The association of the metabolic syndrome with QTc interval in NHANES III

Interrelationships among abnormal P-wave axis, metabolic syndrome and its components, and mortality in US adults

BACKGROUND

Metabolic syndrome (MetS) is associated with increased rates of cardiovascular disease and mortality and is linked to abnormal electrocardiogram (ECG) parameters. We aimed to explore the relationships and interactions among MetS and its components, abnormal P-wave axis (aPWA), and mortality rates.

METHODS

We analyzed data from 7526 adult participants with sinus rhythm recruited from the National Health and Nutrition Examination Survey III. MetS was classified based on the NCEP ATP III-2005 definition. aPWA included all P-wave axis outside 0-75°. The National Death Index was utilized to identify survival status. Hazard ratios (HRs) and 95% confidence intervals (CIs) categorized by aPWA, MetS, and their components were analyzed using Cox proportional hazards models to investigate all-cause and cardiovascular mortalities.

RESULTS

Within a median follow-up period of 20.76 years, 4686 deaths were recorded, of which 1414 were attributable to cardiovascular disease. Participants with both MetS and aPWA had higher all-cause (HR: 1.45, 95% CI: 1.29-1.64, interaction P = 0.043) and cardiovascular (HR: 1.36, 95% CI: 1.02-1.79, interaction P-value = 0.058) mortality rates than participants without MetS and with a normal P-wave axis. Participants with the greatest number of MetS components and aPWA had a higher risk of all-cause mortality (HR: 1.70, 95% CI: 1.13-2.55, P = 0.011).

CONCLUSIONS

Individuals with both aPWA and MetS have a higher risk of mortality, and those with a greater number of MetS components and aPWA have a higher risk of all-cause mortality. These findings highlight the significance of integrating ECG characteristics with metabolic health status in clinical assessment.

Assessment of Corrected QT Interval and QT Dispersion in Patients with Uncomplicated Metabolic Syndrome

Aim

Metabolic syndrome (MS) itself has become a new entity being a constellation of physiological, biochemical, metabolic, and clinical factors that have been related to an increased risk of cardiovascular diseases, type 2 diabetes mellitus (T2DM), and morbidity and mortality. The burden of MS is increasing all over the world with the current prevalence being 30%. The QT interval and QT dispersion (QTd) have been long associated with ventricular arrhythmia and sudden cardiac deaths. The association between QT and diabetes and healthy subjects has been clearly studied, but the association between QT and uncomplicated MS has not been very well defined.

Methods

A total of 400 patients visiting the medicine clinics were assessed for blood pressure, anthropometric measurements, fasting serum lipid profile, FBS, and electrocardiogram (ECG). The patients diagnosed with uncomplicated MS as per the International Diabetic Federation (IDF) criteria were included in the study. QT interval in the ECG was recorded, and the relationship between various parameters of an uncomplicated MetS and the QT interval was recorded.

Results

Our study revealed more females with uncomplicated MS as compared to males and increasing burden as age progressed. Body mass index (BMI), waist circumference (WC), hip circumference (HC), WHP, systolic blood pressure (SBP), Diastolic blood pressure (DBP), Fasting blood sugar (FBS), serum cholesterol, triglyceride (TG), and low-density lipoprotein (LDL) levels were positively correlated with QT values.

Conclusion

QT interval, a strong predictor of malignant ventricular arrhythmias and sudden cardiac deaths, is associated with uncomplicated MS.

Metabolic syndrome and P-wave duration in the American population

PURPOSE

Metabolic syndrome has a high prevalence in the United States. P-wave duration is a valuable indicator for atrial electrical conduction. Abnormalities in atrial electrical conduction can predispose to atrial fibrillation. Our objective was to estimate the effect of metabolic syndrome on P-wave duration in a nationally representative sample.

METHODS

We included 6499 adults who participated in the National Health and Nutrition Examination Survey III (1988-1994). We estimated the effect of metabolic syndrome and its components on P-wave duration after adjusting for confounders such as demographic and lifestyle variables. We stratified the analyses by gender.

RESULTS

Irrespective of gender, participants with metabolic syndrome had a longer P-wave duration than that of those without it. In addition, we observed a positive linear dose-response relation between metabolic syndrome components and P-wave duration.

CONCLUSIONS

Patients with metabolic syndrome had a longer P-wave duration. They might have been at a higher risk for atrial fibrillation and mortality; they need to be periodically checked by their health care providers. However, the results of this study should be confirmed in prospective studies.

