The metabolic syndrome and antioxidant concentrations: findings from the Third National Health and Nutrition Examination Survey

Independent positive association of plasma β-carotene concentrations with adiponectin among non-diabetic obese subjects

PURPOSE

Many epidemiological studies find an inverse correlation between carotenoids intake or carotenoids plasma concentrations and body mass index (BMI), insulin resistance or metabolic syndrome in the general population. However, it is not clear whether these relationships occur in obese population.

METHODS

We conducted a cross-sectional study in 108 obese non-diabetic patients.

RESULTS

There was an inverse correlation between plasma levels of pro-vitamin A carotenoids (α-carotene, β-carotene and β-cryptoxanthin) and both BMI and insulin resistance (estimated by the HOMA-IR). No correlation between plasma concentrations of lycopene or lutein/zeaxanthin and BMI or insulin resistance was found. The inverse association between the three pro-vitamin A carotenoids and HOMA-IR disappeared after adjustment for BMI and waist circumference. Interestingly, we identified a positive association between concentrations of β-carotene and adiponectin in plasma that was independent of sex, age, smoking status, BMI and waist circumference. To our knowledge, such association has never been described in obese patients.

CONCLUSION

These results suggest the existence of a favourable effect of β-carotene on insulin sensitivity in obese individuals that could involve a positive regulation of adiponectin, either directly or via its pro-vitamin A activity. The demonstration of the potential benefits of β-carotene towards insulin sensitivity would open the way to dietary strategies to prevent metabolic syndrome.

Development and phytochemical characterization of high polyphenol red lettuce with anti-diabetic properties

Polyphenol-rich Rutgers Scarlet Lettuce (RSL) (Lactuca sativa L.) was developed through somaclonal variation and selection in tissue culture. RSL may contain among the highest reported contents of polyphenols and antioxidants in the category of common fruits and vegetables (95.6 mg/g dry weight and 8.7 mg/g fresh weight gallic acid equivalents and 2721 µmol/g dry weight and 223 µmol/g fresh weight Trolox equivalents). Three main compounds accumulate at particularly high levels in RSL: chlorogenic acid, up to 27.6 mg/g dry weight, cyanidin malonyl-glucoside, up to 20.5 mg/g dry weight, and quercetin malonyl-glucoside, up to 35.7 mg/g dry weight. Major polyphenolic constituents of RSL have been associated with health promotion as well as anti-diabetic and/or anti-inflammatory activities. Daily oral administration of RSL (100 or 300 mg/kg) for up to eight days acutely reduced hyperglycemia and improved insulin sensitivity in high fat diet-induced obese hyperglycemic mice compared to vehicle (water) control. Data presented here support possible use of RSL as a functional food for the dietary management of diabetes.

Association of fruits and vegetables consumption and related-vitamins with inflammatory and oxidative stress markers in prediabetic individuals

BACKGROUND

Dietary guidelines of 5 servings per day of fruits and vegetables (FV) offer a reasonable amount of vitamins to control organic processes, which may contribute to a favorable cardiometabolic profile. This study aimed at investigating whether the intake of the FV group as well as pro-vitamin A carotenoids and vitamins C and E were associated with circulating markers of oxidative stress, inflammation and insulin resistance in Brazilians individuals at cardiometabolic risk.

METHODS

This cross-sectional study included 205 individuals screened for diabetes prevention program in a healthcare center from the School of Public Health, University of São Paulo, conducted in 2008. Possible associations of consumption of FV group, as well as pro-vitamin A carotenoids and vitamins C and E, with circulating markers of oxidative stress (superoxide dismutase - SOD and oxidized LDL - oxLDL), inflammation (C reactive protein, TNF-α and adiponectin) and insulin resistance (HOMA-IR) were investigated. Pearson correlation coefficient, ANOVA and multiple linear regression were employed.

RESULTS

The sample (64.7% women) had a mean age of 54.1 ± 12.7 years and body mass index of 30.7 ± 5.7 kg/m2. Dietary, physical activity, anthropometric and laboratory data were obtained. Participants consumed a mean of 3.8 servings/day of FV; their FV intake was categorized into three groups: <2.5, 2.5-5.0 and >5.0 servings/day. Significant trends for lower waist circumference (103.4 ± 13.6 vs. 100.1 ± 12.2 vs. 98.2 ± 12.7 cm, p-trend <0.05) and higher adiponectin concentrations (10.4 ± 1.8 vs. 11.9 ± 1.9 vs. 13.6 ± 2.1 ng/mL, p-trend <0.05) were detected across categories. Associations between SOD concentrations (β 0.172 [0.110-0.688]) with FV consumption and between oxLDL concentrations with vitamins C (β -0.333 [-2.568 - -0.218]) and E (β -0.354 [-1.131- -0.110]) intakes, adjusted for age, gender, BMI, saturated fat intake, smoking and physical activity were found. Similar results were observed for the associations between oxLDL and FV intake, but significance disappeared adding adjustment for saturated fat, smoking and physical activity.

CONCLUSION

Our data suggest that the intake of FV or selected vitamins may be useful for identifying the oxidative stress and inflammation involved in the genesis of cardiometabolic diseases and for motivating at-risk patients for changing dietary habits.

Relationship of serum carotenoid concentrations with allostatic load as a measure of chronic stress among middle-aged adults in the USA

OBJECTIVE

Chronic stress and repeated physiological attempts at stress adaptation may result in 'fatigue' and suboptimal performance of multiple physiological systems, i.e. allostatic load (AL). Although carotenoids have been linked with individual cardiovascular, metabolic and inflammatory biomarkers, little is known about the relationship of carotenoids with the multi-system biomarker measure of stress, AL. The present study examined the association of serum concentrations of carotenoids with AL among middle-aged adults.

DESIGN

Cross-sectional. AL score was calculated based on nine risk-rated indicators (systolic and diastolic blood pressure, pulse rate, total and HDL-cholesterol, glycosylated Hb, sex-specific waist-to-hip ratio, albumin and C-reactive protein).

SUBJECTS

Middle-aged (45-64 years, n 3387) men and women participants in the Third National Health and Nutrition Examination Survey, NHANES III (1988-1994).

RESULTS

Serum β-carotene concentration was inversely associated with high AL after adjusting for age, education, race/ethnicity, serum cotinine, alcohol consumption, physical activity and other carotenoids (α-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin). Females in the lowest β-carotene quartile were 2·94 (95 % CI 1·74, 4·94) times and males 2·90 (95 % CI 1·43, 5·89) times as likely to have high AL, compared with peers in the highest quartile (P for linear trend 0·001 and 0·018 for females and males, respectively). Mean serum β-carotene concentrations were also inversely associated with the number of 'high-risk' AL components (P for linear trend <0·001 and 0·004 for females and males, respectively).

CONCLUSIONS

Our study adds to evidence linking low β-carotene levels with unfavourable health outcomes.

Measurement of antioxidant capacity using the biological antioxidant potential test and its role as a predictive marker of metabolic syndrome

BACKGROUND/AIMS

Oxidative stress increases the risk of cardiovascular complications of metabolic syndrome (MetS). This study was conducted to examine the difference in antioxidant capacity according to the presence of MetS, and to characterize the association between antioxidant capacity and MetS-related factors.

