Metabolic syndrome, independent of its components, affects adversely cardiovascular morbidity in essential hypertensives

Independent association between age- and sex-specific metabolic syndrome severity score and cardiovascular disease and mortality

Traditional metabolic syndrome (MetS) criteria have several limitations, which hinder its use in clinical practice. To overcome the limitations, we investigated the association between age- and sex-specific continuous MetS severity score (cMetS-S) and cardiovascular disease (CVD) and mortality beyond MetS components in the framework of the Tehran Lipid and Glucose Study. Participants aged 20-60 years at baseline were included in the study. We excluded participants with CVD, cancer, use of corticosteroids, estimated glomerular filtration rate < 30 ml/min/1.73 m2, and those who were pregnant. We evaluated the association between cMetS-S with CVD and mortality over 18 years of follow-up among 8500 participants with continuous and quantile approaches using the Cox proportional hazard regression model. In addition, the model performance of cMetS-S for predicting CVD events was compared to the conventional MetS criteria. Participants with higher cMetS-S had a significantly increased risk for CVD, coronary (CHD) and non-coronary heart disease (non-CHD), and all-cause, cardiovascular, and sudden cardiac death. Independent of the confounders and MetS components, the cMetS-S had the HRs of 1.67 (95% CI 1.47-1.89), 1.60 (95% CI 1.37-1.86), and 1.88 (95% CI 1.50, 2.35) for CVD, CHD, and non-CHD events upon 1-SD increment, respectively. The risk of mortality was increased for 1-SD of cMetS-S (all-cause mortality, HR 1.24; 95% CI 1.09-1.41; CVD mortality, HR 1.72; 95% CI 1.20-2.45; sudden cardiac death, HR 1.60; 95% CI 1.03-2.49). The model fitness of cMetS-S was superior to the conventional MetS criteria in predicting CVD and mortality. The cMetS-S provided an additional risk for CVD and mortality beyond the individual MetS components. Standardized cMetS-S could be a potential universal measure to define MetS severity while considering the weighted contribution of MetS components and their variations by age, sex, and ethnicity.

Cardiometabolic risk profiles in a Sri Lankan twin and singleton sample

Introduction

Prevention of cardiovascular disease and diabetes is a priority in low- and middle-income countries, especially in South Asia where these are leading causes of morbidity and mortality. The metabolic syndrome is a tool to identify cardiometabolic risk, but the validity of the metabolic syndrome as a clinical construct is debated. This study tested the existence of the metabolic syndrome, explored alternative cardiometabolic risk characterisations, and examined genetic and environmental factors in a South Asian population sample.

Methods

Data came from the Colombo Twin and Singleton follow-up Study, which recruited twins and singletons in Colombo, Sri Lanka, in 2012–2015 (n = 3476). Latent class analysis tested the clustering of metabolic syndrome indicators (waist circumference, high-density lipoprotein cholesterol, triglycerides, blood pressure, fasting plasma glucose, medications, and diabetes). Regression analyses tested cross-sectional associations between the identified latent cardiometabolic classes and sociodemographic covariates and health behaviours. Structural equation modelling estimated genetic and environmental contributions to cardiometabolic risk profiles. All analyses were stratified by sex (n = 1509 men, n = 1967 women).

Results

Three classes were identified in men: 1) “Healthy” (52.3%), 2) “Central obesity, high triglycerides, high fasting plasma glucose” (40.2%), and 3) “Central obesity, high triglycerides, diabetes” (7.6%). Four classes were identified in women: 1) “Healthy” (53.2%), 2) “Very high central obesity, low high-density lipoprotein cholesterol, raised fasting plasma glucose” (32.8%), 3) “Very high central obesity, diabetes” (7.2%) and 4) “Central obesity, hypertension, raised fasting plasma glucose” (6.8%). Older age in men and women, and high socioeconomic status in men, was associated with cardiometabolic risk classes, compared to the “Healthy” classes. In men, individual differences in cardiometabolic class membership were due to environmental effects. In women, genetic differences predicted class membership.