The association of metabolic syndrome and QRS|T angle in US adults (NHANES III)

BACKGROUND

Spatial QRS|T angle is a predictor of cardiovascular events. Those with metabolic syndrome have an increased risk of cardiovascular morbidity and mortality. This study investigated the association between metabolic syndrome and spatial QRS|T angle.

METHODS

We obtained data from the National Health and Nutritional Examination Survey III on 6,249 adults. We calculated spatial QRS|T angle from the standard 12-lead electrocardiogram and classified it as abnormal, borderline, or normal. We identified metabolic syndrome if at least three of the following were present: abdominal obesity, elevated blood pressure, elevated triglycerides, decreased high-density lipoprotein (HDL), and impaired fasting glucose. We used weighted logistic regression to estimate the effect of metabolic syndrome and its components on QRS|T angle while stratifying by gender and adjusting for age, race, smoking status, heart rate, PR, QT, and QRS interval, and QRS amplitude.

RESULTS

Among men and women, metabolic syndrome, the number of components present, elevated blood pressure, and impaired fasting glucose were positively associated with QRS|T angle. Among women, decreased HDL and abdominal obesity were also positively associated with QRS|T angle.

CONCLUSIONS

This study suggests that persons with metabolic syndrome may be at increased risk for ventricular arrhythmias. The use of spatial QRS|T angle to assess this cardiovascular risk is warranted.

Metabolic syndrome and its components as risk factors for prolonged corrected QT interval in apparently healthy Korean men and women

BACKGROUND

Metabolic syndrome (MetS) is clinically important because of its association with increased risk of sudden cardiac death, as well as cardiovascular disease-related mortality. Data between MetS and prolonged corrected QT (QTc) intervals, a useful predictor of sudden cardiac death, are limited in apparently healthy adults.

OBJECTIVE

This study determined the association between MetS and QTc interval in apparently healthy Korean men and women.

METHODS

We examined the association between MetS and QTc interval in 2157 Korean adults (1317 men and 840 women) in a health examination program but excluded participants with a history of ischemic heart disease, stroke, cardiac arrhythmia, cancer, thyroid, respiratory, renal, hepatobiliary, or rheumatologic disease. The QTc interval was calculated using Bazett's formula (QTc = QT/√RR). Multivariate-adjusted mean QTc values by the number of MetS components were calculated after sex stratification and compared using analysis of covariance test.

RESULTS

The overall prevalence of MetS was 30.5% in men and 19.8% in women. The QTc interval positively correlated with age, body mass index, blood pressure, fasting plasma glucose, triglycerides, and potassium level in both men and women and negatively correlated with calcium and potassium levels and smoking status in men. The multivariate-adjusted mean QTc value increased proportionally with increasing number of MetS components (P values < 0.001 for both men and women).

CONCLUSION

We confirmed the arrhythmogenic potential of MetS in apparently healthy Korean men and women. These findings suggest that careful monitoring of electrocardiography is necessary to evaluate possible arrhythmic risk in individuals with MetS.

Effects of Metabolically Healthy and Unhealthy Obesity on Prolongation of Corrected QT Interval

Although obesity and the metabolic syndrome (MS) often co-occur, many obese (OB) subjects have a favorable metabolic profile. It is unclear whether these factors independently influence cardiac electrophysiology including prolongation of the QT interval. We examined associations among obesity, MS, and prolonged corrected QT (QTc) interval in a large sample of Chinese research participants aged ≥35 years recruited from rural areas of Liaoning Province during 2012 to 2013. Of the 11,209 participants, 6,364 (56.8%) were nonobese and metabolically healthy (OB-/MS-), 2,853 (25.5%) were OB-/MS+, 493 (4.4%) were OB+/MS-, and 1,499 (13.4%) were OB+/MS+. Mean (±SD) QTc intervals were higher in OB-/MS+ (436.3 ± 24.3) and OB+/MS+ (436.6 ± 25.9) participants but not OB+/MS- participants (425.4 ± 24.0) than in OB-/MS- participants (426.8 ± 21.5, p <0.001), and the prevalence of QTc prolongation was higher in OB-/MS+ and OB+/MS+ participants (adjusted odds ratios [aOR] 1.68, 95% confidence interval [CI] 1.52 to 1.85; aOR 1.92, 95% CI 1.69 to 2.17, respectively) compared with OB-/MS- group but not in OB+/MS- participants (aOR 0.92, 95% CI 0.73 to 1.15). Prevalence increased with each MS component (aOR 1.27, 95% CI 1.22 to 1.32) but not with body mass index (aOR 1.01, 95% CI 0.99 to 1.02). In conclusion, prolonged QTc interval is associated with the MS and not independently associated with obesity.