METHODS

We used the biological antioxidant potential (BAP) test to estimate antioxidant capacity. The BAP test has recently been used as an indicator of antioxidant capacity. We measured BAP levels in 45 patients with MetS (mean age, 44.6 ± 1.1 years) and 47 age- and sex-matched controls (mean age, 42.7 ± 1.1 years). To evaluate the association between antioxidant capacity and MetS, adiponectin, high-sensitivity C-reactive protein (hs-CRP), interleukin-6, tumor necrosis factor-α, and homeostatic model assessment for insulin resistance (HOMA-IR), linear regression and logistic analyses were performed.

RESULTS

The mean BAP of the MetS group (1,937.3 ± 36.5 µmol/L) was significantly lower than that of the non-MetS group (2,101.7 ± 29.5 µmol/L). Also, the mean BAP was low in persons having low high density lipoprotein and high triglyceride. Reduced antioxidant capacity was significantly associated with adiponectin, HOMA-IR and hs-CRP after adjusting for age and sex. The odds ratios for MetS with BAP, log adiponectin, log HOMA-IR, and log hs-CRP were 0.63 (95% confidence interval [CI], 0.49 to 0.82), 0.22 (0.10 to 0.51), 14.24 (4.35 to 46.58), and 1.93 (1.36 to 2.75), respectively.

CONCLUSIONS

Persons with MetS showed reduced antioxidant capacity. We identified relationships between antioxidant capacity measured by BAP test and MetS, as well as MetS-related factors, such as insulin resistance, hs-CRP, and adiponectin.

MG132 ameliorates kidney lesions by inhibiting the degradation of Smad7 in streptozotocin-induced diabetic nephropathy

BACKGROUND

Smad7 is the main negative regulatory protein in the transforming growth factor-β (TGF-β) downstream signaling pathway, which plays an important role in diabetic nephropathy (DN) and may be related to the ubiquitin proteasome pathway (UPP).

AIM

We investigated the role of UPP in regulating TGF-β/SMAD signaling and explored the therapeutic effect of the ubiquitin proteasome inhibitor MG132 on DN.

METHODS

Wistar rats were randomly divided into a diabetes group and a normal control group. Rats in the diabetes group were injected intraperitoneally with streptozotocin. Diabetic rats were then randomly divided into a diabetic nephropathy group (DN group), an MG132 high concentration (MH) group, and an MG132 low concentration (ML) group. After 8 weeks of treatment, 24-hour urinary microalbumin (UAlb), urinary protein/urinary creatinine (Up/Ucr) values, ALT, AST, Bcr, kidney damage, TGF-β, Smad7, fibronectin (FN), and Smurf2 were detected.

RESULTS

The body mass and Smad7 protein expression decreased in DN group, but kidney weight, kidney weight index, UAlb, Up/Ucr, FN and Smurf2 mRNA expression, and TGF-β protein expression increased. However, these changes diminished following treatment with MG132, and a more pronounced effect was evident in MH group compared to ML group.

CONCLUSION

MG132 alleviates kidney damage by inhibiting Smad7 ubiquitin degradation and TGF-β activation in DN.

Does vitamin C deficiency increase lifestyle-associated vascular disease progression? Evidence based on experimental and clinical studies

SIGNIFICANCE

Despite continuous advances in the prevention of cardiovascular disease (CVD), critical issues associated with an unhealthy lifestyle remain an increasing cause of morbidity and mortality in industrialized countries.

RECENT ADVANCES

A growing body of literature supports a specific role for vitamin C in a number of reactions that are associated with vascular function and control including, for example, nitric oxide bioavailability, lipid metabolism, and vascular integrity.

CRITICAL ISSUES

A large body of epidemiological evidence supports a relationship between poor vitamin C status and increased risk of developing CVD, and the prevalence of deficiency continues to be around 10%-20% of the general Western population although this problem could easily and cheaply be solved by supplementation. However, large intervention studies using vitamin C have not found a beneficial effect of supplementation. This review outlines the proposed mechanism by which vitamin C deficiency worsens CVD progression. In addition, it discusses problems with the currently available literature, including the discrepancies between the large intervention studies and the experimental and epidemiological literature.

FUTURE DIRECTIONS

Increased insights into vitamin C deficiency-mediated CVD progression will enable the design of future randomized controlled trials that are better suited to test the efficacy of vitamin C in disease prevention as well as the identification of high-risk individuals which could possibly benefit from supplementation.

Role of vitamin C in the function of the vascular endothelium

SIGNIFICANCE

Vitamin C, or ascorbic acid, has long been known to participate in several important functions in the vascular bed in support of endothelial cells. These functions include increasing the synthesis and deposition of type IV collagen in the basement membrane, stimulating endothelial proliferation, inhibiting apoptosis, scavenging radical species, and sparing endothelial cell-derived nitric oxide to help modulate blood flow. Although ascorbate may not be able to reverse inflammatory vascular diseases such as atherosclerosis, it may well play a role in preventing the endothelial dysfunction that is the earliest sign of many such diseases.

RECENT ADVANCES

Beyond simply preventing scurvy, evidence is mounting that ascorbate is required for optimal function of many dioxygenase enzymes in addition to those involved in collagen synthesis. Several of these enzymes regulate the transcription of proteins involved in endothelial function, proliferation, and survival, including hypoxia-inducible factor-1α and histone and DNA demethylases. More recently, ascorbate has been found to acutely tighten the endothelial permeability barrier and, thus, may modulate access of ascorbate and other molecules into tissues and organs.

CRITICAL ISSUES

The issue of the optimal cellular content of ascorbate remains unresolved, but it appears that low millimolar ascorbate concentrations are normal in most animal tissues, in human leukocytes, and probably in the endothelium. Although there may be little benefit of increasing near maximal cellular ascorbate concentrations in normal people, many diseases and conditions have either systemic or localized cellular ascorbate deficiency as a cause for endothelial dysfunction, including early atherosclerosis, sepsis, smoking, and diabetes.

FUTURE DIRECTIONS

A key focus for future studies of ascorbate and the vascular endothelium will likely be to determine the mechanisms and clinical relevance of ascorbate effects on endothelial function, permeability, and survival in diseases that cause endothelial dysfunction.

Selenium, zinc, and copper plasma levels in patients with schizophrenia: relationship with metabolic risk factors

The aim of this study was to determine the plasma selenium (Se), copper (Cu), and zinc (Zn) levels and to evaluate their possible association with metabolic syndrome (MetS) components in patients with schizophrenia. The study group consisted of 60 patients with schizophrenia and 60 sex- and age-matched healthy controls. Anthropometric measurements, blood pressure, and biochemical analysis of fasting blood were performed in all subjects. Patients with schizophrenia had significantly higher plasma Cu concentrations compared with controls (0.97 ± 0.31 vs. 0.77 ± 0.32 mg/L, p = 0.001). The plasma Cu concentration showed a positive correlation with plasma glucose and diastolic blood pressure in the patient groups (r s = 0.263, p < 0.05 and r s = 0.272, p < 0.05, respectively). The plasma Se level correlated positive with MetS score (r s = 0.385, p < 0.01), waist circumference (r s = 0.344, p < 0.05), plasma glucose (r s = 0.319, p < 0.05), and triglyceride concentrations (r s = 0.462, p < 0.001) in patients with schizophrenia. Plasma Zn did not correlate with any of the MetS components. These results suggest that alterations in plasma Cu and Se levels in medicated patients with schizophrenia could be associated with metabolic risk factors.

