Metabolic syndrome and its association with morbidity and mortality

Prevalence of Metabolic Syndrome and Combinations of Its Components: Findings from the Mexican National Health and Nutrition Survey, 2021

Background: Metabolic syndrome (MetS) is a clinical construct that conglomerates risk factors interconnected with cardiovascular diseases and type 2 diabetes. More than a thousand million individuals in the world were diagnosed with MetS in 2018. Objective: Our objective was to examine the prevalence of MetS and its components among Mexican adults. Methods: Data from 1733 adults aged ≥20 years who participated in the Mexican National Health and Nutrition Survey 2021. Sociodemographic, and clinical factors were gathered and analyzed. To define MetS, we used the harmonized diagnosis criteria. Results: The prevalence of MetS in Mexican adults was 45.3% (43.7% in men and 46.8% in women). This was mainly driven by increased abdominal obesity (AO) 79.8% and dyslipidemia (low high-density lipoprotein [HDL]-cholesterol and hypertriglyceridemia) 77.1%. The proportion of subjects with a least one MetS component was 90.5% and with any combination of two components was 25.2% and for three was 28.9%. The most frequent combination of MetS components was the cluster of AO, low HDL-cholesterol, and hypertriglyceridemia (15.6%). Conclusions: A high prevalence of MetS was registered in Mexico in 2021. Women and adults aged 40 years or older were the groups with the highest prevalence of MetS and its components. The health system in Mexico must promote strategies for the prevention and control of MetS and its components in adults.

The Disputable Costs of Sleeping

It is currently affirmed that sleep detracts from time for foraging, reproductive, and anti-predatory activities. In contrast, we show that the sleep-related reductions in food intake and reproductive activities may, in fact, be benefits. Furthermore, the present report shows that the optimal prey are the immature, weak, sick, and senescent animals and rarely the sleeping fit adults. Indeed, the reduced sleeping time observed in prey animals occurs, not because of an evolutionary antipredation pressure but because of the time-expensive foraging-related activities and the digestion of the high-cellulose content in the herbivores' diet, an activity that leaves reduced amounts of daily time for sleeping. We conclude that the need for sleep ranks lower than those of foraging, reproduction, and antipredation activities.

Metabolic syndrome in childhood, adolescent, and young adult cancer survivors: recommendations for surveillance from the International Late Effects of Childhood Cancer Guideline Harmonization Group

OBJECTIVE

Survivors of childhood, adolescent, and young adult (CAYA) cancer have an increased risk of metabolic syndrome (MetS). MetS describes the clustering of cardiovascular risk factors including overweight or obesity, hypertension, (pre)diabetes, and dyslipidaemia. While associated cardiovascular sequelae can be serious, MetS is preventable, manageable, and potentially reversible with the appropriate pharmacological and/or behavioral interventions. To optimize health outcomes in CAYA cancer survivors, international, harmonized surveillance recommendations are essential.

DESIGN

Systematic review and guideline development.

METHODS

A multidisciplinary guideline panel evaluated concordances and discordances across national guidelines for MetS surveillance and performed a systematic literature review. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to grade the available evidence and formulate recommendations considering the strength of the underlying evidence as well as potential harms and benefits associated with MetS surveillance. In case evidence was lacking, recommendations were based on expert opinion. In addition, recommendations for surveillance modalities were derived from existing guidelines for MetS components where applicable.

RESULTS

The systematic literature review included 20 studies and highlighted 2 high-risk groups, namely CAYA cancer survivors treated with total body irradiation and those treated with cranial or craniospinal irradiation (moderate-quality evidence). Recommendations were formulated for MetS surveillance in these risk groups, covering preferred screening modalities, age at screening initiation, and surveillance frequency.

CONCLUSIONS

In this international surveillance guideline for MetS in CAYA cancer survivors, we provide evidence-based recommendations for clinical practice, with the aim of ensuring optimal MetS surveillance for CAYA cancer survivors.

A component-based analysis of metabolic syndrome's impact on 30-day outcomes after hip fracture: reduced mortality in obese patients

Introduction

Hip fractures are a common injury associated with significant morbidity and mortality. In the United States, there has been a rapid increase in the prevalence of metabolic syndrome (MetS), a condition comprised several common comorbidities, including obesity, diabetes mellitus, and hypertension, that may worsen perioperative outcomes. This article assesses the impact of MetS and its components on outcomes after hip fracture surgery.

Methods

Patients who underwent nonelective operative treatment for traumatic hip fractures were identified in the 2015-2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Baseline characteristics between groups were compared, and significant differences were included as covariates. Multivariate regression was performed to assess the impact of characteristics of interest on postoperative outcomes. Patients with MetS, or a single one of its constitutive components-hypertension, diabetes, and obesity-were compared with metabolically healthy cohorts.

