 which might contribute to chronic low-grade inflammation, a process known to be involved in the development of cardiovascular diseases and type 2 diabetes.

Effect of metabolic syndrome or type II diabetes mellitus on the occurrence of recurrent vascular events in hypertensive patients

Patients with hypertension and manifest vascular disease are at high risk for recurrent cardiovascular diseases. It is unknown if the metabolic syndrome further increases the risk in these patients. This study aims to quantify the effect of metabolic syndrome and type II diabetes on cardiovascular events in hypertensive patients with vascular disease. A total of 2,196 hypertensive patients with vascular disease (cerebrovascular disease (34%), coronary heart disease (50%), peripheral arterial disease (28%), abdominal aortic aneurysm (13%)) from the Second Manifestations of Arterial Disease study were followed for up to 10 years (mean 3.9 years) for death, stroke and myocardial infarction. Age and sex adjusted hazard ratios (HR) were calculated for hypertensive patients with metabolic syndrome but without diabetes (n=775) and for hypertensive patients with type II diabetes (n=381), compared to merely hypertensive patients (n=1,040). Forty-nine percent had metabolic syndrome (NCEP ATPIII definition) and 17% had type II diabetes. Metabolic syndrome predicted vascular death (HR 1.41, 95% confidence interval (CI) 1.01-1.98), stroke (HR 1.36, 95% CI 0.85-2.16) and myocardial infarction (HR 1.40, 95% CI 0.97-2.01). Type II diabetes accounted for even higher risks of vascular end points (HR 1.41-1.64). The effect of metabolic syndrome on future events could not be explained by the presence of type II diabetes. Even in high-risk patients with hypertension and vascular disease, presence of metabolic syndrome or type II diabetes identifies patients at high risk for future cardiovascular events. Identifying metabolic syndrome patients may direct therapy focusing on treatment of insulin resistance by reducing weight and increasing physical activity.

The impact of Type 2 diabetes and microalbuminuria on future cardiovascular events in patients with clinically manifest vascular disease from the Second Manifestations of ARTerial disease (SMART) study

AIMS

Type 2 diabetes mellitus and microalbuminuria are important risk factors for cardiovascular disease (CVD). Whether these two complications are important and independent risk factors for future CVD events in a high-risk population with clinically manifest vascular disease is unknown. The objectives of this study were to examine the impact of Type 2 diabetes and microalbuminuria on future CVD events.

METHODS

Patients with clinically manifest vascular disease (coronary, cerebral and peripheral vascular disease) from the Second Manifestation of Arterial disease study were followed up for 4 years. Data obtained from 1996-2006 were analysed. At baseline, there were 804 patients with Type 2 diabetes mellitus (mean age 60 years) and 2983 patients without. Incident CVD (n = 458) was defined as hospital-verified myocardial infarction, stroke, vascular death and the composite of these vascular events.

RESULTS

Both Type 2 diabetes [hazard ratio (HR) 1.42, 95% confidence interval (CI) 1.16, 1.75] and microalbuminuria (HR 1.86, 95% CI 1.49, 2.33) increased the risk of new cardiovascular events in univariate analyses. From multivariable models, presence of diabetes remained significantly and independently related to incident CVD (HR 1.42, 95% CI 1.11, 1.80). Presence of microalbuminuria also remained significantly independently related to incident CVD (HR 1.38, 95% CI 1.07, 1.77). In diabetes-stratified analyses, the effect of microalbuminuria on CVD risk was observed only in patients with diabetes. In microalbuminuria-stratified analyses, the significant and independent effect of diabetes on CVD risk was shown only in the non-microalbuminuric group.

CONCLUSIONS

In this high-risk population, both microalbuminuria and Type 2 diabetes are important and independent risk factors for future CVD.

[Infection-induced vascular disease: little evidence according to the Koch's postulates]

Infections with Cytomegalovirus, influenza virus, HIV and Chlamydophila pneumoniae may contribute to the development of vascular disease by infecting the vascular wall directly or by initiating and propagating low-grade chronic inflammation. Although this association appears plausible, it hardly fulfils Koch's postulates. Based on the results of large randomised trials, it appears that antibiotic treatment targeting C. pneumoniae does not reduce the incidence of new vascular events in patients with clinically manifest vascular disease. Influenza vaccination reduces the incidence of vascular disorders. Therefore efforts to optimise participation of high-risk patients in the influenza vaccination programme are advisable.

