Should we dump the metabolic syndrome? No

Polychlorinated biphenyls and risk of metabolic syndrome and comparison with the risk of diabetes: A systematic review and meta-analysis

With the increasing incidence of metabolic syndrome (MetS) worldwide and no consistent results on PCBs and MetS. A meta-analysis to explore their relationship was conducted. Given the high correlation and overlap of MetS with diabetes, analysis of diabetes risk, was used as a supplement to compare with MetS. Seven studies included MetS, 15 studies for diabetes, and one study included both outcomes. It was found that PCBs may not be a risk factor for MetS, but their high heterogeneity indicates that they are under-represented. In addition, our results showed that total PCBs might be a protective factor against diabetes. In the whole blood subgroup, which can reflect the accumulation of more than one body load, heterogeneity was reduced, and its OR value suggested that PCBs increased the risk of MetS in the whole blood biomaterial. DL-PCBs were positively associated with MetS and diabetes, while NDL-PCBs were negatively associated with diabetes. In the subgroup analysis of PCBs homologs, DL-PCB-126 and DL-PCB-118 were risk factors for MetS and diabetes, respectively. In addition, PCB-153 and 180 showed a dose-response relationship between them and diabetes mellitus, respectively. The results of total analysis of MetS and diabetes mellitus and subgroup analysis of PCBs were mixed, and this reason might be attributed to the different mechanisms of action and effect sizes of different PCBs, so based on subgroup results and in vivo and in vitro experiments, we considered PCBs to be a risk factor for MetS and diabetes. Due to various reasons, there are still many shortcomings in the evaluation of PCBs impact on human health, and more high-quality research are needed to further explore the role of PCBs of different species and congeners in MetS and diabetes.

Cardiovascular risk assessment methods yield unequal risk predictions: a large cross-sectional study in psychiatric secondary care outpatients

BACKGROUND

Patients with a mental illness are more likely to develop, and die from, cardiovascular diseases (CVD), necessitating optimal CVD-risk (CVR)-assessment to enable early detection and treatment. Whereas psychiatrists use the metabolic syndrome (MetS)-concept to estimate CVR, GPs use absolute risk-models. Additionally, two PRIMROSE-models have been specifically designed for patients with severe mental illness. We aimed to assess the agreement in risk-outcomes between these CVR-methods.

METHODS

To compare risk-outcomes across the various CVR-methods, we used somatic information of psychiatric outpatients from the PHAMOUS-, and MOPHAR-database, aged 40-70 years, free of past or current CVD and diabetes. We investigated: (1) the degree-of-agreement between categorical assessments (i.e. MetS-status vs. binary risk-categories); (2) non-parametric correlations between the number of MetS-criteria and absolute risks; and (3) strength-of-agreement between absolute risks.

RESULTS

Seven thousand twenty-nine measurements of 3509 PHAMOUS-patients, and 748 measurements of 748 MOPHAR-patients, were included. There was systematic disagreement between the categorical CVR-assessments (all p < 0.036). Only MetS-status versus binary Framingham-assessment had a fair strength-of-agreement (κ = 0.23-0.28). The number of MetS-criteria and Framingham-scores, as well as MetS-criteria and PRIMROSE lipid-scores, showed a moderate-strong correlation (τ = 0.25-0.34). Finally, only the continuous PRIMROSE desk and lipid-outcomes showed moderate strength-of-agreement (ρ = 0.91).

CONCLUSIONS

The varying methods for CVR-assessment yield unequal risk predictions, and, consequently, carry the risk of significant disparities regarding treatment initiation in psychiatric patients. Considering the significantly increased health-risks in psychiatric patients, CVR-models should be recalibrated to the psychiatric population from adolescence onwards, and uniformly implemented by health care providers.

TRIAL REGISTRATION

The MOPHAR research has been prospectively registered with the Netherlands Trial Register on 19th of November 2014 (NL4779).