Results

In total 95,338 patients were included. Patients with MetS had increased complications (OR 1.509; P < 0.001), but reduced mortality (OR 0.71; P < 0.001). Obesity alone was also associated with increased complications (OR 1.14; P < 0.001) and reduced mortality (OR 0.736; P < 0.001). Both hypertension and diabetes alone increased complications (P < 0.001) but had no impact on mortality. Patients with MetS did, however, have greater odds of adverse discharge (OR 1.516; P < 0.001), extended hospital stays (OR 1.18; P < 0.001), and reoperation (OR 1.297; P = 0.003), but no significant difference in readmission rate.

Conclusion

Patients with MetS had increased complications but decreased mortality. Our component-based analysis showed had obesity had a similar effect: increased complications but lower mortality. These results may help surgeons preoperatively counsel patients with hip fracture about their postoperative risks.

The association between continuous metabolic syndrome score and its components with electrocardiographic abnormalities in community-dwelling older adults: the Bushehr elderly health (BEH) program

BACKGROUND

Metabolic syndrome (MetS) known as a risk factor for cardiovascular diseases (CVDs) has developed into a major source of health issue, especially for the elderly. In the present study, we investigated the association between continuous MetS (cMetS) score and its components with electrocardiographic (ECG) abnormalities in the community-dwelling older adults.

METHODS

This cross-sectional study is derived from the second phase of BEH cohort study which is conducted on individuals aged over 60 years old. Standard 12-lead ECGs were recorded and coded by qualified physicians and continuous values of metabolic syndrome risk scores (cMetS) were measured. Data regarding socio-demographic, medical history, and lifestyle variables were collected by trained interviewers. The multinomial regression analysis was used to investigate the relationship between cMetS and its components with ECG abnormalities in the included participants.

RESULTS

2426 individuals (mean age ± standard deviation: 69.30 ± 6.33 years) were included in the final analysis. Overall, 22.5% of the participants showed ECG abnormalities. Among these, 8.0% (n = 139) of participants had minor and 14.6% (n = 354) had major ECG abnormalities. In the final models, cMetS (OR = 1.04), mean arterial pressure (MAP((OR = 1.01), and higher fasting blood glucose (FBG) (OR = 1.01) increased the risk of ECG abnormalities (p < 0.05). Also, cMetS (OR = 1.05) and MAP (OR = 1.02) were associated with an increased risk of major ECG abnormalities (p < 0.05).

CONCLUSION

MetS and MAP were significantly associated with ECG abnormalities. The results of the present study suggest that ECG screening in the older population with MetS could potentially help to detect those at the higher risk of CVDs.

The Role of (Pro)Renin Receptor in the Metabolic Syndrome

The prorenin receptor (PRR) is a complex multi-functional single transmembrane protein receptor that is ubiquitously expressed in organs and tissues throughout the body. PRR is involved in different cellular mechanisms that comprise the generation of Angiotensin II, the activation of Wnt/β-catenin signaling, the stimulation of ERK 1/2 pathway, and the proper functioning of the vacuolar H+-ATPase. Evidence supports the role of PRR and its soluble form, sPRR, in the classical features of the metabolic syndrome, including obesity, hypertension, diabetes, and disruption of lipid homeostasis. This review summarizes our current knowledge and highlights new advances in the pathophysiological function of PRR and sPRR in adipogenesis, adipocyte differentiation, lipolysis, glucose and insulin resistance, lipid homeostasis, energy metabolism, and blood pressure regulation.

A peer-led physical activity intervention in schools for adolescent girls: a feasibility RCT

Background

Girls are less active than boys and few adolescent girls meet physical activity (PA) guidelines. Peers are an important influence on the views and behaviours of adolescent girls, yet many PA interventions involving peers use formal approaches that may not harness the power of peer groups. More informal peer-led PA interventions, which work within proximal peer groups, may hold promise for increasing girls’ PA.

Objectives

To examine the feasibility, evidence of promise and cost of the Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A), a peer-led PA intervention.

Design

Phase 1 comprised formative work and a pilot study conducted in one secondary school. Phase 2 was a feasibility study comprising a pilot randomised controlled trial in six secondary schools, including process and economic evaluations.

Setting

Six secondary schools in South Gloucestershire and Wiltshire, recruited from schools above the median local Pupil Premium (i.e. more deprived).

Participants

Year 8 girls (aged 12–13 years).

