Inflammation, insulin resistance, and atherosclerosis

Association of triglyceride-glucose index and neutrophil-to-lymphocyte ratio with coronary artery disease

OBJECTIVE

The present study aimed to investigate the association of triglyceride-glucose (TyG) index and neutrophil-to-lymphocyte ratio (NLR) with coronary artery disease (CAD), and evaluate the cumulative value of TyG index and NLR in identifying CAD, as well as the severity of CAD.

METHODS

This retrospective study enrolled 2867 patients who underwent coronary angiography (CAG) for the first time between January 2013 and June 2022 in Zhongnan Hospital of Wuhan University. There were 2109 patients with CAD and 758 patients without CAD. The CAD patients were divided into two groups based on the median of Gensini score (mild stenosis CAD group: Gensini score < 26 points; severe stenosis CAD group: Gensini score ≥ 26 points). To further evaluate the cumulative value of TyG index and NLR in identifying CAD and CAD severity, all patients were classified into four groups based on median of TyG index and NLR: (1) the control group: patients with low-TyG and low-NLR; (2) isolated high-NLR group: patients with low-TyG and high- NLR; (3) isolated high- TyG group: patients with high-TyG and low- NLR; (4) high-TyG combined with high-NLR group: patients with high-TyG and high- NLR.

RESULTS

Multivariate logistic regression analysis showed that both the TyG index and NLR were independent risk factors for CAD, and they were also independent risk factors for severe stenosis in CAD (P < 0.05). Compared with the low-TyG and low- NLR group, patients in high-TyG and high- NLR group had a 1.418 times higher odds ratio (OR) of having CAD and a 1.692 times higher OR of having severe stenosis in CAD in the multivariable logistic regression model. It is worth noting that the OR values of the high-TyG and high- NLR group were higher than those of the isolated high-NLR group and the isolated high- TyG group. The ROC analysis showed that the combination of the TyG index and NLR was superior to TyG index or NLR in predicting CAD and CAD severity.

CONCLUSION

Compared to TyG index or NLR, the combination of the TyG index and NLR is beneficial to improve the diagnostic accuracy of CAD and CAD severity.

Association of Muscle Strength with Non-Alcoholic Fatty Liver Disease in Korean Adults

Sarcopenia is known to be associated with non-alcoholic fatty liver disease (NAFLD). However, few studies have revealed the association between muscle strength and prevalence of NAFLD. We investigated the association by using relative handgrip strength in a nationwide cross-sectional survey. The participants were recruited from the Korean National Health and Nutrition Examination Surveys (KNHANES). A total of 27,531 subjects from the KNHANES were selected in our study. We used normalized handgrip strength, which is called relative handgrip strength. The index was defined as handgrip strength divided by BMI. These subjects were divided into quartile groups according to relative handgrip strength. NAFLD was defined as hepatic steatosis index >36. Multinomial logistic regression was analysed to investigate the association between relative handgrip strength with prevalence of NAFLD. The mean age of study population was 45.8 ± 0.3 in men, and 48.3 ± 0.2 in women. The proportion of males was 37.5%. In multiple linear regression, relative handgrip strength was inversely associated with HSI index (Standardized β = −0.70; standard error (SE), 0.08; p < 0.001 in men, Standardized β = −0.94; standard error (SE), 0.07; p < 0.001 in women). According to the logistic regression model, the prevalence of NAFLD decreased with quartile 4 groups in relative handgrip strength, compared with quartile 1 groups (OR 0.42 [0.32–0.55] in men; OR 0.30 [0.22–0.40] in women). Relative handgrip strength, used as a biomarker of sarcopenia, is independently inversely associated with NAFLD.

Nonalcoholic Fatty Liver Disease and Sarcopenia: Where Do We Stand?

The link between metabolic syndrome (MetS) and sarcopenia has not been extensively studied, but it is evident that they share several common features. Crucial mechanisms involved in sarcopenia-nonalcoholic fatty liver disease (NAFLD) interplay are based on effects of insulin resistance, chronic inflammation, oxidative stress, and crosstalk between organs by secretion of cytokines (hepatokines, adipokines, and myokines). Currently, published studies confirm the association of sarcopenia with the degree of NAFLD defined by liver histology. However, prospective studies that will give us information regarding the causal effect of NAFLD and sarcopenia are still needed. Furthermore, there is a need for a patient-friendly, noninvasive, low-cost method for detection of loss of skeletal muscle mass, strength, and physical performance in the context of NAFLD. Moreover, potential treatment strategies such as physical exercise and nutritional supplementation, that are usually a part of management of sarcopenia, should also be investigated in NAFLD patients, especially given the fact that for now, we do not have a good treatment option for NAFLD. Therefore, future investigations should combine studies on NAFLD and sarcopenia in terms of physical activity and nutritional interventions such as vitamin D supplementation. This review aims to report recent evidence concerning the links between sarcopenia and NAFLD and methods to assess sarcopenia.

