A novel view of metabolic syndrome

The metabolic syndrome, as described by Reaven, is a combination of obesity, insulin resistance, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperinsulinemia. The syndrome was recognized as a very high pro-atherogenic risk causing coronary heart disease. More recently, other features like an elevated plasma PAI -1 and CRP have been added to the syndrome. In view of the recent data demonstrating that insulin exerts an anti-inflammatory effect while macronutrients exert a pro-inflammatory effect, we are in a better position to explain not only why an insulin resistant state like the metabolic syndrome is pro-inflammatory but also to explain how it develops. This review discusses the relevance of these recent observations and puts into perspective the pathogenesis of various features of the metabolic syndrome and also predicts some features which may get incorporated into it in the future.

Cardiovascular benefits of exogenous insulin

CONTEXT

Recent studies on mediators of inflammation, experimental models of atherosclerosis, and acute ischemia have identified novel mechanisms through which insulin may exert cardiovascular protective effects. This review aims to summarize current knowledge regarding the cardiovascular, antiinflammatory, and antiatherogenic effects of insulin, and the effect of intensive glycemic control in acute cardiovascular disease.

EVIDENCE ACQUISITION

Publications of interest were identified using preselected MeSH terminology and keywords to search online databases such as PubMed and OVID for the period January 1988 to February 2012. Relevant publications were obtained and reviewed by two independent observers, then evaluated a priori against the following criteria: study quality, main clinical outcomes, and applicability to clinical practice.

EVIDENCE SYNTHESIS

Insulin has been shown to exert vasodilatory, antiinflammatory, and antiatherogenic effects in experimental models, independent of its glucose-lowering effects. Additionally, glucose is known to exert potent proinflammatory, prothrombotic, and proapoptotic effects during myocardial infarct, indicative that hyperglycemia is likely to be injurious to the heart. In this context, through its nonmetabolic and metabolic (glucose-lowering) effects, insulin is likely to be cardioprotective and to improve clinical outcomes in acute myocardial infarction.

CONCLUSIONS

Despite promising experimental data and evidence of benefit from single-center randomized clinical trials, clinical evidence supporting the cardioprotective effects of insulin from a multicenter randomized clinical trial is still lacking. Future prospective studies with insulin infused at adequate concentrations, individually titrated to achieve and maintain euglycemia (blood glucose < 140 mg/dl) and minimize hypoglycemia, are required to investigate the role of insulin in the management of patients with acute cardiovascular disease.

Sitagliptin exerts an antinflammatory action

CONTEXT

Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase-IV (DPP-IV), which degrades the incretins, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, and thus, sitagliptin increases their bioavailability. The stimulation of insulin and the suppression of glucagon secretion that follow exert a glucose lowering effect and hence its use as an antidiabetic drug. Because DPP-IV is expressed as CD26 on cell membranes and because CD26 mediates proinflammatory signals, we hypothesized that sitagliptin may exert an antiinflammatory effect.

PATIENTS AND METHODS

Twenty-two patients with type 2 diabetes were randomized to receive either 100 mg daily of sitagliptin or placebo for 12 wk. Fasting blood samples were obtained at baseline and at 2, 4, and 6 hours after a single dose of sitagliptin and at 2, 4, 8, and 12 wk of treatment.

RESULTS

Glycosylated hemoglobin fell significantly from 7.6 ± 0.4 to 6.9 ± 3% in patients treated with sitagliptin. Fasting glucagon-like peptide-1 concentrations increased significantly, whereas the mRNA expression in mononuclear cell of CD26, the proinflammatory cytokine, TNFα, the receptor for endotoxin, Toll-like receptor (TLR)-4, TLR-2, and proinflammatory kinases, c-Jun N-terminal kinase-1 and inhibitory-κB kinase (IKKβ), and that of the chemokine receptor CCR-2 fell significantly after 12 wk of sitagliptin. TLR-2, IKKβ, CCR-2, and CD26 expression and nuclear factor-κB binding also fell after a single dose of sitagliptin. There was a fall in protein expression of c-Jun N-terminal kinase-1, IKKβ, and TLR-4 and in plasma concentrations of C-reactive protein, IL-6, and free fatty acids after 12 wk of sitagliptin.