Intervention

Year 8 girls nominated other girls in their year who are likely to be influential (e.g. who they look up to, are good listeners); the 18% most nominated were invited to be peer supporters (PSs). PSs attended 2 consecutive days of training (plus a top-up day 5 weeks later) outside the school site, led by pairs of PS trainers, to increase their knowledge about PA and their capabilities and confidence to promote PA in their friendship group.

Main outcome measures

Measures focused on establishing evidence for feasibility and promise: recruitment and retention of Year 8 girls and PSs, data provision rates [accelerometer and questionnaire collected pre randomisation/beginning of Year 8 (T0), end of Year 8 (T1) and beginning of Year 9 (T2)], intervention acceptability, PS training attendance, intervention cost, and the between-arm difference in weekday minutes of moderate to vigorous PA (MVPA). A process evaluation was conducted.

Results

Six schools were recruited: four PLAN-A (n = 269) and two control (n = 158). In total, 94.7% of Year 8 girls participated. A total of 55 (17–24% of Year 8 girls) PSs were trained (attendance rate 91–100%). Five girls were trained as PS trainers. Questionnaire data provision exceeded 92% at all time points. Accelerometer return rates were > 85% and wear-time criteria were met by 83%, 71% and 62% of participants at T0, T1 and T2, respectively. Mean weekday MVPA did not differ between intervention arms at T1 (1.1 minutes, 95% CI –4.3 to 6.5 minutes) but did at T2 (6.1 minutes, 95% CI 1.4 to 10.8 minutes), favouring PLAN-A. The mean cost of intervention delivery was £2685 per school or £37 per Year 8 girl. Process evaluation identified good fidelity, engagement and enjoyment of the PS training and peer-support strategies. PSs needed more guidance on how to start conversations.

Limitations

Accelerometer data provision was lowest at T2, suggesting a need for strategies to increase compliance.

Conclusions

Informal peer-led intervention approaches, such as PLAN-A, hold promise as a means of promoting PA to adolescent girls.

Future work

A definitive randomised controlled trial of PLAN-A is warranted.

Trial registration

Current Controlled Trials ISRCTN12543546.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 7, No. 16. See the NIHR Journals Library website for further project information. The work was undertaken with the support of the Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), a UK Clinical Research Collaboration (UKCRC) Public Health Research Centre of Excellence. Joint funding (MR/KO232331/1) from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the Welsh Government and the Wellcome Trust, under the auspices of the UKCRC, is gratefully acknowledged. This study was designed and delivered in collaboration with the Bristol Randomised Trials Collaboration (BRTC), a UK CRC-registered clinical trials unit in receipt of NIHR clinical trials unit support funding. The intervention costs were jointly funded by South Gloucestershire Council and Wiltshire Council.

Association between serum activin A and metabolic syndrome in older adults: Potential of activin A as a biomarker of cardiometabolic disease

Cardiovascular disease imposes substantial burdens of morbidity and mortality that increase with population aging. Estimating cardiometabolic risk accurately and expediently is challenging, and no single biomarker is satisfactory; hence, we investigated the potential of serum activin A for this purpose. Study data were collected from 433 community-dwelling adults age ≥53 years from Yilan County, Taiwan. Data included: demographics and medical history; physical measurements (blood pressure, body mass index, waist circumference); comprehensive functional assessments (frailty, cognitive function, depressive symptoms, nutritional status); fasting blood biochemistry (glucose, high-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, insulin-like growth factor-1, activin A, stratified into high, medium and low tertiles, and others); and dual-energy X-ray absorptiometry. Metabolic syndrome was considered a proxy for overall cardiometabolic risk. Subjects mean age was 69.3 ± 9.2 years, 48.3% were males. Compared to women, men had higher systolic blood pressure, education levels, relative appendicular skeletal muscle mass, waist circumference, physical activity, walking speed, free androgen index, and levels of serum uric acid, alanine aminotransferase, and dehydroepiandrosterone sulfate. High activin A was significantly associated with age, relative appendicular skeletal muscle mass in both gender, waist circumference in women, current alcohol drinking, hypertension, and Charlson Comorbidity Index. There were dose-dependent relationships (low to high) between serum activin A and frailty, cognitive impairment, malnutrition, metabolic syndrome, uric acid, and high-sensitivity C-reactive protein. Logistic regression analyses showed older age, serum uric acid, and metabolic syndrome were significantly associated with medium and high activin-A status, whereas, skeletal muscle mass, insulin-like growth factor-1 and dehydroepiandrosterone sulphate were associated with high, but not medium, serum activin A. This discovery of a dose-dependent association between serum activin A levels, age, and metabolic syndrome, suggests activin A may be a biomarker of overall cardiometabolic risk; however, further studies are needed to evaluate its potential applications in assessing and managing cardiometabolic risk.