Conclusion

The findings did not support the metabolic syndrome construct. Instead, distinct clinical profiles were identified for men and women, suggesting different aetiological pathways.

Association of metabolic syndrome with cardiovascular outcomes in hypertensive patients: a systematic review and meta-analysis

PURPOSE

The association between metabolic syndrome (MetS) and cardiovascular outcomes in patients with hypertension is still controversial. This meta-analysis sought to evaluate the association of MetS with cardiovascular outcomes in hypertensive patients.

METHODS

Two authors comprehensively searched PubMed and Embase databases from their inception to April 18, 2020 for the longitudinal studies that evaluated the association of MetS with cardiovascular outcomes in patients with hypertension. The main outcomes were major adverse cardiovascular events (myocardial infarction, revascularization, stroke, hospitalization due to heart failure, etc.) and stroke.

RESULTS

Eight studies consisting of 36,614 hypertensive patients were identified and analyzed. Meta-analysis indicated that MetS was associated with an increased risk of major adverse cardiovascular events (risk ratio [RR] 1.55; 95% confidence intervals [CI] 1.28-1.87), cardiovascular mortality (RR 1.44; 95%CI 1.13-1.82), and stroke (RR 1.46; 95%CI 1.22-1.75), respectively. Sensitivity analysis further confirmed the robustness of the prognostic value of MetS.

CONCLUSIONS

MetS is associated with higher risk of major adverse cardiovascular events, cardiovascular mortality, and stroke in patients with hypertension. Determination of MetS may contribute to improving cardiovascular risk stratification in hypertension.

Nonalcoholic Fatty Liver Disease and Fibrosis Associated With Increased Risk of Cardiovascular Events in a Prospective Study

BACKGROUND & AIMS

Patients with non-alcoholic fatty liver disease (NAFLD) are at increased chance for cardiovascular events (CVEs). Severity of liver fibrosis is used to determine prognoses for patients with NAFLD, but little is known about the relationship between liver fibrosis and CVEs in the real world.

METHODS

We analyzed data from the prospective observational progression of liver damage and cardiometabolic disorders in non-alcoholic fatty liver disease study, comprising 898 consecutive outpatients (mean age, 56.4 ± 12.7 years; 37.5% women) screened for liver steatosis by ultrasound according to Hamagughi criteria. Liver fibrosis was defined as FIB-4 score greater than 2.67 and NAFLD fibrosis score greater than 0.676. After enrolment, patients were interviewed by phone every 6 months and examined every 12 months in the outpatient clinic, and CVEs were recorded (fatal or nonfatal ischemic stroke and myocardial infarction, cardiac or peripheral revascularization, new-onset arterial fibrillation and cardiovascular death). The primary outcomes were incidence rate of CVEs in patients with vs without NAFLD and factors associated with CVEs in patients with NAFLD.

RESULTS

Over a median follow-up time of 41.4 months (3044.4 patient-years), 58 CVEs (1.9%/year) were registered. The rate of CVEs was higher in patients with (n = 643, 2.1%/year) vs without NAFLD (n = 255, 1.0%/year) (P = .066). In multivariable Cox proportional regression analysis, NAFLD increased risk for CVEs (hazard ratio [HR], 2.41; 95% CI, 1.06-5.47; P = .036), after adjustment for metabolic syndrome. Among patients with NAFLD, male sex, previous CVEs, metabolic syndrome and FIB-4 scores greater than 2.67 (HR, 4.02; 95% CI, 1.21-13.38; P = .023) were independently associated with risk of incident CVEs. NFS scores greater than 0.676 were also independently associated with risk of incident CVEs (HR, 2.35; 95% CI, 1.05-5.27; P = .038).

CONCLUSIONS

In an analysis of data from a study of patients screened for NAFLD and followed, individuals with NAFLD had more than a 2-fold increase in risk of CVEs, and those with liver fibrosis had a 4-fold increase in risk. In patients with NAFLD, liver fibrosis indexes were independently associated with risk of incident CVEs. ClinicalTrials.gov no:NCT04036357.