The impact of site and extent of clinically evident cardiovascular disease and atherosclerotic burden on new cardiovascular events in patients with Type 2 diabetes. The SMART study

AIMS

Patients with Type 2 diabetes and coronary heart disease (CHD) have an excess cardiovascular risk. The relationship of both other sites [cerebrovascular disease, peripheral arterial disease (PAD)] and the extent of clinically evident cardiovascular disease (CVD) with the occurrence of new cardiovascular events have not been investigated previously in patients with diabetes. We aimed to quantify this relationship and to assess the additional influence of atherosclerotic burden.

METHODS

From 1996 to 2005, 776 patients with Type 2 diabetes with (n = 458) and without (n = 318) clinically evident CVD were followed prospectively for cardiovascular events (cardiovascular death, non-fatal ischaemic stroke or myocardial infarction). CVD was classified according to the site (cerebrovascular disease, CHD, PAD); the extent of atherosclerosis was expressed as the number of affected sites. Carotid intima-media thickness and albuminuria were used as markers of atherosclerotic burden.

RESULTS

Compared with patients with diabetes without CVD, the hazard ratio (HR) for a cardiovascular event was 3.8 (95% confidence interval 1.7, 8.5), adjusted for age, gender and potential confounders, in those with cerebrovascular disease, 4.3 (1.9, 9.5) in those with CHD, and 4.6 (2.1, 10.2) in those with PAD. Findings were similar after additional adjustment for atherosclerotic burden. Adjusted HR was 3.4 (1.6, 6.9) for patients with diabetes with one affected site and 6.6 (3.0, 14.3) for those with two or more sites.

CONCLUSIONS

Patients with Type 2 diabetes and cerebrovascular disease, CHD or PAD have strongly increased risks for future cardiovascular events which are comparable. This risk increases markedly with the number of different cardiovascular sites affected and is irrespective of atherosclerotic burden.

Low plasma levels of adiponectin are associated with low risk for future cardiovascular events in patients with clinical evident vascular disease

BACKGROUND

Adiponectin is considered to have anti-inflammatory, insulin-sensitizing, and antiatherosclerotic properties. In the present prospective study, the relationship between metabolic syndrome (Adult Treatment Panel III) and adiponectin plasma levels and the relationship between plasma adiponectin levels and future cardiovascular events were investigated.

METHODS

A case-cohort study of 431 patients with clinical evident vascular disease from the Second Manifestations of ARTerial Disease study. The relationship between adiponectin plasma levels and new vascular events was investigated with Cox regression, adjusted for potential confounders and effect modifiers (age, sex, renal function [modification of diet in renal disease], body mass index, high sensitive C-reactive protein, use of angiotensin converting enzyme-inhibition and/or AII antagonists, and presence of metabolic syndrome or impaired renal function).

RESULTS

Plasma adiponectin levels were lower in patients with metabolic syndrome as compared with patients without (7.9 +/- 0.3 vs 5.2 +/- 0.3 microg/mL) and decreased with the number of components. During a mean follow-up of 2.3 years, 216 patients had a new cardiovascular event. Lower adiponectin plasma levels were associated with a lower risk for future cardiovascular events (hazard ratio 0.50, 95% confidence interval 0.25-0.99). This relationship was not influenced by renal function, body mass index, and renin-angiotensin system-blocking agents or modified by metabolic syndrome and impaired renal function.

CONCLUSION

In patients with clinical evident vascular disease, lower adiponectin levels were associated with a lower cardiovascular risk. Therefore, it may be hypothesized that the potential antiatherosclerotic properties of adiponectin do not apply for patients with already established vascular disease.