CONCLUSIONS

These effects are consistent with a potent and rapid antiinflammatory effect of sitagliptin and may potentially contribute to the inhibition of atherosclerosis. The suppression of CD26 expression suggests that sitagliptin may inhibit the synthesis of DPP-IV in addition to inhibiting its action.

Clinical use of liraglutide in type 2 diabetes and its effects on cardiovascular risk factors

OBJECTIVE

To assess whether liraglutide, a glucagon-like peptide-1 receptor agonist, has cardioprotective properties in addition to its glycemic effects.

METHODS

We performed a retrospective analysis of medical records of 110 obese patients with type 2 diabetes mellitus treated with liraglutide for at least 6 months between March 2010 and April 2011 at our tertiary care referral center. The variables analyzed were body mass index, hemoglobin A(1c) (A1C), systolic blood pressure (SBP), plasma C-reactive protein (CRP) concentrations, and serum lipids.

RESULTS

In our overall study cohort, we noted a reduction in mean weight from 120 ± 5 kg to 115 ± 3 kg and a decrease in mean A1C from 7.8% ± 0.6% to 7.2% ± 0.2%. The mean triglyceride concentration decreased from 173 ± 19 mg/dL to 151 ± 15 mg/dL, the mean SBP was reduced from 132 ± 6 mm Hg to 125 ± 4 mm Hg, and the mean CRP concentration declined from 4.7 ± 0.8 mg/L to 3.2 ± 0.4 mg/L after treatment with liraglutide for a minimal duration of 6 months and a mean duration of 7.5 months (for all the foregoing changes, P<.05). These variables decreased whether these patients were previously treated with orally administered hypoglycemic agents alone or in combination with insulin or exenatide.

CONCLUSION

Our findings in a clinical practice show that liraglutide is a potent antidiabetes drug, whether given in combination with orally administered agents or insulin or as a substitution for exenatide. It lowers body weight, A1C levels, SBP, and CRP and triglyceride concentrations.

Reduction in inflammation and the expression of amyloid precursor protein and other proteins related to Alzheimer's disease following gastric bypass surgery

OBJECTIVE

Obesity and type 2 diabetes are associated with an increase in the incidence and prevalence of Alzheimer's disease (AD) and an impaired cognitive function. Because peripheral blood mononuclear cells (MNC) express amyloid precursor protein (APP), the precursor of β-amyloid, which forms the pathognomonic plaques in the brain, we hypothesized that APP expression diminishes after the marked caloric restriction and weight loss associated with Roux-en-Y gastric bypass (RYGB) surgery.

RESEARCH DESIGN AND METHODS

Fifteen type 2 diabetic patients with morbid obesity (body mass index, 52.1 ± 13 kg/m(2)) underwent RYGB, and the expression of inflammatory and AD-related genes was examined before and after 6 months in plasma and in MNC.

RESULTS

Body mass index fell to 40.4 ± 11.1 kg/m(2) at 6 months after RYGB. There was a significant fall in plasma concentrations of glucose and insulin and in homeostasis model of assessment for insulin resistance. The expression of APP mRNA fell by 31 ± 9%, and that of protein fell by 36 ± 14%. In addition, there was a reduction in the expression of other AD-related genes including presinilin-2, ADAM-9, GSK-3β, PICALM, SORL-1, and clusterin (P < 0.05 for all). Additionally, the expression of c-Fos, a subunit of the proinflammatory transcription factor AP-1, was also suppressed after RYGB. These changes occurred in parallel with reductions in other proinflammatory mediators including C-reactive protein and monocyte chemoattractant protein-1.

CONCLUSIONS

Thus, the reversal of the proinflammatory state of obesity is associated with a concomitant reduction in the expression of APP and other AD-related genes in MNC. We conclude that obesity and caloric intake modulate the expression of APP in MNC. If indeed, this effect also occurs in the brain, this may have implications for the pathogenesis and the treatment of AD. It is relevant that cognitive function has been shown to improve with weight loss following bariatric surgery.