Changes in hemodynamics associated with metabolic syndrome are more pronounced in women than in men

The increase in cardiovascular risk associated with metabolic syndrome (MS) seems higher in women than in men. We examined hemodynamics during head-up tilt in 252 men and 250 women without atherosclerosis, diabetes, or antihypertensive medication, mean age 48 years, using whole-body impedance cardiography and radial pulse wave analysis. MS was defined according to Alberti et al. 2009. Men and women with MS presented with corresponding elevations of systolic and diastolic blood pressure (10-14%, p ≤ 0.001) versus controls. Supine pulse wave velocity (16-17%, p < 0.001) and systemic vascular resistance (7-9%, p ≤ 0.026), and upright cardiac output (6-11%, p ≤ 0.008) were higher in both MS groups than controls. Elevation of supine aortic characteristic impedance was higher in women than in men with MS (16% vs. 8%, p = 0.026), and in contrast to men, no upright impedance reduction was observed in women. When upright, women but not men with MS showed faster return of reflected pressure wave (p = 0.036), and smaller decrease in left cardiac work (p = 0.035) versus controls. The faster upright return of reflected pressure, lower upright decrease in left cardiac work, and higher elevation of aortic characteristic impedance may contribute to the greater increase in MS-related cardiovascular risk in women than in men.

The Relationship between Aortic Knob Width and Metabolic Syndrome

Background

Both aortic knob width and metabolic syndrome are suggested to be related to atherosclerosis and cardiovascular diseases. However, the association between aortic knob width and metabolic syndrome is unknown. This study aimed to explore this relationship.

METHODS

Participants were 3,705 Korean adults aged 18-79 years who visited the health promotion center of a general hospital. Data on chest radiography, physical measurements, medical and social history, and blood tests were collected. We defined metabolic syndrome according to the National Cholesterol Education Program Adult Treatment Panel III criteria. A single reviewer measured aortic knob width on chest radiography.

RESULTS

Aortic knob width was significantly correlated with age; body mass index; waist circumference; systolic and diastolic blood pressures; total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting glucose, glycated hemoglobin, insulin, and uric acid levels; and homeostatic model assessment of insulin resistance values. Aortic knob width significantly increased as the number of metabolic syndrome components increased. Moreover, metabolic syndrome component values tended to increase across the quartile groups of aortic knob width after adjusting for age, exercise, smoking status, and alcohol use. Through receiver operating characteristic curve analysis, we determined the clinically useful cutoff value for aortic knob width to be 30.47 mm in premenopausal women.

CONCLUSION

Aortic knob width was found to be significantly related to metabolic syndrome and its individual components.

Comparing associations of different metabolic syndrome definitions with ischemic stroke in Chinese elderly population

OBJECTIVES

Studies have showed the associations between different definitions of metabolic syndrome (MetS) and risk of ischemic stroke were inconsistent. In this study, we compared associations of different MetS definitions with ischemic stroke in Chinese elderly population.

METHODS

A total of 1713 individuals aged 70-84years from Rugao Longevity and Ageing Study were analyzed. The MetS was defined by four different criteria: Chinese Adult Dyslipidemia Prevention Guide, International Diabetes Federation (IDF), Updated ATPIII (Updated ATPIII) by American heart association/American heart, lung and blood institute (AHA/NHLBI), and Joint Interim Statement(JIS) recommended by IDF and the American heart association/American national institutes of health/American heart, lung and blood institute (AHA/NIH/NHLBI).

RESULTS

Prevalence of MetS in the whole population was 24.0% (Chinese guide), 32.5% (IDF), 38.8% (Updated ATPIII) and 24.0% (JIS) and in stroke population was 27.1% (Chinese guide), 41.1% (IDF), 48.8% (Updated ATPIII) and 27.1% (JIS), respectively. The agreement between definitions was highest in Updated ATPIII vs. IDF (kappa=0.863). It showed that only definitions of IDF (OR 1.55, 95%CI 1.04-2.31, p=0.031) and Updated ATPIII (OR 1.64, 95%CI 1.11-2.42, p=0.013) were independently associated with risk of ischemic stroke in multivariable logistic regression analysis. The risk of ischemic stroke increased with the increasing of numbers of Mets components in Updated ATPIII (p<0.05).