Metabolomic patterns associated to QTc interval in shiftworkers: an explorative analysis

OBJECTIVES

(1)H NMR-metabolomic approach was used to investigate QTc interval correlation with plasma metabolic profiles in shiftworkers.

METHODS

Socio-demographic data, electrocardiographic QTc interval and plasma metabolic profiles from 32 male shiftworkers, were correlated by multivariate regression analysis.

RESULTS

We found a positive correlation between QTc interval values, body mass index, glycemia and lactate level and a negative correlation between QTc interval and both pyroglutamate and 3-hydroxybutyrate plasma level.

CONCLUSIONS

Our analysis provides evidence of the association between clinical, metabolic profiles and QTc interval values. This could be used to identify markers of early effects and/or susceptibility in shiftworkers.

Association of nonalcoholic fatty liver disease with QTc interval in patients with type 2 diabetes

BACKGROUND AND AIMS

The relationship between nonalcoholic fatty liver disease (NAFLD) and prolonged heart rate-corrected QT (QTc) interval, a risk factor for ventricular arrhythmias and sudden cardiac death, is currently unknown. We therefore examined the relationship between NAFLD and QTc interval in patients with type 2 diabetes.

METHODS AND RESULTS

We studied a random sample of 400 outpatients with type 2 diabetes. Computerized electrocardiograms were performed for analysis and quantification of QTc interval. NAFLD was diagnosed by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. Mean QTc interval and the proportion of those with increased QTc interval (defined as either QTc interval above the median, i.e. ≥416 ms, or QTc interval >440 ms) increased steadily with the presence and ultrasonographic severity of NAFLD. NAFLD was associated with increased QTc interval (odds ratio [OR] 2.16, 95% CI 1.4-3.4, p < 0.001). Adjustments for age, sex, smoking, alcohol consumption, BMI, hypertension, electrocardiographic left ventricular hypertrophy, diabetes-related variables and comorbid conditions did not attenuate the association between NAFLD and increased QTc interval (adjusted-OR 2.26, 95% CI 1.4-3.7, p < 0.001). Of note, the exclusion of those with established coronary heart disease or peripheral artery disease from analysis did not appreciably weaken this association.

CONCLUSION

This is the first study to demonstrate that the presence and severity of NAFLD on ultrasound is strongly associated with increased QTc interval in patients with type 2 diabetes even after adjusting for multiple established risk factors and potential confounders.

Metabolic syndrome is associated with visit-to-visit systolic blood pressure variability in the US adults

Epidemiological studies have shown that blood pressure is not a constant variable. Evidence has accumulated showing that the blood pressure variability is associated with organ damage. A substantial increase in the prevalence of the metabolic syndrome has been documented globally. We examined the association of visit-to-visit blood pressure variability with the metabolic syndrome and its components, using data collected in the Third National Health and Nutrition Examination Survey. A multivariable generalized linear model was performed. The metabolic syndrome and its components, particularly hypertension, increased waist circumference and hyperglycemia, were significantly associated with systolic blood pressure variability across study visits (P<0.05). After adjusting for the effect of age, gender, race and antihypertensive medication, the multivariable analyses did not show significant relationships between the metabolic syndrome and diastolic blood pressure variability (P-values >0.05). Additional research is required to verify the observed results in prospective studies and evaluate approaches to reduce blood pressure variability observed in clinical settings among persons with the metabolic syndrome to reduce its subsequent complications.