Osteoporosis complication is a risk factor for frailty in females with type 2 diabetes mellitus

[Purpose] This study aimed to examine the effect of osteoporosis complications on the physical function, frailty in patients with type 2 diabetes mellitus. [Participants and Methods] The participants were 27 female type 2 diabetes mellitus patients aged ≥65 years. Of these, 14 patients had osteoporosis. In order to evaluate the physical function, we measured the lower limb muscle strength, handgrip, gait speed, etc. We performed statistical comparison of both the groups and examined the applicable number of items on the Linda Fried Frailty scale and the correlation by evaluating the physical function. [Results] The lower limb muscle strength of patients with osteoporosis and type 2 diabetes mellitus was significantly lower than that of type 2 diabetes mellitus patients without osteoporosis. Factors of the osteoporosis group that inversely correlated to the Linda Fried Frailty scale included lower limb muscle strength, handgrip, and gait speed. [Conclusion] We found that osteoporosis reduced lower limb muscle strength in type 2 diabetes mellitus patients and was correlated with frailty.

Hyperhomocysteinemia as a Metabolic Risk Factor for Glucose Intolerance Among High-Risk Groups of Chinese Adults

BACKGROUND Impaired glucose tolerance (IGT) is characterized by insulin resistance and causes atherosclerosis. Hyperhomocysteinemia is associated with insulin resistance and predicts cardiovascular diseases. In this study, we assessed the possible association between homocysteine and IGT. MATERIAL AND METHODS This was a cross-sectional study of 118 consecutive subjects with IGT (IGT group) and 128 consecutive subjects with normal glucose tolerance (NGT group). Homocysteine and clinical characteristics were measured. RESULTS The IGT group had higher homocysteine than the NGT group [18.00 (14.00, 22.25) vs. 12.50 (9.00, 15.00) μmol/L, p<0.001]. Homocysteine was positively associated with body mass index (BMI) (r=0.178, p=0.005), triglycerides (r=0.306, p<0.001), fasting blood glucose (FBG) (r=0.312, p<0.001), 2-hour postchallenge glucose (2hPG) (r=0.363, p<0.001), fasting insulin (FINS) (r=0.655, p<0.001), and homeostasis model assessment for insulin resistance (HOMA-IR) (r=0.643, p<0.001), and was negatively correlated with high-density lipoprotein cholesterol (HDL-C) (r=-0.250, p<0.001). After controlling for confounders, hyperinsulinemia (β=7.430, p<0.001) was independently related to hyperhomocysteinemia. In a logistic regression analysis, high triglycerides (OR=1.177, p<0.001) and homocysteine (OR=1.508, p=0.007), and low HDL-C (OR=0.315, p=0.026) were associated with IGT. CONCLUSIONS Patients with IGT have higher homocysteine levels compared with subjects with normal glucose tolerance, and hyperhomocysteinemia might be correlated with IGT.

Low apoA-I is associated with insulin resistance in patients with impaired glucose tolerance: a cross-sectional study

Background

Low apolipoprotein A-I (apoA-I) is an independent risk factor for atherosclerotic cardiovascular diseases. Insulin resistance predicts the progression of abnormal glucose metabolism, which is the main cause of atherosclerotic cardiovascular disease. In this study, we assessed the potential association between apoA-I levels and insulin resistance in patients with impaired glucose tolerance (IGT) and the possible link between apoA-I and IGT.

Methods

This study evaluated a cross-sectional study of 108 participants with impaired glucose tolerance (IGT group) and 84 controls (control group). ApoA-I and clinical characteristics were measured, and a homeostasis model assessment of insulin resistance (HOMA-IR) was calculated.