Comparing the effects of insulin glargine and thiazolidinediones on plasma lipids in type 2 diabetes: a patient-level pooled analysis

BACKGROUND

The prevalence of dyslipidaemia and the risk of cardiovascular disease are elevated in patients with type 2 diabetes. This analysis compared the effects of insulin glargine versus thiazolidinediones (TZDs) on lipid profiles.

METHODS

Patient-level data were pooled from two randomized clinical studies. The population included 552 men and women aged >18 years, diagnosed with type 2 diabetes for at least 6 months, on metformin and/or sulphonylurea, and with A(1C) ≥7.5% and <12.0% at screening. Lipid outcome measures included change from baseline in lipid levels [low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol, triglycerides, and free fatty acids] and attainment of lipid goals for LDL-C, non-HDL-C, and triglycerides.

RESULTS

Both insulin glargine and TZDs improved lipid profiles from baseline values. Compared with TZDs, treatment with insulin glargine led to 7.9% greater reduction in LDL-C (p < 0.0003), 7.5% greater reduction in non-HDL-C (p < 0.0001), and 7.8% greater reduction in total cholesterol (p < 0.0001), whereas the HDL-C increase with TZD was 7.6% greater than that with insulin glargine (p < 0.0001). The percentage of patients attaining the lipid goals was comparable between insulin glargine and pioglitazone, but lower for rosiglitazone. Insulin glargine improved glycaemic control more than TZDs; however, insulin glargine caused more hypoglycaemia. Treatment with TZDs caused more weight gain and peripheral oedema.

CONCLUSION

These findings suggest that the favourable effects of insulin glargine on plasma lipid profiles should be considered among the advantages of treatment with insulin glargine as they are for TZDs.

Exenatide exerts a potent antiinflammatory effect

OBJECTIVE

Our objective was to determine whether exenatide exerts an antiinflammatory effect.

RESEARCH DESIGN AND METHODS

Twenty-four patients were prospectively randomized to be injected sc with either exenatide 10 μg twice daily [n = 12; mean age = 56 ± 3 yr; mean body mass index = 39.8 ± 2 kg/m(2); mean glycosylated hemoglobin (HbA1c) = 8.6 ± 0.4%] or placebo twice daily (n = 12; mean age = 54 ± 4 yr; mean body mass index = 39.1 ± 1.6 kg/m(2); mean HbA1c = 8.5 ± 0.3%) for 12 wk. Fasting blood samples were obtained at 0, 3, 6, and 12 wk. Blood samples were also collected for up to 6 h after a single dose of exenatide (5 μg) or placebo.

RESULTS

Fasting blood glucose fell from 139 ± 17 to 110 ± 9 mg/dl, HbA1c from 8.6 ± 0.4 to 7.4 ± 0.5% (P < 0.05), and free fatty acids by 21 ± 5% from baseline (P < 0.05) with exenatide. There was no weight loss. There was a significant reduction in reactive oxygen species generation and nuclear factor-κB binding by 22 ± 9 and 26 ± 7%, respectively, and the mRNA expression of TNFα, IL-1β, JNK-1, TLR-2, TLR-4, and SOCS-3 in mononuclear cells by 31 ± 12, 22 ± 10, 20 ± 11, 22 ± 9, 16 ± 7, and 31 ± 10%, respectively (P < 0.05 for all) after 12 wk of exenatide. After a single injection of exenatide, there was a reduction by 20 ± 7% in free fatty acids, 19 ± 7% in reactive oxygen species generation, 39 ± 11% in nuclear factor-κB binding, 18 ± 9% in TNFα expression, 26 ± 7% in IL-1β expression, 18 ± 7% in JNK-1 expression, 24 ± 12% in TLR-4 expression, and 23 ± 11% in SOCS-3 expression (P < 0.05 for all). The plasma concentrations of monocyte chemoattractant protein-1, matrix metalloproteinase-9, serum amyloid A, and IL-6 were suppressed after 12 wk exenatide treatment by 15 ± 7, 20 ± 11, 16 ± 7, and 22 ± 12%, respectively (P < 0.05 for all).