miR-322 regulates insulin signaling pathway and protects against metabolic syndrome-induced cardiac dysfunction in mice

We identified murine miR-322, orthologous to human miR-424, as a new regulator of insulin receptor, IGF-1 receptor and sirtuin 4 mRNA in vitro and in vivo in the heart and found that miR-322/424 is highly expressed in the heart of mice. C57Bl/6N mice fed 10weeks of high fat diet (HFD) presented signs of cardiomyopathy and a stable miR-322 cardiac level while cardiac function was slightly affected in 11week-old ob/ob which overexpressed miR-322. We thus hypothesized that mmu-miR-322 could be protective against cardiac consequences of hyperinsulinemia and hyperlipidemia. We overexpressed or knocked-down mmu-miR-322 using AAV9 and monitored cardiac function in wild-type C57Bl/6N mice fed a control diet (CD) or a HFD and in ob/ob mice. The fractional shortening progressively declined while the left ventricle systolic diameter increased in HFD mice infected with an AAVcontrol or with an AAVsponge (decreasing miR-322 bioavailability) but also in ob/ob mice infected with AAVsponge. Similar observations were also found in CD-fed mice infected with AAVsponge. On the contrary over-expressing miR-322 with AAVmiR-322 was efficient in protecting the heart from HFD effects in C57Bl/6N mice. This cardioprotection could be associated with the regulation of identified targets IGF1R, INSR and CD1, a decrease in insulin signaling pathway and an enrichment of genes involved in mitochondrial function and fatty acid oxidation as demonstrated by transcriptome analysis. Altogether, these results emphasize miR-322 as a new potential therapeutic target against cardiac consequences of metabolic syndrome, which represents an increasing burden in the western countries.

Intensity of bouted and sporadic physical activity and the metabolic syndrome in adults

Background. Physical activity guidelines for adults only recognize the health benefits of accumulating bouted moderate-to-vigorous physical activity (MVPA), or MVPA occurring over at least 10 consecutive minutes. There is a lack of evidence supporting the health benefits of other patterns and intensities of activity including sporadic MVPA (i.e., MVPA occurring in periods of fewer than 10 consecutive minutes) and light intensity physical activity (LIPA). The objective of this study was to examine the health benefits associated with physical activity that does not meet the physical activity guidelines criteria for bouted MVPA. Specifically, we examined the association between sporadic MVPA and bouted and sporadic LIPA with the metabolic syndrome. Methods. We studied a representative cross-sectional sample of 1,974 adults aged 20 years and older from the 2003-2006 US National Health and Nutrition Examination Survey. Physical activity was measured over 7 days using Actigraph AM-7164 accelerometers. Each minute over the 7-day measurement period was classified as being of a sedentary, light, or moderate-to-vigorous intensity. A 10 min threshold differentiated bouted activity from sporadic activity. Average minutes/day of sporadic LIPA, sporadic MVPA, bouted LIPA, bouted MVPA, and embedded MVPA (MVPA occurring within bouts of primarily LIPA) were calculated. Metabolic syndrome status was determined using established criteria. Associations were examined using logistic regression and controlled for relevant covariates. Results. For every 30 min/day of physical activity, the odds ratio (95% confidence interval) of the metabolic syndrome was reduced by 4% (1-7%) for bouted LIPA, 64% (51-71%) for bouted MVPA, and 57% (45-67%) for embedded MVPA. Sporadic LIPA was not independently associated with the metabolic syndrome. We could not examine the association between sporadic MVPA and the metabolic syndrome because participants accumulated such a marginal amount of this type of activity (i.e., median = 2 min/day, only 11% of participants accumulated ≥5 min/day). Conclusion. The intensity of non-bouted activity is important, as embedded MVPA had a stronger association with the metabolic syndrome than sporadic LIPA and a comparable association to bouted MVPA.

Gender- and race-specific metabolic score and cardiovascular disease mortality in adults: A structural equation modeling approach--United States, 1988-2006

OBJECTIVE

Consider all metabolic syndrome (MetS) components [systolic (SBP) and diastolic (DBP) blood pressures, waist circumference, HDL cholesterol, triglycerides (TG), and fasting glucose] and gender/race differential risk when assessing cardiovascular disease (CVD) risk.

METHODS

We estimated a gender- and race-specific continuous MetS score using structural equation modeling and tested its association with CVD mortality using data from National Health and Nutrition Examination Survey III linked with the National Death Index. Cox proportional hazard regression tested the association adjusted for sociodemographic and behavior characteristics.