Results

The IGT group exhibited significantly lower apoA-I and higher HOMA-IR levels than the control group (apoA-I: 1.37 ± 0.36 vs 1.57 ± 0.39 g/L; HOMA-IR: 4.21 ± 1.56 vs 2.15 ± 0.99; P < 0.001 for both). ApoA-I was negatively correlated with HOMA-IR in both the IGT and control groups (IGT group: r = −0.269, P = 0.005; control group: r = −0.262, P = 0.016). Multiple stepwise regression analysis showed that low apoA-I levels (β = −1.470, P = 0.002) were independently correlated with high HOMA-IR levels in the IGT group. Moreover, logistic regression analysis identified that low apoA-I was an independent influencing factor for IGT (β = −1.170, OR = 0.310, P = 0.007).

Conclusions

ApoA-I is inversely associated with insulin resistance in patients with impaired glucose tolerance, and low apoA-I is an independent risk factor for impaired glucose tolerance. These results indicate that apoA-I plays an important role in regulating insulin sensitivity and glucose metabolism in patients with IGT.

PPAR-α Agonist Fenofibrate Reduces Insulin Resistance in Impaired Glucose Tolerance Patients with Hypertriglyceridemia: A Cross-Sectional Study

INTRODUCTION

Peroxisome proliferator-activated receptor-α (PPAR-α) agonists can regulate metabolism and protect the cardiovascular system. This study investigated the effects of PPAR-α agonist fenofibrate on insulin resistance in patients with impaired glucose tolerance (IGT).

METHODS

This research evaluated cross-sectional and interventional studies. 191 subjects with IGT were divided into a hypertriglyceridemia group (HTG group, n = 118) and a normal triglyceride (TG) group (NTG group, n = 73). 79 subjects with normal glucose tolerance were recruited as a control group. The HTG group was treated with fenofibrate (200 mg/day) for 12 weeks. The homeostatic model assessment index 2 (HOMA2) and the McAuley index (McA) were calculated.

RESULTS

HOMA2 for β-cell function (HOMA2-%B) was 93.47 ± 26.28, 68.47 ± 21.29, and 79.92 ± 23.15 in HTG, NTG, and control groups, respectively. HOMA2 for insulin sensitivity (HOMA2-%S) was 48.40 (39.70, 68.70), 110.20 (62.55, 141.95), and 101.20 (79.90, 140.10) in HTG, NTG, and control groups, respectively. HOMA2 for insulin resistance (HOMA2-IR) was 2.09 (1.46, 2.52), 0.92 (0.70, 1.61), and 0.99 (0.71, 1.25) in HTG, NTG, and control groups, respectively. McA was 5.05 ± 0.76, 7.99 ± 1.79, and 8.34 ± 1.55 in HTG, NTG, and control groups, respectively. The HTG group had higher HOMA2-%B and HOMA2-IR, and lower HOMA2-%S and McA than NTG and control groups (P < 0.001 for all). Fenofibrate decreased HOMA2-%B and HOMA2-IR and increased HOMA2-%S and McA in the HTG group (HOMA2-%B: from 93.47 ± 26.28 to 89.34 ± 23.53, P = 0.018; HOMA2-%S: from 48.40 (39.70, 68.70) to 56.75 (44.88, 72.53), P < 0.001; HOMA2-IR: from 2.07 (1.46, 2.52) to 1.76 (1.38, 2.30), P < 0.001; McA: from 5.05 ± 0.76 to 9.34 ± 0.88, P < 0.001).

CONCLUSION

PPAR-α agonists improve parameters of glucoregulation in IGT patients with hypertriglyceridemia.

A Dietary Supplement Containing Cinnamon, Chromium and Carnosine Decreases Fasting Plasma Glucose and Increases Lean Mass in Overweight or Obese Pre-Diabetic Subjects: A Randomized, Placebo-Controlled Trial

BACKGROUND

Preventing or slowing the progression of prediabetes to diabetes is a major therapeutic issue.

OBJECTIVES

Our aim was to evaluate the effects of 4-month treatment with a dietary supplement containing cinnamon, chromium and carnosine in moderately obese or overweight pre-diabetic subjects, the primary outcome being change in fasting plasma glucose (FPG) level. Other parameters of plasma glucose homeostasis, lipid profile, adiposity and inflammatory markers were also assessed.

METHODS

In a randomized, double-blind, placebo-controlled study, 62 subjects with a FPG level ranging from 5.55 to 7 mmol/L and a body mass index ≥ 25 kg/m(2), unwilling to change their dietary and physical activity habits, were allocated to receive a 4-month treatment with either 1.2 g/day of the dietary supplement or placebo. Patients were followed up until 6 months post-randomization.

