The presence of impaired glucose tolerance (IGT) and metabolic syndrome (MetS) are two risk factors for Type 2 diabetes. The inter-relatedness of these factors among adolescents is unclear.
We evaluated the sensitivity and specificity of MetS for identifying IGT in an unselected group of adolescents undergoing oral glucose tolerance tests (OGTT) in the National Health and Nutrition Evaluation Survey 1999–2010. We characterized IGT as a 2-hour glucose ≥140 mg/dL and MetS using ATP-III-based criteria and a continuous sex- and race/ethnicity-specific MetS Z-score at cut-offs of +1.0 and +0.75 standard deviations (SD) above the mean.
Among 1513 adolescents, IGT was present in 4.8%, while ATP-III-MetS was present in 7.9%. MetS performed poorly in identifying adolescents with IGT with a sensitivity/specificity of 23.7%/92.9% for ATP-III-MetS, 23.6%/90.8% for the MetS Z-score at +1.0 SD and 35.8%/85.0 for the MetS Z-score at +0.75 SD. Sensitivity was higher (and specificity lower) but was still overall poor among overweight/obese adolescents: 44.7%/83.0% for ATP-III-MetS, 43.1%/77.1% for the MetS Z-score at +1.0 SD and 64.3%/64.3% for MetS Z-score at +0.75 SD.
This lack of overlap between MetS and IGT may indicate that assessment of MetS is not likely to be a good indicator of which adolescents to screen using OGTT. These data further underscore the importance of other potential contributors to IGT, including Type 1 diabetes and genetic causes of poor beta-cell function. Practitioners should keep these potential causes of IGT in mind, even when evaluating obese adolescents with IGT.
Insulin resistance; Metabolic syndrome; Impaired glucose tolerance; Type 2 diabetes; Adolescents
Background. The NCEP metabolic syndrome (MetS) is a combination of dichotomized interrelated risk factors from predominantly Caucasian populations. We propose a continuous MetS score based on principal component analysis (PCA) of the same risk factors in a multiethnic cohort and compare prediction of incident CVD events with NCEP MetS definition. Additionally, we replicated these analyses in the Health, Aging, and Body composition (Health ABC) study cohort. Methods and Results. We performed PCA of the MetS elements (waist circumference, HDL, TG, fasting blood glucose, SBP, and DBP) in 2610 Caucasian Americans, 801 Chinese Americans, 1875 African Americans, and 1494 Hispanic Americans in the multiethnic study of atherosclerosis (MESA) cohort. We selected the first principal component as a continuous MetS score (MetS-PC). Cox proportional hazards models were used to examine the association between MetS-PC and 5.5 years of CVD events (n = 377) adjusting for age, gender, race, smoking and LDL-C, overall and by ethnicity. To facilitate comparison of MetS-PC with the binary NCEP definition, a MetS-PC cut point was chosen to yield the same 37% prevalence of MetS as the NCEP definition (37%) in the MESA cohort. Hazard ratio (HR) for CVD events were estimated using the NCEP and Mets-PC-derived binary definitions. In Cox proportional models, the HR (95% CI) for CVD events for 1-SD (standard deviation) of MetS-PC was 1.71 (1.54–1.90) (P < 0.0001) overall after adjusting for potential confounders, and for each ethnicity, HRs were: Caucasian, 1.64 (1.39–1.94), Chinese, 1.39 (1.06–1.83), African, 1.67 (1.37–2.02), and Hispanic, 2.10 (1.66-2.65). Finally, when binary definitions were compared, HR for CVD events was 2.34 (1.91–2.87) for MetS-PC versus 1.79 (1.46–2.20) for NCEP MetS. In the Health ABC cohort, in a fully adjusted model, MetS-PC per 1-SD (Health ABC) remained associated with CVD events (HR = 1.21, 95%CI 1.12–1.32) overall, and for each ethnicity, Caucasian (HR = 1.24, 95%CI 1.12–1.39) and African Americans (HR = 1.16, 95%CI 1.01–1.32). Finally, when using a binary definition of MetS-PC (cut point 0.505) designed to match the NCEP definition in terms of prevalence in the Health ABC cohort (35%), the fully adjusted HR for CVD events was 1.39, 95%CI 1.17–1.64 compared with 1.46, 95%CI 1.23–1.72 using the NCEP definition. Conclusion. MetS-PC is a continuous measure of metabolic syndrome and was a better predictor of CVD events overall and in individual ethnicities. Additionally, a binary MetS-PC definition was better than the NCEP MetS definition in predicting incident CVD events in the MESA cohort, but this superiority was not evident in the Health ABC cohort.
The apoB/apoA1 ratio has been reported to be associated with the metabolic syndrome (MetS), and it may be a more convenient biomarker in MetS predicting. However, whether apoB/apoA1 ratio is a better indicator of metabolic syndrome than other biomarkers and what is the optimal cut-off value of apoB/apoA1 ratio as an indicator of metabolic syndrome in Chinese population remain unknown. Thus, we carried out the current study to assess the predictive value of apoB/apoA1 ratio and determine the optimal cut-off value of apoB/apoA1 ratio for diagnosing MetS in a Chinese population.
We selected 1,855 subjects with MetS and 6,265 individuals without MetS based on the inclusion and exclusion criteria from the China Health Nutrition Survey (CHNS) in 2009. MetS was identified based on the diagnostic criteria of International Diabetes Federation (2005). Logistic regression was used to estimate the association between the apoB/apoA1 ratio and risk of MetS, and receiver operating characteristics (ROC) curve analysis was performed to test the predictive value of apoB/apoA1 ratio and calculate the appropriate cut-off value.
