Metabolic syndrome, haemostatic and inflammatory markers, cerebrovascular and peripheral arterial disease: The Edinburgh Artery Study

Prediabetes and the risk of peripheral artery disease: a meta-analysis

BACKGROUND

Peripheral artery disease (PAD) is a significant vascular condition that can lead to severe complications, including limb ischemia and cardiovascular events. This meta-analysis aims to evaluate the association between prediabetes, an intermediate state between normoglycemia and diabetes, and the risk of developing PAD.

METHODS

A comprehensive search of PubMed, EMBASE, and Web of Science databases was conducted to identify relevant cohort studies up to April 12, 2024. Data extraction was performed independently by two reviewers, and any discrepancies were resolved by consensus. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model to account for heterogeneity among studies.

RESULTS

A total of eight cohort studies comprising 90133 participants were included in the meta-analysis. The pooled analysis revealed that individuals with prediabetes had a significantly higher risk of PAD compared to those with normoglycemia (RR = 1.27, 95% CI: 1.13-1.42, p < 0.001; I2 = 55%). Subgroup analyses indicated that the association was stronger in prediabetes defined by mildly elevated hemoglobin A1c (RR: 1.47) compared to those defined by impaired fasting glucose (RR: 1.21) or impaired glucose tolerance (RR: 1.17, p for subgroup difference < 0.001). In addition, a stronger association was observed for studies reporting clinically diagnosed PAD compared to studies that included asymptomatic PAD (RR: 1.32 versus 0.92, p for subgroup difference = 0.02).

CONCLUSIONS

This meta-analysis demonstrates a significant association between prediabetes and an increased risk of PAD in generally community-derived population.

Metabolic Syndrome and Risk of Peripheral Arterial Disease: A Systematic Review and Meta-Analysis

This systematic review aimed to evaluate metabolic syndrome as a risk factor for the development of peripheral arterial disease (PAD). We searched in four databases: (1) PubMed, (2) Web of Science, (3) Scopus, and (4) Embase until March 2021. We included cohort studies that evaluated the risk of PAD in patients with and without metabolic syndrome. Study selection, data extraction, and risk of bias analysis were performed independently by 2 authors. We used a random-effects model to conduct a meta-analysis of effect measures [hazard ratio (HR), risk ratio (RR), and odds ratio (OR)]. Individual analyses were performed according to the diagnostic criterion used for metabolic syndrome. We included 7 cohort studies with a total of 43 824 participants. Most of the studies were performed in the general adult population. The metabolic syndrome and PAD diagnostic criteria used in the individual studies were heterogeneous. Almost all studies using RR found an association between metabolic syndrome and the development of PAD (RR: 1.31; confidence interval 95%: 1.03-1.59; I 2 : 15.6%). On the other hand, almost all the studies that used HR found no association between the two variables. All studies had a low risk of bias. In conclusion, available evidence on the association between metabolic syndrome and the risk of developing PAD is inconsistent. However, given the high prevalence of risk factors that patients with metabolic syndrome have, testing to rule out PAD could be recommended. Future studies should analyze each component of the metabolic syndrome separately and according to the severity of PAD.

Association of 25-hydroxyvitamin D levels with lipid profiles in osteoporosis patients: a retrospective cross-sectional study

BACKGROUND

In the literature, scarce data investigate the link between 25-hydroxyvitamin D (25[OH]D) and blood lipids in the osteoporosis (OP) population. 25(OH)D, as a calcium-regulating hormone, can inhibit the rise of parathyroid hormone, increase bone mineralization to prevent bone loss, enhance muscle strength, improve balance, and prevent falls in the elderly. This retrospective cross-sectional study aimed to investigate the association between serum 25(OH)D levels and lipid profiles in patients with osteoporosis, with the objective of providing insight for appropriate vitamin D supplementation in clinical settings to potentially reduce the incidence of cardiovascular disease, which is known to be a major health concern for individuals with osteoporosis.

METHODS

This is a retrospective cross-sectional study from the Affiliated Kunshan Hospital of Jiangsu University, including 2063 OP patients who received biochemical blood analysis of lipids during hospitalization from January 2015 to March 2022. The associations between serum lipids and 25(OH)D levels were examined by multiple linear regression. The dependent variables in the analysis were the concentrations of serum lipoprotein, total cholesterol (TC), triglycerides (TGs), apolipoprotein-A, lipoprotein A, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol (LDL-C). The independent variable was the concentration of blood serum 25(OH)D. At the same time, age, body mass index, sex, time and year of serum analysis, primary diagnosis, hypertension, diabetes, statins usage, beta-C-terminal telopeptide of type I collagen, procollagen type I N-terminal propeptide were covariates. Blood samples were collected in the early morning after the overnight fasting and were analyzed using an automated electrochemiluminescence immunoassay on the LABOSPECT 008AS platform (Hitachi Hi-Tech Co., Ltd., Tokyo, Japan). The generalized additive model was further applied for nonlinear associations. The inception result for smoothing the curve was evaluated by two-piecewise linear regression exemplary.

RESULTS

Our results proved that in the OP patients, the serum 25(OH)D levels were inversely connected with blood TGs concentration, whereas they were positively associated with the HDL, apolipoprotein-A, and lipoprotein A levels. In the meantime, this research also found a nonlinear relationship and threshold effect between serum 25(OH)D and TC, LDL-C. Furthermore, there were positive correlations between the blood serum 25(OH)D levels and the levels of TC and LDL-C when 25(OH)D concentrations ranged from 0 to 10.04 ng/mL. However, this relationship was not present when 25(OH)D levels were higher than 10.04 ng/mL.

CONCLUSIONS

Our results demonstrated an independent relationship between blood lipids and vitamin D levels in osteoporosis patients. While we cannot establish a causal relationship between the two, our findings suggest that vitamin D may have beneficial effects on both bone health and blood lipid levels, providing a reference for improved protection against cardiovascular disease in this population. Further research, particularly interventional studies, is needed to confirm these associations and investigate their underlying mechanisms.