The paradox of the role of resistin in early-onset obesity hypertension: A comparative study among four Chinese adult subgroups

Objective: To explore the role of resistin in the onset and development of obesity-related hypertension.Methods: Resistin serum levels were tested by ELISA in 153 adult subjects among four characteristic Chinese adult physical examination groups. Waist circumference (WC), body mass index (BMI), systolic blood pressure (SB), diastolic blood pressure (DB), and other clinical laboratory data were collected. Following, correlations between research index and differences between groups were analyzed using SPSS.Results: Serum resistin levels statistically significantly negatively correlated with SB, DB and BMI, but statistically significantly positively correlated with serum creatinine (SCR) and serum albumin (ALB), even after adjustment for age and/or gender. The serum level of resistin in the normal healthy subject group (NH) was higher than in other groups.Conclusions: Resistin's role in the onset of obesity-related hypertension may be more important than what has been previously assumed. More pathway substances in the early onset of obesity-related hypertension should be tested.Abbreviations: WC, waist circumference; GGT, Gamma-glutamyltransferase; ALB, Albumin; ALT, Alanine aminotransferase; LDL, Low density lipoprotein cholesterol; TG, Triglyceride; HDLC, High density lipoprotein cholesterol; FA Fructosamine; SCR, serum creatinine; IB, Indirect bilirubin; ALP, Alkaline phosphatase; CB, Conjugated bilirubin; UREA, Urea; Ua, Uric acid; FBG, fasting blood glucose; TC, Total cholesterol; TB, Total bilirubin; TP, Total protein; TC/HDLC, TC/HDLC ratio; SB, systolic blood pressure; DB, diastolic blood pressure.

An update on metabolic syndrome: Metabolic risk markers and adipokines in the development of metabolic syndrome

Metabolic syndrome is a collection of physiological and biochemical abnormalities about 20-25% of adult population in developing countries is suffering from metabolic syndrome. Previous research demonstrated that adipose tissue plays an important role in energy regulation via endocrine, paracrine and autocrine signals as results of obesity due to accumulation of adipose tissue to excess that by time affects negatively both physical and psychological health and well being, it has been found that adipose tissues produces a variety of factors known as "adipokines" which play a key role in the development and progression of the disease and also hypothesized that adipokines are a possible link between obesity and the other risk components of the Metabolic syndrome. Many of the adipokines exert multiple actions in a variety of cellular processes leading to a complex array of abnormal characteristic of Metabolic syndrome. Abnormal production of these adipokines by expanded visceral fat during Adiposity contributes to a pro-inflammatory state. Increasing evidence suggests that aberrant production/release of adipokine from adipocyte i.e. adiponectin, leptin and resistin etc, may contribute to the health problems associated with Adiposity such as dyslipidemia, insulin resistance and atherosclerosis. This study conclusively have shown a significant role of adipokines secreted by adipose tissue and various metabolic risk markers play a important role in the development of Metabolic syndrome.

The association of metabolic syndrome components and diabetes mellitus: evidence from China National Stroke Screening and Prevention Project

Background

The metabolic syndrome (MetS) is related with cardiovascular disease. However, its relationship with diabetes mellitus (DM) has not been examined in Chinese population with a larger sample. We aimed to assess the relationship between metabolic syndrome (MetS) and its components, and DM, and to determine the best one from the available definitions of Mets when assessing the risk of DM.

Methods

This was a cross-sectional survey in a nationally representative sample of 109,551 Chinese adults aged ≥40 years in 2014–15. MetS was defined according to three criteria including the updated International Diabetes Federation (IDF) criterion, the National Cholesterol Education Program Third Adult Treatment Panel (NCEP ATP III) criterion and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) criterion. Logistic regression models were used to estimate the odds of DM.

Results

MetS as defined by three criteria including IDF, NCEP ATP III,and AHA/NHLBI all increased the prevalence of DM, and the adjusted ORs with 95% CI was more higher using NCEP ATP III (3.65, 3.52–3.79) than IDF (2.50, 2.41–2.60) and AHA/NHLBI (3.03, 2.92–3.24). The odds of DM was highest in hyperglycemia with cut-off glucose≥6.1 mmol/L (14.55, 13.97–15.16), and other components were also associated significantly with DM. There was heterogeneity for OR of DM associated with various trait combinations.

Conclusions

The NCEP ATPIII MetS definition may be more suitable for assessment of DM risk in Chinese population. Hyperglycemia, as previous study reported, are important risk factors of DM. Besides, other traits of Mets are also significantly associated with DM and should therefore be of greater concern.

Pathophysiological domains underlying the metabolic syndrome: an alternative factor analytic strategy

PURPOSE

Factor analysis (FA) has become part and parcel in metabolic syndrome (MBS) research. Both exploration- and confirmation-driven factor analyzes are rampant. However, factor analytic results on MBS differ widely. A situation that is at least in part attributable to misapplication of FA. Here, our purpose was (i) to review factor analytic efforts in the study of MBS with emphasis on misusage of the FA model and (ii) to propose an alternative factor analytic strategy.