Compared with the lowest quartile of apoB/apoA1 ratio, subjects in the fourth quartile had a higher risk of MetS in both men [odds ratio (OR) = 2.64, 95% confidence interval (CI) =1.82-3.83] and women (OR = 5.18, 95% CI = 3.87-6.92) after adjustment for potential confounders. The optimal cut-off value of apoB/apoA1 ratio for MetS detection was 0.85 in men and 0.80 in women. Comparisons of ROC curves indicated that apoB/apoA1 ratio was better than traditional biomarkers in predicting MetS.
Our results suggest that, apoB/apoA1 ratio has a promising predictive effectiveness in detection of MetS. An apoB/apoA1 ratio higher than 0.85 in men and 0.80 in women may be a promising and convenient marker of MetS.
Metabolic syndrome; Apolipoprotein ratio; ROC curve
To assess the predictive values of various adiposity indices for the metabolic syndrome (MetS) among adults using baseline data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) cohort.
In a cross-sectional study, body mass index (BMI), waist circumference (WC), body composition by dual-energy x-ray absorptiometry (DXA) and metabolic risk factors such as triglycerides, HDL-cholesterol, blood pressure, fasting glucose and insulin, uric acid and C-reactive protein were measured. Receiver-operating characteristic (ROC) curves and logistic regression analyses were conducted.
1,981 White and African-American US adults, aged 30-64 years.
In predicting risk of MetS using obesity-independent National Cholesterol Education Program Adult Treatment Panel III criteria, % body fat mass (TtFM) assessed using DXA measuring overall adiposity had no added value over WC. This was true among both men (Areas under curve; AUC=0.680 vs. 0.733 for TtFM and WC, respectively, p<0.05) and women (AUC=0.581 vs. 0.686). Rib fat mass (RbFM) was superior to TtFM only in women for MetS (AUC=0.701 and 0.581 for RbFM and TtFM, respectively, p<0.05), particularly among African-American women. Elevated Leg fat mass (LgFM) was protective against MetS among African-American men. Among White men, BMI was inferior to WC in predicting MetS. Optimal WC cut points varied across ethnic-sex groups and differed from those recommended by the NIH/NAASO.
We provide evidence that WC is among the most powerful tools to predict MetS, and that optimal cut-points for various indices including WC may differ by sex and race.
Metabolic syndrome; percent body fat mass; central obesity; body mass index
Uric acid is tightly linked to the metabolic syndrome (MetS) and among adults higher uric acid levels are associated with future risk for diabetes, cardiovascular disease, hypertension and renal disease.
Evaluate the sensitivity of MetS to identify adolescents with elevated uric acid levels on a race/ethnicity and gender-specific basis.
We evaluated 3,296 males and female adolescents 12-19y participating in the National Health and Nutrition Evaluation Survey ‘99-’06, comprised of 67.6% non-Hispanic whites, 15.1% non-Hispanic blacks, and 17.3% Hispanics. We used a definition of MetS modified for use in adolescents and evaluated the sensitivity of a diagnosis of MetS to identify individuals with uric acid elevations (approximately the 95th percentile of uric acid by gender among normal-weight adolescents).
When used as a screening test to identify individuals with uric acid elevations MetS performed more poorly among females (18.0%) than among males (37.0%)(p<0.001). Among males, MetS exhibited a lower sensitivity among non-Hispanic blacks (17.8%) compared to Hispanics (45.9%)(p<0.01) and non-Hispanic whites (37.4%)(p<0.05). There were no race/ethnicity differences in detecting elevated uric acid levels among females (non-Hispanic-white 15.5%, non-Hispanic-black 19.4%, Hispanic 26.5%, p>0.05).
Current criteria to diagnose MetS exhibit racial/ethnic and gender differences in the ability to identify adolescents with elevated uric acid levels, performing poorly among non-Hispanic-black males and among females. Given emerging data regarding the ability of uric acid elevations for predicting future disease, these data may have implications regarding the use of MetS as a marker of risk among all gender and racial/ethnic groups.
metabolic syndrome; uric acid; adolescents; insulin resistance; cardiovascular disease risk
Metabolic syndrome (MetS) refers to a cluster of cardiovascular risk factors including hyperglycemia, dyslipidemia, abdominal obesity and hypertension. An effective detection of MetS not only reflects the prediction risk of diabetes mellitus and cardiovascular diseases but also helps to plan for management strategy which could reduce the healthcare burden of the society. This study aimed to compare the use of hemoglobin A1c (HbA1c) to fasting plasma glucose (FPG) as the hyperglycemic component in MetS diagnosis.
Waist circumference, blood pressure, blood triglyceride, high-density lipoprotein (HDL)-cholesterol, FPG, and HbA1c were examined in 120 Hong Kong Chinese adults with MetS and 120 without MetS. After reviewing the subject basal characteristics, 11 of them were found with undiagnosed diabetes (FPG ≧7.0 mmol/L) and were excluded for further analysis.
The most prevalent MetS components among the included subjects were elevated systolic blood pressure and central obesity. Significant correlation relationships existed between FPG and HbA1c in both subject pools diagnosed with and without MetS (p < 0.001). The diagnostic rate of MetS using HbA1c was compared to FPG by the receiver operating characteristics (ROC) analysis which suggested an area under curve of 0.807 (95% CI: 0.727 to 0.887). The agreement was 90.7% in MetS-positive group with increased FPG as one of the criterion co-existed with elevated HbA1c. If including HbA1c as an additional criterion to FPG in the MetS diagnosis, 30 more participants in MetS-negative group would be MetS-positive leading to an increase in detection rate. Furthermore, 47 subjects (38 from MetS-positive group and 9 from MetS-negative group) were found having HbA1c ≧6.5%, who would have been diagnosed with diabetes based on the diagnostic criteria implemented by the Expert Group in 2009.