RESULTS

Four-month treatment with the dietary supplement decreased FPG compared to placebo (-0.24 ± 0.50 vs +0.12 ± 0.59 mmol/L, respectively, p = 0.02), without detectable significant changes in HbA1c. Insulin sensitivity markers, plasma insulin, plasma lipids and inflammatory markers did not differ between the treatment groups. Although there were no significant differences in changes in body weight and energy or macronutrient intakes between the two groups, fat-free mass (%) increased with the dietary supplement compared to placebo (p = 0.02). Subjects with a higher FPG level and a milder inflammatory state at baseline benefited most from the dietary supplement.

CONCLUSIONS

Four-month treatment with a dietary supplement containing cinnamon, chromium and carnosine decreased FPG and increased fat-free mass in overweight or obese pre-diabetic subjects. These beneficial effects might open up new avenues in the prevention of diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01530685.

A cohort study of incident microalbuminuria in relation to HOMA-IR in Korean men

BACKGROUND

Despite the previous studies showing the relationship between microalbuminuria and insulin resistance, longitudinal effect of insulin resistance on development of microalbuminuria is not clearly identified in non-diabetic population.

METHODS

One thousand six hundred three non-diabetic Korean men without microalbuminuria in 2005 had been followed up for the development of microalbuminuria until 2010. Microalbuminuria was evaluated by urine-albumin creatinine ration, and insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR). Cox proportional hazards model was used to estimate the risk for microalbuminuria according to the tertile of HOMA-IR.

RESULTS

During 5465.8 person-y of average follow-up, microalbuminuria developed in 76 (4.7%) participants. Incidence of microalbuminuria increased in proportion to the level of HOMA-IR (tertile 1: 3.0%, tertile 2: 4.1%, tertile 3: 7.1%, P<0.001). When the 1st tertile of HOMA-IR was set as reference, hazard ratios and 95% confidence interval were 1.15 (0.56-2.35) and 2.07 (1.05-4.09) for those in the 2nd and 3rd tertiles of HOMA-IR, even after adjusting multiple covariates, respectively (P for linear trend=0.054).

CONCLUSIONS

Increased insulin resistance was a predictor of microalbuminuria in Korean men.

Simvastatin inhibits ox-LDL-induced inflammatory adipokines secretion via amelioration of ER stress in 3T3-L1 adipocyte

Adipocytes behave as a rich source of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Endoplasmic reticulum (ER) stress in adipocytes can alter adipokines secretion and induce inflammation. The aim of this study is to evaluate the effect of simvastatin on the ox-LDL-induced ER stress and expression and secretion of TNF-α and MCP-1 in 3T3-L1 adipocytes. Differentiated adipocytes were treated with various concentrations of ox-LDL (0-100 μg/ml) for 24h with or without simvastatin pre-treatment. The protein expressions of ER stress markers, glucose-regulated protein 78 (GRP78) and C/EBP homology protein (CHOP), were determined by Western blot analysis. The mRNA expressions of TNF-α and MCP-1 were measured by real-time PCR. The protein release of TNF-α and MCP-1 in culture medium were evaluated by ELISA. Ox-LDL treatment led to significant up-regulation of GRP78 and CHOP in dose-dependent manner. The expressions of TNF-α and MCP-1 were dose-dependently increased at mRNA and protein levels after ox-LDL intervention. The effects of ox-LDL on adipocytes were abolished by pre-treatment with 4-phenylbutyrate (4-PBA), a chemical chaperone known to ameliorate ER stress. Simvastatin could inhibit ox-LDL-induced ER stress and reduce the expression of TNF-α and MCP-1 at mRNA and protien level in dose dependent manner. In conclusion, ox-LDL can stimulate the expression and secretion of TNF-α and MCP-1 through its activation of ER stress in adipocytes. Simvastatin might exert direct anti-inflammatory effects in adipocytes through amelioration of ER stress.

GH levels and insulin sensitivity are differently associated with biomarkers of cardiovascular disease in active acromegaly

CONTEXT

Acromegaly is characterized by GH excess and insulin resistance. It is not known which of these disorders is responsible for the increased atherogenic risk in these patients.

OBJECTIVE

To analyse the associations of GH and homoeostasis model assessment (HOMA) with biomarkers of cardiovascular disease and to compare the above-mentioned variables between patients with active acromegaly and controls.

DESIGN AND SETTING

This open cross-sectional study was conducted at a University Hospital.

PATIENTS

Twenty-two outpatients were compared with sex- and age-matched control subjects.

MAIN OUTCOMES

Included clinical features, hormonal status, markers of insulin resistance, lipoprotein profile and biomarkers of cardiovascular disease.