The pathological growth of the prostate gland in atherogenic contexts

The human prostate is an androgen-dependent gland where an imbalance in cell proliferation can lead to benign prostatic hyperplasia (BPH), which results in voiding lower urinary tract symptoms in the elderly. In the last decades, novel evidence has suggested that BPH might represent an element into the wide spectrum of disorders conforming the Metabolic Syndrome (MS). The dyslipidemic state and the other atherogenic factors of the MS have been shown to induce, maintain and/or aggravate the pathological growth of different organs, with data regarding the prostate being still limited. We here review the available epidemiological and experimental studies about the association of BPH with dyslipidemias. In particular, we have focused on Oxidized Low-Density Lipoproteins (OxLDL) as a potential trigger for vascular disease and cellular proliferation in atherogenic contexts, analyzing their putative molecular mechanisms, including the induction of specific extracellular vesicles (EVs)-derived miRNAs. In addition to the epidemiological evidence, OxLDL is proposed to play a fundamental role in the upregulation of prostatic cell proliferation by activating the Rho/Akt/p27^Kip1 pathway in atherogenic contexts. miR-21, miR-141, miR-143, miR-145, miR-155, and miR-221 would be involved in the transcription of genes related to the proliferative process. Although much remains to be investigated regarding the impact of OxLDL, its receptors, and molecular mechanisms on the prostate, it is clear that EVs and miRNAs represent a promising target for proliferative pathologies of the prostate gland.

Effects of Probiotic Supplementation on Dyslipidemia in Type 2 Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Trials

The effectiveness of probiotic consumption in controlling dyslipidemia in type 2 diabetes mellitus (T2DM) has been unclear. We reviewed relevant randomized controlled trials (RCTs) to clarify the effect of probiotic intake on dyslipidemia in T2DM patients. The Web of Science, Scopus, PubMed and Cochrane Library databases were used for searching relevant RCTs published up to October 2020. The total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) concentrations were selected as the primary indicators for dyslipidemia. The results of 13 eligible RCTs showed that probiotic intake could significantly reduce TC (SMD: −0.23, 95% CI: (−0.37, −0.10)) and TG (SMD: −0.27, 95% CI: (−0.44, −0.11)) levels, but did not regulate LDL-C or HDL-C concentrations. Subgroup analysis showed that multispecies probiotics (≥two species), but not single-species probiotics, significantly decreased TC and TG concentrations. Furthermore, powder, but not liquid, probiotics could reduce TC and TG concentrations. This meta-analysis demonstrated that probiotic supplementation is helpful in reducing TC and TG concentrations in T2DM patients. However, more well-controlled trials are needed to clarify the benefits of probiotics on dyslipidemia in T2DM patients.

Sex-influenced association of metabolic syndrome with lower extremity arterial disease in type 2 diabetes

AIM

The present study is undertaken to investigate the relationship between metabolic syndrome (MS) and lower extremity arterial disease (LEAD) in type 2 diabetes mellitus (T2DM) patients.

METHODS

A multi-center cross-sectional study was conducted on 8374 T2DM patients (4521 males and 3853 females) from 30 hospitals across China from June 2016 to January 2017. The odds ratios (ORs) and 95% confidence intervals (CIs) were presented to show the association between MS and LEAD. The univariate and multiple logistic analyses were performed to examine the association between MS and the prevalence of LEAD. Furthermore, the relationship was analyzed in different sex groups. Subgroup analysis was performed based on the number and individual of MS components.

RESULTS

Finally, 1809(21.60%) T2DM patients meet the diagnostic criteria of LEAD. Of the 3853 female subjects, 841(21.83%) patients were in the LEAD group and of the 4521 male subjects, 968(21.41%) patients were in the LEAD group. When adjusting for confounding variables, MS was significantly associated with the prevalence of LEAD in all enrolled T2DM patients (OR = 1.22, 95%CI: 1.09-1.37, P = 0.001). However, upon analyzing LEAD in different sex groups, the significant association remained in females (OR = 1.33, 95%CI: 1.12-1.58, P < 0.001), but not in males (OR = 1.11, 95%CI: 0.95-1.29, P = 0.202).

CONCLUSIONS

Our results suggest that MS is specifically associated with an increased risk of LEAD in female T2DM patients. However, MS may not be a significant factor in the prevalence of LEAD in male T2DM patients.

Different inflammatory cytokines release after open and endovascular reconstructions influences wound healing