These findings suggest that HbA1c enhances the detection of hyperglycemia for the diagnosis of MetS.
Among adolescents uric acid is associated with insulin resistance, hypertension and the metabolic syndrome (MetS) and in adults high uric acid levels are an independent risk factor for cardiovascular disease and diabetes.
Determine whether the relationship of uric acid with MetS varies in adolescents by race/ethnicity and gender.
We used linear regression to evaluate associations between uric acid and other MetS-associated clinical and laboratory measures among 3,296 non-Hispanic-white, non-Hispanic-black and Hispanic adolescents age 12–19y participating in the National Health and Nutrition Evaluation Survey (1999–2006).
Overall, non-Hispanic-white males and females had the highest uric acid levels among the three racial/ethnic groups. In each racial/ethnic group there were higher uric acid levels for those adolescents with vs. without MetS. However, the extent of the MetS-related increase in uric acid level varied by race and gender. Among males, MetS was associated with the greatest increases in uric acid among non-Hispanic whites. However, among females, the MetS-related increase in uric acid was greatest among non-whites. Non-Hispanic-white females exhibited the lowest degrees of correlation between levels of uric acid and MetS-associated variables. Uric acid levels did not correlate with insulin levels in non-Hispanic-white females.
These data suggest the relationship between uric acid and MetS varies by race/ethnicity and gender. In particular, non-Hispanic-white males exhibit a strong relationship and non-Hispanic-white females exhibit a relatively poor correlation between uric acid and MetS-related factors. These data may have implications for the use of uric acid as a marker of future risk among adolescents.
obesity; insulin resistance; hypertension
The metabolic syndrome (MetS) is a risk factor for diabetes, stroke, myocardial infarction, and increased mortality, and has been associated with cognition in some populations. We hypothesized that MetS would be associated with lower Mini-Mental State Examination (MMSE) scores in a multi-ethnic population, and that MetS is a better predictor of cognition than its individual components or diabetes.
We conducted a cross-sectional analysis among 3,150 stroke-free participants. MetS was defined by the modified National Cholesterol Education Program guidelines-Adult Treatment Panel III (NCEP-ATPIII) criteria. Linear regression and polytomous logistic regression estimated the association between MMSE score and MetS, its individual components, diabetes, and inflammatory biomarkers.
MetS was inversely associated with MMSE score (unadjusted β = −0.67; 95% CI −0.92, −0.41). Adjusting for potential confounders, MetS was associated with lower MMSE score (adjusted β = −0.24; 95% CI −0.47, −0.01), but its individual components and diabetes were not. Those with MetS were more likely to have an MMSE score of <18 than a score of ≥24 (adjusted OR = 1.94; 95% CI 1.26, 3.01). There was an interaction between MetS and race-ethnicity, such that MetS was associated with lower MMSE score among non-Hispanic whites and Hispanics but not non-Hispanic blacks.
MetS was associated with lower cognition in a multi-ethnic population. Further studies of the effect of MetS on cognition are warranted, and should account for demographic differences.
Cognitive performance; Cognitive impairment; Vascular dementia; Vascular cognitive impairment; Cerebrovascular disorders; Metabolic syndrome
The Family Blood Pressure Program is an ongoing, NHLBI-sponsored, multi-center program to study the genetic determinants of high blood pressure. The goal of this particular study was to study patterns of metabolic syndrome (MetS) in four ethnic groups: African Americans, Caucasians, Hispanics, and Asians.
A major part of participants in three networks GENOA, HyperGEN and SAPPHIRe were recruited mainly through hypertensive probands. MetS was defined as a categorical trait following the National Cholesterol Education Program definition (c-MetS). MetS was also characterized quantitatively through multivariate factor analyses (FA) of 10 risk variables (q-MetS). Logistic regression and frequency tables were used for studying associations among traits.
Using the NCEP definition, the Hispanic sample, which by design was enriched for type 2 diabetes (T2D), had a very high prevalence of MetS (73%). In contrast, its prevalence in Chinese was the lowest (17%). In African Americans and Hispanics, c-MetS was more prevalent in women than in men. Association of c-MetS with type 2 diabetes (T2D) was prominent in the Hispanics and African Americans, less pronounced in the Whites and Japanese, (although still significant), and weakest in the Chinese sample.
Using FA without rotation, we found that the main factor loaded obesity (OBS) and blood pressure (BP) in African Americans; OBS and insulin (INS) in Hispanics, in Japanese, and in Whites; and OBS alone in Chinese. In Hispanics, Whites, and Japanese, BP loaded as a separate factor. Lipids in combination with INS also loaded in a separate factor. Using FA with Varimax rotation, 4 independent factors were identified: "Obesity-INS," "Blood pressure," "Lipids-INS," and "Central obesity." They explained about 60% of the variance present in the original risk variables.
MetS ethnic differences were identified. Ascertaining for hypertension or T2D increased the MetS prevalence in networks compared with the one in the US general population. Obesity was the most prominent risk factor contributing to both c-MetS and q-MetS. INS contributed in two important factors (obesity and lipids). The information imbedded into c-MetS trait /q-MetS factors scores can contribute in future research of the MetS, especially its utilization in the genetic analysis.
Although many studies have reported an association between self-reported physical activity and metabolic syndrome (MetS), there is limited information on the optimal level of physical activity required to prevent MetS. This study aimed to determine the association between objectively measured physical activity and MetS in middle-aged Japanese individuals. We also determined the optimal cutoff value for physical activity required to decrease the risk of developing MetS.