Selected dietary nutrients and the prevalence of metabolic syndrome in adult males and females in Saudi Arabia: a pilot study

During the last decade, the rapid economic development in Saudi Arabia resulted in an unbalanced dietary intake pattern within the general population. Consequently, metabolic syndrome was also documented to be highly prevalent in the Middle-East region. We aimed to examine the relationship between selected dietary nutrient intakes and the prevalence of metabolic syndrome in the general adult population of Riyadh, Saudi Arabia. In this cross-sectional study, 185 adult Saudis aged 19 to 60 years (87 males and 98 females (mean age 35.6 ± 13.2 and 37.6 ± 11.7 years, respectively)) were included. The criteria for metabolic syndrome were based on the International Diabetes Foundation (IDF) criteria, and the dietary food intake was assessed by two 24-h dietary recall methods. The odd ratios (ORs) of metabolic syndrome risk across quartiles of selected dietary nutrients were significantly lower for carbohydrates and proteins, as well as for vitamins A, C, E and K, calcium, zinc and magnesium (p < 0.05 for all) in the female group with metabolic syndrome than those without. The pattern of daily dietary intake of selected nutrients among the general population of Saudi Arabia raises concern, and this dietary imbalance could increase the risk of metabolic syndrome, particularly in adult Saudi females.

Exercise and type 1 diabetes (T1DM)

Physical exercise is firmly incorporated in the management of type 1 diabetes (T1DM), due to multiple recognized beneficial health effects (cardiovascular disease prevention being preeminent). When glycemic values are not excessively low or high at the time of exercise, few absolute contraindications exist; practical guidelines regarding amount, type, and duration of age-appropriate exercise are regularly updated by entities such as the American Diabetes Association and the International Society for Pediatric and Adolescent Diabetes. Practical implementation of exercise regimens, however, may at times be problematic. In the poorly controlled patient, specific structural changes may occur within skeletal muscle fiber, which is considered by some to be a disease-specific myopathy. Further, even in well-controlled patients, several homeostatic mechanisms regulating carbohydrate metabolism often become impaired, causing hypo- or hyperglycemia during and/or after exercise. Some altered responses may be related to inappropriate exogenous insulin administration, but are often also partly caused by the "metabolic memory" of prior glycemic events. In this context, prior hyperglycemia correlates with increased inflammatory and oxidative stress responses, possibly modulating key exercise-associated cardio-protective pathways. Similarly, prior hypoglycemia correlates with impaired glucose counterregulation, resulting in greater likelihood of further hypoglycemia to develop. Additional exercise responses that may be altered in T1DM include growth factor release, which may be especially important in children and adolescents. These multiple alterations in the exercise response should not discourage physical activity in patients with T1DM, but rather should stimulate the quest for the identification of the exercise formats that maximize beneficial health effects.

Serum Retinol and Carotenoids in Association with Biomarkers of Insulin Resistance among Premenopausal Women

Objective. The aim of this study was to investigate how serum retinol and carotenoids (β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene) are associated with biomarkers of insulin resistance. Research Methods and Procedures. The BioCycle Study (2005–2007) is a prospective cohort of 259 healthy premenopausal women. Fasting serum samples were collected at up to sixteen clinic visits, from which retinol, carotenoids, insulin, glucose, and sex hormone-binding globulin (SHBG) were measured. Insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). Linear mixed models were used to determine associations adjusting for age, race, body mass index (BMI), education, smoking, physical activity, triglycerides, and energy intake. Results. Retinol was positively associated with HOMA-IR (β = 0.19 (95% CI: 0.07, 0.32)) units per ug/mL increase in retinol; the relationship was driven by insulin (β = 0.20 (95% CI: 0.08, 0.31)). Retinol was inversely associated with SHBG (β = −0.22 (95% CI: −0.28, −0.16)). Although no significant associations were found between serum carotenoids and HOMA-IR, β-carotene was positively associated with SHBG and β-cryptoxanthin inversely with fasting plasma glucose. Conclusion. Results indicate a possible role for serum retinol in the pathogenesis of type 2 diabetes. However, they do not support a strong association between individual or total serum carotenoids and insulin resistance.

The antioxidant status and concentrations of coenzyme Q10 and vitamin E in metabolic syndrome

The purpose of this study was to investigate the levels of coenzyme Q10 and vitamin E and the antioxidant status in subjects with metabolic syndrome (MS). Subjects with MS (n = 72) were included according to the criteria for MS. The non-MS group (n = 105) was comprised of healthy individuals with normal blood biochemical values. The plasma coenzyme Q10, vitamin E concentrations, lipid profiles, and antioxidant enzymes levels (catalase, superoxide dismutase, and glutathione peroxidase) were measured. The subjects with MS had significantly higher concentrations of plasma coenzyme Q10 and vitamin E than those in the non-MS group, but these differences were not significant after being normalized for triglyceride level. The levels of antioxidant enzymes were significantly lower in the MS group than in the non-MS group. The subjects with the higher antioxidant enzymes activities had significant reductions in the risk of MS (P < 0.01) after being adjusted for coenzyme Q10 and vitamin E. In conclusion, the subjects with MS might be under higher oxidative stress resulting in low levels of antioxidant enzyme activities. A higher level of antioxidant enzymes activities was significantly associated with a reduction in the risk of MS independent of the levels of coenzyme Q10 and vitamin E.

Micronutrient intake and the presence of the metabolic syndrome

Background:

Dietary micronutrients have been proposed to protect against oxidative damage and related clinical complications.

Aims:

We aimed to compare the micronutrient intake between individuals with and without metabolic syndrome (MS).

Materials and Methods:

This cross-sectional study included 3800 men and women who were aged between 35 and 65 years. The diagnosis of the MS was based on International Diabetes Federation criteria. Dietary intake of participants was assessed using a questionnaire for 24 h dietary recall. Student's t-test and Mann–Whitney U-tests were used for comparing the micronutrient intake of subjects with or without the MS and the odds ratio for the presence of the MS was calculated for each micronutrient by control for total energy intake adjusted by the residue method.

Results:

The mean age of MS subjects and the control group was 48.8 ± 7.9 years and 47.6 ± 7.6 years, respectively. Energy-adjusted intake of vitamin E (P < 0.05), B2 (P < 0.01), and B12 (P < 0.05) was higher in normal women compared with women with MS. Energy-adjusted intake of vitamin B1 was significantly higher in women with MS. After logistic regression analysis, no significant association between micronutrient intake and MS was shown.

Conclusion:

We found no significant association between micronutrient intake and MS.

Phytochemicals targeting genes relevant for type 2 diabetes

Nutrigenomic approaches based on ethnopharmacology and phytotherapy concepts have revealed that type 2 diabetes mellitus (T2DM) may be susceptible to dietary intervention. Interaction between bioactive food components and the genome may influence cell processes and modulate the onset and progression of the disease. T2DM, characterized by insulin resistance and beta cell dysfunction, is one of the leading causes of death and disability. Despite the great advances that have been made in the understanding and management of this complex, multifactorial disease, T2DM has become a worldwide epidemic in the 21st century. Population and family studies have revealed a strong genetic component of T2DM, and a number of candidate genes have been identified in humans. Variations in the gene sequences such as single nucleotide polymorphisms, explain the individual differences in traits like disease susceptibility and response to treatment. A clear understanding of how nutrients affect the expression of genes should facilitate the development of individualized intervention and, eventually, treatment strategies for T2DM. Review of the literature identified many phytochemicals/extracts from traditional medicinal plants that can target diabetogenic genes. This review focuses on the genetic aspects of T2DM, nutrient modification of genes relevant for diabetes, and future prospects of nutritional therapy of T2DM.

