Metabolic syndrome and coronary heart disease risk in a population-based study of middle-aged men from France and Northern Ireland

Small dense LDL cholesterol is associated with metabolic syndrome traits independently of obesity and inflammation

Background

Small dense LDL cholesterol (sdLDL-c) has been established to be highly associated with metabolic disorder. However, the relationship between circulating sdLDL-c and the presence of metabolic syndrome (MetS) has not been fully established.

Methods

A total of 1065 Chinese males (45.07 ± 11.08 years old) without diabetes and general obesity was recruited into a population-based, cross-sectional study. The MetS was defined based on the updated National Cholesterol Education Program/ Adult Treatment Panel III criteria for Asian Americans. Serum sdLDL-c concentration was measured by a homogeneous assay method and its relationship with MetS and its traits was investigated.

Results

Serum sdLDL-c concentrations increased gradually with increasing numbers of MetS components (p < 0.001) and the proportion of patients with MetS increased gradually with increasing sdLDL-c levels (p for trend< 0.001). For the second, third, and fourth sdLDL-c quartiles versus the first, the OR (95% CI) for MetS were 4.47(2.41,8.28), 5.47(2.97,10.07) and 8.39(4.58,15.38) (p < 0.001 for trend) after multivariate adjustment. The stratified analysis conducted according to LDL-c levels showed that the OR between serum sdLDL-c levels and MetS was greater in those LDL-c levels lower than 3.3 mmol/L (OR = 22.97; 95% CI, 7.64-69.09) than in those LDL-c levels higher than 3.3 mmol/L (OR = 17.49; 95% CI, 4.43-68.98). Mediation analysis showed sdLDL-c mediated 38.6% of the association of waist circumference with triglycerides, while the association between sdLDL-c and MetS components did not mediate by hsCRP.

Conclusions

This study found that high sdLDL-c concentrations were associated with the presence of MetS independently of central obesity and inflammation.

Basal ganglia morphology links the metabolic syndrome and depressive symptoms

The metabolic syndrome (MetS) is a clustering of cardiovascular and cerebrovascular risk factors that are often comorbid with depressive symptoms. Individual components of the MetS also covary with the morphology of basal ganglia regions that are altered by depression. However, it remains unknown whether the covariation between the MetS and depressive symptomatology can be accounted for in part by morphological changes in the basal ganglia. Accordingly, we tested the hypothesis that increased depressive symptoms among individuals with the MetS might be statistically mediated by reduced gray matter volume in basal ganglia regions. The presence of the MetS was determined in 147 middle-aged adults using the criteria of the National Cholesterol Education Program, Adult Treatment Panel III. Basal ganglia volumes were determined on an a priori basis by automated segmentation of high-resolution magnetic resonance images. Depressive symptoms were assessed using the Patient Health Questionnaire. Even after controlling for demographic and other confounding factors, having the MetS and meeting more MetS criteria covaried with reduced globus pallidus volume. Meeting more MetS criteria and reduced pallidal volume were also related to depressive symptoms. Moreover, the MetS-depression association was statistically mediated by pallidal volume. In summary, reduced globus pallidus volume is a neural correlate of the MetS that may partly account for its association with depressive symptoms.

Association of hepatic lipase -514T allele with coronary artery disease and ankle-brachial index, dependence on the lipoprotein phenotype: the GENES study

Objectives

Relationship between hepatic lipase (LIPC) polymorphism and coronary artery disease (CAD) has often led to contradictory results. We studied this relation by genotyping rs1800588 in the LIPC promoter in a case-control study on CAD (the GENES study). We also investigated the relationship between this polymorphism and the ankle-brachial index (ABI), which is predictive of atherosclerosis progression and complications in patients at high cardiovascular risk.

Methods

557 men aged 45–74 with stable coronary artery disease and 560 paired controls were genotyped for rs1800588. Medical data, clinical examination including determination of ABI and biological measurements related to cardiovascular risk factors enabled multivariate analyses and multiple adjustments.

Results

CAD cases showed a higher T-allele frequency than controls (0.246 vs 0.192, p = 0.003). An interaction has been found between LIPC polymorphism and triglycerides (TG) levels regarding risk of CAD: TT-homozigosity was associated with an Odds ratio (OR) of 6.4 (CI: 1.8–22.3) when TG were below 1.5 g/L, but no association was found at higher TG levels (OR = 1.34, CI: 0.3–5.9). The distribution of LIPC genotypes was compared between CAD patients with normal or abnormal ABI and impact of LIPC polymorphism on ABI was determined. Following multiple adjustments, association of the T-allele with pejorative ABI (<0.90) was significant for heterozygotes and for all T-carriers (OR = 1.55, CI: 1.07–2.25).

Conclusion

The -514T LIPC allele is associated with CAD under normotriglyceridemic conditions and constitutes an independent determinant of pejorative ABI in coronary patients.