Patients transplanted for nonalcoholic steatohepatitis are at increased risk for postoperative cardiovascular events

Nonalcoholic steatohepatitis (NASH) is an independent predictor of coronary artery disease (CAD). Our aim was to compare the incidence of cardiovascular (CV) events between patients transplanted for NASH and alcohol (ETOH)-induced cirrhosis. This is a retrospective cohort study (August 1993 to March 2010) of 242 patients (115 NASH and 127 ETOH) with ≥12 months follow-up after liver transplantation (LT). Those with hepatocellular carcinoma or coexisting liver diseases were excluded. Kaplan-Meier's and Cox's proportional hazard analyses were conducted to compare survival. Logistic regression was used to calculate the likelihood of CV events, defined as death from any cardiac cause, myocardial infarction, acute heart failure, cardiac arrest, arrhythmia, complete heart block, and/or stroke requiring hospitalization <1 year after LT. Patients in the NASH group were older (58.4 versus 53.3 years) and were more likely to be female (45% versus 18%; P < 0.001). They were more likely to be morbidly obese (32% versus 9%), have dyslipidemia (25% versus 6%), or have hypertension (53% versus 38%; P < 0.01). On multivariate analysis, NASH patients were more likely to have a CV event <1 year after LT, compared to ETOH patients, even after controlling for recipient age, sex, smoking status, pretransplant diabetes, CV disease, and the presence of metabolic syndrome (26% versus 8%; odds ratio = 4.12; 95% confidence interval = 1.91-8.90). The majority (70%) of events occurred in the perioperative period, and the occurrence of a CV event was associated with a 50% overall mortality. However, there were no differences in patient, graft, or CV mortality between groups.

CONCLUSIONS

CV complications are common after LT, and NASH patients are at increased risk independent of traditional cardiac risk factors, though this did not affect overall mortality.

ELECTROCARDIOGRAPHIC ABNORMALITIES AMONG MEXICAN AMERICANS: CORRELATIONS WITH DIABETES, OBESITY, AND THE METABOLIC SYNDROME

BACKGROUND

Resting ischemic electrocardiographic abnormalities have been associated with cardiovascular mortality. Simple markers of abnormal autonomic tone have also been associated with diabetes, obesity, and the metabolic syndrome in some populations. Data on these electrocardiographic abnormalities and correlations with coronary risk factors are lacking among Mexican Americans wherein these conditions are prevalent.

OBJECTIVE

This study aimed to evaluate the prevalent resting electrocardiographic abnormalities among community-dwelling Mexican Americans, and correlate these findings with coronary risk factors, particularly diabetes, obesity, and the metabolic syndrome.

METHODS

Study subjects (n=1280) were drawn from the Cameron County Hispanic Cohort comprised of community-dwelling Mexican Americans living in Brownsville, Texas at the United States-Mexico border. Ischemic electrocardiographic abnormalities were defined as presence of ST/T wave abnormalities suggestive of ischemia, abnormal Q waves, and left bundle branch block. Parameters that reflect autonomic tone, such as heart rate-corrected QT interval and resting heart rate, were also measured.

RESULTS

Ischemic electrocardiographic abnormalities were more prevalent among older persons and those with hypertension, diabetes, obesity, and the metabolic syndrome. Subjects in the highest quartiles of QTc interval and resting heart rate were also more likely to be diabetic, hypertensive, obese, or have the metabolic syndrome.

CONCLUSIONS

Among Mexican Americans, persons with diabetes, obesity, and the metabolic syndrome were more likely to have ischemic electrocardiographic abnormalities, longer QTc intervals, and higher resting heart rates. A resting electrocardiogram can play a complementary role in the comprehensive evaluation of cardiovascular risk in this minority population.

Association between alcohol consumption and metabolic syndrome in 19,215 middle-aged and elderly Chinese

AIMS

To assess the association of alcohol consumption with metabolic syndrome (Mets) in a Chinese population.

METHODS

A community-based cross-sectional study was performed in 19,215 participants aged 40 years or over in Shanghai of China during June 2008-April 2009. Information about the alcohol consumption including quantity and type of alcoholic beverage was obtained using a standard questionnaire. Physical examination was performed and fasting blood samples were obtained for the measurements of biochemical indicators.

RESULTS

In male wine-only consumers, after adjusted for age, sex, BMI, education levels, exercise and smoking habit, severe alcohol consumption (≥ 50.0 g/d), compared with non-alcohol consumption, conferred 53% increased risk of having MetS. In women, alcohol consumption did not have relation to the prevalence of Mets. In the beer-only, liquor-only and mixed type consumers, no significant associations between MetS or its components and the quantity of alcohol consumption were detected.

CONCLUSIONS

Our findings suggest that excessive wine consumption (alcohol ≥ 50.0 g/d) is associated with higher prevalence of MetS in Chinese men.

