Positive association between high-sensitivity C-reactive protein and incidence of type 2 diabetes mellitus in Japanese workers: 6-year follow-up

Atherogenic index of plasma, high sensitivity C-reactive protein and incident diabetes among middle-aged and elderly adults in China: a national cohort study

BACKGROUND

The atherogenic index of plasma (AIP) and systematic inflammation, as measured by high-sensitivity C-reactive protein (hsCRP), are predictors of diabetes, but their combined impacts on incident diabetes are poorly understood. Using a nationally representative cohort in China, we aimed to investigate the association of AIP and hsCRP with incident diabetes among middle-aged and elderly adults.

METHODS

This cohort comprised 9,112 participants aged at least 45 years from 125 cities in the China Health and Retirement Longitudinal Study who were free of diabetes at baseline in 2011. Of these, 5,048 participants were followed up until 2015. The AIP was calculated as Log10[TG (mg/dL)/HDL-C(mg/dL)]. Multivariate logistic regression and linear mixed-effect (LME) models were performed to evaluate the associations of AIP, hsCRP, and incident diabetes as well as glycemic biomarkers. Receiver operating characteristic (ROC) curves were used to evaluate their diagnostic values. We conducted a mediation analysis to assess the direct and indirect associations between AIP and hsCRP with diabetes.

RESULTS

489 (9.7%) cases developed diabetes during four years. Higher levels of AIP and hsCRP were independently associated with diabetes. Compared to the lowest quartile of AIP or hsCRP, the highest quartile of AIP (adjusted odds ratio, aOR 2.53, 95% CI: 1.90-3.38) and hsCRP (aOR 2.38, 1.79-3.16) was significantly associated with incident diabetes. The joint effects showed that participants with higher levels of AIP and hsCRP had significantly higher aOR of 2.76 (2.13-3.57). The LME models showed AIP and hsCRP were related to an increased level of fasting blood glucose and glycated hemoglobin. The combination of AIP and hsCRP has better predictive efficacy (area under the curve, AUC: 0.628, 0.601-0.654) for incident diabetes than alone. Mediation analyses showed that high AIP significantly mediated 25.4% of the association between hsCRP and diabetes, and hsCRP simultaneously mediated 5.7% of the association between AIP and diabetes.

CONCLUSIONS

This cohort suggests combined effects and mutual mediation between the AIP and hsCRP on incident diabetes in China. Our findings provide clinical implications for monitoring and managing AIP and hsCRP levels to mitigate the development of diabetes.

The postprandial actions of GLP-1 receptor agonists: The missing link for cardiovascular and kidney protection in type 2 diabetes

Recent clinical trials in people with type 2 diabetes have demonstrated beneficial actions on heart and kidney outcomes following treatment with GLP-1RAs. In part, these actions are consistent with improved glucose control and significant weight loss. But GLP-1RAs may also have additive benefits by improving postprandial dysmetabolism. In diabetes, dysregulated postprandial nutrient excursions trigger inflammation, oxidative stress, endothelial dysfunction, thrombogenicity, and endotoxemia; alter hormone levels; and modulate cardiac output and regional blood and lymphatic flow. In this perspective, we explore the actions of GLP-1RAs on the postprandial state and their potential role in end-organ benefits observed in recent trials.

Effects of red raspberry polyphenols and metabolites on biomarkers of inflammation and insulin resistance in type 2 diabetes: A pilot study

Berry fruits are rich in polyphenolic compounds (PCs) and may promote health benefits. Anthocyanin (ACNs) concentrations of red raspberry (RR)(Rubus idaeus) extracts were 887.6 ± 262.8 μg/g consisting mainly of...