CONCLUSIONS

Exenatide exerts a rapid antiinflammatory effect at the cellular and molecular level. This may contribute to a potentially beneficial antiatherogenic effect. This effect was independent of weight loss.

Effects of insulin and other antihyperglycaemic agents on lipid profiles of patients with diabetes

Increased morbidity and mortality risk due to diabetes-associated cardiovascular diseases is partly associated with hyperglycaemia as well as dyslipidaemia. Pharmacological treatment of diabetic hyperglycaemia involves the use of the older oral antidiabetic drugs [OADs: biguanides, sulphonylureas (SUs), α-glucosidase inhibitors and thiazolidinediones], insulin (human and analogues) and/or incretin-based therapies (glucagon-like peptide-1 analogues and dipeptidyl peptidase 4 inhibitors). Many of these agents have also been suggested to improve lipid profiles in patients with diabetes. These effects may have benefits on cardiovascular risk beyond glucose-lowering actions. This review discusses the effects of OADs, insulins and incretin-based therapies on lipid variables along with the possible mechanisms and clinical implications of these findings. The effects of intensive versus conventional antihyperglycaemic therapy on cardiovascular outcomes and lipid profiles are also discussed. A major conclusion of this review is that agents within the same class of OADs can have different effects on lipid variables and that contrary to the findings in experimental models, insulin has been shown to have beneficial effects on lipid variables in clinical trials. Further studies are needed to understand the precise effect and the mechanisms of these effects of insulin on lipids.

Update: Hypogonadotropic hypogonadism in type 2 diabetes and obesity

Studies over the last few years have clearly established that at least 25% of men with type 2 diabetes have subnormal free testosterone concentrations in association with inappropriately low LH and FSH concentrations. Another 4% have subnormal testosterone concentrations with elevated LH and FSH concentrations. The Endocrine Society, therefore, now recommends the measurement of testosterone in patients with type 2 diabetes on a routine basis. The subnormal testosterone concentrations are not related to glycosylated hemoglobin or duration of diabetes, but are associated with obesity, very high C-reactive protein concentrations, and mild anemia. In addition, subnormal testosterone concentrations in these men are associated with a two to three times elevated risk of cardiovascular events and death in two early studies. Short-term studies of testosterone therapy in hypogonadal men with type 2 diabetes have demonstrated an increase in insulin sensitivity and a decrease in waist circumference. However, the data on the effect of testosterone replacement on glycemic control and cardiovascular risk factors such as cholesterol and C-reactive protein concentrations are inconsistent. As far as sexual function is concerned, testosterone treatment increases libido but does not improve erectile dysfunction and thus, phosphodiesterase inhibitors may be required. Trials of a longer duration are clearly required to definitively establish the benefits and risks of testosterone replacement in patients with type 2 diabetes and low testosterone.

Low estradiol concentrations in men with subnormal testosterone concentrations and type 2 diabetes

OBJECTIVE

It has been suggested that the high prevalence of subnormal free testosterone concentrations, along with low or inappropriately normal gonadotropins in men with type 2 diabetes, may be the result of an increase in plasma estradiol concentrations secondary to an increase in aromatase activity in the adipose tissue that leads to the suppression of the hypothalamo-hypophyseal-gonadal axis.

RESEARCH DESIGN AND METHODS

To investigate this hypothesis, plasma estradiol, testosterone, leutinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin (SHBG) concentrations were measured in fasting blood samples of 240 men with type 2 diabetes. Free estradiol concentrations were either calculated (n = 198) using total estradiol and SHBG measured by immunoassay or directly measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) and equilibrium dialysis (n = 102).