Prodromal signs of a non-healing wound after revascularisation, which might be strictly linked with impending failure of vascular reconstructions, are associated with an inflammatory response mediated by several circulating adhesion molecules, extracellular endopeptidases, and cytokines. The aim of our study was to investigate the role of selected plasma biomarkers in the prediction of both wound healing and failure of infrapopliteal vein graft or percutaneous trans-luminal angioplasty (PTA) with selective stent positioning of the superficial femoral artery (SFA) in a population affected with critical limb ischaemia. A total of 68 patients who underwent either surgical or endovascular revascularisation of the inferior limb with autologous saphenous vein infrapopliteal bypass or PTA and selective stenting of the SFA were enrolled in our study. Patients were divided into two groups according to treatment: 41 patients were included in Group 1 (open surgery) and 27 in Group 2 (endovascular procedure). Plasma and blood samples were collected on the morning of surgery and every 6 months thereafter for up to 2 years of follow-up or until an occlusion occurred of either the vein bypass graft or the vessel treated endovascularly. Fifteen age-matched healthy male volunteers were considered a reference for biological parameters. Vascular cell adhesion molecule 1 [VCAM-1]/CD106, inter-cellular adhesion molecule-1 [ICAM-1]/CD54), interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α), and metalloproteinases (MMP)-2 and -9 plasma levels were measured with enzyme-linked immunosorbent assay (ELISA) kits. The mean observed time to heal of 54 wounds was 13 ± 4 months, with no statistically significant differences among the groups. The healing failure of the remaining wounds was strictly related to an unsuccessful open (n = 12) or endovascular (n = 8) treatment. The 2-year primary patency rate was 65% (SE = .09) in Group 1 and 52% (SE = .1) in Group 2. When compared with mean concentration values of Group 1, VCAM-1 and ICAM-1 were always significantly higher during follow-up in patients of Group 2 (P < .05). Furthermore, in the same group, IL-6 and tumour necrosis factor alpha (TNF-α) were found to be significantly higher at 6- and 12-month (P < .05) when compared with surgically treated patients. Cox regression analysis showed that elevated plasma levels of VCAM-1, ICAM-1, IL-6, and TNF-α during follow up were strongly related to impaired wound healing and/or revascularisation failure (P < .05). Elevated plasma levels of inflammatory markers VCAM-1, ICAM-1, IL-6, and TNF-α may be related to the failure of wound healing and revascularisation procedures. Interestingly, we have observed that endovascular treatments cause a higher level of these inflammation biomarkers when compared with a vein graft, although wound-healing and patency and limb salvage rates are not influenced.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY GUIDELINES FOR MANAGEMENT OF DYSLIPIDEMIA AND PREVENTION OF CARDIOVASCULAR DISEASE

OBJECTIVE

The development of these guidelines is mandated by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPGs).

METHODS

Recommendations are based on diligent reviews of the clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols.

RESULTS

The Executive Summary of this document contains 87 recommendations of which 45 are Grade A (51.7%), 18 are Grade B (20.7%), 15 are Grade C (17.2%), and 9 (10.3%) are Grade D. These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world medical care. The evidence base presented in the subsequent Appendix provides relevant supporting information for Executive Summary Recommendations. This update contains 695 citations of which 203 (29.2 %) are EL 1 (strong), 137 (19.7%) are EL 2 (intermediate), 119 (17.1%) are EL 3 (weak), and 236 (34.0%) are EL 4 (no clinical evidence).

CONCLUSION

This CPG is a practical tool that endocrinologists, other health care professionals, health-related organizations, and regulatory bodies can use to reduce the risks and consequences of dyslipidemia. It provides guidance on screening, risk assessment, and treatment recommendations for a range of individuals with various lipid disorders. The recommendations emphasize the importance of treating low-density lipoprotein cholesterol (LDL-C) in some individuals to lower goals than previously endorsed and support the measurement of coronary artery calcium scores and inflammatory markers to help stratify risk. Special consideration is given to individuals with diabetes, familial hypercholesterolemia, women, and youth with dyslipidemia. Both clinical and cost-effectiveness data are provided to support treatment decisions.

ABBREVIATIONS

4S = Scandinavian Simvastatin Survival Study A1C = glycated hemoglobin AACE = American Association of Clinical Endocrinologists AAP = American Academy of Pediatrics ACC = American College of Cardiology ACE = American College of Endocrinology ACS = acute coronary syndrome ADMIT = Arterial Disease Multiple Intervention Trial ADVENT = Assessment of Diabetes Control and Evaluation of the Efficacy of Niaspan Trial AFCAPS/TexCAPS = Air Force/Texas Coronary Atherosclerosis Prevention Study AHA = American Heart Association AHRQ = Agency for Healthcare Research and Quality AIM-HIGH = Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides trial ASCVD = atherosclerotic cardiovascular disease ATP = Adult Treatment Panel apo = apolipoprotein BEL = best evidence level BIP = Bezafibrate Infarction Prevention trial BMI = body mass index CABG = coronary artery bypass graft CAC = coronary artery calcification CARDS = Collaborative Atorvastatin Diabetes Study CDP = Coronary Drug Project trial CI = confidence interval CIMT = carotid intimal media thickness CKD = chronic kidney disease CPG(s) = clinical practice guideline(s) CRP = C-reactive protein CTT = Cholesterol Treatment Trialists CV = cerebrovascular CVA = cerebrovascular accident EL = evidence level FH = familial hypercholesterolemia FIELD = Secondary Endpoints from the Fenofibrate Intervention and Event Lowering in Diabetes trial FOURIER = Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects With Elevated Risk trial HATS = HDL-Atherosclerosis Treatment Study HDL-C = high-density lipoprotein cholesterol HeFH = heterozygous familial hypercholesterolemia HHS = Helsinki Heart Study HIV = human immunodeficiency virus HoFH = homozygous familial hypercholesterolemia HPS = Heart Protection Study HPS2-THRIVE = Treatment of HDL to Reduce the Incidence of Vascular Events trial HR = hazard ratio HRT = hormone replacement therapy hsCRP = high-sensitivity CRP IMPROVE-IT = Improved Reduction of Outcomes: Vytorin Efficacy International Trial IRAS = Insulin Resistance Atherosclerosis Study JUPITER = Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin LDL-C = low-density lipoprotein cholesterol Lp-PLA2 = lipoprotein-associated phospholipase A2 MACE = major cardiovascular events MESA = Multi-Ethnic Study of Atherosclerosis MetS = metabolic syndrome MI = myocardial infarction MRFIT = Multiple Risk Factor Intervention Trial NCEP = National Cholesterol Education Program NHLBI = National Heart, Lung, and Blood Institute PCOS = polycystic ovary syndrome PCSK9 = proprotein convertase subtilisin/kexin type 9 Post CABG = Post Coronary Artery Bypass Graft trial PROSPER = Prospective Study of Pravastatin in the Elderly at Risk trial QALY = quality-adjusted life-year ROC = receiver-operator characteristic SOC = standard of care SHARP = Study of Heart and Renal Protection T1DM = type 1 diabetes mellitus T2DM = type 2 diabetes mellitus TG = triglycerides TNT = Treating to New Targets trial VA-HIT = Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial VLDL-C = very low-density lipoprotein cholesterol WHI = Women's Health Initiative.