The role of vitamin D deficiency and elevated inflammatory biomarkers as risk factors for the progression of diabetic nephropathy in patients with type 2 diabetes mellitus

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. Albuminuria is the most sensitive marker for the early recognition of DN. Therefore, we aimed to study the risk factors of albuminuria as a marker of DN among diabetic patients. The study included 41 patients with type 2 diabetes mellitus (T2DM), 50 type 2 diabetic nephropathy (T2DN) patients with macroalbuminuria, 43 T2DN patients with microalbuminuria and 38 healthy controls. Logistic regression was used to detect the most significant risk factors for albuminuria. A high statistically significant difference was found between the groups regarding age, sex, body mass index (BMI), diabetes mellitus (DM) duration, glucose, glycated haemoglobin (HbA1c), creatinine, glomerular filtration rate (GFR), lipid profile, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), the albumin–creatinine ratio (ACR), vitamin D, total parathyroid hormone (PTH), urea, total calcium and chemerin (p < 0.001). It was found that the duration of DM, BMI, glucose, GFR, total cholesterol (TC), low-density lipoprotein (LDL), TNF-α, IL-6, CRP, ACR, vitamin D, PTH and chemerin are significant albuminuria risk factors in DN. Vitamin D deficiency and associated inflammatory mediators such as chemerin, TNF-α, IL-6 and CRP are the most essential risk factors for albuminuria in T2DM patients.

High-sensitivity C-reactive protein and risk of type 2 diabetes: A nationwide cohort study and updated meta-analysis

OBJECTIVE

To prospectively examine the association of high sensitivity C-reactive protein (hs-CRP) with incident type 2 diabetes mellitus (T2DM) among middle-aged and elderly Chinese, and validate the association in an updated meta-analysis of prospective studies.

METHODS

We used data from the China Health and Retirement Longitudinal Study, started in 2011-2012 with follow ups in 2013-2014 and 2015-2016. Multivariable Cox proportional hazard regressions were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between hs-CRP level and incident T2DM. An updated meta-analysis was conducted to combine our estimates with those in previous prospective studies.

RESULTS

Included in the analyses were 7985 participants (mean age: 59.38 years; men: 46.73%). Higher hs-CRP was associated with increased risk of T2DM (multivariable-adjusted HR, 1.30; 95% CI: 1.03, 1.64 for comparing extreme quartiles). The association was stronger in participants with body mass index (BMI) of 24.0 kg/m2 or higher than those with a BMI lower than 24.0 kg/m2 (p for interaction = 0.038). In a meta-analysis of 28 cohorts, 2 case-cohort, and 6 nested case-control studies among 125,356 participants with 10,759 cases, the pooled relative risk for T2DM was 1.77 (95% CI: 1.60, 1.96) for the highest versus lowest level of hs-CRP.

CONCLUSIONS

Hs-CRP was associated with higher risk of T2DM in middle-aged and elderly Chinese, and this association was confirmed by an updated meta-analysis of prospective studies. Our findings highlight the role of elevated hs-CRP in the development of T2DM.

Associations between high-sensitivity C-reactive protein and non-communicable diseases in an Asian population: findings from the IFLS study

Background: There has been no comprehensive study on how high-sensitivity C-reactive protein (hs-CRP) levels, a biomarker of inflammation, are associated with subsequent diagnoses of various non-communicable diseases (NCDs) in Asians. Our study is the first to do so to better compare these associations in an Asian population.Methods: This is a nationwide longitudinal study of 3,410 male and 4,004 female participants of the RAND Indonesian Family Life Survey with a mean age of 42.4 years, to examine associations between increasing hs-CRP levels and risks of heart diseases, stroke, hypertension, diabetes, arthritis, non-cancerous stomach or other digestive diseases, and non-cancerous kidney diseases. We used unadjusted and confounding-adjusted weighted Poisson regression models to respectively examine associations involving hs-CRP as a risk predictor or indicator of chronic inflammation. Several stratified subpopulation analyses were also performed.Results: Increasing hs-CRP levels predicted significantly higher risks of being diagnosed with all of the studied NCDs except stomach or other digestive diseases. After adjusting for confounding, increasing hs-CRP levels were significantly associated with higher risks of diabetes, heart diseases, hypertension, and kidney diseases.Conclusions: Our comprehensive findings on the associations between hs-CRP levels and risks of several NCDs in Asians may have clinical implications and promote additional studies on this topic.