RESULTS

Patients presented higher triglyceride (median [IQR]) (1·2[1·1-1·6] vs 0·9[0·6-1·1] mm, P < 0·05), low-density lipoprotein-cholesterol (LDL-C) (mean ± SD) (3·5 ± 0·9 vs 3·0 ± 0·7mm, P < 0·05), apoB (0·98 ± 0·23 vs 0·77 ± 0·22 g/l, P < 0·05), free fatty acid (0·69 ± 0·2 vs 0·54 ± 0·2 mM, P < 0·05), oxidized-LDL (120 ± 22 vs 85 ± 19 U/l, P < 0·05) and endothelin-1 (0·90 ± 0·23 vs 0·72 ± 0·17 ng/l, P < 0·05) levels, increased cholesteryl ester transfer protein (CETP) activity (179 ± 27 vs 138 ± 30%/ml/h, P < 0·01) and lower C reactive protein (CRP) (0·25[0·1-0·9] vs 0·85[0·4-1·4] mg/l; P < 0·05) levels than control subjects. Vascular cell adhesion molecule (VCAM-1) concentration was not different. By multiple linear regression analyses, HOMA explained the variability of triglycerides (25%), high-density lipoprotein-cholesterol (HDL-C) (30%) and CETP activity (28%), while GH independently predicted LDL-C (18%), oxidized-LDL (40%) and endothelin-1 levels (19%).

CONCLUSIONS

In patients with active acromegaly, GH excess contributes to the development of insulin resistance, and the interaction between both disturbances would be responsible for the appearance of atherogenic pro-oxidative and pro-inflammatory factors. Insulin resistance would be preferably associated with an atherogenic lipoprotein profile and to high CETP activity, while high GH levels would independently predict the increase in LDL-C, ox-LDL and endothelin-1.

Insulin resistance, metabolic stress, and atherosclerosis

Atherosclerosis, a pathological process that underlies the development of cardiovascular disease, is the primary cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). T2DM is characterized by hyperglycemia and insulin resistance (IR), in which target tissues fail to respond to insulin. Systemic IR is associated with impaired insulin signaling in the metabolic tissues and vasculature. Insulin receptor is highly expressed in the liver, muscle, pancreas, and adipose tissue. It is also expressed in vascular cells. It has been suggested that insulin signaling in vascular cells regulates cell proliferation and vascular function. In this review, we discuss the association between IR, metabolic stress, and atherosclerosis with focus on 1) tissue and cell distribution of insulin receptor and its differential signaling transduction and 2) potential mechanism of insulin signaling impairment and its role in the development of atherosclerosis and vascular function in metabolic disorders including hyperglycemia, hypertension, dyslipidemia, and hyperhomocysteinemia. We propose that insulin signaling impairment is the foremost biochemical mechanism underlying increased cardiovascular morbidity and mortality in atherosclerosis, T2DM, and metabolic syndrome.

Evolving paradigms for repair of tissues by adult stem/progenitor cells (MSCs)

In this review, we focus on the adult stem/progenitor cells that were initially isolated from bone marrow and first referred to as colony forming units-fibroblastic, then as marrow stromal cells and subsequently as either mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs). The current interest in MSCs and similar cells from other tissues is reflected in over 10,000 citations in PubMed at the time of this writing with 5 to 10 new publications per day. It is also reflected in over 100 registered clinical trials with MSCs or related cells (http//www.clinicaltrials.gov). As a guide to the vast literature, this review will attempt to summarize many of the publications in terms of three paradigms that have directed much of the work: an initial paradigm that the primary role of the cells was to form niches for haematopoietic stem cells (paradigm I); a second paradigm that the cells repaired tissues by engraftment and differentiation to replace injured cells (paradigm II); and the more recent paradigm that MSCs engage in cross-talk with injured tissues and thereby generate microenvironments or ‘quasi-niches’ that enhance the repair tissues (paradigm III).