Differential associations of metabolic risk factors on cortical thickness in metabolic syndrome

Objective

Metabolic syndrome (MetS) refers to a cluster of risk factors for cardiovascular disease, including obesity, hypertension, dyslipidemia, and hyperglycemia. While sizable prior literature has examined associations between individual risk factors and quantitative measures of cortical thickness (CT), only very limited research has investigated such measures in MetS. Furthermore, the relative contributions of these risk factors to MetS-related effects on brain morphology have not yet been studied. The primary goal of this investigation was to examine how MetS may affect CT. A secondary goal was to explore the relative contributions of individual risk factors to regional alterations in CT, with the potential to identify risk factor combinations that may underlie structural changes.

Methods

Eighteen participants with MetS (mean age = 59.78 years) were age-matched with 18 healthy control participants (mean age = 60.50 years). CT measures were generated from T1-weighted images and groups were contrasted using whole-brain general linear modeling. A follow-up multivariate partial least squares correlation (PLS) analysis, including the full study sample with complete risk factor measurements (N = 53), was employed to examine which risk factors account for variance in group structural differences.

Results

Participants with MetS demonstrated significantly reduced CT in left hemisphere inferior parietal, rostral middle frontal, and lateral occipital clusters and in a right hemisphere precentral cluster. The PLS analysis revealed that waist circumference, high-density lipoprotein cholesterol (HDL-C), triglycerides, and glucose were significant contributors to reduced CT in these clusters. In contrast, diastolic blood pressure showed a significantly positive association with CT while systolic blood pressure did not emerge as a significant contributor. Age was not associated with CT.

Conclusion

These results indicate that MetS can be associated with regionally specific reductions in CT. Importantly, a novel link between a risk factor profile comprising indices of obesity, hyperglycemia, dyslipidemia and diastolic BP and localized alterations in CT emerged. While the pathophysiological mechanisms underlying these associations remain incompletely understood, these findings may be relevant for future investigations of MetS and might have implications for treatment approaches that focus on specific risk factor profiles with the aim to reduce negative consequences on the structural integrity of the brain.

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Cortical thickness is reduced bilaterally in metabolic syndrome.

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Five out of six risk factor components contribute to altered cortical thickness.

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Particular risk factor combination may be an important target for intervention.

Elevated Serum Cyclophilin B Levels Are Associated with the Prevalence and Severity of Metabolic Syndrome

OBJECTIVE

Inflammation plays a central role in the pathogenesis of metabolic syndrome (MetS). Cyclophilin B (CypB) can be constitutively secreted in response to inflammatory stimuli and oxidative stress, participating in tissue or systemic inflammation. We investigated the relationship between CypB and MetS in both humans and mice.

METHODS

Serum CypB levels were determined in 211 subjects with MetS and 292 subjects without MetS (non-MetS) (133 healthy controls and 159 high-risk subjects with one to two MetS components). Additionally, CypB expression in metabolic organs was examined in mice fed with high-fat diet (HFD) and genetically obese (ob/ob) mice.

RESULTS

Serum CypB level was significantly higher in MetS subjects compared with both groups of non-MetS subjects (193.80 ± 83.22 vs. 168.38 ± 65.01 vs. 124.26 ± 47.83 ng/mL, P < 0.001). Particularly, serum CypB level was significantly higher in subjects with hypertension, central obesity, diabetes mellitus or hyperglycemia, elevated levels of triglycerides, or reduced levels of high-density lipoprotein than in those without. Moreover, CypB was positively associated with the number of MetS components (r = 0.404, P < 0.001), indicating that a higher serum CypB level reflected more severe MetS. Multivariate regression revealed that a one SD increase in CypB was associated with an odds ratio of 1.506 (1.080-2.101, P = 0.016) for MetS prevalence after adjusting for age, gender, conventional risk factors, and medication. Stratified analyses by age and gender demonstrated that subjects >60 years old with higher CypB levels were more likely to have MetS, and the risk for MetS was higher and more significant in women compared with men. Additionally, CypB expression levels were lower at baseline and dramatically enhanced in metabolic organs (such as the liver) and visceral and subcutaneous adipose tissue from HFD-induced obese mice and ob/ob mice.

CONCLUSION

Increased CypB levels were significantly and independently associated with the presence and severity of MetS, indicating that CypB could be used as a novel biomarker and clinical predictor of MetS.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

Metabolic syndrome and incident peripheral artery disease - the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

We evaluated whether metabolic syndrome (MetS) is associated with an increased incidence of lower extremity peripheral artery disease (PAD) in community dwelling people free of clinical cardiovascular disease at baseline. We assessed whether higher levels of inflammatory biomarkers may mediate the association of MetS with incident PAD.

METHODS

MetS was defined at baseline as the presence of three or more of the following components: elevated waist circumference, triglycerides ≥150 mg/dL, reduced high-density lipoprotein (HDL) cholesterol, blood pressure ≥130/85 mm Hg or taking blood pressure medication, and fasting glucose ≥100 mg/dL and <126 mg/dL. People with diabetes were excluded. Incident New PAD was defined among people with a normal ankle brachial index (ABI) at baseline (i.e. baseline ABI of 0.90 to 1.40) and consisted of one of the following outcomes during 3-year follow-up: ABI decline to < 0.90 combined with a decline ≥0.15 or medical record confirmed PAD outcome. Multivariable Poisson regression was used to estimate the association between MetS and incident PAD.

RESULTS

Among 4817 participants without PAD at baseline, 1382 (29%) had MetS. Adjusting for age, sex, race, smoking, physical activity, low-density lipoprotein cholesterol, baseline ABI, and other confounders, 23/1382 (1.7%) people with MetS developed PAD vs. 30/3435 (0.87%) people without MetS (risk ratio = 1.78 [95% Confidence Interval (CI), 1.04 to 2.82], P = 0.031). Adjusting for C-reactive protein, fibrinogen, or interleukin-6 did not attenuate this association.