Overexpression of lipoic acid synthase gene alleviates diabetic nephropathy of Leprdb/db mice

INTRODUCTION

Diabetic nephropathy (DN) develops in about 40% of patients with type 2 diabetes and remains the leading cause of end-stage renal disease. The mechanisms of DN remain to be elucidated. Oxidative stress is thought to be involved in the development of DN but antioxidant therapy has produced conflicting results. Therefore, we sought to define the role of antioxidant in retarding the development of DN in this study.

RESEARCH DESIGN AND METHODS

We generated a new antioxidant/diabetes mouse model, Lias^H/HLepr^db/db mice, by crossing db/db mice with Lias^H/H mice, which have overexpressed Lias gene (~160%) compared with wild type, and also correspondingly increased endogenous antioxidant capacity. The new model was used to investigate whether predisposed increased endogenous antioxidant capacity was able to retard the development of DN. We systemically and dynamically examined main pathological alterations of DN and antioxidant biomarkers in blood and kidney mitochondria.

RESULTS

Lias^H/HLepr^db/db mice alleviated major pathological alterations in the early stage of DN, accompanied with significantly enhanced antioxidant defense. The model targets the main pathogenic factors by exerting multiple effects such as hypoglycemic, anti-inflammation, and antioxidant, especially protection of mitochondria.

CONCLUSION

The antioxidant animal model is not only very useful for elucidating the underlying mechanisms of DN but also brings insight into a new therapeutic strategy for clinical applications.

Epidemiology of Isolated Impaired Glucose Tolerance Among Adults Aged Above 50 Years in Rural China

INTRODUCTION

Isolated impaired glucose tolerance (i-IGT) is a subtype of prediabetes in which an individual demonstrates elevated 2-h post-glucose load glucose levels but normal fasting plasma glucose levels. However, few studies have explored the prevalence and risk factors of i-IGT among adults in rural China. Thus, we aimed to explore the prevalence and risk factors of i-IGT among adults ≥50 years old in a low-income, rural population in China.

MATERIALS AND METHODS

Individuals aged ≥50 years with normal fasting plasma glucose levels were included in the final analysis. Fasting and 2-h venous blood samples were collected to assess the selected parameter measurements.

RESULTS

A total of 2175 individuals were included in this study. The i-IGT prevalence was 22.9% and significantly higher among females than among males (P<0.05). Older age [odds ratio (OR), 1.606; 95% confidence interval (CI), 1.101-2.342; P=0.014), hypertension (OR, 1.554; 95% CI, 1.152-2.019; P=0.004), and central obesity (OR, 1.395; 95% CI, 1.099-1.771; P=0.006) were associated with i-IGT. Moreover, white blood cell (OR, 1.089; 95% CI, 1.009-1.175; P=0.029), high-sensitivity C-reactive protein (OR, 1.049; 95% CI, 1.020-1.078; P=0.001), serum uric acid (OR, 1.0003; 95% CI, 1.001-1.004; P=0.001), triglyceride (OR, 1.540; 95% CI, 1.105-2.147; P=0.011), and alanine aminotransferase (OR, 1.012; 95% CI, 1.004-1.021; P=0.004) levels were also linked to i-IGT in the analyzed population.

CONCLUSION

Health promotion education and a standardized approach to managing body weight, BP, and lipid and uric acid levels would benefit this low-income population in rural China for reducing the risk of cardiovascular disease.

Effect of dietary anthocyanins on biomarkers of glycemic control and glucose metabolism: A systematic review and meta-analysis of randomized clinical trials