Antioxidant status and its association with elevated depressive symptoms among US adults: National Health and Nutrition Examination Surveys 2005-6

We examined the relationship of elevated depressive symptoms with antioxidant status. Cross-sectional data from the National Health and Nutrition Examination Surveys 2005–6 on US adults aged 20–85 years were analysed. Depressive symptoms were measured using the Patient Health Questionnaire with a score cut-off point of 10 to define ‘elevated depressive symptoms’. Serum antioxidant status was measured by serum levels of carotenoids, retinol (free and retinyl esters), vitamin C and vitamin E. The main analyses consisted of multiple logistic and zero-inflated Poisson regression models, taking into account sampling design complexity. The final sample consisted of 1798 US adults with complete data. A higher total serum carotenoid level was associated with a lower likelihood of elevated depressive symptoms with a reduction in the odds by 37 % overall with each sd increase in exposure, and by 34 % among women (P< 0·05). A dose–response relationship was observed when total serum carotenoids were expressed as quartiles (Q4 (1·62–10·1 μmol/l) v. Q1 (0·06–0·86 μmol/l): OR 0·41; 95 % CI 0·23, 0·76, P< 0·001; P for trend = 0·035), though no significant associations were found with the other antioxidant levels. Among carotenoids, β-carotene (men and women combined) and lutein+zeaxanthins (women only, after control for dietary lutein+zeaxanthin intake and supplement use) had an independent inverse association with elevated depressive symptoms among US adults. None of the other serum antioxidants had a significant association with depressive symptoms, independently of total carotenoids and other covariates. In conclusion, total carotenoids (mainly β-carotene and lutein+zeaxanthins) in serum were associated with reduced levels of depressive symptoms among community-dwelling US adults.

Why it is necessary to translate curcumin into clinical practice for the prevention and treatment of metabolic syndrome?

Curcumin (diferuloylmethane) is the yellow-orange pigment of dried Curcuma longa L. rhizomes (turmeric). During the past two decades, there has been a large volume of published studies describing the biological and pharmacological properties of this phytochemical including anticancer, anti-inflammatory, antioxidant, antithrombotic, antiatherosclerotic, cardioprotective, neuroprotective, memory enhancing, antiparkinsonism, antirheumatic, anti-infectious, antiaging, antipsoriatic, and anticonvulsant activities. In addition, curcumin has been shown to be extremely safe and interact with multiple molecular targets that are involved in the pathogenesis of metabolic syndrome. Curcumin could favorably affect all leading components of metabolic syndrome including insulin resistance, obesity, hypertriglyceridemia, decreased HDL-C and hypertension, and prevent the deleterious complications of MetS including diabetes and cardiovascular disease. Owing to its antioxidant and anti-inflammatory properties, curcumin can also exert several pleiotropic effects and improve endothelial dysfunction, adipokine imbalances, and hyperuricemia which usually accompany MetS. Despite the potential tremendous benefit of this multifaceted phytopharmaceutical, no trial result has yet been publicized on this issue. This review seeks to briefly summarize the ample scientific evidence that supports the therapeutic efficacy of curcumin, at least as an adjunctive treatment, in patients with MetS.

Cardiac dysfunction and oxidative stress in the metabolic syndrome: an update on antioxidant therapies

The metabolic syndrome (MetS) is a cluster of risk factors including obesity, insulin resistance, dyslipidemia, elevated blood pressure and glucose intolerance. The MetS increases the risk for cardiovascular disease (CVD) and type 2 diabetes. Each component of the MetS causes cardiac dysfunction and their combination carries additional risk. The mechanisms underlying cardiac dysfunction in the MetS are complex and might include lipid accumulation, increased fibrosis and stiffness, altered calcium homeostasis, abnormal autophagy, altered substrate utilization, mitochondrial dysfunction and increased oxidative stress. Mitochondrial and extra-mitochondrial sources of reactive oxygen species (ROS) and reduced antioxidant defense mechanisms characterize the myocardium of humans and animals with the MetS. The mechanisms for increased cardiac oxidative stress in the MetS are not fully understood but include increased fatty acid oxidation, mitochondrial dysfunction and enhanced NADPH oxidase activity. Therapies aimed to reduce oxidative stress and enhance antioxidant defense have been employed to reduce cardiac dysfunction in the MetS in animals. In contrast, large scale clinical trials using antioxidants therapies for the treatment of CVD have been disappointing because of the lack of efficacy and undesired side effects. The focus of this review is to summarize the current knowledge about the mechanisms underlying cardiac dysfunction in the MetS with a special interest in the role of oxidative stress. Finally, we will update the reader on the results obtained with natural antioxidant and mitochondria-targeted antioxidant therapies for the treatment of CVD in the MetS.

Relationships between serum total bilirubin levels and metabolic syndrome in Korean adults

BACKGROUND AND AIMS

Metabolic syndrome (MS) is associated with insulin resistance in all parts of its natural history, which is accompanied by oxidative stress. Bilirubin is a potent endogenous antioxidant and cytoprotectant. The current study was performed to identify the major predictors of the total bilirubin level and to assess the relationships between the total bilirubin levels and MS in Korean adults.

METHODS AND RESULTS

This is a cross-sectional study involving 12342 adults aged 20 years and over who visited a Health Promotion Center. Physical examinations and laboratory tests including total and direct bilirubin levels were performed. MS was defined based on the modified NCEP-ATP III definition and the determinations of the Korean Society for the Study of Obesity. The results showed that hemoglobin had the strongest influence on the total bilirubin levels after adjusting for age, gender, and all other variables. The high-bilirubin group (≥15.4 μmol/L in males and ≥12.1 μmol/L in females) was associated with significantly decreased odds of MS compared to the low-bilirubin group (OR 0.74 [95% CI 0.64-0.86]). High levels of bilirubin also were negatively associated with abdominal obesity and hypertriglyceridemia. The total bilirubin levels decreased with an increase in the number of MS components after adjustment for all covariates.

CONCLUSION

Within the physiological range, the serum total bilirubin level was negatively associated with the MS in subjects without overt metabolic or cardiovascular diseases. This may be partially due to the negative association between the total bilirubin level and abdominal obesity and hypertriglyceridemia.

Association of serum ferritin and the development of metabolic syndrome in middle-aged Korean men: a 5-year follow-up study

OBJECTIVE

Elevated serum ferritin has been known to be associated with the prevalence of metabolic syndrome (MetS). However, there was no research to examine whether serum ferritin levels have been actually associated with the prospective development of MetS. Accordingly, we carried out a prospective study to evaluate the longitudinal effects of baseline serum ferritin levels on the development of MetS.

RESEARCH DESIGN AND METHODS

A MetS-free cohort of 18,022 healthy Korean men, who had participated in a medical health checkup program in 2005, was followed until 2010. MetS was defined according to the joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. Cox proportional hazards models were performed.