METHODS

The proposed factor analytic strategy consists of four steps and confronts weaknesses in application of the FA model. At its heart lies the explicit separation of dimensionality and pattern selection and the direct evaluation of competing inequality-constrained loading patterns. A high-profile MBS data set with anthropometric measurements on overweight children and adolescents is reanalyzed using this strategy.

RESULTS

The reanalysis implied a more parsimonious constellation of pathophysiological domains underlying phenotypic expressions of MBS than the original analysis (and many other analyses). The results emphasize correlated factors of impaired glucose metabolism and impaired lipid metabolism.

CONCLUSIONS

Pathophysiological domains underlying phenotypic expressions of MBS included in the analysis are driven by multiple interrelated metabolic impairments. These findings indirectly point to the possible existence of a multifactorial etiology.

Correlation of serum leptin, adiponectin and resistin with glucose-lipid metabolism and blood pressure regulation in patients with metabolic syndrome

AIM: To investigate the correlation of serum leptin, adiponectin and resistin with glucose-lipid metabolism and blood pressure regulation in patients with metabolic syndrome.

METHODS: One hundred patients with metabolic syndrome were selected, and 60 healthy subjects were used as normal controls. The general indicators were observed, homeostasis model assessment of insulin resistance (HOMA-IR) was calculated, and serum leptin, resistin, adiponectin and other indicators were measured.

RESULTS: The levels of serum leptin and resistin in patients with metabolic syndrome were significantly higher than those in normal controls, while serum adiponectin level was significantly lower in patients with metabolic syndrome. Serum leptin and resistin had significant positive correlations with body mass index (BMI), blood pressure (SBP and DBP), fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG) and HOMA-IR, and showed significant negative correlations with high-density lipoprotein cholesterol (HDL-C). Serum adiponectin had a significant positive correlation with HDL-C, and showed significant negative correlations with BMI, SBP, DBP, FBG, FINS, TG and HOMA-IR.

CONCLUSION: The changes in serum levels of leptin, resistin and adiponectin may promote the development of insulin resistance, give rise to disorders of glucose-lipid metabolism and blood pressure regulation. These serum fat factors may have important effects on the development of metabolic syndrome.

Hypothalamic ATF3 is involved in regulating glucose and energy metabolism in mice

AIMS/HYPOTHESIS

The pancreas and hypothalamus are critical for maintaining nutrient and energy homeostasis, and combined disorders in these organs account for the onset of the metabolic syndrome. Activating transcription factor 3 (ATF3) is an adaptive response transcription factor. The physiological role of ATF3 in the pancreas has been controversial, and its role in the hypothalamus remains unknown. To elucidate the roles of ATF3 in these organs, we generated pancreas- and hypothalamus-specific Atf3 knockout (PHT-Atf3-KO) mice in this study.

METHODS

We crossed mice bearing floxed Atf3 alleles with Pdx1-cre mice, in which cre is specifically expressed in the pancreas and hypothalamus, and analysed metabolic variables, pancreatic morphology, food intake, energy expenditure and sympathetic activity in adipose tissue. We also used a hypothalamic cell line to investigate the molecular mechanism by which ATF3 regulates transcription of the gene encoding agouti-related protein (Agrp).

RESULTS

Although PHT-Atf3-KO mice displayed better glucose tolerance, neither plasma glucagon nor insulin level was altered in these mice. However, these mice exhibited higher insulin sensitivity, which was accompanied by a leaner phenotype due to decreased food intake and increased energy expenditure. We also observed decreased hypothalamic Agrp expression in PHT-Atf3-KO mice. Importantly, an increase in ATF3 levels is induced by fasting or low glucose in the hypothalamus. We also showed that ATF3 interacts with forkhead box-containing protein, O subfamily 1 (FoxO1) on the Agrp promoter and activates Agrp transcription.

CONCLUSIONS/INTERPRETATION

Our results suggest that ATF3 plays an important role in the control of glucose and energy metabolism by regulating Agrp.