The Generation R Study: design and cohort update 2010

The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health during fetal life, childhood and adulthood. The study focuses on four primary areas of research: (1) growth and physical development; (2) behavioural and cognitive development; (3) diseases in childhood; and (4) health and healthcare for pregnant women and children. In total, 9,778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. General follow-up rates until the age of 4 years exceed 75%. Data collection in mothers, fathers and preschool children included questionnaires, detailed physical and ultrasound examinations, behavioural observations, and biological samples. A genome wide association screen is available in the participating children. Regular detailed hands on assessment are performed from the age of 5 years onwards. Eventually, results forthcoming from the Generation R Study have to contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.

Preoperative abnormal P and QTc dispersion intervals in patients with metabolic syndrome

We evaluated P wave dispersion (Pwd), QT, corrected QT (QTc), QT dispersion, and corrected QT dispersion (QTcd) intervals in patients with metabolic syndrome (MetS). Patients scheduled to undergo elective noncardiac surgery were included in the study. The main diagnoses, anthropometric measurements, waist circumferences, body mass index, electrocardiograms, serum levels of electrolytes, glucose, and lipids were recorded for all patients. QTc, QTcd intervals were determined with the Bazett formula. MetS (group M, n = 36) was diagnosed using the Adult Treatment Panel III. Controls (group C, n = 40) were chosen on the basis of patients with no MetS and matched for age and gender. There were no differences between groups in terms of age, sex, or serum electrolyte levels (P > 0.05). Waist circumferences, body mass index, serum glucose, and triglyceride values in group M were significantly higher than those in group C (P < 0.001). In group M, Pwd, QTc, QT dispersion and QTcd intervals were significantly longer than those in group C (P < 0.001). This finding and our retrospective analysis suggest that these patients may be at greater risk of perioperative arrhythmias.

Association of increased QTc interval with the cardiometabolic syndrome

Recent studies indicate a high prevalence of increased QTc interval length in patients affected by the metabolic syndrome, but there is no data available to demonstrate the correlation of the QTc interval with severity of the cardiometabolic syndrome (CMS). The objective of this study was to estimate the association between increasing number of cardiometabolic abnormalities and increasing QTc interval length. Electrocardiograms were collected from 1420 participants in a cross-sectional study. The QTc interval lengths were corrected for heart rate using Bazett's formula. CMS was determined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) guidelines. Multiple linear regression models were used examining associations between increasing number of individual components of syndrome with QTc interval length. Participants with CMS had significantly longer QTc interval length, controlling for age, body mass index (BMI), sex, and ethnic group. Increasing number of CMS components was significantly associated with increased QTc interval length, even after adjusting for age, BMI, total cholesterol, fasting C peptide, and history of heart disease. These findings suggest that QTc interval length is increased in the presence of CMS and is linearly related to an increase in number of metabolic abnormalities.

Increased left ventricular arrhythmogenicity in metabolic syndrome and relationship with myocardial performance, risk factors for atherosclerosis, and low-grade inflammation

Metabolic syndrome (MetS) is a clustering of cardiovascular risk factors recently associated with left ventricular dysfunction. Limited data exist on the association between MetS and ventricular arrhythmogenicity. This study examined differences in ventricular arrhythmogenicity assessed by classic (QT interval) and newer (spatial QRS-T angle [spQRS-Ta]) electrocardiographic markers in subjects with and without MetS. A total of 306 subjects, 153 with and 153 without MetS, matched for sex and age were examined. The spQRS-Ta, which vectorcardiographically quantifies the deviation between the directions of ventricular depolarization and repolarization, was measured using a computer-based electrocardiograph. Left ventricular mass index and myocardial performance were evaluated echocardiographically. The spQRS-Ta was significantly higher in subjects with in comparison with those without MetS. Left ventricular mass index, QT interval, and its dispersion were not different between the 2 groups. Left ventricular myocardial performance was worse in subjects with MetS and was associated with higher values of the spQRS-Ta. Multivariate linear regression analysis demonstrated MetS status as the strongest predictor of ventricular arrhythmogenicity. Addition of the high-sensitivity C-reactive protein in the model increased the explained variance of the spQRS-Ta by 11%. In conclusion, ventricular arrhythmogenicity is present in MetS and is associated with myocardial dysfunction, risk factors for atherosclerosis, and low-grade inflammation. The independent association between the spQRS-Ta and MetS implies that the clustering of the metabolic disturbances has additional prognostic information than its individual components in terms of ventricular arrhythmogenicity and may explain in part the excess cardiovascular risk in subjects with MetS.