RESULTS

The calculated free estradiol concentration in men with subnormal free testosterone concentrations was lower than that in men with normal free testosterone concentrations (median 0.047 vs. 0.063 ng/dL, P < 0.001). Directly measured (LC-MS/MS) free estradiol concentrations were also lower in men with subnormal free testosterone concentrations (median 0.025 vs. 0.045 ng/dL, P = 0.008). Free estradiol concentrations were directly related to free testosterone but not to BMI or age.

CONCLUSIONS

These data show that the suppression of the hypothalamo-hypophyseal-gonadal axis in patients with subnormal free testosterone concentrations and type 2 diabetes is not associated with increased estradiol concentrations. The pathogenesis of subnormal free testosterone concentrations in type 2 diabetes needs to be investigated further.

Liraglutide as additional treatment for type 1 diabetes

OBJECTIVE

To determine whether the addition of liraglutide to insulin to treat patients with type 1 diabetes leads to an improvement in glycemic control and diminish glycemic variability.

SUBJECTS AND METHODS

In this study, 14 patients with well-controlled type 1 diabetes on continuous glucose monitoring and intensive insulin therapy were treated with liraglutide for 1 week. Of the 14 patients, eight continued therapy for 24 weeks.

RESULTS

In all the 14 patients, mean fasting and mean weekly glucose concentrations significantly decreased after 1 week from 130±10 to 110±8  mg/dl (P<0.01) and from 137.5±20 to 115±12  mg/dl (P<0.01) respectively. Glycemic excursions significantly improved at 1 week. The mean s.d. of glucose concentrations decreased from 56±10 to 26±6  mg/dl (P<0.01) and the coefficient of variation decreased from 39.6±10 to 22.6±7 (P<0.01). There was a concomitant fall in the basal insulin from 24.5±6 to 16.5±6 units (P<0.01) and bolus insulin from 22.5±4 to 15.5±4 units (P<0.01). In patients who continued therapy with liraglutide for 24 weeks, mean fasting, mean weekly glucose concentrations, glycemic excursions, and basal and bolus insulin dose also significantly decreased (P<0.01). HbA1c decreased significantly at 24 weeks from 6.5 to 6.1% (P=0.02), as did the body weight by 4.5±1.5  kg (P=0.02).

CONCLUSION

Liraglutide treatment provides an additional strategy for improving glycemic control in type 1 diabetes. It also leads to weight loss.

Insulin suppresses the expression of amyloid precursor protein, presenilins, and glycogen synthase kinase-3beta in peripheral blood mononuclear cells

OBJECTIVE

Our objective was to determine whether peripheral blood mononuclear cells express amyloid precursor protein (APP) and other mediators involved in the pathogenesis of Alzheimer's disease and whether their expression is suppressed by insulin.

RESEARCH DESIGN AND METHODS

Ten obese type 2 diabetic patients were infused with insulin (2 U/h with 100 ml 5% dextrose/h) for 4 h. Patients were also infused with 5% dextrose/h or normal physiological saline for 4 h, respectively, on two other days as controls. Blood samples were obtained at 0, 2, 4, and 6 h.

RESULTS

Insulin infusion significantly suppressed the expression of APP, presenilin-1, presenilin-2, and glycogen synthase kinase-3β in peripheral blood mononuclear cells. Dextrose and saline infusions did not alter these indices. Insulin infusion also caused significant parallel reductions in nuclear factor-κB binding activity and plasma concentrations of serum amyloid A and intercellular adhesion molecule-1.

CONCLUSIONS

A low dose infusion of insulin suppresses APP, presenilin-1, presenilin-2, and glycogen synthase kinase-3β, key proteins involved in the pathogenesis of Alzheimer's disease, in parallel with exerting its other antiinflammatory effects.

A resveratrol and polyphenol preparation suppresses oxidative and inflammatory stress response to a high-fat, high-carbohydrate meal

BACKGROUND

High-fat, high-carbohydrate (HFHC) meals are known to induce oxidative and inflammatory stress, an increase in plasma endotoxin concentrations, and an increase in the expression of suppressor of cytokine signaling-3 (SOCS-3).