RESULTS

For men, continuous MetS components associated with CVD mortality were SBP (hazard ratio = 1.50, 95% confidence interval = 1.14-1.96), DBP (1.48, 1.16-1.90), and TG (1.15, 1.12-1.16). In women, SBP (1.44, 1.27-1.63) and DBP (1.24, 1.02-1.51) were associated with CVD mortality. MetS score was not significantly associated with CVD mortality in men; but significant associations were found for all women (1.34, 1.06-1.68), non-Hispanic white women (1.29, 1.01-1.64), non-Hispanic black women (2.03, 1.12-3.69), and Mexican-American women (3.57, 2.21-5.76). Goodness-of-fit and concordance were overall better for models with the MetS score than MetS (yes/no).

CONCLUSIONS

When assessing CVD mortality risk, MetS score provided additional information than MetS (yes/no).

Obstructive sleep apnea syndrome and cardiovascular disease: The influence of C-reactive protein

Obstructive sleep apnea syndrome (OSAS) is a common medical condition, associated with atherosclerosis and cardiovascular disease (CVD). The underlying pathophysiologic mechanisms of this association have not been completely understood and may be multifactorial in origin. A number of studies suggest that inflammatory processes have emerged critical in the pathogenesis of CVD in OSAS. A range of circulating inflammatory molecules has been identified and measured, with a view to assess inflammation and predict vascular damage risk, such as plasma cytokines, adhesion molecules, and C-reactive protein (CRP). CRP is a relevant marker worthy of further study, because not only is elevated in patients with OSAS, but also is rapidly becoming a risk factor for cardiac disease. Furthermore, in selected OSAS patients, aggressive treatment of the disorder may lead to retarding or even improvement of CVD progression. However, still there is a debate on the true correlation between CRP and OSAS, as well as the clinical effect of any reduction after OSAS treatment. Further research is required to define those OSAS patients who will have a considerable reduction with treatment, as well as to understand the significance of the interaction between cardiovascular risk factor and CRP reduction in patients with OSAS.

Dietary regulation of histone acetylases and deacetylases for the prevention of metabolic diseases

Age-related diseases such as type 2 diabetes, cardiovascular disease, and cancer involve epigenetic modifications, where accumulation of minute changes in the epigenome over time leads to disease manifestation. Epigenetic changes are influenced by life style and diets. This represents an avenue whereby dietary components could accelerate or prevent age-related diseases through their effects on epigenetic modifications. Histone acetylation is an epigenetic modification that is regulated through the opposing action of histone acetylases (HATs) and deacetylases (HDACs). These two families of enzymes play critical roles in metabolic processes and their dysregulation is associated with pathogenesis of several diseases. Dietary components, such as butyrate, sulforaphane, and curcumin, have been shown to affect HAT and HDAC activity, and their health benefits are attributed, at least in part, to epigenetic modifications. Given the decades that it takes to accumulate epigenetic changes, it is unlikely that pharmaceuticals could undo epigenetic changes without side effects. Therefore, long term consumption of dietary components that can alter the epigenome could be an attractive means of disease prevention. The goal of this review is to highlight the roles of diets and food components in epigenetic modifications through the regulation of HATs and HDACs for disease prevention.

Association of metabolic factors with high-sensitivity C-reactive protein in patients with sleep-disordered breathing

Sleep-disordered breathing (SDB) such as snoring or obstructive sleep apnea and metabolic syndrome are both related to cardiovascular diseases. Being a surrogate marker of high risk for cardiovascular disorder, the high-sensitivity C-reactive protein (hs-CRP) level is thought to be elevated in patients with both SDB and metabolic syndrome. To understand better the development of cardiovascular disease in patients with SDB, we examined the association of metabolic variables with hs-CRP levels in adult patients with symptoms of SDB and without any previous treatment, who were selected to participate in the study. Metabolic parameters including fasting blood glucose, lipid profile and hs-CRP were measured following an overnight polysomnography. Laboratory and polysomnographic data were analyzed to identify variables related to high hs-CRP levels. A total of 309 patients with SDB participated in this study. Of these, 139 presented with hs-CRP <1 mg/L and 52 presented with hs-CRP >3 mg/L. Patients with high hs-CRP showed a higher apnea-hypopnea index (AHI), body mass index (BMI), fasting glucose, and triglyceride level, and a lower mean and minimal oxygen saturation and HDL-cholesterol level. However, ordinal regression analysis demonstrated that only a higher BMI and fasting glucose level and a lower HDL-cholesterol level were independent risk factors for cardiovascular diseases (OR = 1.076, 95 % CI = 1.009-1.147, p = 0.005; OR = 1.011, 95 % CI = 1.004-1.019, p = 0.008; OR = 0.966, 95 % CI = 0.947-0.984, p < 0.001, respectively). The results showed that elevated hs-CRP is common in patients with SDB but is not independently associated with the severity of SDB. Metabolic factors such as a higher BMI and fasting blood glucose and a lower HDL-cholesterol level were more strongly associated with elevated hs-CRP rather than with SDB severity, suggesting that metabolic parameters are important contributors to cardiovascular diseases and should be corrected in patients with SDB.