Anthocyanins, as natural food colorants, are bioactive substances with several health advantages. In this research, the effects of dietary anthocyanins on biomarkers of glycemic control and glucose metabolism was evaluated through a meta-analysis. The results revealed a significant reduction in levels of fasting blood sugar (FBS; -2.70 mg/dl, 95% CI: -4.70 to -1.31; P < 0.001), 2-h postprandial glucose (2-h PPG; -11.1 mg/dl, 95% CI: -18.7 to -3.48; P = 0.004), glycated hemoglobin (HbA1c; -11.1 mg/dl, 95% CI: -18.7 to -3.48; P = 0.004), homeostasis model assessment of insulin resistance (HOMA-IR; -0.54, 95% CI: -0.94 to -0.14; P = 0.008), resistin (-1.23 µg/l, 95% CI: -2.40 to -0.05; P = 0.041), and plasminogen activator inhibitor-1 (PAI-1; -5.09 µg/l, 95% CI: -9.45 to -0.73; P = 0.022) following administration of anthocyanins, whilst changes in the levels of fasting insulin (0.33 mU/l, 95% CI: -0.18 to 0.85; P = 0.207) and C-peptide (-0.02 µg/l, 95 %CI: -0.20 to 0.16; P = 0.816) was not statistically significant. Consumption of anthocyanins for >8 weeks and at doses >300 mg/day significantly reduced levels of FBS, 2-h PPG, HbA1c, and HOMA-IR. Moreover, anthocyanins administration reduced the levels of FBS, 2-h PPG, HbA1c, and HOMA-IR in type 2 diabetic subjects and HOMA-IR in overweight/obese individuals. Overall, dietary anthocyanins can be used as an adjuvant therapy to improve biomarkers of glycemic control and glucose metabolism specially in diabetic subjects.

High Sensitivity C-Reactive Protein Predictive Value for Cardiovascular Disease: A Nested Case Control from Isfahan Cohort Study (ICS)

Background:

High sensitivity C-reactive protein (hs-CRP) was proven to be an independent risk factor for cardiovascular diseases (CVDs). The aim of this study was to investigate the benefits of assessing hs-CRP among individuals with different cardiovascular risk factors.

Methods:

This nested case-control study was obtained from the Isfahan Cohort Study (ICS). Anyone who has been suffering from any CVDs, including myocardial infarction, unstable angina, sudden cardiac death and stroke was put in the case group. Density sampling method was utilized to choose the control group who had no aforementioned CVDs during follow-up. Four quartiles of hs-CRP (Q1: 0.1–2.3, Q2: 2.4–3, Q3: 3.1–4 and Q4: 4.1–14 mg/l) were assessed defining odds ratios (OR) of CVDs prediction in different CVDs risk factor categories. Confidence intervals of 95% are put in brackets.

Results:

A total of 502 cases and 538 controls were recruited. All hs-CRP quartiles showed increased CVDs likelihood compared to normal subjects in terms of diabetes mellitus (DM) and hypertension (HTN). Second quartile showed a 1.93 [1.33–2.81] and 3.34 [1.36–8.17] increased risks in patients with hypertriglyceridemia or dyslipidemia, respectively. Smokers in the third quartile group revealed increased CVDs risk. The fourth quartile showed significant increased risks in patients suffering from hypercholesterolemia (OR = 1.91 [1.33–2.74]), high LDL-C (OR = 1.88 [1.33–2.66]), and hypertriglyceridemia (OR = 2.31 [1.57–3.41]).

Conclusions:

Our findings suggested that assessing hs-CRP is beneficial for predicting CVDs in patients with HTN and DM. Furthermore, specific patients with lipid abnormalities or history of smoking benefits from checking hs-CRP.

The frequency of Tim-3 on circulating Tfh cells was increased in type 2 diabetes mellitus patients

Type 2 diabetes mellitus (T2DM) is a chronic, low-grade inflammation disease. T follicular helper (Tfh) cells and T cell immunoglobulin and mucin domain 3 (Tim-3) are implicated in many immune diseases. This study aims to explore whether Tim-3 expression on Tfh cells is associated with T2DM progression. White blood cells (WBCs) were harvested from 30 patients with T2DM and 20 healthy donors. The abundance of circulating Tfh cells (cTfh) and the frequency of Tim-3 were analyzed by flow cytometry. Levels of fasting plasma glucose (FPG), insulin, hemoglobin A1C (HbA1C), and fasting plasma C-peptide were measured. Body mass index (BMI) and diabetes duration were also recorded. Patients with T2DM had higher numbers of cTfh cells. In addition, cTfh cells showed a negative correlation with HbA1C and diabetes duration, a positive correlation with fasting plasma C-peptide. The frequency of Tim-3 on cTfh cells was higher among T2DM patients compared with healthy donors. The in vitro experiment showed that high glucose levels increased the abundance cTfh cells but had no effect on Tim-3 expression. Our results suggest that cTfh cells and associated Tim-3 frequency may contribute to the progression of T2DM, and high glucose levels may influence cTfh cells directly.