RESULTS

During 45,919.3 person-years of follow-up, 2,127 incident cases of MetS developed between 2006 and 2010. After adjusting for multiple covariates, the hazard ratios (95% CI) for incident MetS comparing the second quintile to the fifth quintile of serum ferritin levels versus the first quintile were 1.19 (0.98-1.45), 1.17 (0.96-1.43), 1.36 (1.12-1.65), and 1.66 (1.38-2.01), respectively (P for trend <0.001). These associations were apparent in the clinically relevant subgroup analyses.

CONCLUSIONS

Elevated serum ferritin levels were independently associated with future development of MetS during the 5-year follow-up period.

Evaluation of oxidative stress in overweight subjects with or without metabolic syndrome

Although oxidative stress is considered the underlying mechanism by which dysfunctional metabolism occurs in obese subjects, there are few studies on oxidative stress in overweight subjects. The objective of this study was to verify the influence of metabolic syndrome (MetS) on oxidative stress and antioxidant defense in overweight subjects. There were 123 subjects (50 in the control group and 73 in the overweight group) chosen to participate in this cross-sectional study. The control group included 50 healthy individuals with a BMI between 20 and 24.9 kg/m(2) and without MetS. The overweight group included 73 subjects with a BMI between 25 and 29.9 kg/m(2). Overweight subjects were divided into two groups: with MetS (29 subjects) and without MetS (44 subjects). Control group and overweight group subjects without MetS showed no differences in oxidative stress parameters and total antioxidant capacity (TRAP). Overweight subjects with MetS had higher hydroperoxide concentrations measured by chemiluminescence compared to the control group (P < 0.05), higher hydroperoxide and hydrogen peroxide concentrations determined by ferrous oxidation-xylenol orange assay compared to overweight subjects without MetS (P < 0.001), and higher advanced oxidation protein product (AOPP) concentrations (P < 0.001) compared to the other groups. AOPP was directly correlated with uric acid concentrations. Overweight subjects with MetS had lower TRAP concentrations compared to the control group (P < 0.001). In conclusion, this study showed that overweight subjects with MetS, in contrast to overweight subjects without MetS, have a redox imbalance characterized by increased plasma oxidation and reduced antioxidant capacity.

Antioxidants and diabetes

Hyperglycemia promotes auto-oxidation of glucose to form free radicals. The generation of free radicals beyond the scavenging abilities of endogenous antioxidant defenses results in macro- and microvascular dysfunction. Antioxidants such as N-acetylcysteine, vitamin C and α-lipoic acid are effective in reducing diabetic complications, indicating that it may be beneficial either by ingestion of natural antioxidants or through dietary supplementation. However, while antioxidants are proving essential tools in the investigation of oxidant stress-related diabetic pathologies and despite the obvious potential merit of a replacement style therapy, the safety and efficacy of antioxidant supplementation in any future treatment, remains to be established.

Moderate weight loss decreases oxidative stress and increases antioxidant status in patients with metabolic syndrome

Background. Oxidative stress is enhanced in metabolic syndrome (MetS) and believed to contribute to accelerated atherosclerosis. Weight loss is associated with lowered oxidative stress. Methods. We performed a cross-sectional study in 92 consecutive patients with metabolic syndrome and 80 without. A dietary intervention with moderately low-calorie diet (600 calories/day negative energy balance) was carried out in 53 of metabolic syndrome patients. Oxidative stress, assessed by sNOX2-dp and urinary 8-iso-PGF2α, and antioxidant status, assessed by serum levels of vitamin E and adiponectin, were measured before and after 6 months. Results. Serum vitamin E/cholesterol ratio was significantly lower in metabolic syndrome compared to controls (P < 0.001) and decreased by increasing the number of metabolic syndrome components (P < 0.001). After six months, 23 and 30 patients showed >5% (group A) or <5% (group B) weight loss, respectively. Urinary 8-iso-PGF2α (−39.0%), serum sNOX2-dp (−22.2%), adiponectin (+125%), and vitamin E/cholesterol ratio (+129.8%) significantly changed only in A group. Changes in body weight and in serum adiponectin were independent predictors of vitamin E/cholesterol ratio variation. Conclusion. Our findings show that in metabolic syndrome moderate weight loss is associated with multiple health benefits including not only oxidative stress reduction but also enhancement of antioxidant status.

Oxidative stress in metabolic syndrome

As antioxidants play a protective role in the pathophysiology of diabetes and cardiovascular diseases, understanding the physiological status of antioxidant concentration among people at high risk for developing these conditions, such as Metabolic Syndrome, is of interest. In present study out of 187 first degree non-diabetic relatives and 192 non-diabetic spouses, 33.1% and 19.7% were found to have metabolic syndrome respectively. Subjects with metabolic syndrome (≥3 risk factors) had poor antioxidants status as reflected by significantly low levels of vitamin A, C & E and significantly increased (p<0.01) oxidative stress as compared to those without metabolic syndrome. At the same time serum insulin levels and insulin resistance were found to be significantly high (p<0.001) in metabolic syndrome. A strong positive correlation (r=0.946; p<0.001) between oxidative stress and insulin resistance was observed in metabolic syndrome. Low levels of antioxidants and increased oxidative stress with insulin resistance in metabolic syndrome suggests that besides therapeutic life style changes (TLC) as suggested in ATP III guidelines inclusion of antioxidant vitamins, fruits and vegetable could be beneficial to ward off the consequences of metabolic syndrome.

Dietary intake is not associated to the metabolic syndrome in elderly women

Background:

The metabolic syndrome is a complex metabolic disturbance due to an interaction between genetic factors, poor dietary habits and physical inactivity.

Aims:

To investigate the role of dietary intake on the prevalence of the metabolic syndrome in a population of elderly, socially active women in Brazil.

Patients and Methods:

A total of 284 women with mean age 69.3 ± 6.3 years were evaluated in a cross-sectional retrospective study. The metabolic syndrome was diagnosed according to criteria of the International Diabetes Federation. The dietary intake was evaluated through a questionnaire for 24-hour dietary recall. The groups with or without the metabolic syndrome were compared for dietary intake and risk factors for metabolic syndrome by the multiple regression model adjusted for age, smoking, physical activity, educational level, total energy intake and fiber contents of the diet. The odds ratio for the presence of the metabolic syndrome was calculated for each nutrient by quartile for total energy intake adjusted by the residue method.

Results:

The prevalence of metabolic syndrome was 32% in the sample. There was not found any association between dietary intake, including all macronutrients and several micronutrients, and the presence of metabolic syndrome.

Conclusion:

No associations were observed between nutritional factors and the prevalence of the metabolic syndrome in elderly women, a result possibly due to the fact that these factors have an influence in earlier phases of life, or to a recent modification of dietary habits, which however was not able to prevent the establishment of the syndrome.