Metabolic syndrome and all-cause mortality in older men and women

BACKGROUND

Prevalence of metabolic syndrome (MetS) increases with age, but its association with all-cause mortality in older persons remains uncertain. This study investigated the association of all-cause mortality with MetS and its individual components in older men and women.

METHODS

A total of 917 men and 1043 women aged 65 years and older from two Italian population-based cohorts were included in the study. MetS was defined according to four different definitions: National Cholesterol Education Program (NCEP), NCEP revised according to the American Heart Association and National Heart Lung Blood Institute (NCEP-R), International Diabetes Organization (IDF) and Joint Interim Statement (JIS). All of these definitions include abdominal obesity, hyperglycaemia, hypertriglyceridaemia, low high-density lipoprotein cholesterol and hypertension. Hazard Ratios (HR) and their corresponding 95% confidence interval (95%CI) estimated from multivariable-adjusted Cox regression models were used to investigate the associations of all-cause mortality with baseline MetS status and individual MetS components.

RESULTS

After 6·5 ± 1·8 years of follow-up, there were 179 deaths among women and 193 among men. Mortality risk was increased in women with MetS by any definition, regardless of individual components, but limited to age 70-79 years (NCEP, HR = 2·02, 95%CI, 1·16-3·53; NCEP-R, HR = 2·51, 95%CI, 1·45-4·34; IDF, HR = 2·16, 95%CI, 1·26-3·72; JIS, HR = 2·16, 95%CI, 1·26-3·72). Mortality risk of men was associated with hypertriglyceridaemia below age 70 years (HR = 2·50, 95%CI, 1·19-5·25), but unrelated to MetS status.

CONCLUSIONS

Metabolic Syndrome is associated with all-cause mortality in older women but not in men. The association, however, is limited to a narrow age range.

Vigorous intensity physical activity is related to the metabolic syndrome independent of the physical activity dose

BACKGROUND

Current physical activity guidelines imply that, by comparison with moderate physical activity (MPA), the benefits of engaging in vigorous physical activity (VPA) are attributed to the greater energy expenditure dose per unit of time and do not relate to intensity per se. The purpose of this study was to determine whether VPA influences the metabolic syndrome (MetS) independent of its influence on the energy expenditure dose of moderate-to-vigorous physical activity (MVPA).

METHODS

Participants consisted of 1841 adults from the 2003-06 National Health and Nutrition Examination Survey, a representative cross-sectional study. MPA and VPA were measured objectively over 7 days using Actigraph accelerometers. MetS was determined using an established clinical definition. Associations between physical activity and the MetS were determined using logistic regression and controlled for relevant covariates.

RESULTS

Analyses revealed that VPA remained a meaningful predictor of the MetS after controlling for the total energy expenditure dose of MVPA such that the relative odds of the MetS was 0.28 (95% confidence interval 0.17-0.46) in the group with the highest VPA compared with the group with no VPA. VPA had a greater influence on the MetS than an equivalent energy expenditure dose of MPA. For instance, between 0 and 500 MET min/week of MPA the adjusted prevalence of the MetS decreased by 15.5%, whereas between 0 and 500 MET min/week of VPA the prevalence decreased by 37.1%.

CONCLUSION

These cross-sectional findings suggest that VPA per se has an important role in cardiometabolic disease prevention.

Metabolic syndrome is associated with change in subclinical arterial stiffness: a community-based Taichung community health study

BACKGROUND

The aim of this study was to evaluate the effect of MetS on arterial stiffness in a longitudinal study.

METHODS

Brachial-ankle pulse wave velocity (baPWV), a measurement interpreted as arterial stiffness, was measured in 1518 community-dwelling persons at baseline and re-examined within a mean follow-up period of 3 years. Multivariate linear regression with generalized estimating equations (GEE) were used to examine the longitudinal relationship between MetS and its individual components and baPWV, while multivariate logistic regression with GEE was used to examine the longitudinal relationship between MetS and its individual components and the high risk group with arterial stiffness.