Prevalence of the metabolic syndrome using two proposed definitions in a Japanese-Brazilians community

Metabolic Syndrome (MetS) is associated with increased risk of morbi-mortality, thus the characterization of the population magnitude of this syndrome is critical for allocating health care. However, prevalence estimates of MetS in the same population could differ depending on the definition used. Therefore, we compared the prevalence of the MetS using definitions proposed by: National Cholesterol Education Panel Revised (NCEP) and International Diabetes Federation (IDF) 2009 in a Japanese-Brazilians community (131 individuals, age 57 ± 16 years, 1st and 2nd generation). All individuals went through a clinical and laboratorial evaluation for assessment of weigh, height, waist circumference, blood pressure, triglycerides, HDL-cholesterol and fasting plasma glucose. The prevalence of MetS was 26.7% (n = 35) and 37.4% (n = 49) under the NCEP and IDF definitions, respectively. Despite higher blood pressure measurements, waist circumference and serum triglyceride levels and lower HDL cholesterol levels (p < 0.01), individuals identified with MetS did not show increased blood glucose levels. IDF definition classified 14 individuals (10.7%) with MetS that were not classified under the NCEP and 35 individuals were identified with MetS by both criteria. We observed, in this group, more severe lipid disorders, compared to individuals identified only under the IDF definition, and the BMI and waist circumference (p = 0.01; p = 0.006, respectively) were lower. In conclusion, the IDF revised criteria, probably because of the ethnic specific values of waist circumference, was able to identify a larger number of individuals with MetS. However, our data suggesting that additional studies are necessary to define best MetS diagnostic criteria in this population.

High sensitivity C-reactive protein, tumor necrosis factor-α, interleukin-6, and vascular cell adhesion molecule-1 levels in Asian Indians with metabolic syndrome and insulin resistance (CURES-105)

AIM

The aim of this study was to assess levels of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and vascular cell adhesion molecule-1 (VCAM-1) in South Indian subjects with and without MS and among MS subjects with and without insulin resistance (IR).

METHODOLOGY

From the population-based Chennai Urban Rural Epidemiology Study, 334 subjects with MS and 342 subjects without MS were selected. Metabolic syndrome was diagnosed based on modified National Cholesterol Education Program criteria. High-sensitivity C-reactive protein, TNF-α, IL-6, and VCAM-1 were measured by enzyme-linked immunosorbent assay. Insulin resistance was calculated using the homeostasis model assessment (HOMA-IR) using the following formula: fasting insulin (µIU/ml) × fasting glucose (mmol/liter)/22.5.

RESULTS

Subjects with MS had significantly higher levels of all four inflammatory markers compared to those without MS: hs-CRP (2.57 vs 2.19 mg/liter) (p < .05), TNF-α (4.47 vs 3.89 pg/ml) (p < .05), IL-6 (16.22 vs 10.96 pg/ml) (p < .05), and VCAM-1 (13.8 vs 7.94 pg/ml) (p < .05). In the total study subjects, hs-CRP (r = 0.089, p = .047), TNF-α (r = 0.113, p = .040), IL-6 (r = 0.176, p = .042), and VCAM-1 (r = 0.230, p = .06) were significantly correlated with MS. With increasing quartiles of IR, mean levels of hs-CRP (p for trend <.001) and TNF-α (p for trend <.05) increased linearly. MS subjects with IR had higher levels of hs-CRP (p < .001) and TNF-α (p < .05) compared to MS subjects without IR.

CONCLUSION

In Asian Indians, inflammatory cytokines hs-CRP, TNF-α, IL-6, and VCAM-1 are elevated in subjects with MS while hs-CRP and TNF-α are further elevated in those with MS and IR.

The metabolic syndrome in HIV

The metabolic syndrome (MS) is a term used to describe the clustering of risk factors for cardiovascular disease (CVD), including elevated triglyceride (TG), low high density lipoprotein cholesterol (HDL), hypertension, hyperglycemia/ insulin resistance and intra-abdominal obesity. This paper discusses why the prevalence of MS in the setting of HIV has been reported to range from 7-45% and how antiretroviral drugs might contribute to the development of MS. The MS has been reported to be a 'CVD risk enhancer', and much debate is ongoing on the independent risk of CVD associated with the MS. Based on a limited number of studies on MS in HIV with clinical end-points, there is no data to support that the MS is independently associated with an increased risk of CVD.

The global challenge of type 2 diabetes and the strategies for response in ethnic minority groups

Ethnic minorities living in high-income countries usually exhibit a greater risk of developing diabetes along with higher morbidity and mortality rates. We evaluated the effectiveness of interventions to improve glycaemic control in ethnic minority groups. Results of major controlled trials, systematic reviews and meta-analyses were included in the review. Only 1/47 studies addressing diet and exercise interventions reported details on the ethnicity of the studied population. Self-management education was successful if associated with increased self-efficacy; delivered over a longer period; of high intensity; culturally tailored; and when using community educators. Strategies adopted in community-gathering places, family-based, multifaceted, and those tackling the social context were likely to be more effective. A positive relationship was found between social support and self-management behaviour as well as quality of life, but there is little evidence about the impact of organizational changes within health-care services on diabetes control. More research is needed to strengthen the evidence on effective strategies for response to diabetes in ethnic minorities. Also, there is a need to take into account diabetes beliefs and communication difficulties, as well as potential protective factors. Globally, many health-care systems are inadequately equipped to improve diabetes prevention and disease outcomes in these communities.