High-Sensitivity C-Reactive Protein Is Associated with Prediabetes and Adiposity in Korean Youth

Background: Obesity, a chronic low-grade inflammatory state, increases the risk of cardiovascular disease. Elevated high-sensitivity C-reactive protein (hs-CRP) levels are associated with cardiovascular disease, type 2 diabetes, and metabolic syndrome in adults. This study aimed to determine the association of hs-CRP and cardiometabolic risk factors, including obesity, prediabetes, hypertension, and dyslipidemia, in the nationally representative data of Korean youth. Methods: Anthropometric, biochemical, physical activity (PA), and nutritional survey data were collected for 1,723 youths (918 boys, 53.5%), aged 10-18 years, from the Korea National Health and Nutrition Examination Survey (2015-2017). Participants were classified into three groups according to hs-CRP tertile. Abdominal obesity, impaired fasting glucose, elevated triglyceride, decreased high-density lipoprotein (HDL) cholesterol and elevated blood pressure, and prediabetes [glycated hemoglobin (HbA1c) 5.7%-6.4%] were compared according to sex and hs-CRP tertile. Results: The ranges of each hs-CRP tertile were ≤0.3, 0.31-0.5, and >0.5 mg/L, respectively. hs-CRP was positively associated with body mass index (BMI) z-score (P < 0.001) and HbA1c (P = 0.012), and negatively with HDL cholesterol (P = 0.029), after adjusting confounding variables, including age, sex, BMI, white blood cell count, PA, and nutritional factors. The upper tertile of hs-CRP was associated with obesity [adjusted odds ratio (aOR) 12.07, P < 0.001] and prediabetes (aOR 3.08, P = 0.002). Conclusions: Elevated hs-CRP is associated with high BMI z-score and HbA1c, and low HDL cholesterol in Korean children and adolescents. Hence, hs-CRP could be a reliable indicator for adiposity, prediabetes, and abnormal lipid metabolism in the pediatric population.

hs-CRP Is Associated With Incident Diabetic Nephropathy: Findings From the Jackson Heart Study

OBJECTIVE

African Americans (AA) suffer disproportionately from diabetic nephropathy (DN). C-reactive protein (CRP) has been associated with prevalent DN, but its association with incident DN in AA is unknown. We examined hs-CRP and incident DN in AA.

RESEARCH DESIGN AND METHODS

We conducted a longitudinal analysis of data from exams 1, 2, and 3 in 4,043 eligible Jackson Heart Study (JHS) participants. Participants with DN or without hs-CRP at exam 1 were excluded. Incident DN was defined as urinary albumin-to-creatinine ratio (ACR) >30 mg/g or self-reported dialysis/transplantation and type 2 diabetes mellitus (DM) or HbA1c >6.5% by exam 2 or 3 among participants free of DN at exam 1. Kaplan-Meier curves examined DN event-free survival probability by hs-CRP. With Cox proportional hazards regression we estimated hazard ratios (HRs) and 95% CI for DN by hs-CRP tertiles, adjusting for demographics and clinical and laboratory data.

RESULTS

During 7.8 years of median follow-up time, participants who developed DN had significantly higher baseline hs-CRP, age, fasting glucose, triglycerides, ACR, systolic blood pressure, waist circumference, and duration of DM (P < 0.05). The overall incident rate of DN was 7.9%. The mean time to incident DN was shorter for participants with hs-CRP in the high tertile (>4.24 mg/L) than in the low tertile (<1.46 mg/L); P < 0.001. Participants with high hs-CRP had higher incidence of DN (HR 2.34, 95% CI 1.04-5.24) versus the reference group.