A total of 179 men and 304 women, aged between 30 and 64 years, participated in this study. Participants were divided into two groups using the Japanese criteria for MetS as those with MetS or pre-MetS, and those without MetS. Participants were considered to be physically active if they achieved a physical activity level of 23 metabolic equivalents (METs) h/week, measured using a triaxial accelerometer. The association between physical activity and MetS was analyzed using logistic regression with the following covariates: sex, age, sedentary time, low intensity activity, calorie intake, smoking, menopause and body mass index. We also evaluated the factors that determined the association between the prevalence of MetS and pre-MetS and the physical activity cutoff value using classification and regression tree (CART) analysis.
The odds ratio for MetS and pre-MetS was 2.20 for physically inactive participants (< 23 METs h/week), compared with physically active participants (≥ 23 METs h/week). The corresponding odds ratios for men and women were 2.27 (P < 0.01) and 1.95 (not significant), respectively. CART analyses revealed that moderate-vigorous physical activity of > 26.5 METs h/week was sufficient to decrease the prevalence of MetS and pre-MetS in middle-aged Japanese men and women.
The results of this cross-sectional study indicate that the Exercise and Physical Activity Reference for Health Promotion 2006 is inversely associated with the prevalence of MetS in men. Our results also suggest that moderate physical activity of > 26.5 METs h/week may decrease the risk of developing MetS and pre-MetS in middle-aged Japanese individuals.
Whereas it is known that the metabolic syndrome (MetS) has a paradoxically lower prevalence in non–Hispanic black adolescents than in non–Hispanic whites or Hispanics, the relative severity of MetS by race/ethnicity is unknown. Inflammation, indicated by high-sensitivity C-reactive protein (hsCRP), is a key factor linking MetS to cardiovascular disease and type 2 diabetes. Our goal was to determine whether elevations of hsCRP vary by race/ethnicity among adolescents with MetS.
RESEARCH DESIGN AND METHODS
We used the National Health and Nutrition Examination Survey (1999–2008) and evaluated adolescents (age 12–19 years) using a pediatric/adolescent adaptation of the ATP III definition of MetS. We used linear regression to evaluate the interaction between MetS status and ethnicity with respect to hsCRP concentration.
For male and female adolescents, MetS was associated with elevated hsCRP levels compared with adolescents without MetS. However, the elevation in hsCRP between adolescents with and without MetS was greater in non–Hispanic blacks compared with that in non–Hispanic whites (P = 0.04) but not that in Hispanics (P = 0.18). hsCRP concentrations correlated with individual MetS components similarly among all ethnicities. In an evaluation of adolescents diagnosed with MetS, non–Hispanic blacks had higher BMI and more hypertension than other ethnicities but there were no other racial/ethnic differences in the features of MetS.
Non–Hispanic black adolescents have a greater differential in hsCRP between those with and those without MetS than the differential in non–Hispanic whites but not that in Hispanics. Therefore, even though MetS has a low prevalence in non–Hispanic blacks, MetS is a particularly good indicator of inflammation in non–Hispanic black adolescents.
Metabolic syndrome (MetS) and hyperuricemia are important risk factors for cardiovascular disease. However, findings regarding the relationship between serum uric acid (UA) level and components of MetS have been inconsistent. This study was performed to explore the potential value of UA level as a marker of MetS among male and female Chinese of different ages.
A total of 5896 subjects (2960 females and 2936 males) were recruited from the Department of Health Management at the Chang Gung Medical Center. Hyperuricemia was defined as a serum UA value >7.0 mg/dL for males or >6.0 mg/dL for females. MetS was defined according to the criteria of the Adult Treatment Panel III, as modified for Chinese subjects. Serum UA was used to differentiate MetS and to calculate epidemiological indices by means of discriminate analysis and logistic regression.
The sensitivity and specificity of serum UA concentration as a marker of MetS ranged from 55.2% to 61.4% and 61.9% to 68.4%, respectively. Subjects with high UA had a higher risk of MetS, with odds ratios ranging from 1.23 to 1.82 (P < 0.01). A positive correlation between serum UA and MetS was observed in both sexes. Serum UA and the occurrence of MetS rose with increasing age in females; in males, however, UA values did not vary with age.
Serum UA is more closely associated with MetS in females than in males. High UA among middle-aged women may predict the development of MetS.
serum uric acid; hyperuricemia; metabolic syndrome; discriminate analysis; cardiovascular risk factor
It has been well documented that obesity is closely associated with metabolic syndrome (MetS). Although body mass index (BMI) is the most frequently used method to assess overweightness and obesity, this method has been criticized because BMI does not always reflect true body fatness, which may be better evaluated by assessment of body fat and fat-free mass. The objective of this study was to investigate the best indicator to predict the presence of MetS among fat mass index, BMI and percentage of body fat (BF %) and determine its optimal cut-off value in the screening of MetS in practice.
A cross-sectional study of 1698 subjects (aged 20–79 years) who participated in the annual health check-ups was employed. Body composition was measured by bioelectrical impedance analysis (BIA). Fat mass index (FMI) was calculated. Sex-specific FMI quartiles were defined as follows: Q1: <4.39, Q2:4.39- < 5.65, Q3:5.65- < 7.03, Q4:≥7.03,in men; and Q1:<5.25, Q2:5.25- < 6.33, Q3:6.33- < 7.93,Q4:≥7.93, in women. MetS was defined by National Cholesterol Education Program/Adult Treatment Panel III criteria. The association between FMI quartiles and MetS was assessed using Binary logistic regression. Receiver operating curve(ROC) analysis was used to determine optimal cutoff points for BMI,BF% and FMI in relation to the area under the curve(AUC),sensitivity and specificity in men and women.