Serum antioxidant concentrations and metabolic syndrome are associated among U.S. adolescents in recent national surveys

Specific micronutrients, including retinol, retinyl esters, carotenoids [α-carotene, β-carotene (cis+trans), β-cryptoxanthin, lutein+zeaxanthin, and total lycopene], vitamin E, and vitamin C have antiinflammatory and antioxidant effects, properties shown to reduce oxidative stress, a process that accompanies the pathogenesis of many chronic diseases. It is still largely unknown whether they are associated with the occurrence of metabolic syndrome (MetS) in the adolescent U.S. population. MetS was defined by the International Diabetes Federation (IDF) criteria. Other non-MetS outcomes relying on blood measurements were elevated HOMA-IR, C-reactive protein (CRP), and hyperuricemia. We tested associations between serum antioxidants and MetS outcomes among adolescents aged 12-19 y using cross-sectional data from NHANES 2001-2006 (n = 782-4285). IDF MetS prevalence was estimated at 7% among boys and 3% among girls. In adjusted models, adolescents with MetS had consistently lower carotenoid concentrations compared with their counterparts without MetS. Total carotenoids were also inversely related to HOMA-IR and CRP. Vitamin C was inversely related to uric acid level and MetS binary outcome. Retinol+retinyl esters exhibited an inverse relationship with CRP and a positive relationship with uric acid and HOMA-IR as well as MetS binary outcome. Vitamin E had no association with MetS, particularly after controlling for serum cholesterol and TG. In conclusion, among U.S. adolescents, serum carotenoid concentrations were inversely associated with MetS status, HOMA-IR, and CRP, whereas serum vitamin C was inversely related to MetS status and serum uric acid. Vitamin E had no consistent association with MetS, whereas retinol+retinyl esters had a positive relationship with HOMA-IR, uric acid, and MetS, while being inversely related to CRP. These associations need further study.

Metabolic syndrome meets osteoarthritis

Metabolic osteoarthritis (OA) has now been characterized as a subtype of OA, and links have been discovered between this phenotype and metabolic syndrome (MetS)--both with individual MetS components and with MetS as a whole. Hypertension associates with OA through subchondral ischaemia, which can compromise nutrient exchange into articular cartilage and trigger bone remodelling. Ectopic lipid deposition in chondrocytes induced by dyslipidemia might initiate OA development, exacerbated by deregulated cellular lipid metabolism in joint tissues. Hyperglycaemia and OA interact at both local and systemic levels; local effects of oxidative stress and advanced glycation end-products are implicated in cartilage damage, whereas low-grade systemic inflammation results from glucose accumulation and contributes to a toxic internal environment that can exacerbate OA. Obesity-related metabolic factors, particularly altered levels of adipokines, contribute to OA development by inducing the expression of proinflammatory factors as well as degradative enzymes, leading to the inhibition of cartilage matrix synthesis and stimulation of subchondral bone remodelling. In this Review, we summarize the shared mechanisms of inflammation, oxidative stress, common metabolites and endothelial dysfunction that characterize the aetiologies of OA and MetS, and nominate metabolic OA as the fifth component of MetS. We also describe therapeutic opportunities that might arise from uniting these concepts.

Epigenetic manifestation of metabolic syndrome and dietary management

SIGNIFICANCE

Metabolic syndrome constitutes a group of disorders such as insulin resistance, hypertension, and hypertriglyceridemia, predisposing an individual to risk factors such as cardiovascular disease, diabetes, obesity, and dyslipidemia. A majority of these diseases are influenced by the environmental factors, nutrient uptake, and genetic profile of an individual that together dysregulate gene function. These genetic and nongenetic factors are reported to introduce epigenetic cues that modulate the gene function which is inherited by the offspring.

RECENT ADVANCES

Considering the epigenetic modulation of the metabolic disorders, nutrigenomics has been distinctly categorized as a branch that deals with modulatory effect of nutrients on metabolic disorders and disease progression by supplementing the individuals with key nutrient-enriched diets which are derived from plant and animal sources.

CRITICAL ISSUES

Nutritional components of the diet regulate the metabolic health of an individual either by controlling the expression of some key genes related to metabolic pathways or by modulating the epigenetic events on such genes. The present article discusses various metabolic disorders in detail and the effect of nutrients on the specific genes causing those disorders. We also highlight the molecular mechanisms of some metabolic disorders through epigenetic modifications and possible therapeutic interventions.

FUTURE DIRECTIONS

With the advent of high-throughput technologies and epigenetic modulation of the metabolic disorders, an altered epigenetic code that is programmed due to improper nutrients can be reverted back by supplementing the diet with various plant-derived compounds. The implication of small molecular drugs is also of utmost significance for challenging the metabolic disorders.

The metabolic syndrome, oxidative stress, environment, and cardiovascular disease: the great exploration

The metabolic syndrome affects 30% of the US population with increasing prevalence. In this paper, we explore the relationship between the metabolic syndrome and the incidence and severity of cardiovascular disease in general and coronary artery disease (CAD) in particular. Furthermore, we look at the impact of metabolic syndrome on outcomes of coronary revascularization therapies including CABG, PTCA, and coronary collateral development. We also examine the association between the metabolic syndrome and its individual component pathologies and oxidative stress. Related, we explore the interaction between the main external sources of oxidative stress, cigarette smoke and air pollution, and metabolic syndrome and the effect of this interaction on CAD. We discuss the apparent lack of positive effect of antioxidants on cardiovascular outcomes in large clinical trials with emphasis on some of the limitations of these trials. Finally, we present evidence for successful use of antioxidant properties of pharmacological agents, including metformin, statins, angiotensin II type I receptor blockers (ARBs), and angiotensin II converting enzyme (ACE) inhibitors, for prevention and treatment of the cardiovascular complications of the metabolic syndrome.

Gender differences in copper, zinc and selenium status in diabetic-free metabolic syndrome European population - the IMMIDIET study

BACKGROUND AND AIMS

The European 'IMMIDIET' study was designed to evaluate the effect of genetic and dietary habit interactions on cardiovascular disease risk factors in non-diabetic subjects. Copper, zinc and selenium are involved in redox balance and modifications of their homeostasis could be associated with metabolic syndrome. Because few studies have dealt with trace element status in metabolic syndrome with conflicting results, we aimed at investigating the relationships between plasma copper, zinc and selenium concentrations and metabolic syndrome in the IMMIDIET population.

METHODS AND RESULTS

Male-female couples born and living in Abruzzo, Italy (n = 271); Limburg, Belgium (n = 267), southwest part of London, England (n = 263) and 205 Italian-Belgian mixed couples living in Belgium were enrolled. Data on medical history, hypertension and blood lipid profile, medication use, smoking and alcohol habits, physical activity and socioeconomic status were collected using a standardised questionnaire. Anthropometric, blood pressure, glucose, insulin, lipid profile and copper, zinc and selenium measurements were performed. Participants were classified in two groups according to the presence of metabolic syndrome (Yes/No). Comparison between these two groups, performed separately in men and women, indicated no association in men whereas, in women, metabolic syndrome was associated with higher plasma selenium concentrations (odds ratio (OR) = 1.55(1.28-1.89)); this association remained significant after adjustment for age, group, social status, physical activity, energy intake, alcohol consumption, smoking and hormonal status (OR = 1.33 (1.06-1.67)).

CONCLUSION

Our results indicate gender differences in the association between plasma selenium concentration and metabolic syndrome without diabetes and may suggest a sub-clinical deleterious effect of high selenium status in women.