CONCLUSION

In this population, Updated ATPIII criteria was a more suitable definition of Mets than definitions of Chinese guide, IDF and JIS for screening high-risk individuals of ischemic stroke, and the additive effects of Mets components might play a greater role than its composition alone in ischemic stroke.

Metabolic syndrome is independently associated with increased 20-year mortality in patients with stable coronary artery disease

Background

Data regarding long-term association of metabolic syndrome (MetS) with adverse outcomes are conflicting. We aim to determine the independent association of MetS (based on its different definitions) with 20 year all-cause mortality among patients with stable coronary artery disease (CAD).

Methods

Our study comprised 15,524 patients who were enrolled in the Bezafibrate Infarction Prevention registry between February 1, 1990, and October 31, 1992, and subsequently followed-up for the long-term mortality through December 31, 2014. MetS was defined according to two definitions: The International Diabetes Federation (IDF); and the National Cholesterol Education Program–Third Adult Treatment Panel (NCEP).

Results

According to the IDF criteria 2122 (14%) patients had MetS, whereas according to the NCEP definition 7446 (48%) patients had MetS. Kaplan–Meier survival analysis showed that all-cause mortality was significantly higher among patients with MetS defined by both the IDF (67 vs. 61%; log rank-p < 0.001) as well as NCEP (67 vs. 54%; log rank-p < 0.001) criteria. Multivariate adjusted mortality risk was 17% greater [Hazard Ratio (HR) 1.17; 95% Confidence Interval (CI) 1.07–1.28] in patients with MetS according to IDF and 21% (HR 1.21; 95% CI 1.13–1.29) using the NCEP definition. Subgroup analysis demonstrated that long-term increased mortality risk associated with MetS was consistent among most clinical subgroups excepted patients with renal failure (p value for interaction < 0.05).

Conclusions

Metabolic syndrome is independently associated with an increased 20-year all-cause mortality risk among patients with stable CAD. This association was consistent when either the IDF or NCEP definitions were used.

Trial registration retrospective registered

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0466-6) contains supplementary material, which is available to authorized users.

The clinical value of metabolic syndrome and risks of cardiometabolic events and mortality in the elderly: the Rotterdam study

Background

To evaluate the clinical value of metabolic syndrome based on different definitions [American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI), International Diabetes Federation (IDF) and European Group for the Study of Insulin Resistance (EGIR)] in middle-aged and elderly populations.

Methods

We studied 8643 participants from the Rotterdam study (1990–2012; mean age 62.7; 57.6 % female), a large prospective population-based study with predominantly elderly participants. We performed cox-proportional hazards models for different definitions, triads within definitions and each separate component for the risk of incident type 2 diabetes mellitus, coronary heart disease, stroke, cardiovascular- and all-cause mortality.

Results

In our population of 8643 subjects, metabolic syndrome was highly prevalent (prevalence between 19.4 and 42.4 %). Metabolic syndrome in general was associated with incident type 2 diabetes mellitus (median follow-up of 6.8 years, hazard ratios 3.13–3.78). The associations with coronary heart disease (median follow-up of 7.2 years, hazard ratios 1.08–1.32), stroke (median follow-up of 7.7 years, hazard ratios 0.98–1.32), cardiovascular mortality (median follow-up of 8.2 years, ratios 0.95–1.29) and all-cause mortality (median follow-up of 8.7 years, hazard ratios 1.05–1.10) were weaker. AHA/NHLBI- and IDF-definitions showed similar associations with clinical endpoints compared to the EGIR, which was only significantly associated with incident type 2 diabetes mellitus. All significant associations disappeared after correcting metabolic syndrome for its individual components.

Conclusions

Large variability exists between and within definitions of the metabolic syndrome with respect to risk of clinical events and mortality. In a relatively old population the metabolic syndrome did not show an additional predictive value on top of its individual components. So, besides as a manner of easy identification of high risk patients, the metabolic syndrome does not seem to add any predictive value for clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0387-4) contains supplementary material, which is available to authorized users.