Metabolic syndrome predicts vascular changes in whole body magnetic resonance imaging in patients with long standing diabetes mellitus

BACKGROUND

Although diabetic patients have an increased rate of cardio-vascular events, there is considerable heterogeneity with respect to cardiovascular risk, requiring new approaches to individual cardiovascular risk factor assessment. In this study we used whole body-MR-angiography (WB-MRA) to assess the degree of atherosclerosis in patients with long-standing diabetes and to determine the association between metabolic syndrome (MetS) and atherosclerotic burden.

METHODS

Long standing (> or = 10 years) type 1 and type 2 diabetic patients (n = 59; 31 males; 63.3 +/- 1.7 years) were examined by WB-MRA. Based on the findings in each vessel, we developed an overall score representing the patient's vascular atherosclerotic burden (MRI-score). The score's association with components of the MetS was assessed.

RESULTS

The median MRI-score was 1.18 [range: 1.00-2.41] and MetS was present in 58% of the cohort (type 2 diabetics: 73%; type 1 diabetics: 26%). Age (p = 0.0002), HDL-cholesterol (p = 0.016), hypertension (p = 0.0008), nephropathy (p = 0.0093), CHD (p = 0.001) and MetS (p = 0.0011) were significantly associated with the score. Adjusted for age and sex, the score was significantly (p = 0.02) higher in diabetics with MetS (1.450 [1.328-1.572]) compared to those without MetS (1.108 [0.966-1.50]). The number of MetS components was associated with a linear increase in the MRI-score (increase in score: 0.09/MetS component; r2 = 0.24, p = 0.038). Finally, using an established risk algorithm, we found a significant association between MRI-score and 10-year risk for CHD, fatal CHD and stroke.

CONCLUSION

In this high-risk diabetic population, WB-MRA revealed large heterogeneity in the degree of systemic atherosclerosis. Presence and number of traits of the MetS are associated with the extent of atherosclerotic burden. These results support the perspective that diabetic patients are a heterogeneous population with increased but varying prevalence of atherosclerosis and risk.

Prevalence, detection, and management of the metabolic syndrome in patients with acute myocardial infarction: role of an obesity-centric definition

Background. We sought to determine and compare the prevalence of the Metabolic Syndrome (MS) in patients with acute myocardial infarction (AMI) utilizing the new International Diabetes Federation (IDF) definition with the older National Cholesterol Education Program (NCEP) definition. We also examined the clinical utility of MS in this context. Methods. A total of 107 consecutive patients with AMI were prospectively evaluated for MS. Fasting lipids obtained at admission and fasting glucose at discharge were used. A postdischarge folder audit verified rates of discharge coding and implementation of specific management strategies for MS. Results. Baseline patient characteristics included: mean age 59 +/- 13 years; males 80%; diabetes 19%; mean BMI 29.7 +/- 8.4 kg/m(2). MS prevalence was 54% by the IDF definition and 49% by the NCEP definition, with good agreement between definitions: kappa = 0.664, P < .001. Factors predictive of MS after multivariate analysis included: hypertension, fasting glucose, waist circumference, and serum HDL (all P < .05). Despite the high prevalence, MS was recognized at discharge in only 1 patient, and referral for exercise and/or weight-loss programs was undertaken in 5 patients. Conclusion. There is a high prevalence of MS utilizing contemporary definitions in patients with AMI: 54% by the IDF definition and 49% by NCEP criteria. Despite the high prevalence, MS was under-recognized and under-treated in this population.

Chewing ability in conjunction with food intake and energy status in later life affects survival in Taiwanese with the metabolic syndrome

OBJECTIVES

To examine chewing ability and survival in older adults after 8 years of follow-up and consider any interaction with the metabolic syndrome (MetS).

DESIGN

Prospective cohort.

SETTING

The Elderly Nutrition and Health Survey in Taiwan during 1999/00, a nationally representative sample of Taiwanese aged 65 and older.

PARTICIPANTS

One thousand four hundred ten people (729 men and 681 women).

MEASUREMENTS

Chewing ability and food intake were ascertained using a questionnaire, supplemented by 24-hour dietary recall. The MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria for Asians. Death according to the National Death Registry by December 31, 2006, was the outcome measure.