RESULTS

Subjects with MetS showed significantly greater baPWV at the end point than those without MetS, after adjusting for age, gender, education, hypertension medication and mean arterial pressure (MAP). MetS was associated with the top quartile of baPWV (the high-risk group of arterial stiffness, adjusted odds ratio [95% confidence interval] 1.52 [1.21-1.90]), and a significant linear trend of risk for the number of components of MetS was found (p for trend < 0.05). In further considering the individual MetS component, elevated blood pressure and fasting glucose significantly predicted a high risk of arterial stiffness (adjusted OR [95% CI] 3.72 [2.81-4.93] and 1.35 [1.08-1.68], respectively).

CONCLUSIONS

MetS affects the subject's progression to arterial stiffness. Arterial stiffness increased as the number of MetS components increased. Management of MetS is important for preventing the progression to advanced arterial stiffness.

The impact of non- and genetically modified soybean diets in aorta wall remodeling

The aim of this study was to evaluate the influence of nongenetically modified soybean (non-GMS) and genetically modified soybean (GMS) meal on growth and cardiometabolic parameters in rats. Thirty male Wistar rats were divided into 3 groups (n= 10): non-GMS, GMS, and control group (CG). All animals received water and an isocaloric diet ad libitum for 455 d. Blood was drawn by cardiac puncture, and serum was separated for subsequent biochemical analyses (total cholesterol, triacylglycerols, insulin, glucose, and testosterone). The aorta was quickly harvested and fixed; the body fat mass was removed and weighed. Non-GMS and GMS had a growth index (GI) similar to CG but with a lower body weight (P < 0.05) and a lower amount of body fat mass (P < 0.05). Total cholesterol, triacylglycerol, glucose concentrations, and aortic tunics were reduced (P < 0.05) in non-GMS and GMS compared to CG. Non-GMS and GMS are able to reduced serum cholesterol, triacylglycerols, glucose, and aortic remodeling in aged rats. No differences were observed between non-GMS and GMS in all parameters.

Fitness and abdominal obesity are independently associated with cardiovascular risk

OBJECTIVES

To examine the relationship between cardiovascular fitness (VO(2)max) and abdominal obesity (waist circumference) and individual cardiovascular disease (CVD) risk factors, as well as a clustered risk factor profile, and to study the impact of gender, age and smoking on these relationships.

DESIGN

Cross-sectional.

SETTING

Astrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, Stockholm, Sweden.

SUBJECTS

Men (n = 781) and women (n = 890) from two random population-based samples of Swedish women and men aged 20 to 65 years.

MAIN OUTCOMES

Odds ratios.

RESULTS

Each unit of higher fitness was associated with a decrease in all individual risk factors ranging from 2% to 4% independent of waist circumference, each unit of higher waist circumference was associated with an increased risk ranging from 2% to 5% independent of fitness. For clustering of three or more of the risk factors, each unit of fitness was associated with a 5% decrease in risk and each unit of waist circumference with a 5% increase in risk. The clustered risk was higher in unfit participants who were older or smoked daily, regardless of waist circumference. Obese participants were at higher risk if they were men or older, regardless of fitness level. However, neither a higher fitness level nor lean status reduced the risk associated with smoking.

CONCLUSIONS

Higher fitness and lower waist circumference are each independently associated to a similar extent with a lower CVD risk. Simultaneous evaluation of both fitness and abdominal obesity status in clinical practice is important.

The metabolic syndrome adds utility to the prediction of mortality over its components: The Vietnam Experience Study

BACKGROUND

The metabolic syndrome increases mortality risk. However, as "non-affected" individuals may still have up to two risk factors, the utility of using three or more components to identify the syndrome, and its predictive advantage over individual components have yet to be determined.

METHODS

Participants, male Vietnam-era veterans (n=4265) from the USA, were followed-up from 1985/1986 for 14.7 years (61,498 person-years), and all-cause and cardiovascular disease deaths collated. Cox's proportional-hazards regression was used to assess the effect of the metabolic syndrome and its components on mortality adjusting for a wide range of potential confounders.

RESULTS

At baseline, 752 participants (17.9%) were identified as having metabolic syndrome. There were 231 (5.5%) deaths from all-causes, with 60 from cardiovascular disease. After adjustment for a range of covariates, the metabolic syndrome increased the risk of all-cause, HR 2.03, 95%CI 1.52, 2.71, and cardiovascular disease mortality, HR 1.92, 95%CI 1.10, 3.36. Risk increased dose-dependently with increasing numbers of components. The increased risk from possessing only one or two components was not statistically significant. The adjusted risk for four or more components was greater than for only three components for both all-cause, HR 2.30, 95%CI 1.45, 3.66 vs. HR 1.70, 95%CI 1.11, 2.61, and cardiovascular disease mortality, HR 3.34, 95%CI 1.19, 9.37 vs. HR 2.81, 95%CI 1.07, 7.35. The syndrome was more informative than the individual components for all-cause mortality, but could not be assessed for cardiovascular disease mortality due to multicollinearity. Hyperglycaemia was the individual strongest parameter associated with mortality.