The adjusted odds ratios (95% CI) for the presence of MetS in the highest FMI quartile versus lowest quartile were 79.143(21.243-294.852) for men( P < 0.01) and 52.039(4.144-653.436) for women( P < 0.01) after adjusting age, BMI, BF%, TC, LDL, CRP, smoking status and exercise status, and the odds ratios were 9.166(2.157-38.952) for men( P < 0.01) and 25.574(1.945-336.228) for women( P < 0.05) when WC was also added into the adjustment. It was determined that BMI values of 27.45 and 23.85 kg/m2, BF% of 23.95% and 31.35% and FMI of 7.00 and 7.90 kg/m2 were the optimal cutoff values to predict the presence of MetS among men and women according to the ROC curve analysis. Among the indicators used to predict MetS, FMI was the index that showed the greatest area under the ROC curve in both sexes.
Higher FMI levels appear to be independently and positively associated with the presence of MetS regardless of BMI and BF%. FMI seems to be a better screening tool in prediction of the presence of metabolic syndrome than BMI and percentage of body fat in men and women.
Metabolic syndrome X; Body composition; Fat mass index; Body mass index; Percentage of body fat; Screening
Waist circumference, a metabolic syndrome (MetSy) criterion, is not routinely measured in clinical practice making early identification of individuals with MetSy challenging. It has been argued that ratios of commonly measured parameters such as lipids and lipoproteins may be an acceptable alternative for identifying individuals with MetSy. The objective of our study was to explore clinical utility of lipid ratios to identify men and women with MetSy; and to explore the association between lipid ratios and the number of MetSy components.
Men and women (N = 797) of Aboriginal, Chinese, European, and South Asian origin (35–60 years), recruited across ranges of body mass index (BMI), with no diagnosed cardiovascular disease (CVD) or on medications to treat CVD risk factors were assessed for anthropometrics, family history of CVD, MetSy components (waist circumference, blood pressure, glucose, triglycerides (TG), high-density-lipoprotein-cholesterol (HDL-C)), low-density-lipoprotein-cholesterol (LDL-C), nonHDL-C, and health-related behaviours.
Mean levels of lipid ratios significantly increased with increasing number of MetSy components in men and women (p < 0.05). After adjustment for age, ethnicity, smoking, alcohol consumption, physical activity, family history of CVD and BMI, (and menopausal status in women), all lipid ratios were associated with the number of MetSy components in men and women (Poisson regression, p < 0.001). Compared to the rest of the lipid ratios (ROC curve analysis), TG/HDL-C was best able to discriminate between individuals with and without MetSy (AUC = 0.869 (95% CI: 0.830, 0.908) men; AUC = 0.872 (95% CI: 0.832, 0.912) women). The discriminatory power of TC/HDL-C and nonHDL-C/HDL-C to identify individuals with MetSY was the same (for both ratios, AUC = 0.793 (95% CI: 0.744, 0.842) men; 0.818 (95% CI: 0.772, 0.864) women). Additionally, LDL-C/HDL-C was a good marker for women (AUC = 0.759 (95% CI: 0.706, 0.812)), but not for men (AUC = 0.689 (95% CI: 0.631, 0.748)). Based on a multiethnic sample, we identified TG/HDL-C cut-off values of 1.62 in men and 1.18 in women that were best able to discriminate between men and women with and without MetSY.
Our results indicate that TG/HDL-C is a superior marker to identify men and women with MetSy compared to TC/HDL-C, LDL-C/HDL-C, and nonHDL-C/HDL-C.
Electronic supplementary material
The online version of this article (doi:10.1186/1476-511X-13-159) contains supplementary material, which is available to authorized users.
Metabolic syndrome; Lipid ratios; Triglyceride-to-high-density-lipoprotein-cholesterol; Low-density-lipoprotein-cholesterol-to-high-density-lipoprotein-cholesterol; Non-high-density-lipoprotein-cholesterol-to-high-density-lipoprotein-cholesterol; and total cholesterol-to-high-density-lipoprotein-cholesterol
Inflammation markers and MetS are associated with risk of CHF. We evaluated whether combining inflammation markers and metabolic syndrome (MetS) provided additive information for incident congestive heart failure (CHF), and if incorporating inflammation markers to the MetS definition added prognostic information.
Methods and Results
We studied 4017 men and women ≥ 65 years old, without baseline CHF or diabetes, participating in the Cardiovascular Health Study, an observational study with 12.2 years follow-up and 966 cases of incident CHF. Baseline “C-reactive protein (CRP)-MetS” or “interleukin-6 (IL-6)-MetS” were defined as presence of 3 out of 6 components, with elevated CRP (≥3 mg/L) or IL-6 (≥2.21 pg/mL) as a 6th component added to ATPIII criteria. Cox models adjusted for CHF risk factors and incident coronary disease, were used to calculate HRs for CHF. MetS and elevated inflammation markers were independently associated with CHF risk (HRs, 95 % CI: 1.32, 1.16–1.51 for MetS; 1.53, 1.34–1.75 for CRP; 1.37, 1.19–1.55 for IL-6). There was a 20% relative excess risk attributed to the combination of MetS and CRP (95% CI −44% to 88%). CRP-MetS and IL-6-MetS definitions reclassified 18% and 13%, respectively of participants as MetS. Both CRP-MetS and IL-6-MetS increased risk of CHF by 60% compared to those without MetS.
MetS and inflammation markers provided additive information on CHF risk in this elderly cohort. Inflammation-incorporated MetS definitions identified more participants with the same risk level as ATPIII MetS. Considering inflammation markers and MetS together may be useful in clinical and research settings.
heart failure; metabolism; inflammation
OBJECTIVE: To describe the association between intima-media thickness (IMT) and metabolic syndrome (MetS) and to examine if the addition of IMT to a traditional MetS definition adds value to the assessment of predicted cardiovascular disease (CVD) risk in a large multiethnic population.