RESULTS

During follow-up, 368 subjects died. A significantly higher age- and sex-adjusted hazard ratio (HR=1.44, 95% confidence interval (CI)=1.10-1.78, P=.009) for mortality was found in those who had unsatisfactory chewing ability. Age, sex, and appetite together explain the effect of chewing on mortality. Dietary diversity, body mass index, and health status may also play a role in mediating a possible mortality effect of chewing. Significant interactions between chewing ability and the MetS and mortality were found (P=.04 for five components and .006 for three energy-related components). Jointly, those who had unsatisfactory chewing ability and the MetS were at higher risk of death than those who had satisfactory chewing ability without the MetS (HR=1.65, 95% CI=1.11-2.46 for 5 MetS components; HR=2.58, 95% CI=1.58-4.23 for 3 MetS components).

CONCLUSION

Self-reported unsatisfactory chewing ability is associated with greater mortality risk in older adults, and MetS increases the risk of mortality in people with chewing difficulty.

Insulin resistance indexes in renal transplant recipients maintained on tacrolimus immunosuppression

BACKGROUND

Insulin resistance is common posttransplantation and contributes to both new onset diabetes after transplantation and the metabolic syndrome. Insulin resistance indexes have never been validated in transplant recipients on tacrolimus compared with cyclosporine, although it is more diabetogenic. We aimed to assess these indexes in renal transplant recipients on tacrolimus as primary immunosuppressant.

METHODS

Retrospective analysis of 76 frequently sampled, intravenous glucose tolerance tests (for insulin sensitivity) in 38 nondiabetic renal transplant recipients on tacrolimus-centered immunosuppression. Indexes tested were fasting glucose/insulin ratio, homeostasis model assessment (HOMA) index, 1/HOMA, log (HOMA), quantitative insulin sensitivity check index, and the McAuley's index. Indexes were also compared against waist/hip ratio and C-reactive protein (CRP). Multivariate linear regression analysis was performed to determine independent variables predictive for insulin resistance.

RESULTS

Insulin sensitivity successfully correlated with all indexes: fasting glucose/insulin ratio (r=0.246, P=0.033), HOMA index (r=-0.240, P=0.038), 1/HOMA (r=0.282, P=0.014), log (HOMA) (r=-0.316, P=0.006), quantitative insulin sensitivity check index (r=0.320, P=0.005), and McAuley's index (r=0.323, P=0.005). McAuley's index also correlated strongest with waist/hip ratio (r=-0.425, P<0.001). All indexes failed to correlate with CRP. Variables independently associated with insulin sensitivity were HbA1c (r=0.189, P=0.019), pulse pressure (r=0.146, P=0.021), and CRP (r=0.210, P=0.010).

CONCLUSIONS

Insulin resistance indexes are valid in transplant recipients taking tacrolimus, with McAuley's index the strongest surrogate.

Metabolic syndrome: an occupational perspective

OBJECTIVE

To study the prevalence of Metabolic Syndrome (MS) in an Indian industrial setup and to study disparity in occurrence of MS in a working population based on occupational status.

MATERIALS AND METHODS

Cross-sectional study of 651 employees who underwent periodic medical examination. The International Diabetes Federation (IDF) definition of MS and International Standard Classification of Occupations (ISCO)-88 classification of occupations were used.

RESULTS

The overall crude prevalence of MS was found to be 18.5%. Nineteen percent of the non-manual workers and 18.3% of the manual workers suffered from MS. The single largest occupational category with MS was ISCO-88 group 1, which included the managers and senior officials. However, no difference was found among the manual and non-manual workers in prevalence of MS.

Far from easy and accurate - detection of metabolic syndrome by general practitioners

Background

Metabolic syndrome (MetS) is a major public health challenge. General practitioners (GPs) could play a key role in its recognition. However, it often remains undiagnosed in primary care. This study assesses how well GPs and patients recognise MetS among patients with coronary heart disease or at least one of its risk factors.

Methods

Twenty-six health centres around Finland were randomly selected for the purpose of identifying, over a two-week period in April 2005, patients meeting the inclusion criteria of coronary heart disease or one of its risk factors. GPs and identified patients (n = 1880) were asked to complete surveys that included a question about the patient's MetS status. A trained nurse conducted health checks (n = 1180) of the identified patients, utilising criteria of MetS modified from the National Cholesterol Program. Data from the GPs' survey were compared with those from the health check to establish the extent of congruence of identification of MetS.