CONCLUSION

People free of clinical cardiovascular disease with MetS are at increased risk for PAD. Our findings suggest that this association is not mediated by inflammation.

Cerebral Cortical Microvascular Rarefaction in Metabolic Syndrome is Dependent on Insulin Resistance and Loss of Nitric Oxide Bioavailability

OBJECTIVE

Chronic presentation of the MS is associated with an increased likelihood for stroke and poor stroke outcomes following occlusive cerebrovascular events. However, the physiological mechanisms contributing to compromised outcomes remain unclear, and the degree of cerebral cortical MVD may represent a central determinant of stroke outcomes.

METHODS

This study used the OZR model of MS and clinically relevant, chronic interventions to determine the impact on cerebral cortical microvascular rarefaction via immunohistochemistry with a parallel determination of cerebrovascular function to identify putative mechanistic contributors.

RESULTS

OZR exhibited a progressive rarefaction (to ~80% control MVD) of the cortical microvascular networks vs. lean Zucker rats. Chronic treatment with antihypertensive agents (captopril/hydralazine) had limited effectiveness in blunting rarefaction, although treatments improving glycemic control (metformin/rosiglitazone) were superior, maintaining ~94% control MVD. Chronic treatment with the antioxidant TEMPOL severely blunted rarefaction in OZR, although this ameliorative effect was prevented by concurrent NOS inhibition.

CONCLUSIONS

Further analyses revealed that the maintenance of glycemic control and vascular NO bioavailability were stronger predictors of cerebral cortical MVD in OZR than was prevention of hypertension, and this may have implications for chronic treatment of CVD risk under stroke-prone conditions.

Acute hyperglycemia reduces cerebrovascular reactivity: the role of glycemic variability

CONTEXT

Cerebral vasomotor reactivity (CVR) is reduced in patients with diabetes mellitus (DM), and glucose variability (GV) might be responsible for cerebrovascular damage.

OBJECTIVE

Studying patients with insulin resistance without DM, we explored the role of GV in impairing CVR.

PATIENTS

We studied 18 metabolic syndrome (MS) patients without DM, 9 controls (C), and 26 patients with DM.

MAIN OUTCOME MEASURES

Groups were compared in terms of CVR, GV, and 24-hour blood pressure. To evaluate the impact of acute hyperglycemia on CVR, a hyperglycemic clamp was performed in MS patients and controls.

RESULTS

Baseline CVR was reduced in DM vs C and MS (C vs DM = 20.2, 95% CI = 3.5-36.9, P = .014; and MS vs DM = 22.2, 95% CI = 8.6-35.8, P = .001), but similar between MS and C (MS vs C = 2.0, 95% CI = -14.7 to 18.7, P = .643). During acute hyperglycemia, CVR fell in MS and C to values comparable to DM. GV progressively increased from C to MS to DM. In MS, CVR at 120 minutes and GV displayed a negative correlation (r = -0.48, P = .043), which did not change after controlling for mean 24-hour systolic and diastolic blood pressure. In MS, the CVR reduction was significantly correlated to GV (r = 0.55, P = .02).

CONCLUSIONS

GV is increased in patients with MS but without DM and is the major predictor of CVR reduction induced by acute hyperglycemia, possibly representing the earliest cause of cerebrovascular damage in DM.

Metabolic syndrome in patients with peripheral arterial disease

BACKGROUND AND OBJECTIVE

The prevalence of metabolic syndrome (MS) in patients with peripheral arterial disease (PAD) and coronary or cerebrovascular disease is increasing, but it is not known whether this association also exists in patients with isolated PAD. The aim of the current study was to assess the prevalence of MS in patients with PAD who had no coronary or cerebrovascular disease, the prescription rate of evidence-based cardiovascular therapies and the attainment of therapeutic goals in patients with PAD and with and without MS.

PATIENTS AND METHODS

Multicenter, cross-sectional study of 3.934 patients aged ≥ 45 years with isolated PAD who were treated in primary care and specialized outpatient clinics during 2009. A diagnosis of PAD was reached for ankle brachial indices <0.9, a previous history of amputation or revascularization.

RESULTS

In the overall population, the mean age was 67.6 years, 73.8% were males and 63% had MS (95% CI 61.5-64.3%). Patients with MS had a higher prevalence of cardiovascular risk factors and comorbidities, more severe PAD and higher prescription rate of evidence-based cardiovascular therapies. After adjusting for risk factors and comorbidity, there was a more frequent use of renin-angiotensin system blockers, beta-blockers, diuretics and statins among the patients with MS. A lower percentage of patients with MS achieved the therapeutic goals for blood pressure (22% vs. 41.5%, p<0.001). Similarly, a lower percentage of patients with diabetes achieved the glycated hemoglobin goals (44% vs. 53.1%, p<0.001), with no differences in LDL-cholesterol levels (29.8% vs. 39.1%, p=0.265).

CONCLUSION

Patients with PAD have a high prevalence of MS. Patients with MS do not attain therapeutic goals as frequently as those without, despite taking more cardiovascular drugs.

Strategies for treating lipids for prevention: risk stratification models with and without imaging

Cardiovascular disease (CVD) remains the leading cause of mortality both in the United States and worldwide. Traditional risk factors are essential to CVD risk prediction and explain a significant portion of the between-population and between-individual variance in CVD. Nonetheless, due to the large size of the group, a substantial portion of cardiovascular events occur in individuals predicted to be at low risk based on traditional risk factor models such as the Framingham risk score. The problem is that by disregarding this low risk group, a significant proportion of events are ignored and deemed 'unpreventable'. As such, it is imperative to find new ways to improve CVD risk prediction and thereby apply preventive measures to persons more likely to develop 'preventable' disease. Focus has consequently shifted towards identification of novel markers to improve cardiovascular risk prediction. We review the role of various risk stratification models, and assess the incorporation of imaging markers to guide treatment for lipids in prevention of CVD.