PARTICIPANTS AND METHODS: In this cross-sectional study, carotid IMT was measured in 2268 men and women as part of a wellness physical examination between August 1, 2000, and October 1, 2001. The wellness examination included a fasting lipid panel, physical examination, and medical history. Mean IMT was described by sex, ethnicity, and the MetS. Predicted risk for CVD was determined with IMT as a component of the diagnostic criteria for MetS.
RESULTS: Intima-media thickness increased with each additional component of the MetS, increasing from 0.516 mm for 0 components to 0.688 mm for 4 or more components (P<.001). In each ethnic group (non-Hispanic whites, blacks, Hispanics, and Asians), those with the MetS had higher mean IMT (increased by 0.084 mm to 0.134 mm) than those without MetS. The addition of IMT as a “new” component in the diagnosis of MetS allowed us to identify 78 (3.4%) participants who were not previously diagnosed as having MetS but who had a high 10-year estimated risk of MetS as measured by the Framingham risk score (11.67%).
CONCLUSION: The addition of IMT to the traditional criteria for the diagnosis of the MetS may help identify individuals who otherwise would not have been identified to be at high risk of CVD.
This article describes the association between intima-media thickness and metabolic syndrome and concludes that the addition of intima-media thickness to the traditional criteria for the diagnosis of the metabolic syndrome may help identify individuals who otherwise would not have been identified to be at high risk of cardiovascular disease.
Nonalcoholic fatty liver disease (NAFLD) exhibits tight links with insulin resistance (IR) and the metabolic syndrome (MetS), a cluster of cardiovascular risk factors. Compared with non-Hispanic whites, non-Hispanic black adolescents have more IR but a lower prevalence of NAFLD and MetS. Our hypothesis was that IR would be a better predictor of alanine aminotransferase (ALT) elevations than is MetS among non-Hispanic blacks.
We analyzed data from 4124 adolescents aged 12 to 19 years in the 1999 to 2010 NHANES, using unexplained elevations in ALT (>30 U/L) to characterize presumed NAFLD and using a pediatric adaptation of the Adult Treatment Panel III definition of MetS.
Prevalence of elevated ALT varied by race/ethnicity (Hispanics 13.7%, non-Hispanic white 8.6%, non-Hispanic blacks 5.4%, P < .0001). Among non-Hispanic whites and Hispanics, a classification of MetS performed well in identifying adolescents with elevated ALT (odds ratios [ORs] 9.53 and 5.56, respectively), as did MetS-related indices. However, among non-Hispanic blacks, the association between MetS and ALT elevations was smaller in magnitude and technically nonsignificant (OR = 3.24, P = .051). Furthermore, among non-Hispanic blacks, the presence of IR and elevated waist circumference performed more poorly at identifying ALT elevations (ORs 3.93 and 2.28, respectively: significantly smaller than ORs for non-Hispanic whites, P < .05), with triglyceride elevations being a better predictor (OR = 4.44).
Non-Hispanic black adolescents exhibit a lower relationship between IR and elevated ALT, supporting racial/ethnic differences in the link between MetS and NAFLD. These data may have implications regarding triggers for screening for NAFLD among non-Hispanic black adolescents, focusing particularly on those with triglyceride elevations.
metabolic syndrome; visceral obesity; inflammation; racial/ethnic difference
We have recently determined the optimal cut-off of the homeostatic model assessment of insulin resistance for the diagnosis of insulin resistance (IR) and metabolic syndrome (MetS) in non-diabetic residents of Tehran, the capital of Iran. The aim of the present study is to establish the optimal cut-off at the national level in the Iranian population with and without diabetes.
Data of the third National Surveillance of Risk Factors of Non-Communicable Diseases, available for 3,071 adult Iranian individuals aging 25-64 years were analyzed. MetS was defined according to the Adult Treatment Panel III (ATPIII) and International Diabetes Federation (IDF) criteria. HOMA-IR cut-offs from the 50th to the 95th percentile were calculated and sensitivity, specificity, and positive likelihood ratio for MetS diagnosis were determined. The receiver operating characteristic (ROC) curves of HOMA-IR for MetS diagnosis were depicted, and the optimal cut-offs were determined by two different methods: Youden index, and the shortest distance from the top left corner of the curve.
The area under the curve (AUC) (95%CI) was 0.650 (0.631-0.670) for IDF-defined MetS and 0.683 (0.664-0.703) with the ATPIII definition. The optimal HOMA-IR cut-off for the diagnosis of IDF- and ATPIII-defined MetS in non-diabetic individuals was 1.775 (sensitivity: 57.3%, specificity: 65.3%, with ATPIII; sensitivity: 55.9%, specificity: 64.7%, with IDF). The optimal cut-offs in diabetic individuals were 3.875 (sensitivity: 49.7%, specificity: 69.6%) and 4.325 (sensitivity: 45.4%, specificity: 69.0%) for ATPIII- and IDF-defined MetS, respectively.
We determined the optimal HOMA-IR cut-off points for the diagnosis of MetS in the Iranian population with and without diabetes.
Rationale: Metabolic syndrome (MetS) affects 4 to 10% of adolescents. Risk factors include overweight, male sex, and Hispanic ethnicity. Although sleep-disordered breathing (SDB) has been implicated as a risk factor for MetS in adults, its association with SDB in adolescents is unknown.
Objectives: To define the association of SDB with MetS in adolescents.
Methods: Standardized measurements of SDB, anthropometry and bioassays, were made in 270 adolescents, aged 13.6 ± 0.7 years. MetS was identified if threshold levels were exceeded in three of five areas: waist circumference, blood pressure, triglyceride level, high-density lipoprotein cholesterol level, and glucose levels.