Quantification of epicardial and peri-coronary fat using cardiac computed tomography; reproducibility and relation with obesity and metabolic syndrome in patients suspected of coronary artery disease

OBJECTIVE

Adipose tissue surrounding coronary arteries may contribute to the development of coronary atherosclerosis given its localisation and potential for local production of inflammatory cytokines. We compared various measurements for quantifying epicardial adipose tissue (EAT) and peri-coronary fat using cardiac CT. Additionally, we estimated their relationship with obesity and metabolic syndrome in patients suspected of coronary artery disease (CAD).

METHODS

EAT and peri-coronary fat measurements were performed on cardiac multi-slice CT scans in 60 patients (aged 50-70 years) referred for coronary angiography. EAT was measured as thickness on the right ventricular free wall, as area at the base of the ventricles, and as volume. Peri-coronary fat was assessed as thickness and cross-sectional area surrounding the three main coronary arteries. Linear regression analysis was used to assess the relation of EAT and peri-coronary fat with obesity and metabolic syndrome (ATPIII criteria).

RESULTS

Volumetric EAT measurements showed good reproducibility with low coefficients of variation (CVs) varying between 3.0% and 5.0%. Measurements of EAT and peri-coronary fat thickness and area were moderately reproducible (CVs 11.0-23.4%). The amount of EAT and peri-coronary fat (per standard deviation) was related with obesity (BMI > or =30 kg/m(2)) (beta 1.24; 95% CI 0.66; 1.81) and metabolic syndrome (beta 0.81; 95% CI 0.28; 1.33).

CONCLUSIONS

Volumetric quantification of EAT using cardiac CT is highly reproducible compared to more simple measurements as EAT and peri-coronary fat thickness and area. The quantity of EAT and peri-coronary fat is related with the presence of obesity and metabolic syndrome in patients suspected of CAD.

Defining the metabolic syndrome: Resolving unresolved issues?

BACKGROUND

Several definitions exist for the metabolic syndrome. In concert with the blood pressure and glucose criteria of the NCEP definition, it has now been suggested that the use of fibrates and nicotinic acid be incorporated into the dyslipidemia criteria. While statins are the drugs most widely prescribed for lowering LDL-cholesterol, they also affect triglyceride and HDL-cholesterol levels. The aims of the present study were (1) to investigate how adding lipid-lowering therapy to the NCEP definition might influence the prevalence of the metabolic syndrome and (2) to compare the characteristics of patients identified according to the newly proposed IDF definition with those identified according to the NCEP definition.

METHODS

We conducted a cross-sectional study on 2373 patients with clinically manifest vascular disease. In order to allow for the influence of lipid-lowering therapy on the identification of patients with the metabolic syndrome, the NCEP definition was modified in two ways. In NCEP-rev1, the use of lipid-lowering agents fulfilled the hypertriglyceridemia criterion; in NCEP-rev2, triglycerides and HDL-cholesterol plasma concentrations were recalculated for lipid-lowering agents.

RESULTS

The prevalence of the metabolic syndrome was 41% according to the NCEP definition, 50% according to the NCEP-rev1, 44% according to the NCEP-rev2, and 52% according to the IDF definition. Patients identified only with the NCEP definition had lower HDL-cholesterol, higher triglycerides, and higher fasting glucoses levels than patients only diagnosed with the IDF definition.

CONCLUSION

Adding the use of lipid-lowering drugs to the NCEP definition may lead to the identification of an additional group of patients at an elevated risk for cardiovascular diseases and diabetes. The NCEP definition of the metabolic syndrome identifies patients with a worse cardiovascular risk profile than patients qualifying for the metabolic syndrome with the IDF definition in a cohort of patients with clinical manifestations of vascular disease.

Abdominal fat and risk of coronary heart disease in patients with peripheral arterial disease

OBJECTIVE

We investigated whether the presence of concomitant coronary heart disease (CHD) in patients with peripheral arterial disease (PAD) can be explained by intra-abdominal fat accumulation and compared different measures of adiposity as predictors of CHD in patients with PAD.

RESEARCH METHODS AND PROCEDURES

Data were collected from patients enrolled in the Second Manifestations of ARTerial disease (SMART) study, an ongoing prospective cohort study of patients with manifest vascular disease or vascular risk factors at the University Medical Centre Utrecht. The current analysis includes 315 patients, mean age 59 +/- 10 years, who had PAD with (n = 79) or without (n = 236) CHD. Parameters of adiposity were measured, and intra-abdominal fat and subcutaneous fat were measured ultrasonographically. Metabolic syndrome was defined according to Adult Treatment Panel III.