Metabolic syndrome and risk of incident peripheral artery disease: the cardiovascular health study

Prior studies evaluating metabolic syndrome (MetS) and incident peripheral artery disease (PAD) have been limited by use of modified MetS criteria and restriction to clinical PAD end points. We investigated MetS and risk of developing a low ankle-brachial index (ABI) and clinical PAD in the Cardiovascular Health Study, a population-based cohort of adults aged ≥65 years. Participants with MetS met at least 3 of 5 Adult Treatment Panel III criteria. Baseline C-reactive protein-MetS or fibrinogen-MetS were defined as presence of 3 of 6 components, with elevated C-reactive protein (>3 mg/L) or fibrinogen (>341 mg/dL) as a sixth component. Incident low ABI, defined as ABI <0.9 and decline of ≥0.15, was assessed among a subset of 1899 individuals with 2 ABI measurements 6 years apart. Over a median follow-up of 13.7 years, 4632 individuals were followed up for clinical PAD, defined as revascularization or diagnosed claudication. Adult Treatment Panel III MetS was associated with both incident low ABI (risk ratio, 1.26; 95% confidence interval [CI], 1.00-1.58) and clinical PAD (hazard ratio, 1.47; 95% CI, 1.11-1.94). Incorporating C-reactive protein or fibrinogen into Adult Treatment Panel III criteria identified an additional 16% to 20% of individuals as having MetS, and both C-reactive protein-MetS and fibrinogen-MetS were associated with incident low ABI (risk ratio, 1.36; 95% CI, 1.07-1.72 and risk ratio, 1.43; 95% CI, 1.13-1.81, respectively) and clinical PAD (hazard ratio, 1.56; 95% CI, 1.17-2.08 and hazard ratio, 1.55; 95% CI, 1.17-2.07, respectively). Among Adult Treatment Panel III MetS criteria, risk of PAD was most strongly associated with hypertension.

Impaired hypoxic cerebral vasodilation in younger adults with metabolic syndrome

Metabolic syndrome (MetSyn) increases the risk of cerebrovascular disease and stroke; however, its impact on human cerebral circulation remains unclear. Reduced cerebral dilation is also associated with an increased risk of stroke and may occur in MetSyn adults. We hypothesised that MetSyn adults would exhibit reduced cerebral vasodilation to hypoxia and hypercapnia. Middle cerebral artery velocity (MCAv) was insonated with Doppler ultrasound in younger (approximately 35 years) MetSyn and healthy adults. We measured mean arterial blood pressure (MABP), arterial oxygen saturation (S(p)O(2)) and end tidal carbon dioxide (Pet (CO2)). Cerebrovascular conductance index (CVCi) was calculated as MCAv*100/MABP. Cerebral vasodilation (ΔCVCi) to hypoxia (S(p)O(2) = 90% and 80%) and hypercapnia (+10 mm Hg Pet (CO2)) was assessed. Baseline MCAv was similar, while adults with MetSyn had lower baseline CVCi. MetSyn adults demonstrated markedly reduced ΔCVCi compared to healthy adults in response to hypoxia (90% S(p)O(2): 1±2 vs 6±2; 80% S(p)O(2): 5±2 vs 15±3 cm/s/mmHg, p<0.05). Both groups demonstrated similar ΔCVCi to hypercapnia (18±2 vs 20±2 cm/s/mmHg). These data are the first to demonstrate that younger MetSyn adults have impaired hypoxia-mediated cerebral vasodilation prior to clinically overt cerebrovascular disease. These findings provide novel insight into cerebrovascular disease onset in MetSyn adults.

Evaluation of serum adipokines in peripheral arterial occlusive disease

Aim. Out study aimed to assess the serum levels of adipokines in patients with peripheral arterial occlusive disease (PAOD) caused by atherosclerosis. Methods. Serum samples were obtained from 221 patients. One hundred and forty patients, (26 females and 114 males) met the inclusion criteria and were assigned into the case group. Eighty one patients (17 females and 64 males), were included in the control group. Circulating plasma levels of adiponectin, leptin, resistin, and TNF-α were measured using the enzyme-linked immunosorbent assay (ELISA) method. Results. Significant lower levels of adiponectin were present (P = 0.0061) in PAOD patients (2380.23 ± 1634.42 pg/mL) compared to the control group (3065.06 ± 1901.2 pg/mL). The mean value of leptin (2844.42 ± 3301.08 pg/mL) and resistin (2047.81±3301.08 pg/mL) patients included in the PAOD group was higher, as compared to the control group. Statistically significant difference was found between the two groups for leptin (P = 0.0332) and for resistin (P = 0.0352). No statistically significant difference for TNF-α was found between the two groups (P > 0.05). Conclusion. The markers of inflammation secreted by the adipose tissue (adiponectin, leptin, resistin) showed significant differences in patients from the case group (with PAOD) compared to the control group.