Evolving paradigms for repair of tissues by adult stem/progenitor cells (MSCs)

In this review, we focus on the adult stem/progenitor cells that were initially isolated from bone marrow and first referred to as colony forming units-fibroblastic, then as marrow stromal cells and subsequently as either mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs). The current interest in MSCs and similar cells from other tissues is reflected in over 10,000 citations in PubMed at the time of this writing with 5 to 10 new publications per day. It is also reflected in over 100 registered clinical trials with MSCs or related cells (http//www.clinicaltrials.gov). As a guide to the vast literature, this review will attempt to summarize many of the publications in terms of three paradigms that have directed much of the work: an initial paradigm that the primary role of the cells was to form niches for haematopoietic stem cells (paradigm I); a second paradigm that the cells repaired tissues by engraftment and differentiation to replace injured cells (paradigm II); and the more recent paradigm that MSCs engage in cross-talk with injured tissues and thereby generate microenvironments or 'quasi-niches' that enhance the repair tissues (paradigm III).

Elevated serum chemerin levels are associated with the presence of coronary artery disease in patients with metabolic syndrome

OBJECTIVE

Patients with metabolic syndrome (MetS) are at a high risk for developing atherosclerosis and cardiovascular disease. Serum levels of chemerin have been found elevated in subjects with MetS and are associated with several cardiovascular factors. This study was undertaken to determine whether serum chemerin levels are associated with coronary artery disease (CAD) in patients with MetS.

METHODS

A total of 112 patients with MetS (66 patients with CAD and 46 without CAD) and 52 healthy subjects who underwent coronary angiography for the evaluation of CAD were enrolled in this study. Serum levels of chemerin were measured by enzyme-linked immunosorbent assay.

RESULTS

Serum chemerin levels were significantly elevated in MetS patients with CAD compared to in those without CAD and healthy subjects. MetS patients without CAD also had higher serum chemerin levels compared with healthy subjects. Multivariate logistic regression analysis revealed that serum chemerin levels were significantly associated with the presence of CAD in patients with MetS. Simple linear regression analysis showed that the serum levels of chemerin were positively correlated with body mass index (BMI), systolic blood pressure (SBP), serum triglycerides and C-reactive protein (CRP) in patients with MetS. Only BMI and CRP remained significantly associated with serum chemerin after multiple stepwise regression analysis.

CONCLUSION

Elevated serum chemerin levels could be considered as an independent predictive marker of the presence of CAD in patients with MetS.

Low insulin level is associated with aortic stiffness

Recent studies have demonstrated that hyperinsulinemia is a risk factor for cardiovascular disease. The aim of this study was to evaluate the relationship between serum insulin level and the cardio-ankle vascular index (CAVI), which was developed as a marker of arterial stiffness. We performed a cross-sectional study of 260 consecutive and nondiabetic subjects with clinical suspicion of coronary heart disease. We measured CAVI in all subjects. A standard 75-g oral glucose tolerance test was performed, and plasma glucose and serum insulin levels were measured in venous blood collected at 0, 30, 60 and 120 min after the test. Statistical analyses were conducted for four subgroups according to the insulin area under the concentration time curve (InsAUC). Mean CAVI and InsAUC were 8.7 and 109.5 μIUml(-1)h(-1), respectively. Unadjusted analysis demonstrated that the InsAUC quartiles were significantly associated with CAVI (P<0.0001), and the lowest InsAUC quartile (P=0.001) had a lower glucose AUC. Analysis of covariance demonstrated that the lowest InsAUC quartile had the highest CAVI, and, after adjusting for several coronary risk factors, the highest InsAUC quartile had a higher CAVI than the second and third InsAUC quartiles (P<0.0001). In conclusion, the lowest InsAUC quartile was related to CAVI, although the lowest InsAUC quartile maintained glucose homeostasis in this study population. Both hyperinsulinemia and low insulin level are independently associated with CAVI.

Smoking and atherosclerotic cardiovascular disease: part II: role of cigarette smoking in cardiovascular disease development

Potential mechanisms and biomarkers of atherosclerosis related to cigarette smoking - a modifiable risk factor for that disease - are discussed in this article. These include smoking-associated inflammatory markers, such as leukocytes, high-sensitivity C-reactive protein, serum amyloid A, ICAM-1 and IL-6. Other reviewed markers are indicative for smoking-related impairment of arterial endothelial function (transcapillary leakage of albumin, inhibition of endogenous nitric oxide synthase activity and reduced endothelium-dependent vasodilation) or point to oxidative stress caused by various chemicals (cholesterol oxidation, autoantibodies to oxidized low-density lipoprotein, plasma levels of malondialdehyde and F(2)-isoprostanes and reduced antioxidant capacity). Smoking enhances platelet aggregability, increases blood viscosity and shifts the pro- and antithrombotic balance towards increased coagulability (e.g., fibrinogen, von Willebrand factor, ICAM-1 and P-selectin). Insulin resistance is higher in smokers compared with nonsmokers, and hemoglobin A1c is dose-dependently elevated, as is homocysteine. Smoke exposure may influence the kinetics of markers with different response to transient or chronic changes in cigarette smoking behavior.