RESULTS

The prevalence of metabolic syndrome was higher among patients with CHD (63%) than among patients without CHD (48%). All parameters of adiposity indicated more fat in patients with CHD, except for subcutaneous fat. Waist circumference was associated with 64% higher prevalence of CHD (confidence interval, 20% to 123%) per 1 standard deviation increase in waist circumference after adjustment for age and sex. The odds ratio for waist circumference remained virtually the same after additional adjustment for the components of the metabolic syndrome and smoking.

DISCUSSION

An increased waist circumference, a crude measure of intra-abdominal fat, is associated with an increased risk of concomitant CHD in patients with PAD.

Asymptomatic Carotid Artery Stenosis and the Risk of New Vascular Events in Patients With Manifest Arterial Disease

Background and Purpose— The frequency of asymptomatic carotid artery stenosis (CAS) increases with age from 0.5% in individuals below 50 years of age to 5% to 10% in individuals over 65 years of age in the general population. Its prognostic value has been examined in the general population but less often in patients with clinical manifestations of arterial disease other than retinal or cerebral ischemia. We examined the relationship between asymptomatic CAS and the risk of subsequent events in this specific group of patients.

Methods— This study involved 2684 consecutive patients with clinical manifestations of arterial disease or type 2 diabetes mellitus, but without a history of cerebral ischemia, enrolled in the SMART study (Second Manifestations of ARTerial disease). The degree of asymptomatic CAS was assessed with Duplex scanning and defined on the basis of the blood flow velocity patterns at baseline in both carotid arteries. None of the patients underwent carotid endarterectomy or endovascular intervention. During the follow-up period, vascular events (vascular death, ischemic stroke, and myocardial infarction) were documented in detail. Data were analyzed with Cox proportional hazards regression and adjusted for age, gender, and classic vascular risk factors.

Results— Asymptomatic CAS of 50% or greater was present in 221 (8%) patients. During a mean follow up of 3.6 years (SD=2.3), a first vascular event occurred in 253 patients (9%). The cumulative incidence rate for the composite of subsequent vascular events after 5 years was 12.3% (95% CI=10.7 to 13.9), for cerebral infarction 2.2% (95% CI=1.4 to 2.8), and for myocardial infarction 8.0% (95% CI=6.6 to 9.4). Adjusted for age and gender, asymptomatic CAS of 50% or greater was related to a higher risk of subsequent vascular events (hazard ratio=1.5, 95% CI=1.1 to 2.1), in particular of vascular death (hazard ratio=1.8, 95% CI=1.2 to 2.6). After additional adjustment for vascular risk factors, the hazard ratios remained essentially the same.

Conclusion— Asymptomatic carotid artery stenosis is an independent predictor of vascular events, especially vascular death, in patients with clinical manifestations of arterial disease or type 2 diabetes but without a history of cerebral ischemia.

Carotid arterial stiffness is marginally higher in the metabolic syndrome and markedly higher in type 2 diabetes mellitus in patients with manifestations of arterial disease

INTRODUCTION

Insulin resistance is generally considered to be of major importance in the pathophysiology of the metabolic syndrome and type 2 diabetes mellitus, both high-risk conditions for cardiovascular complications. Carotid artery stiffness is increasingly recognized as an important predictor of cardiovascular morbidity and mortality. Therefore, in the present study we determined whether the metabolic syndrome (MetSyn) and type 2 diabetes mellitus (DM2) are associated with carotid artery stiffness in patients with already clinical manifestations of arterial disease.