The relationship of peripheral arterial disease and metabolic syndrome prevalence in asymptomatic US adults 40 years and older: results from the National Health and Nutrition Examination Survey (1999-2004)

Peripheral arterial disease (PAD) is a subclinical marker of coronary artery disease and identifies asymptomatic individuals at high risk for cardiovascular disease (CVD) events. The metabolic syndrome (MetS) is a constellation of clinical factors that increases the risk of developing diabetes and CVD. The authors' objectives were to estimate the prevalence of MetS in patients with PAD and to determine the prevalence of PAD in the population of asymptomatic US adults 40 years and older with MetS. The authors analyzed data from 3 National Health and Nutrition Examination Surveys (NHANES, 1999-2004). Prevalence of MetS as defined by the Third Report of the Adult Treatment Panel criteria and prevalence of associated cardiac risk factors were determined in 5376 asymptomatic participants 40 years and older. Presence of PAD was defined as ankle-brachial index <0.9. Estimates were weighted with the sample weights accounting for the unequal selection probability of complex NHANES sampling and over sampling of selected population subgroups. Prevalence of PAD in asymptomatic US adults 40 years and older was 4.2%. PAD prevalence in persons with MetS was 7.0% compared with 3.3% in persons without MetS. A total of 38% of the population with PAD also had MetS. High rates of abdominal obesity, hypertension, hyperglycemia, and low high-density lipoprotein cholesterol are significant contributors to both MetS and PAD. Persons with MetS have twice the risk of having PAD. Of persons with PAD, almost 40% have MetS. The presence of either PAD or MetS should warrant screening for both conditions so that risk stratification and management of risk factors may be performed.

Evidence for an exercise induced increase of TNF-α and IL-6 in marathon runners

Regular physical activity of moderate intensity improves cardiovascular risk factors including low-grade inflammation. However, acute vigorous exercise such as marathon running results in marked increases of circulating pro-inflammatory markers. Up to now, the origin of this pro-inflammatory boost is still debated equivocally. We analyzed the change of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and leptin from pre- to immediately post-race in 15 male runners (age 43 ± 10.9 years and body mass index 24.5 ± 2.7 kg/m(2) ) both on the protein level in the plasma and on the messenger ribonucleic acid (mRNA) level in blood mononuclear cells (BMNC). We observed a significant increase of IL-6 (prerace 2.08 ± 0.10 ng/L and postrace 40.14 ± 24.85 ng/L, P < 0.001) and TNF-α (prerace 8.14 ± 1.38 ng/L and postrace 12.40 ± 3.15 ng/L, P < 0.001) and a decrease of leptin (prerace 1.64 ± 2.64 μg/L and postrace 0.80 ± 1.70 μg/L, P = 0.04) serum levels after the marathon race. Furthermore, TNF-α, IL-6, and leptin were expressed (mRNA level) in BMNC. However no significant differences in mRNA levels were seen before and after the run in these cells. We found an up-regulation of TNF-α and IL-6 in the plasma during vigorous exercise. This increase is not attributable to BMNC. We assume a local production in, or release from, exercised tissues.

Metabolic syndrome and cerebral vasomotor reactivity

BACKGROUND AND PURPOSE

Metabolic syndrome has been proposed as a risk factor for stroke and transient ischaemic attack. One pathophysiological mechanism could be impairment of endothelial function. Thus, we hypothesized that cerebral vasomotor reactivity would be decreased in patients with metabolic syndrome, compared to patients without metabolic syndrome.

METHODS

In this retrospective analysis, 83 consecutive patients (aged 59.19 ± 15.98; 33 women) underwent Doppler examination for carotid artery disease including bi-hemispherical vasomotor reactivity assessment using transcranial Doppler monitoring. Vasomotor reactivity data were analyzed from the hemisphere with no or low-grade carotid stenosis (<40%). Cerebral vasomotor reactivity was calculated as percent increase in mean flow velocity per mmHg pCO(2) during 2 min of 5% CO(2) inhalation delivered by anesthesia mask (normal if ≥ 2%/mmHg). Univariate and multivariable linear regression models were used to determine factors, including metabolic syndrome, that were independently associated with pathologic vasomotor reactivity.

RESULTS

After adjusting for the presence of contralateral carotid stenosis and ipsilateral stroke in the multivariable model, metabolic syndrome was independently associated with lower vasomotor reactivity values (2.27 ± 1.24% vs. 2.68 ± 1.37; ß = -0.258, P = 0.033). In this model, there was no association of cerebral vasomotor reactivity with age, gender, race, cardiac disease, current statin therapy, or small vessel disease.

CONCLUSIONS

Our findings suggest that impaired cerebral vasomotor reactivity may be a mediator of stroke in patients with metabolic syndrome, a syndrome affecting a significant and growing proportion of the population. A prospective longitudinal study is warranted to study the cerebral haemodynamic effect of metabolic syndrome.

The association between the metabolic syndrome and peripheral, but not coronary, artery disease is partly mediated by endothelial dysfunction: the CODAM study

BACKGROUND

The metabolic syndrome is associated with coronary artery disease (CAD) and with peripheral artery disease (PAD), but the underlying mechanisms explaining these associations have not yet been completely clarified. The aim was to investigate (i) whether endothelial dysfunction can explain the association between the metabolic syndrome and CAD and/or the severity of PAD, as measured by the ankle-arm index (AAIx); and (ii) whether any such mediation is independent of that from low-grade inflammation.

MATERIALS AND METHODS

We studied 539 subjects (232 men) aged 59·4 ± 6·9 years, with an increased risk of type 2 diabetes and cardiovascular diseases. Endothelial dysfunction and inflammation scores were calculated from three markers of endothelial dysfunction (soluble E-selectin, soluble vascular cell adhesion molecule-1 and von Willebrand factor) and six of inflammation (C-reactive protein, interleukin 6, soluble intercellular adhesion molecule-1, serum amyloid A, ceruloplasmin and haptoglobin). The association between the metabolic syndrome and CAD and/or PAD, and the mediating role of endothelial dysfunction herein was examined with logistic and linear regression analyses, all adjusted for age, sex and smoking.

RESULTS

Subjects with the metabolic syndrome (n = 289; 54%) had higher prevalence of CAD [OR (95%CI) = 1·75 (1·14; 2·69)] and lower AAIx [β (95% CI) = -0·036 (-0·056; -0·016)]. Endothelial dysfunction explained 6% of the association between the metabolic syndrome and CAD, and 19% of the association with AAIx, whereas low-grade inflammation explained 26% and 28% of these associations, respectively. Together, the two scores explained 24% and 36% of the association between the metabolic syndrome and CAD and AAIx, respectively.