Measurements and Main Results: Although 70% of children with SDB (apnea–hypopnea index ⩾ 5) were overweight and 59% had MetS, 16% of children without SDB had MetS. Twenty-five percent of those with MetS had SDB. After adjusting for age, race, sex, and preterm status, children with SDB had a 6.49 (95% confidence interval, 2.52, 16.70) increased odds of MetS compared with children without SDB. Indices of SDB stress associated with MetS included respiratory event frequency, degree of oxygen desaturation, and sleep efficiency. Analyses of individual metabolic parameters showed that, after adjustment for body mass index, SDB was associated with systolic and diastolic blood pressure, low-density lipoprotein cholesterol, and fasting insulin levels.
Conclusions: A majority of adolescents with SDB are overweight and meet criteria for MetS. The close association between MetS and SDB and their putative interacting pathophysiologies suggests a need to develop screening, prevention, and treatment strategies for both disorders in high-risk, overweight adolescents.
sleep apnea; metabolic syndrome; obesity
Metabolic syndrome (MetS) management programs conventionally focus on the adults having MetS. However, risk assessment for MetS development is also important for many adults potentially at risk but do not yet fulfill MetS criteria at screening. Therefore, we conducted this follow-up study to explore whether initial screening records can be efficiently applied on the prediction of the MetS occurrence in healthy middle-aged employees.
Utilizing health examination data, a five-year follow-up observational study was conducted for 1384 middle-aged Taiwanese employees not fulfilling MetS criteria. Data analyzed included: gender, age, MetS components, uric acid, insulin, liver enzymes, sonographic fatty liver, hepatovirus infections and lifestyle factors. Multivariate logistic regression was used to estimate the adjusted odds ratios (OR) and 95% confidence interval (CI) of risk for MetS development. The synergistic index (SI) values and their confidence intervals of risk factor combinations were calculated; and were used to estimate the interacting effects of coupling MetS components on MetS development.
Within five years, 13% (175 out of 1384) participants fulfilled MetS criteria. The ORs for MetS development among adults initially having one or two MetS components were 2.8 and 7.3, respectively (both p < 0.01), versus the adults having zero MetS component count at screening. Central obesity carried an OR of 7.5 (p < 0.01), which far exceeded other risk factors (all ORs < 2.7). Synergistic effects on MetS development existed between coupling MetS components: 1. High blood pressure plus low-HDL demonstrated an OR of 11.7 (p < 0.01) for MetS development and an SI of 4.7 (95% CI, 2.1-10.9). 2. High blood pressure plus hyperglycemia had an OR of 7.9 (p < 0.01), and an SI of 2.7 (95% CI, 1.2-6.4).
MetS component count and combination can be used in predicting MetS development for participants potentially at risk. Worksite MetS screening programs simultaneously allow for finding out cases and for assessing risk of MetS development.
All of the components of Metabolic syndrome (MetS) have been regarded as risk factors for coronary artery disease (CAD). Early detection of CAD in asymptomatic patients with MetS remains a challenge. Cystatin C,which has been proposed as a novel marker of renal dysfunction,is correlated with mortality in CAD, The purpose of the study was to evaluate whether cystatin C is a potential marker of asymptomatic CAD in MetS patients with normal kidney function.
A total of 211asymptomatic MetS patients without prior history of CAD patients were included in a cross-sectional study. Patients were divided into MetS with asymptomatic CAD (n = 136) and MetS without CAD (n = 75) groups according to coronary angiograph results. Serum cystatin C levels were measured using particle enhanced immunonephelometric assays. We first assessed whether there is an independent association of cystatin C with the presence and severity of asymptomatic CAD. Then, we investigated the association between cystatin C and other biochemical risk factors for atherosclerosis.
Serum cystatin C levels in patients with asymptomatic CAD were significantly higher than those without CAD (P = 0.004). A multiple logistic regression analysis demonstrated cystatin C was independently associated with the presence of asymptomatic CAD (OR = 1.326, 95%CI: 1.086-1.619). On receiver operating characteristics (ROC) analysis, the area under the curve (AUC) was 0.622 (95 % CI: 0543–0.701, P = 0.003), and cystatin C showed a moderate predictive value. Furthermore, cystatin C was independently correlated with Gensini score (standardized β = 0.183, P = 0.007), and serum cystatin C levels increased with the increasing of number of disease vessels (P = 0.005). In a multiple stepwise regression analysis, uric acid (UA)(P < 0.001), body mass index (BMI)(P = 0.002), triglyceride(TG)(P = 0.03), estimated glomerular filtration rate (eGFR)(P < 0.001), and fibrinogen(P = 0.001) were independently associated with cystatin C.
Serum cystatin C in our study was significantly associated with the presence and severity of asymptomatic CAD in MetS patients with normal kidney function, suggesting that cystatin C is probably more than a marker of glomerular filtration rate.
Cystatin C; Gensini score; Metabolic syndrome; Asymptomatic coronary artery disease
To evaluate racial/ethnic and sex differences in the relationship between metabolic syndrome (MetS) diagnosis and fasting insulin among adolescents.
We analyzed data from the National Health and Nutrition Evaluation Survey 1999–2008 for 3,693 non-Hispanic-white, non-Hispanic-black and Hispanic adolescents (12–19y). We used linear regression to evaluate differences in fasting insulin between those with and without an adolescent adaptation of ATPIII-MetS in a sex- and race/ethnicity-specific basis.
Females had higher insulin levels than males and non-Hispanic blacks and Hispanics had higher levels than non-Hispanic whites. Adolescents with MetS had higher insulin levels than those without MetS. The difference in insulin levels between those with and without MetS was greater among non-Hispanic blacks compared with non-Hispanic whites (p<0.05) but not Hispanics (p=0.10). The sensitivity of MetS for detecting elevated insulin levels was lower among non-Hispanic blacks and females compared with other ethnicities and males, respectively. Correlations between insulin and individual MetS components were similar among ethnicities.