Metabolic syndrome, peripheral vascular disease and coronary artery disease: A concise review

Metabolic syndrome has a very strong association with both forms of cardiovascular (CV) disease - coronary artery disease and peripheral vascular disease. There is also a marked interrelationship between the two forms of CV disease. When one form of CV disease is present, the other should be strongly suspected and the possible occurrence of associated vascular events should be clinically evaluated. When three of the five major components that define metabolic syndrome are present, the clinical evidence indicates that one or both forms of CV disease are present, at least in incipient form. To give maximum clinical benefit to the patient at risk, the clinician must be aware of these associations, look for them and institute the measures that can reduce the risk of progression.

The prevalence of metabolic syndrome in Latin America: a systematic review

OBJECTIVE

To assess the available data on the prevalence of metabolic syndrome (MS) in Latin-American countries.

DESIGN

Systematic review. Searches were carried out in PubMed, ISIWeb, SCielo and Redalyc, using 'metabolic syndrome x' and 'prevalence' as keywords for titles and/or abstracts. Articles selected were cross-sectional studies in Latin-American countries, whose main objective was to study MS and whose study population is described below. MS must be determined using Adult Treatment Panel III criteria. Twelve studies with these criteria were selected, one of which was multi-centric.

SETTING

Latin America.

SUBJECTS

Apparently healthy subjects aged 18-65 years (including young adult, mature adult and elderly populations) of both genders.

RESULTS

The general prevalence (weighted mean) of MS in Latin-American countries was 24·9 (range: 18·8-43·3) %. MS was slightly more frequent in women (25·3 %) than in men (23·2 %), and the age group with the highest prevalence of MS consisted of those over 50 years of age. The most frequent components of MS were low HDL cholesterol levels (62·9 %) and abdominal obesity (45·8 %). Similar outcomes were obtained from the multi-centre study on Latin-American populations analysed.

CONCLUSIONS

The present review brings us closer to an understanding of the prevalence of MS in Latin-American countries. However, it is not possible to know the full scope of the problem, partly because data from some countries are not available, and because the methodological differences among the studies published up to the present limit a joint analysis of their results.

Resistin level is positively correlated with thrombotic complications in Southern Chinese metabolic syndrome patients

BACKGROUND

The metabolic syndrome (MetS) has been found to be closely related with thrombotic diseases. The mechanism, however, is far from elucidated.

AIM

This study was designed to investigate the relationship between endogenous resistin and thrombosis mediating factors, as well as its potential effects on the gene expression of cardiovascular disease biomarkers.

METHODS

Ninety patients satisfied the MetS criteria, and 55 healthy subjects were recruited as part of a single-center clinical study. Plasma levels of resistin, tissue factor (TF), tissue factor pathway inhibitor (TFPI), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) were measured by enzymelinked immunosorbent assays. The effect of resistin on the expression of cardiovascular disease biomarkers in human umbilical vein endothelial cells (HUVEC) was assayed by gene microarray.

RESULTS

1) The average levels of resistin in MetS patients with or without acute myocardial or cerebral infarction were significantly higher than those of the controls. 2) The TF and TFPI increase was higher in MetS with infarction patients than in MetS patients. 3) In MetS with infarction patients, resistin was positively correlated with TF and PAI-1 (r=0.313, p=0.008; r=0.401, p=0.002, respectively). 4) In HUVEC, the microarray showed that apolipoprotein C-I, ACE, tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) and member 5 (CD40) genes expression were dramatically increased by resistin.

CONCLUSION

In patients with MetS, resistin is strongly associated with hypercoagulative and hypofibrinolitic activities. Moreover, resistin may induce thrombotic complications via mediating the lipoprotein metabolism and stimulating inflammation.

Recent advances in metabolic syndrome and cardiovascular disease

Metabolic syndrome is defined as an association of central obesity and several other cardiometabolic risk factors. Dysfunctional visceral adipose tissue and inflammatory status appear to be involved in its genesis. New definitions have decreased the threshold for glycaemia and one has lowered the threshold for waist circumference, leading to an increase in the prevalence of metabolic syndrome. However, the impact on mortality with these new definitions is lower than with the National Cholesterol Education Program-Adult Treatment Panel III 2001 definition. An increase in waist circumference, along with increased glycaemia, triglycerides and/or blood pressure is more highly associated with an increased risk of mortality than are other associations, while a decrease in high density lipoprotein cholesterol increases risk of coronary heart disease. The risk of sudden death and stroke is particularly notable with metabolic syndrome. Metabolic syndrome is associated with an increase in heart rate, pulse pressure, arterial stiffness and left ventricular hypertrophy, impairment of diastolic function, enlargement of the left atrium and atrial fibrillation. In the 2007 European recommendations for the management of high blood pressure, metabolic syndrome is now taken into consideration for both risk stratification and in selecting the optimal therapeutic strategy for arterial hypertension.

[Metabolic syndrome: epidemiology and its risks]

The prevalence of the metabolic syndrome is rising, particularly in developed countries, and this is largely driven by increasing obesity and sedentarity rates. Regardless of the definition, the prevalence found in France was lower than in North America and in other European countries; it varied from 11.7 p. cent in men and 7.5 p. cent in women according to the National Cholesterol Education Program (NCEP) definition to 26 p. cent in men and 18.4 p. cent in women according to the International Diabetes Federation (IDF) definition. The presence of the metabolic syndrome promotes the occurrence of type 2 diabetes and clinical atherosclerosis. Relative risk of cardiovascular morbidity and mortality is close to 2 in subjects with metabolic syndrome. The informative value of identifying metabolic syndrome has been demonstrated in the general population as well as in hypertensive subjects. However, it could provide only limited clinical value for cardiovascular disease risk stratification in type 2 diabetes mellitus.