Sarcopenia exacerbates obesity-associated insulin resistance and dysglycemia: findings from the National Health and Nutrition Examination Survey III

Background

Sarcopenia often co-exists with obesity, and may have additive effects on insulin resistance. Sarcopenic obese individuals could be at increased risk for type 2 diabetes. We performed a study to determine whether sarcopenia is associated with impairment in insulin sensitivity and glucose homeostasis in obese and non-obese individuals.

Methodology

We performed a cross-sectional analysis of National Health and Nutrition Examination Survey III data utilizing subjects of 20 years or older, non-pregnant (N = 14,528). Sarcopenia was identified from bioelectrical impedance measurement of muscle mass. Obesity was identified from body mass index. Outcomes were homeostasis model assessment of insulin resistance (HOMA IR), glycosylated hemoglobin level (HbA1C), and prevalence of pre-diabetes (6.0≤ HbA1C<6.5 and not on medication) and type 2 diabetes. Covariates in multiple regression were age, educational level, ethnicity and sex.

Principal Findings

Sarcopenia was associated with insulin resistance in non-obese (HOMA IR ratio 1.39, 95% confidence interval (CI) 1.26 to 1.52) and obese individuals (HOMA-IR ratio 1.16, 95% CI 1.12 to 1.18). Sarcopenia was associated with dysglycemia in obese individuals (HbA1C ratio 1.021, 95% CI 1.011 to 1.043) but not in non-obese individuals. Associations were stronger in those under 60 years of age. We acknowledge that the cross-sectional study design limits our ability to draw causal inferences.

Conclusions

Sarcopenia, independent of obesity, is associated with adverse glucose metabolism, and the association is strongest in individuals under 60 years of age, which suggests that low muscle mass may be an early predictor of diabetes susceptibility. Given the increasing prevalence of obesity, further research is urgently needed to develop interventions to prevent sarcopenic obesity and its metabolic consequences.

Increased risk of colon cancer associated with a genetic polymorphism of SMAD7

Genome-wide association studies (GWAS) have identified SMAD7 on 8q21 as being associated with colorectal cancer. We evaluated single nucleotide polymorphisms (SNP) in the SMAD7 gene, including rs4939827, rs12953717, and rs4464148, previously identified from GWAS in a large population-based case-control study of colon cancer. We observed that rs12953717 was associated with a statistically significant increased risk of colon cancer [odds ratio, 1.38; 95% confidence intervals (CI), 1.13-1.68; P linear trend < 0.01] for the TT genotype compared with the CC genotype, whereas the CC genotype of the rs4939827 SNP was inversely associated with colon cancer (0.77; 95% CI, 0.64-0.93) relative to the TT genotype. There were no significant differences in association for either of these polymorphisms when stratified by age, tumor site, sex, or family history. The odds ratios between SMAD7 and colon cancer among individuals reporting recent aspirin/nonsteroidal anti-inflammatory drug use was 0.60 (95% CI, 0.43-0.85) for the CC genotype of the rs4939827 polymorphism and 1.69 (95% CI, 1.20-2.38) for the TT genotype of the rs1295371 polymorphism. This result compares to odds ratios of 0.86 (95% CI, 0.68-1.09) for rs4939827 and 1.22 (95% CI, 0.96-1.56) among individuals who did not use aspirin/nonsteroidal anti-inflammatory drugs. An assessment of SMAD7 genotypes with tumor markers did not reveal any significant differences by KRAS2, TP53, CpG island methylator phenotype, or microsatellite instability status. No significant associations were observed for the rs4464148 SNP or other SNPs evaluated in the SMAD7. These results corroborate the findings of GWAS in colon cancer pointing to SMAD7 and reinforce interest in SNPs in this gene.

Intravenous hMSCs improve myocardial infarction in mice because cells embolized in lung are activated to secrete the anti-inflammatory protein TSG-6

Quantitative assays for human DNA and mRNA were used to examine the paradox that intravenously (i.v.) infused human multipotent stromal cells (hMSCs) can enhance tissue repair without significant engraftment. After 2 x 10(6) hMSCs were i.v. infused into mice, most of the cells were trapped as emboli in lung. The cells in lung disappeared with a half-life of about 24 hr, but <1000 cells appeared in six other tissues. The hMSCs in lung upregulated expression of multiple genes, with a large increase in the anti-inflammatory protein TSG-6. After myocardial infarction, i.v. hMSCs, but not hMSCs transduced with TSG-6 siRNA, decreased inflammatory responses, reduced infarct size, and improved cardiac function. I.v. administration of recombinant TSG-6 also reduced inflammatory responses and reduced infarct size. The results suggest that improvements in animal models and patients after i.v. infusions of MSCs are at least in part explained by activation of MSCs to secrete TSG-6.