Dietary intakes of zinc and heme iron from red meat, but not from other sources, are associated with greater risk of metabolic syndrome and cardiovascular disease

Metabolic syndrome (MetS), Type 2 diabetes (T2D), and cardiovascular disease (CVD) share an inflammatory etiology and are known to be influenced by diet. We investigated associations of hypothesized prooxidative (Fe) and antioxidative (Zn, Mg, β-carotene, vitamin C, vitamin E) micronutrients with incident MetS, T2D, and CVD in the Multi-Ethnic Study of Atherosclerosis. Participants, 45-84 y at baseline (2000-2002), were followed through 2010. Diet was assessed by FFQ. After adjusting for demographics and behavioral confounders, including BMI, dietary vitamin E intake was inversely associated with incident MetS and CVD [HR for extreme quintiles: MetS = 0.78 (95% CI = 0.62, 0.97), P-trend = 0.01; CVD: HR = 0.69 (95% CI = 0.46, 1.03), P-trend = 0.04]. Intakes of heme iron and Zn from red meat, but not from other sources, were positively associated with risk of MetS [heme iron from red meat: HR = 1.25 (95% CI = 0.99,1.56), P-trend = 0.03; Zn from red meat: HR = 1.29 (95% CI = 1.03,1.61), P-trend = 0.04] and CVD [heme iron from red meat: HR = 1.65 (95% CI = 1.10,2.47), P-trend = 0.01; Zn from red meat: HR = 1.51 (95% CI = 1.02, 2.24), P-trend = 0.01]. Dietary intakes of nonheme iron, Mg, vitamin C, and β-carotene were not associated with risk of MetS, T2D, or CVD. Data provided little support for the associations between specific micronutrients and MetS, T2D, or CVD. However, nutrients consumed in red meat, or red meat as a whole, may increase risk of MetS and CVD.

Serum ferritin level is associated with the prevalence of metabolic syndrome in Korean adults: the 2007-2008 Korean National Health and Nutrition Examination Survey

BACKGROUND

Increased ferritin concentrations, which reflect body iron stores, contribute to insulin dysfunction and metabolic syndrome (MetS).

METHODS

This cross-sectional study included 7346 subjects (3229 men and 4117 women) who participated in the 2007-2008 Korean National Health and Nutrition Examination Survey (KNHANES). We adopted the modified Asian criteria for MetS from the American Heart Association/National Heart, Lung, and Blood Institute.

RESULTS

In comparison with participants in the first serum ferritin quartile, the odds ratio (95% confidence interval) for MetS for participants in the fourth serum ferritin quartile was 1.67 (1.24-2.23) in men and 1.41 (1.06-1.88) in women after adjusting for multiple covariates (including menopausal status in women) except insulin resistance. This association was attenuated, however, after additionally adjusting for insulin resistance [1.46 (1.08-1.98) in men and 1.22 (0.91-1.65) in women]. In particular, higher serum ferritin concentrations were associated with increased triglyceride concentrations in men and glucose intolerance in women.

CONCLUSIONS

Increased serum ferritin level was positively associated with the prevalence of MetS and with some diagnostic components of MetS, i.e., we found that increased serum ferritin concentrations were associated with high triglyceride and glucose concentrations in men and women, respectively.

Catheter Ablation of Atrial Fibrillation in Overweight and Obese Patients

Obesity has reached epidemic proportions, and is associated with increased all-cause mortality. Atrial fibrillation(AF), the most common sustained arrhythmia in the clinical practice, is associated with an increased longterm risk of stroke, heart failure, and all-cause mortality. Accumulating data points out to an indispensable role of inflammation in both obesity and AF. Recent studies have documented an increasing risk of AF with increasing body mass index (BMI). The pathophysiological alterations associated with overweight and obesity lead to atrial stretch and atrial enlargement creating the substrate for AF development. Catheter ablation of AF has been widely accepted as an important therapeutic modality for the treatment of patients with symptomatic,drug-refractory AF. Previous studies assessing the impact of BMI on AF catheter ablation outcomes have given conflicting data. Given that overweight and obesity, as defined by BMI, and AF are closely linked,the present review sought to investigate the impact of BMI on the efficacy and safety of AF catheter ablation.

Effect of lipoic acid on expression of angiogenic factors in diabetic rat retina

BACKGROUND

This study evaluated the effect of a lipoic acid on reactive oxygen species formation and the simultaneous changes of several angiogenic factors in an experimental diabetic rat retina.

METHODS

Diabetes was induced chemically by intraperitoneal injection of streptozotocin in 30 Sprague-Dawley rats. After inducing diabetes, lipoic acid (10 mg/kg) was administered to 10 rats orally. The rats were divided into normal, diabetes mellitus, and lipoic acid-treated groups (each group n = 10). The eyeballs were harvested 8 weeks after inducing diabetes. The expression of vascular endothelial growth factor, erythropoietin, angiopoietin 1 and 2 and NADPH oxidase was examined in the rat retina using reverse transcription-polymerase chain reaction and Western blot. Superoxide formation was examined using dihydroethidium stain.

RESULTS

Dihydroethidium analyses showed increased superoxide formation in the retina of the diabetic group. The superoxide formation was suppressed with lipoic acid treatment. Western blot analysis showed that NADPH oxidase was decreased in the diabetic group and returned to normal level in the lipoic acid-treated group. Treatment with lipoic acid blocked hyperglycaemia induced increases of vascular endothelial growth factor, angiopoietin 2 and erythropoietin shown by reverse transcription-polymerase chain reaction and Western blot analysis.

CONCLUSIONS

Lipoic acid treatment suppressed expression of vascular endothelial growth factor, angiopoietin 2 and erythropoietin via blockade of superoxide formation. Antioxidant treatment is suspected to have an antiangiogenic effect.

LDL from obese patients with the metabolic syndrome show increased lipid peroxidation and activate platelets

AIMS/HYPOTHESIS

This study assessed oxidative stress in LDL from obese patients with the metabolic syndrome and compared it with that in LDL from type 2 diabetic patients or control volunteers. It also determined the effect on platelets of LDL from the three groups.

METHODS

The profiles of lipids, fatty acids and fatty acid oxidation products were determined in LDL isolated from plasma of patients with the metabolic syndrome, patients with type 2 diabetes and volunteers (n = 10 per group). The effects of LDL from the participant groups on the platelet arachidonic acid signalling cascade and aggregation were investigated.

RESULTS

Compared with LDL from control volunteers, LDL from obese metabolic syndrome and type 2 diabetic patients had lower cholesteryl ester, higher triacylglycerol and lower ethanolamine plasmalogen levels. Proportions of linoleic acid were decreased in phosphatidylcholine and cholesteryl esters in LDL from both patient groups. Among the markers of lipid peroxidation, oxidation products of linoleic acid (hydroxy-octadecadienoic acids) and malondialdehyde were increased by 59% and twofold, respectively in LDL from metabolic syndrome and type 2 diabetic patients. LDL from metabolic syndrome and type 2 diabetic patients were equally potent in activating the platelet arachidonic acid signalling cascade through increased phosphorylation of p38 mitogen-activated protein kinase and cytosolic phospholipase A(2), and through increased thromboxane B(2) formation. LDL from patients with the metabolic syndrome and type 2 diabetes potentiated platelet aggregation by threefold and 3.5-fold respectively, whereas control LDL had no activating effects on platelets.

CONCLUSIONS/INTERPRETATION

The metabolic syndrome in obese patients, without or with diabetes, is associated with increased oxidative stress in LDL, which triggers platelet activation.

Fatty liver index as an indicator of metabolic syndrome

OBJECTIVE

The aim of this study was to find an early indicator of metabolic syndrome (MetS).

DESIGN AND METHODS

We measured several anthropometric, biochemical, haematological, and oxidative damage parameters in 128 middle-aged Caucasian men divided into two groups: patients with MetS (n=69) and healthy controls (n=59), and used Weka REPTree and SimpleCART algorithms to identify the most reliable predictor of MetS.