Results

Almost half (49.4%) of the patients met the criteria of MetS as established by objective measures. However, in the GPs' survey responses, only 28.5% of the patients were identified as having MetS. Additionally, these groups of MetS patients were not congruent. The sensitivity of the GPs' diagnosis of MetS was 0.31 with a specificity of 0.73. Only 7.1% of the study patients stated that they were suffering from MetS.

Conclusion

Detection of MetS is inaccurate among GPs in Finland. Most patients were not aware of having MetS. The practical relevance of MetS in primary care should be reconsidered.

Optimal waist cutpoint for screening for dysglycaemia and metabolic risk: evidence from a Maori cohort

We sought to identify the sex-specific cut-off in waist circumference which best identifies those with metabolic abnormalities consistent with the metabolic syndrome (MS) among Maori, the indigenous people of New Zealand of Polynesian origin. In 3816 self-identified Maori (2742 women, 1344 men) a 75 g oral glucose tolerance test, fasting lipid, anthropometric and blood pressure measurements were made. MS components were defined by Adult Treatment Panel (ATP) III criteria. Waist cut-off was defined using receiver operating characteristic (ROC) curve analysis to define the presence of at least two of the other MS components ( ≥ 2MS). Prevalence of ≥ 2MS was high (42·1 %). In males and females, waist was as good, or better, a predictor of ≥ 2MS (area under ROC 0·73 women, 0·68 men) as waist:hip ratio (0·66, 0·67), BMI (0·72, 0·68) or percentage body fat (0·70, 0·68). The prediction of dysglycaemia using anthropometric variables followed a similar pattern to ≥ 2MS. Waist circumference to predict ≥ 2MS or dysglycaemia in Maori women and men was 98 cm and 103 cm. Applying this cut-off to the International Diabetes Federation (IDF) criteria would identify 27·8 % (34·0 % males, 25·5 % females) with the MS with an OR for ≥ 2MS (adjusted for sex, smoking and age) of 3·5 (95 % CI 3·1, 4·0). Age >48 years, smoking and being male increased the odds of the MS. These waist cut-offs should be considered in both clinical practice and to optimise the definition of the MS for Maori. The validity of these criteria in other Polynesian groups should be confirmed.

Prevalence of metabolic syndrome and factors associated with its components in Chinese adults

The purpose of this study was to assess the prevalence of metabolic syndrome (MetS) and its components among middle-aged and elderly adults in Jiangsu province, China. Moreover, factors associated with MetS were also assessed. A population-based cross-sectional survey was conducted with 4 randomly selected areas including both urban and rural areas from Jiangsu province, China. After the procedure, 3914 adults aged 35 to 74 years were included in the study. Metabolic syndrome was defined by the modified National Cholesterol Education Program Adult Treatment Panel III report. Data were collected by interviewer-administered questionnaire, biophysical assessment, and biochemical examination. Crude and age-standardized prevalence of MetS was 31.5% and 30.5%, respectively. Prevalence rate increased significantly with age in female but not in male subjects, whereas this was true for both sexes with increased body mass index. High blood pressure was the most prevalent component of MetS (45.2%), followed by elevated triglycerides (40.1%) and low high-density lipoprotein cholesterol (40.1%). Multivariate ordinal regression analysis revealed that women had significantly higher risk of MetS than men (odds ratio = 1.72, P < .001). Older age, living in urban area, income, family history of diabetes, and family history of hypertension were positively associated with MetS risk. However, higher education and tea drinking everyday were found to be negatively associated with MetS (P < .05). Moreover, substantial agreement (kappa = 0.79) was found between the International Diabetes Federation and modified Adult Treatment Panel III criteria among 3 comparisons of MetS definitions. Metabolic syndrome was highly prevalent in middle-aged and elderly Chinese population in Jiangsu province. Community-based strategies for diet and lifestyle modifications are strongly suggested, especially in women and the elderly.

Metabolic syndrome and its components as predictors of incident type 2 diabetes mellitus in an Aboriginal community

BACKGROUND

Risk factors for type 2 diabetes remain poorly characterized among Aboriginal Canadians. We aimed to determine the incidence of type 2 diabetes in an Aboriginal community and to evaluate prospective associations with metabolic syndrome and its components.

METHODS

Of 606 participants in the Sandy Lake Health and Diabetes Project from 1993 to 1995 who were free of diabetes at baseline, 540 (89.1%) participated in 10-year follow-up assessments. Baseline anthropometry, blood pressure, fasting insulin and serum lipid levels were measured. Fasting and 2-hour postload glucose levels were obtained at follow-up to determine incident cases of type 2 diabetes.