HYPOTHESIS

The intake of a nutritional supplement containing resveratrol and muscadine grape polyphenols reduces HFHC meal-induced oxidative and inflammatory stress and stimulates the activity of the antioxidant transcription factor, NF-E2-related factor-2 (Nrf-2), and its downstream targets.

METHODS

Ten normal, healthy subjects were given a 930-kcal HFHC meal either with placebo or with the supplement. Indices of oxidative stress, inflammation, Nrf-2 binding activity, the concentrations of endotoxin (lipopolysaccharide) and lipoprotein binding protein (LBP), and the expression of toll-like receptor 4 (TLR-4), CD14, IL-1β, TNFα, SOCS-3, Keap-1, NAD(P)H:quinone oxidoreductase-1 (NQO-1), and GST-P1 were measured.

RESULTS

The intake of the supplement suppressed the meal-induced elevations of plasma endotoxin and LBP concentrations, the expression of p47(phox), TLR-4, CD14, SOCS-3, IL-1β, and Keap-1, while enhancing Nrf-2 binding activity and the expression of NQO-1 and GST-P1 genes.

CONCLUSION

A supplement containing resveratrol and muscadine polyphenols suppresses the increase in oxidative stress, lipopolysaccharide and LBP concentrations, and expression of TLR-4, CD14, IL-1β and SOCS-3 in mononuclear cells after an HFHC meal. It also stimulates specific Nrf-2 activity and induces the expression of the related antioxidant genes, NQO-1 and GST-P1. These results demonstrate the acute antioxidant and antiinflammatory effects of resveratrol and polyphenolic compounds in humans in the postprandial state.

Prediction of adverse outcomes by blood glucose level after endovascular therapy for acute ischemic stroke

OBJECT

The authors evaluated the prognostic significance of blood glucose level at admission (BGA) and change in blood glucose at 48 hours from the baseline value (CG48) in nondiabetic and diabetic patients before and after endovascular therapy for acute ischemic stroke (AIS).

METHODS

The BGA and CG48 data were analyzed in 614 patients with AIS who received endovascular therapy at 7 US centers between 2006 and 2009. Data reviewed included demographics, stroke risk factors, diabetic status, National Institutes of Health Stroke Scale (NIHSS) score at presentation, recanalization grade, intracranial hemorrhage (ICH) rate, and 90-day outcomes (mortality rate and modified Rankin Scale score of 3-6 [defined as poor outcome]). Variables with p values < 0.2 in univariate analysis were included in a binary logistic regression model for independent predictors of 90-day outcomes.

RESULTS

The mean patient age was 67.3 years, the median NIHSS score was 16, and 27% of patients had diabetes. In nondiabetic patients, BGA ≥ 116 mg/dl (≥ 6.4 mmol/L) and failure of glucose level to drop > 30 mg/dl (> 1.7 mmol/L) from the admission value were both significant predictors of 90-day poor outcome and death (p < 0.001). In patients with diabetes, BGA ≥ 116 mg/dl (≥ 6.4 mmol/L) was an independent predictor of poor outcome (p = 0.001). The CG48 was not a predictor of outcome in diabetic patients. A simplified 6-point scale including BGA, Thrombolysis in Myocardial Infarction (TIMI) Grade 2-3 Reperfusion, Age, presentation NIHSS score, CG48, and symptomatic ICH (BRANCH) corresponded with poor outcomes at 90 days; the area under the curve value was > 0.79.

CONCLUSIONS

Failure of blood glucose values to decrease in the first 48 hours after AIS intervention correlated with poor 90-day outcomes in nondiabetic patients. The BRANCH scale shows promise as a simple prognostication tool after endovascular therapy for AIS, and it merits prospective validation.

Insulin suppresses endotoxin-induced oxidative, nitrosative, and inflammatory stress in humans

OBJECTIVE

To investigate whether insulin reduces the magnitude of oxidative, nitrosative, and inflammatory stress and tissue damage responses induced by endotoxin (lipopolysaccharide [LPS]).