Changes in inflammatory biomarkers across weight classes in a representative US population: a link between obesity and inflammation

BACKGROUND

Obesity has been linked with a chronic state of inflammation which may be involved in the development of metabolic syndrome, cardiovascular disease, non-alcoholic steatohepatitis, and even cancer. The objective of this study was to examine the association between obesity class and levels of inflammatory biomarkers from men and women who participated in the 1999-2004 National Health and Nutrition Examination Survey (NHANES).

METHODS

Serum concentrations of C-reactive protein (CRP) and fibrinogen were measured among US participants of the 1999-2004 NHANES. We examined biomarker levels across different weight classes with normal weight, overweight, and obesity classes 1, 2, and 3 were defined as BMI of < 25.0, 25.0-29.9, 30.0-34.9, 35.0-39.9, and > or = 40.0, respectively.

RESULTS

With CRP levels for normal weight individuals as a reference, CRP levels nearly doubled with each increase in weight class: +0.11 mg/dl (95% CI, 0.06-0.16) for overweight, +0.21 mg/dl (95% CI, 0.16-0.27) for obesity class 1, +0.43 mg/dl (95% CI, 0.26-0.61) for obesity class 2, and +0.73 mg/dl (95% CI, 0.55-0.90) for obesity class 3. With normal weight individuals as a reference, fibrinogen levels increase with increasing weight class and were highest for obesity class 3 individuals, +93.5 mg/dl (95% CI, 72.9-114.1). Individuals with hypertension or diabetes have higher levels of CRP and fibrinogen levels compared to individuals without hypertension or diabetes, even when stratified according to BMI.

CONCLUSIONS

There is a direct association between increasing obesity class and the presence of obesity-related comorbidities such as diabetes and hypertension with high levels of inflammatory biomarkers.

Insulin resistance: a proinflammatory state mediated by lipid-induced signaling dysfunction and involved in atherosclerotic plaque instability

The dysregulation of the insulin-glucose axis represents the crucial event in insulin resistance syndrome. Insulin resistance increases atherogenesis and atherosclerotic plaque instability by inducing proinflammatory activities on vascular and immune cells. This condition characterizes several diseases, such as type 2 diabetes, impaired glucose tolerance (IGT), impaired fasting glucose (IFG), obesity, hypertension, dyslipidemia, and other endocrinopathies, but also cancer. Recent studies suggest that the pathophysiology of insulin resistance is closely related to interferences with insulin-mediated intracellular signaling on skeletal muscle cells, hepatocytes, and adipocytes. Strong evidence supports the role of free fatty acids (FFAs) in promoting insulin resistance. The FFA-induced activation of protein kinase C (PKC) delta, inhibitor kappaB kinase (IKK), or c-Jun N-terminal kinase (JNK) modulates insulin-triggered intracellular pathway (classically known as PI3-K-dependent). Therefore, reduction of FFA levels represents a selective target for modulating insulin resistance.

Oral antidiabetic agents as cardiovascular drugs

The increased risk of cardiovascular disease associated with type 2 diabetes is well documented. Lesser degrees of abnormal glucose metabolism including impaired fasting glycaemia and impaired glucose tolerance are also associated with increased cardiovascular risk. Studies showing improved cardiovascular outcomes with oral antidiabetic agents are limited, with the UKPDS demonstrating improved macrovascular outcomes only in a subgroup of obese patients with type 2 diabetes treated with metformin, and the heavily criticized STOP NIDDM trial showing a reduction in the number of cardiovascular events with the alpha glucosidase inhibitor acarbose. In recent years there has been an increase in the number of oral antidiabetic drugs available to treat the hyperglycaemia of diabetes. Some of these drugs have complex metabolic properties, additional to their antihyperglycaemic effect, improving endothelial function and markers of atherogenesis, with the potential to reduce cardiovascular morbidity and mortality, as supported by the recently published results of the PROACTIVE study. The results of further long-term cardiovascular outcome studies with these newer agents are awaited.