Hyperuricemia, gout and the metabolic syndrome

PURPOSE OF REVIEW

The metabolic syndrome is defined by the clustering of a number of cardiovascular risk factors and entails an increased risk for cardiovascular disease and mortality from both cardiovascular disease and all causes. In the present paper, we review the most recent evidence on the association between hyperuricemia, metabolic syndrome, and cardiovascular disease.

RECENT FINDINGS

Serum urate is frequently elevated in patients with the metabolic syndrome and increases with the number of components of this condition. Hyperuricemia has been related to decreased renal uric acid excretion, which may be mediated by enhanced proximal tubular sodium reabsorption and hyperinsulinemia. Recent epidemiologic studies have shed some light on the prognosis of hyperuricemia. While hyperuricemia appears to show a benign significance in low cardiovascular risk individuals, it clearly increases cardiovascular mortality in patients at high cardiovascular disease risk.

SUMMARY

Clinicians should be aware of the presence of metabolic syndrome in patients with hyperuricemia or gout in order to control its components (high blood pressure, obesity, etc.) and hence reduce the risk for cardiovascular disease. Long-term, randomized interventional clinical trials are needed to test the hypothesis that urate-lowering therapy can reduce cardiovascular risk in these patients.

Metabolic syndrome pandemic

The metabolic syndrome is a multiplex risk factor that consists of several risk correlates of metabolic origin. In addition, to dyslipidemia, hypertension, and hyperglycermia, the syndrome carries a prothrombotic state and a proinflammatory state. Persons with the metabolic syndrome are at essentially twice the risk for cardiovascular disease compared with those without the syndrome. It further raises the risk for type 2 diabetes by about 5-fold. Although some investigators favor keeping risk factors separate for purposes of clinical management, others believe that identifying individuals with an aggregation of risk factors provides additional useful information to guide clinical management. In particular it focuses attention on obesity and sedentary life habits that are the root of the syndrome. This review addresses the prevalence of this clustering phenomenon throughout the world. Such seems appropriate because of the increasing prevalence of obesity in almost all countries. The available evidence indicates that in most countries between 20% and 30% of the adult population can be characterized as having the metabolic syndrome. In some populations or segments of the population, the prevalence is even higher. On the other hand, in parts of developing world in which young adults predominate, the prevalence is lower; but with increasing affluence and aging of the population, the prevalence undoubtedly with rise.

A review of the metabolic syndrome

While the concept of this syndrome has been described more than 60 years ago, and more formally almost 20 years ago, the controversy continues as to its utility, which of the various syndrome definitions should be used and their ability to predict diabetes and/or cardiovascular disease. The metabolic syndrome, of cardiovascular risk factors, provides an early warning of at risk subjects and emphasises the need to treat more aggressively (by at least lifestyle modification) patients with multiple abnormalities even though the abnormalities might be slight. Further, the syndrome can be easily used in clinical practice and when it is assessed against the background of the patient's age, sex and smoking habits, it provides an evaluation of potential cardiovascular risk. Prospective intervention studies are the only means of definitively accepting or refuting the usefulness of the syndrome. The metabolic syndrome is an entity which merits attention from both the medical profession and public health authorities.

Impaired coronary function in Wistar Ottawa Karlsburg W rats—a new model of the metabolic syndrome

The metabolic syndrome is associated with an increased risk for coronary heart disease. The underlying mechanisms are not well understood. The present study was designed to investigate coronary function in Wistar Ottawa Karlsburg W (WOKW) rats, a new animal model of the metabolic syndrome. The responses of coronary artery segments from WOKW and Dark Agouti (DA) control rats of different ages to several physiological vasoconstrictors and vasodilators were measured in a small vessel wire myograph, and potential mechanisms involved in the differential responses between the two strains were investigated. WOKW showed increased alpha(1)-adrenoceptor-mediated coronary constriction at 3 and 10 months of age, as well as seriously blunted beta-adrenoceptor-mediated coronary relaxation at 16 months of age. Responses to non-adrenergic agonists were not altered in WOKW compared to DA. The alpha(1)-adrenoceptor-mediated coronary constriction in WOKW was completely blocked by rho-kinase inhibition. Induced hyperinsulinemia did not cause increased alpha(1)-adrenoceptor-mediated coronary constriction or impaired beta-adrenoceptor-mediated coronary relaxation in DA. The association between blunted coronary beta-adrenoceptor responsiveness and the metabolic syndrome was confirmed in Zucker diabetic fatty rats. We conclude that the metabolic syndrome in WOKW rats is associated with impaired coronary function due to altered adrenoceptor sensitivity. The latter may contribute to inappropriately elevated coronary tone in insulin-resistant subjects, especially when sympathetic activity to the heart is increased.