RESEARCH DESIGN AND METHODS

Nine normal subjects were injected intravenously with 2 ng/kg LPS prepared from Escherichia coli. Ten others were infused with insulin (2 units/h) for 6 h in addition to the LPS injection along with 100 ml/h of 5% dextrose to maintain normoglycemia.

RESULTS

LPS injection induced a rapid increase in plasma concentrations of nitric oxide metabolites, nitrite and nitrate (NOM), and thiobarbituric acid-reacting substances (TBARS), an increase in reactive oxygen species (ROS) generation by polymorphonuclear leukocytes (PMNLs), and marked increases in plasma free fatty acids, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), macrophage migration inhibition factor (MIF), C-reactive protein, resistin, visfatin, lipopolysaccharide binding protein (LBP), high mobility group-B1 (HMG-B1), and myoglobin concentrations. The coinfusion of insulin led to a total elimination of the increase in NOM, free fatty acids, and TBARS and a significant reduction in ROS generation by PMNLs and plasma MIF, visfatin, and myoglobin concentrations. Insulin did not affect TNF-α, MCP-1, IL-6, LBP, resistin, and HMG-B1 increases induced by the LPS.

CONCLUSIONS

Insulin reduces significantly several key mediators of oxidative, nitrosative, and inflammatory stress and tissue damage induced by LPS. These effects of insulin require further investigation for its potential use as anti-inflammatory therapy for endotoxemia.

Macronutrient intake induces oxidative and inflammatory stress: potential relevance to atherosclerosis and insulin resistance

With the global increase in the epidemic of obesity and type 2 diabetes with a concomitant increase in atherosclerotic disease, an investigation into the effects of various macronutrients and food products has become necessary. Such investigation will allow us to better understand the relationship between the intake of various macronutrients and the pathogenesis of mechanisms underlying the regulation of insulin sensitivity and resistance, oxidative stress and inflammation, the regulation of hunger and satiety and atherogenesis. This review covers the first decade of work in this area relating the intake of usual foods and diets to their immediate and long term outcomes. The review also covers the exciting novel area of anti-inflammatory effects of certain foods. Hopefully, a comprehensive understanding of these actions of macronutrients and their long term effects will allow us to formulate food combinations which will lead to healthy eating habits and improvement in our overall health status.

An antiinflammatory and reactive oxygen species suppressive effects of an extract of Polygonum cuspidatum containing resveratrol

BACKGROUND

Resveratrol have been shown to exert an antiinflammatory and antiaging effects in vitro and in animal models.

OBJECTIVE

The objective of the study was to investigate the effect of a Polygonum cuspidatum extract (PCE) containing resveratrol on oxidative and inflammatory stress in normal subjects.

RESEARCH DESIGN AND METHODS

Two groups (10 each) of normal-weight healthy subjects were randomized to placebo or PCE containing 40 mg resveratrol daily for 6 wk. Fasting blood samples were obtained prior to and after treatment at 1, 3, and 6 wk. Mononuclear cells were prepared for reactive oxygen species generation, RNA isolation, nuclear extract, and total cell homogenate preparation. Indices of oxidative and inflammatory stress, suppressor of cytokine signaling-3, phosphotyrosine phosphatase-1B, jun-N-terminal kinase-1, and inhibitor of kappaB-kinase-beta were measured by RT-PCR and Western blotting.

RESULTS

The extract induced a significant reduction in reactive oxygen species generation, the expression of p47(phox), intranuclear nuclear factor-kappaB binding, and the expression of jun-N-terminal kinase-1, inhibitor of kappaB-kinase-beta, phosphotyrosine phosphatase-1B, and suppressor of cytokine signaling-3 in mononuclear cells when compared with the baseline and the placebo. PCE intake also suppressed plasma concentrations of TNF-alpha, IL-6, and C-reactive protein. There was no change in these indices in the control group given placebo.

CONCLUSIONS

The PCE-containing resveratrol has a comprehensive suppressive effect on oxidative and inflammatory stress.