MetS diagnosis performed more poorly in predicting elevated insulin levels among non-Hispanic blacks and among females. These data support the hypothesis that non-Hispanic blacks do not meet current criteria for MetS until they have reached a more advanced degree of insulin resistance.
Metabolic syndrome; ethnicity; insulin resistance; adolescents
Aim. This study aimed to investigate which anthropometric indices could be a better predictor of metabolic syndrome (MetS)
and the cut-off points for these surrogates to appropriately differentiate MetS in the Iranian elderly. Method. The present cross-sectional
study was conducted on a sample of Isfahan Healthy Heart Program (IHHP). MetS was defined according to Third Adult Treatment Panel (ATPIII). In total,
206 elderly subjects with MetS criteria were selected. Anthropometric indices were measured and plotted using receiver operating characteristic (ROC)
curves. Results. WC followed by WHtR yielded the highest area under the curve (AUC) (0.683; 95% CI 0.606–0.761 and 0.680;
95% CI 0.602–0.758, resp.) for MetS. WC at a cut of 94.5 cm resulted in the highest Youden index with sensitivity
64% and 68% specificity to predict the presence of ≥2 metabolic risk factors. BMI had the lowest sensitivity and specificity for MetS and MetS
components. WC has the best ability to detect MetS which followed by WHtR and BMI had a lower discriminating value comparatively. Conclusion.
WC is the best predictor for predicting the presence of ≥2 metabolic risk factors among Iranian elderly population and the best value of WC is
94.5 cm. This cut-off values of WC should be advocated and used in Iranian men until larger cross-sectional studies show different results.
The value of metabolic syndrome (MetS) in childhood and adolescence and its stability into young adulthood have been questioned. This study compared the MetS in late childhood (mean age 13) versus a cluster score of the MetS components as predictors of young adult (mean age 22) cardiovascular risk.
Anthropometrics, blood pressure, lipid profile, and insulin resistance (insulin clamp) were obtained in 265 individuals at mean ages 13 and 22. MetS was defined dichotomously by current pediatric and adult criteria. The MetS cluster score used the average of deviates of the MetS components standardized to their means and standard deviations at mean age 13.
The MetS was rarely present at mean age 13 and did not predict MetS at mean age 22 but identified individuals who continued to have adverse levels of risk factors at mean age 22. In contrast to the standard MetS definition, the MetS cluster score tracked strongly and at mean age 22 was significantly higher in the individuals with MetS at mean age 13 (0.78 ± 0.71) than those without MetS at mean age 13 (0.09 ± 0.70, p<0.0001).
Although MetS at mean age 13, using the conventional definition, is not a reliable method for predicting MetS at mean age 22, it does predict adverse levels of cardiovascular risk factors. A cluster score, using the MetS components as continuous variables, is more reliable in predicting young adult risk from late childhood.
Metabolic Syndrome; Risk Factors; Obesity; Insulin Resistance; Children
Cardiovascular diseases (CVD) are a leading cause of death worldwide including the Middle East. This is caused in part by the dysregulation of adipose tissue leading to increased production of pro-inflammatory adipokines and reduction in cardio-protective adipokines such as adiponectin. Ethnicity has been recognized as a major factor in the association between CVD risk factors and the different circulating adipokines. In this study, for the first time, the relationship between traditional cardiovascular risk factors, Metabolic Syndrome (MetS) and circulating level of adipokines in Arab ethnicity was investigated.
We conducted a population-based cross-sectional survey on 379 adult Arab participants living in Kuwait. Traditional cardiovascular risk factors such as blood pressure (BP), low density lipoprotein (LDL) and triglyceride (TG) were measured. Plasma levels of circulating Leptin, Plasminogen Activator Inhibitor (PAI-1) visfatin, adiponectin, resistin and adipsin were assessed using the multiplexing immunobead-based assay.
Circulating levels of High sensitivity C-Reactive Protein (hsCRP), Leptin, PAI-1 and adiponectin were significantly higher in Arab women than men (p < 0.0001). In multi-variate analysis, the homeostasis model assessment-insulin resistance (HOMA-IR) and body mass index (BMI) showed strong association with most of the biomarkers (p < 0.05). HsCRP showed significant association with all risk factors (p < 0.05). Leptin, PAI-1 and adipsin showed significant positive correlation with BMI, unlike adiponectin which showed inverse correlation (p < 0.05). Subjects in the highest tertile of leptin, PAI-1 and hsCRP had higher odds of having Metabolic Syndrome (MetS) (odd ratio [OR] = 3.02, 95% confidence interval [CI] = 1.47 – 6.19) and (OR = 2.52, 95% CI = 1.45 – 4.35), (OR = 4.26, 95% CI = 2.39 – 7.59) respectively. On the other hand subjects with highest tertile of adiponectin had lower odds of having MetS (OR = 0.22, 95% CI = 0.12 – 0.40). Leptin, PAI-1 and hsCRP showed significant positive association with increased MetS components (P-trend <0.05), while adiponectin was negatively associated with increased MetS components (P-trend <0.0001).
Our results show positive association between hsCRP, leptin, PAI-1 with increased MetS components and increase the odds of having MetS. Adiponectin on the other hand showed inverse correlation with MetS components and associated with reduction in MetS. Overall, our data highlights the significant clinical value these markers have in MetS especially hsCRP which can be used as good marker of low grade inflammation in Arabs.
Adipokine; Arab; Metabolic syndrome; Cardiometabolic risk factors; Lipid profile; hsCRP; Leptin; Adiponectin; Visfatin; Resistin; Adipsin; Low grade inflammation