METHODS AND RESULTS

A cross-sectional study in 2105 patients with manifest arterial disease (cerebral, coronary or peripheral artery disease, renal artery stenosis or an aneurysm of the abdominal aorta) was performed. The difference in carotid stiffness between patients with and without MetSyn and with and without DM2 was studied with linear regression analysis. Compared to patients without DM2 (N=1112), patients with DM2 (N=301) had significantly higher arterial stiffness (distension -18.5 (-35.1;-1.9) 95% CI/distensibility -1.8 (-2.2;-1.4) 95% CI). Generally, there was a trend of higher carotid stiffness in patients with MetSyn (N=922) compared to patients without (N=1112) MetSyn (distension -9.6 (-21.5;2.3) 95% CI/distensibility -2.0 (-2.6;-1.4) 95% CI). Excluding the patients with also DM2 (N=230) from the MetSyn-group diminished this relation (distension -5.7 (-18.8;7.4) 95% CI/distensibility -1.1 (-1.6;-0.6) 95% CI). Furthermore, in the population as a whole, carotid artery stiffness increased with increasing number of components of the metabolic syndrome (p=0.08 for distension/p< or =0.001 for distensibility). In addition, this association was not as clear after exclusion of the patients with DM2 from the MetSyn-group (p=0.24 for distension/p<0.001 for distensibility). From all the components of the MetSyn only high blood pressure and high fasting glucose influenced the carotid artery stiffness.

CONCLUSIONS

We concluded that (increasing number of components of) the metabolic syndrome were associated with marginally higher carotid artery stiffness, while type 2 diabetes was associated with a marked increase in carotid artery stiffness, in patients with already clinical manifestations of arterial disease.

The operative risk factors in the metabolic syndrome: is it lipids and high BP or are there direct vascular effects of insulin resistance and obesity

Increase in patients with central obesity and insulin resistance is an important cause for the worldwide increased incidence of type 2 diabetes. Several risk factors such as glucose intolerance, hyperinsulinemia, obesity, dyslipidemia, and hypertension, but also endothelial dysfunction and inflammation, have been found to cluster and often precede type 2 diabetes mellitus. Seeing the importance of early identification, the US National Cholesterol Education Program created a readily applicable definition of the metabolic syndrome for daily clinical practice. It is assumed that the cardiovascular risk for patients belonging to the metabolic syndrome can just be calculated out of the sum of the separate cardiovascular risk factors dyslipidemia and hypertension. However, there are also data pointing toward a higher risk than expected from these separate cardiovascular risk factors because of possible direct vascular effects of insulin resistance and obesity. Awareness of the underlying disorders of insulin resistance and its associated (non-) traditional risk factors such as endothelial dysfunction and inflammation is important for understanding the pathophysiology and thus coherent treatment.

Levels of homocysteine are increased in metabolic syndrome patients but are not associated with an increased cardiovascular risk, in contrast to patients without the metabolic syndrome

AIM

The metabolic syndrome is associated with increased cardiovascular risk. Elevated plasma homocysteine may cause or result from insulin resistance, and may indicate vascular risk or be actively involved in atherogenesis. The aim of the study was to investigate the relationship between homocysteine, the metabolic syndrome and the incidence of cardiovascular events in patients with manifest vascular disease.

METHODS

A cohort of 2169 patients with manifest vascular disease was followed for a mean period of 2.8 years. Plasma homocysteine was measured at baseline. Metabolic syndrome was defined by NCEP criteria.

RESULTS

Homocysteine levels were higher in metabolic syndrome patients compared to patients without the metabolic syndrome (14.9+/-0.2 v 14.1+/-0.2 micromol/l; p = 0.002) and increased with the presence of its components (from 0 to 5) (12.7 to 15.9 micromol/l; p<0.001). During follow-up, 52 strokes, 67 myocardial infarctions, 5 fatal ruptures of aortic aneurysms and 53 vascular deaths occurred. Patients without the metabolic syndrome and homocysteine levels in the highest tertile had increased risk for events (HR 1.9; 95% CI 1.0 to 3.5) compared to patients without the metabolic syndrome and homocysteine levels in the lowest tertile. The presence of the metabolic syndrome increased the risk (HR 2.2; 95% CI 1.2 to 4.2), but elevated homocysteine levels further increased the risk only marginally (2.5; 95% CI 1.4 to 4.6).

CONCLUSIONS

Metabolic syndrome patients have elevated homocysteine levels, but these higher levels are not associated with an increased risk for new cardiovascular events. In contrast, elevated homocysteine levels confer increased risk in patients without the metabolic syndrome.