RESULTS

The 10-year cumulative incidence of diabetes was 17.5%. High adiposity, dyslipidemia, hyperglycemia, hyperinsulinemia and hypertension at baseline were associated with an increased risk of diabetes after adjustment for age and sex (all p < or = 0.03). Metabolic syndrome had high specificity (75%-88%) and high negative predictive value (85%-87%) to correctly detect diabetes-free individuals at follow-up. It had low sensitivity (26%-48%) and low positive predictive value (29%-32%) to detect future diabetes. Metabolic syndrome at baseline was associated with incident diabetes after adjustment for age and sex, regardless of whether the syndrome was defined using the National Cholesterol Education Program criteria (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.10-3.75) or the International Diabetes Federation criteria (OR 2.14, 95% CI 1.29-3.55). The association was to the same degree as that for impaired glucose tolerance assessed using the oral glucose tolerance test (OR 2.87, 95% CI 1.52-5.40; p > 0.05 for comparison of C statistics).

INTERPRETATION

Metabolic syndrome and its components can be identified with readily available clinical measures. As such, the syndrome may be useful for identifying individuals at risk of type 2 diabetes in remote Aboriginal communities.

Presence of the metabolic syndrome is not a better predictor of cardiovascular disease than the sum of its components in HIV-infected individuals: data collection on adverse events of anti-HIV drugs (D:A:D) study

OBJECTIVE

It is much debated whether the metabolic syndrome contributes additional information over and above that provided by the individual components of the syndrome alone. Among HIV-infected individuals, we investigated whether any particular combinations of the components included in the definition of the metabolic syndrome are associated with a higher risk of cardiovascular disease (CVD).

RESEARCH DESIGN AND METHODS

We followed 33,347 HIV-infected individuals in a prospective observational study. The effect of combinations of components of the metabolic syndrome (low HDL cholesterol, high triglycerides, high BMI, hypertension, and diabetes) on the risk of CVD was assessed by Poisson regression incorporating interactions between each component pair and adjusting for age, sex, family history of CVD, smoking status, calendar year, and exposure to antiretroviral therapy. We reduced the risk of type 1 errors by randomly splitting the data set for training (70% of sample) and validation (remaining 30%).

RESULTS

In the training data set, 671 patients experienced a CVD event over 110,652 person-years. Unadjusted, the presence of metabolic syndrome at study enrollment (>or=3 of the factors) was associated with a 2.89 higher risk of CVD (95% CI 2.34-3.59; P = 0.0001) compared with individuals without the metabolic syndrome. After adjustment for the individual components, the metabolic syndrome as an entity no longer predicted the risk of CVD (adjusted relative risk 0.85; 95% CI 0.61-1.17; P = 0.32). No significant positive interactions were found among the components of the metabolic syndrome.

CONCLUSIONS

The presence of the metabolic syndrome in HIV-infected individuals did not appear to increase the CVD risk over and above that conferred by the components of the syndrome separately.

Liver and heart: a new link?

Alanine aminotransferase (ALT) is a marker of non-alcoholic fatty liver disease (NAFLD) and predicts incident type 2 diabetes mellitus (DM2). Recently, ALT was shown to be also associated with endothelial dysfunction and carotid atherosclerosis. We studied the predictive value of ALT for all-cause mortality, incident cardiovascular disease (CVD) and coronary heart disease (CHD) events in a population-based cohort of Caucasian men and women aged 50-75 years, at baseline. The 10-year risk of all-cause mortality, fatal and non-fatal CVD and CHD events in relation to ALT was assessed in 1439 subjects participating in the Hoorn Study, using Cox survival analysis. Subjects with prevalent CVD/CHD and missing data were excluded. As compared with the first tertile, the age- and sex-adjusted hazard ratios (95% confidence intervals) for all-cause mortality, CVD events and CHD events were 1.30 (0.92-1.83), 1.40 (1.09-1.81) and 2.04 (1.35-3.10), respectively, for subjects in the upper tertile of ALT. After adjustment for components of the metabolic syndrome and traditional risk factors, the association of ALT and CHD events remained significant for subjects in the third relative to those in the first tertile, with a hazard ratio of 1.88 (1.21-2.92) and 1.75 (1.12-2.73), respectively. In conclusion, the predictive value of ALT for coronary events, seems independent of traditional risk factors and the features of the metabolic syndrome in a population-based cohort. Further studies should confirm these findings and elucidate the pathophysiological mechanisms.