RESULTS

Oxidative damage parameters did not differ between the groups, suggesting that oxidative damage is less prominent at the early stage of MetS. The algorithms singled out fatty liver index (FLI) as the best variable for discriminating between healthy and MetS subjects. This finding was confirmed by the receiver-operating characteristic (ROC) curve analysis, which set FLI 68.53 as the threshold value for MetS diagnosis.

CONCLUSIONS

FLI is the most reliable tool for diagnosing MetS. The absence of oxidative damage does not rule out oxidative stress but may indicate that MetS is at an early stage.

Frequent consumption of selenium-enriched chicken meat by adults causes weight loss and maintains their antioxidant status

To assess the effects of a moderately high-protein intake on the body composition, biochemical, and antioxidant status parameters in young adults depending on either selenium- (Se) or non-enriched chicken consumption. The volunteers (n = 24) that completed the 10-week nutritional intervention were distributed in two parallel groups and randomly assigned to follow an isocaloric diet with moderately high content in protein (30% energy), either with the consumption of four 200 g portions/week of Se- or non-enriched chicken breasts. Blood samples were taken at the beginning and at the end of the study and body composition was monitored during the trial. There was a significant reduction in weight, accompanying a decrease on fat mass in both groups, while fat-free mass remained unchanged during the 10 weeks of intervention, without differences between both dietary groups. Selenium blood levels and plasma glutathione peroxidase activity, as well as lipid, glucose, and selected inflammation biomarkers remained stable during the intervention period in both dietary groups. Frequent chicken consumption, within a controlled diet with a moderately high content in protein, produced a slight but statistically significant weight reduction mainly due to the loss of fat mass. An extra Se supplementation (22 μg/day) in the Se-enriched chicken breast did not affect tachyphylactic antioxidant status of the participants neither inflammatory-related markers after weight loss.

Low serum total bilirubin concentrations are associated with increased prevalence of metabolic syndrome in Chinese

BACKGROUND

To investigate the association between serum concentrations of total bilirubin (TBil) in the physiological range and metabolic syndrome (MS) in middle-aged and elderly Chinese, as well as any associations between serum TBil concentrations and insulin resistance, hyperinsulinemia, and systemic inflammation.

METHODS

A cross-sectional study was conducted on 1423 individuals recruited from an urban community of Shanghai (average age 62.3 years) to investigate the relationship between bilirubin and cardiovascular diseases. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria for Asian Americans.

RESULTS

Total bilirubin concentrations were significantly lower in individuals with MS compared with those without (0.65 ± 0.21 vs 0.69 ± 0.22 mg/dL, respectively; P=0.002). The adjusted mean concentration of TBil decreased gradually with an increase in the number of components of MS (P(trend) < 0.0001). After adjustment for a range of potential confounders (e.g. age, sex, body mass index, smoking, alcohol intake, homeostasis model assessment of insulin resistance etc.), each 1 SD increase in TBil was found to be associated with a 17% reduction in the risk of MS (odds ratio 0.83; 95% confidence interval 0.73-0.95; P=0.006). Furthermore, after adjustment for all covariables, each 1 SD increase in TBil was found to be associated with lower odds of central obesity, hypertriglyceridemia, low high-density lipoprotein-cholesterol, and hyperglycemia. Serum TBil concentrations were inversely associated with hyperinsulinemia, insulin resistance, and systemic inflammation.

CONCLUSIONS

Serum TBil concentrations within the physiological range were inversely associated with MS and insulin resistance, hyperinsulinemia, and systemic inflammation in middle-aged and elderly Chinese.

Relation between glucose levels, high-sensitivity C-reactive protein (hs-CRP), body mass index (BMI) and serum and dietary retinol in elderly in population-based study

The aim of this study was to evaluate the relationships between fasting glucose levels, hs-CRP, BMI and serum retinol and diet in elderly people. For this study, a cross-sectional, epidemiological, population-based format was adopted. One hundred and sixty-three individuals between 60 and 90 years of age participated; the participants were from different socioeconomic and health backgrounds, except for the individuals diagnosed with diabetes. Most subjects had serum concentrations in the reference ranges for all variables. There was not a significant relationship between fasting glucose and serum retinol or diet. There was a significant correlation between hs-CRP and BMI (r=0.22, p=0.0082) and hs-CRP and total calorie intake (p=0.0091), which reinforces the notion that an increased intake of calories results in being overweight and/or obese. Considering the importance of vitamin A in various physiological processes, more studies on these relationships are necessary to establish a recommendation of vitamin A for the treatment and prevention of changes in fasting glucose and obesity in the elderly population.

Consumption of Purple/Blue Produce Is Associated With Increased Nutrient Intake and Reduced Risk for Metabolic Syndrome: Results From the National Health and Nutrition Examination Survey 1999-2002

To determine the effect of consuming purple/blue fruit and vegetables (P/B) on nutrient intakes and physiological parameters, a secondary analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2002 data for children aged 5 to 18 years (n = 6345) and adults 19+ years (n = 8827) was conducted. Compared with nonconsumers (n = 13 304), P/B consumers (n = 1559) had increased intakes of total fruit (P < .0001), dietary fiber (P ≤ .0001), vitamin C (P < .001), and potassium (P < .0001) and decreased intakes of added sugar (P < .0001). P/B consumers had higher energy intakes (P < .001), but among children, there were no differences in weight or body mass index (BMI) for age between groups; among adults, lower weight and BMI (P < .0001) were found as compared with nonconsumers. Adult P/B consumers had significantly reduced risk for 3 of the 5 risk factors that define the metabolic syndrome (MetS): elevated blood pressure, low HDL cholesterol, and increased waist circumference. An additional analysis for the subgroup of 100% grape juice (GJ) consumers was conducted. GJ consumers (n = 270) also had higher intakes of fruit (P < .001), vitamin C (P < .001), and potassium (P < .005) and lower intakes of added sugar (P < .01) compared with GJ nonconsumers (n = 14 902), with no differences in weight, BMI, or waist circumference. Consumption of P/B produce was associated with increased fruit and nutrient intakes and with reduced risk for MetS. GJ consumption was also associated with increased nutrient intake.

Nontraditional risk factors and biomarkers for cardiovascular disease: mechanistic, research, and clinical considerations for youth: a scientific statement from the American Heart Association

The rapid increase in the prevalence and severity of obesity in children is likely to lower the age of onset and increase the incidence of cardiovascular disease worldwide. Understanding the pathophysiology and improving the clinical management of cardiovascular disease involve a knowledge of novel risk factors and biomarkers. The clinical and mechanistic roles of these novel biological factors during childhood are currently being investigated. The goals of this scientific statement are to present the existing knowledge and theoretical framework of nontraditional risk factors for cardiovascular disease as they relate to children and adolescents, to describe the relevance and weight of available experimental and clinical evidence and the therapeutic implications pertaining to nontraditional risk factors in the pediatric population, and to stimulate further research with a goal of developing valid and reliable approaches to identify and validate novel risk factors that will aid in the clinical evaluation and perhaps prediction of cardiovascular disease in the pediatric population. Although several biomarkers are promising, substantial research is required before nontraditional risk factors can be used to identify and reduce cardiovascular disease risk in children and adolescents.