CONCLUSIONS

Endothelial dysfunction explains part of the association between the metabolic syndrome and the severity of PAD, but is not involved in the association between the metabolic syndrome and CAD. This indicates that the pathophysiologies of coronary and peripheral artery disease are essentially distinct.

Plasma Proteomic Signature in Overweight Girls Closely Correlates with Homeostasis Model Assessment (HOMA), an Objective Measure of Insulin Resistance

Obesity is known to be associated with a large number of long-term morbidities, and while in some cases the relationship of obesity and the consequences is clear (for example, excess weight and lower extremity orthopedic problems) in others the mechanism is not as clear. One common system of categorizing overweight in terms of the likelihood of negative consequences involves using the concept of “metabolic syndrome”. We hypothesized that the development of a plasma protein profile of overweight adolescents with and without the metabolic syndrome might give a more precise and informative picture of the disease process than the current clinical categorization and permit early targeted intervention. For this paper, we used antibody microarrays to analyze the plasma proteome of a group of 15 overweight female adolescent patients. Upon analysis of the proteome, the overweight patients diverged from the nonoverweight female controls. Furthermore, the overweight patients were divided by the analysis into two population clusters, each with distinctive protein expression patterns. Interestingly, the clusters were characterized by differences in insulin resistance, as measured by HOMA. Categorization according to the presence or absence of the metabolic syndrome did not yield such clusters.

Metabolic syndrome and cardiovascular risk prediction in peripheral arterial disease

BACKGROUND AND AIMS

Metabolic syndrome (MetS) was reported to be associated with increased cardiovascular risk in various settings, however its prognostic impact in peripheral arterial disease (PAD) is scanty.

METHODS AND RESULTS

We prospectively studied 173 patients with intermittent claudication and ankle/brachial index (ABI)<0.90, in whom MetS was defined using the criteria of both the revised version of the Adults Treatment Panel III (rATP III) and the International Diabetes Federation (IDF). Of these patients, 52.6% met the rATP III and 54.9% the IDF criteria for MetS. During a median follow-up of 31 months, 54 cardiovascular events occurred. Kaplan-Meier curves showed a greater incidence of ischemic events in patients with MetS than in those without. However, adjusted Cox analyses revealed that only IDF-MetS was independently associated with increased cardiovascular risk (HR=1.91, 95% CI 1.03-3.51, p=0.038). Kaplan-Meier curves for the four groups of patients delineated according to the bootstrapped ABI cut-off value (0.73) and the presence or absence of IDF-MetS revealed that the syndrome improved the predictive power of ABI alone. Actually, among patients with an ABI≤0.73, those with IDF-MetS had a higher cardiovascular risk than those without the syndrome (HR=2.55, 95% CI 1.22-5.12, p=0.012). This was confirmed by c-statistic, which was 0.56 for ABI alone and increased to 0.65 (p=0.046) when IDF-Mets was added to the pressure index.

CONCLUSION

In PAD, IDF-MetS, but not rATP III-MetS, is associated with an increased risk of cardiovascular events. Furthermore, IDF-MetS adds to the prognostic value of ABI, currently the most powerful prognostic indicator in PAD.

Metabolic syndrome, inflammation, and risk of symptomatic peripheral artery disease in women: a prospective study

BACKGROUND

The metabolic syndrome (MetS) is associated with incident myocardial infarction and stroke and is linked with subclinical inflammation; however, prospective data pertaining to MetS and future peripheral artery disease (PAD) are sparse, with few studies examining the role of inflammation. We therefore evaluated the relationship between MetS, inflammation, and incident PAD.

METHODS AND RESULTS

We conducted a prospective cohort study among 27 111 women free of baseline cardiovascular disease who were participating in the Women's Health Study. Subjects were followed for incident symptomatic PAD (n=114; median cohort follow-up 13.3 years). We used Cox proportional hazards models to compare PAD risk among women with and without MetS. We also evaluated relationships between MetS and subclinical inflammation as measured by high-sensitivity C-reactive protein and soluble intercellular adhesion molecule-1 and adjusted for these biomarkers in multivariable models. Women with MetS had a 62% increased risk of future PAD (hazard ratio 1.62, 95% confidence interval 1.10 to 2.38). After multivariable adjustment, MetS remained significantly associated with PAD (adjusted hazard ratio 1.48, 95% confidence interval 1.01 to 2.18), with a 21% risk increase per additional MetS-defining trait (adjusted hazard ratio 1.21, 95% confidence interval 1.06 to 1.39). In women with and without MetS, respectively, median levels of high-sensitivity C-reactive protein were 4.0 versus 1.5 mg/L (P<0.0001), and median levels of soluble intercellular adhesion molecule-1 were 374 versus 333 ng/mL (P<0.0001). When high-sensitivity C-reactive protein and soluble intercellular adhesion molecule-1 were added to multivariable models, risk associated with MetS was substantially attenuated and no longer significant (hazard ratio 1.14, 95% confidence interval 0.75 to 1.73).

CONCLUSIONS

MetS is associated with an increased risk of future symptomatic PAD in women. This risk appears to be mediated largely by the effects of inflammation and endothelial activation.

Nonalcoholic fatty liver disease and cardiovascular risk

Nonalcoholic fatty liver disease (NAFLD) is a very common cause of chronic liver disease in the United States. A large proportion of patients with NAFLD have coexisting metabolic syndrome, a major risk factor for cardiovascular disease. A strong association between NAFLD and cardiovascular disease has been long suspected, and recent studies have confirmed that cardiovascular disease is the single most important cause of mortality in this patient population. NAFLD may pose cardiovascular risk beyond the risk conferred by traditional factors such as dyslipidemia, diabetes, and smoking. Health care providers managing patients with NAFLD should recognize this increased cardiovascular risk and should undertake early, aggressive risk factor modification.