CONCLUSIONS

The metabolic syndrome is informative in predicting mortality, with risk increasing as the number of components increase above the threshold required for diagnosis.

Asthma, environmental risk factors, and hypertension among Arab Americans in metro Detroit

Asthma and obesity-related health problems disproportionately impact low-income ethnic minority communities residing in urban areas. Environmental risk factors, particularly those related to housing and indoor air, may impact the development or exacerbation of asthma. There is increasing evidence to suggest a link between obesity-related health problems and asthma. Previous studies have also reported that immigrant status may influence myriad risk factors and health outcomes among immigrant populations. The Arab American Environmental Health Project (AAEHP) was the first study to explore environmental health problems among Arab Americans. This paper examined whether hypertensive status modified the relationship between environmental risk factors and asthma among Arab Americans in metro Detroit. An environmental risk index (ERI) was used to quantify household environmental risk factors associated with asthma. Physician diagnosed hypertension was self-reported, and asthma status was determined using responses to a validated symptoms checklist and self-reported diagnosis by a physician. Hypertension significantly modified the relationship between ERI and asthma in this study population. The positive association between household environmental risk factors and asthma was stronger among participants diagnosed with hypertension. Effect modification of the relationship between environmental risk factors and asthma could have serious implications among high-risk communities. However, further research is needed to elucidate the relationships between hypertension, environmental risk factors, and asthma.

Inflammation, obesity, and fatty acid metabolism: influence of n-3 polyunsaturated fatty acids on factors contributing to metabolic syndrome

Metabolic syndrome (MetS) comprises an array of metabolic risk factors including abdominal obesity, dyslipidemia, hypertension, and glucose intolerance. Individuals with MetS are at elevated risk for diabetes and cardiovascular disease. Central to the etiology of MetS is an interrelated triad comprising inflammation, abdominal obesity, and aberrations in fatty acid metabolism, coupled with the more recently recognized changes in metabolism during the postprandial period. We review herein preliminary evidence regarding the role of dietary n-3 polyunsaturated fatty acids in modulating each of the components of the triad of adiposity, inflammation, and fatty acid metabolism, with particular attention to the role of the postprandial period as a contributor to the pathophysiology of MetS.

Physical activity in prevention and treatment of the metabolic syndrome

Randomised controlled trials have shown that exercise training has a mild or moderate favourable effect on many metabolic and cardiovascular risk factors that constitute or are related to the metabolic syndrome (MetS). Epidemiological studies suggest that regular physical activity prevents type 2 diabetes, cardiovascular disease, and premature mortality in large part through these risk factors. Although randomized controlled trials with the prevention or treatment of the MetS as the main outcome have not been published, several large randomized controlled trials provide strong evidence that favourable lifestyle changes, including regular physical activity, are effective in the prevention of type 2 diabetes in individuals who are overweight and have impaired glucose tolerance. Compliance with the current recommendations to increase the total volume of moderate-intensity physical activity and to maintain good cardiorespiratory and muscular fitness appears to markedly decrease the likelihood of developing the MetS, especially in high-risk groups. Walking is the most common form of physical activity--it improves health in many ways and is generally safe. Therefore, brisk walking for at least 30 min daily can be recommended as the principal form of physical activity at the population level. If there are no contraindications, more vigorous physical exercise or resistance training should also be considered to obtain additional health benefits. Unstructured and low-intensity physical activity may also decrease the likelihood of developing the MetS, especially when substituted for sedentary behaviours such as watching television. The measurement of maximal oxygen consumption may provide an efficient means to target even individuals with relatively few metabolic risk factors who may benefit from more intensive intervention.

The metabolic syndrome: an introduction

It is my pleasure to introduce this special thematic issue of Applied Physiology, Nutrition, and Metabolism (APNM) on metabolic syndrome (MetS). This publication comes at an exciting time, in the midst of debates encompassing the most appropriate clinical definition of MetS, its potential etiological pathways, and questions about the very existence of MetS as an entity unto itself. This compilation of invited reviews and original research articles provides an overview and sampling of the latest research on MetS. It has been designed to meet the interests of the diverse readership of APNM and to stimulate further research in this important area of investigation.