CONCLUSIONS

Inflammation, as measured by hs-CRP levels, may be associated with incident DN in AA. Further studies are warranted to replicate and elucidate the basis for this association.

The Impact of O-Glycosylation on Cyanidin Interaction with RBCs and HMEC-1 Cells-Structure⁻Activity Relationships

With the aim of contributing to the knowledge about their potential therapeutic activity, we determined the biological activities of cyanidin and its selected O-glycosides in relation to erythrocytes (RBCs) and human dermal vascular endothelial cells (HMEC-1). Furthermore, on the basis of changes in the physical/functional properties of the cells, the structure–activity relationships of the compounds were determined. Concerning erythrocytes, we analyzed the antioxidant activity of the compounds and their impact on the RBCs’ shape and transmembrane potential. The compounds’ cytotoxic activity, ability to modulate apoptosis, cell cycle, and intracellular ROS generation, as well as inhibitory activity against AAPH-inducted oxidative stress, were determined in relation to HMEC-1 cells. We demonstrated that biological activity of cyanidin and its O-glycosides strongly depends on the number and type of sugar substituents, and varies depending on the extracellular environment and type of cells. The compounds are practically non-cytotoxic, and do not induce apoptosis or disturb the progression of the cell cycle. Additionally, the compounds alter the shape of RBCs, but they do not affect their transmembrane potential. They effectively protect erythrocytes against free radicals and affect intracellular reactive oxygen spices (ROS) generation under physiological and AAPH-induced oxidative stress conditions. Our results suggest a potential beneficial effect of cyanidin on the cardiovascular system.

Elevated C-reactive Protein Levels Independently Predict the Development of Prediabetes Markers in Subjects with Normal Glucose Regulation

AIMS

Prediabetes is a precursor of diabetes and increases the risk of cardiovascular disease. Individuals with prediabetes reportedly have higher C-reactive protein levels, which is a risk factor for diabetes, relative to individuals with normal glucose regulation. Inflammation may play a role in the very early-phase deterioration of glucose metabolism, although there is insufficient knowledge regarding this relationship. Thus, we examined the association between serum C-reactive protein level and the development of three prediabetes markers.

METHODS

This study included 743 subjects with normal glucose regulation at baseline who completed oral glucose tolerance tests at baseline and after approximately 5 years. Subjects with a history of cardiovascular disease were excluded.

RESULTS

During the 5-year follow-up, 55 subjects developed isolated impaired glucose tolerance (IGT; 2h-plasma glucose levels of 7.8-11.0 mmol/L), 24 subjects developed isolated impaired fasting glucose (IFG; fasting plasma glucose levels of 6.1-7.0 mmol/L), 3 subjects developed IFG plus IGT, and 53 subjects developed isolated elevated glycated hemoglobin levels (HbA1c; level of 41-47 mmol/mol). The multivariate analysis revealed that, relative to the lowest quartile, the highest serum C-reactive protein quartile was independently associated with an increased risk of developing isolated elevated HbA1c levels (odds ratio: 2.95, 95% confidence interval: 1.16-7.51, P=0.024) and marginally associated with an increased risk of developing impaired glucose tolerance plus diabetes. However, C-reactive protein levels were not associated with an increased risk of developing IFG.

CONCLUSIONS

Elevated serum C-reactive protein levels independently predicted elevated HbA1c levels, but not IFG.

Telomerase RNA Component Genetic Variants Interact With the Mediterranean Diet Modifying the Inflammatory Status and its Relationship With Aging: CORDIOPREV Study

Background

Leukocyte telomere length (LTL) attrition has been associated with age-related diseases. Telomerase RNA Component (TERC) genetic variants have been associated with LTL; whereas fatty acids (FAs) can interact with genetic factors and influence in aging. We explore whether variability at the TERC gene locus interacts with FA profile and two healthy diets (low-fat diet vs Mediterranean diet [MedDiet]) modulating LTL, glucose metabolism, and inflammation status in coronary heart disease (CHD) patients.

Methods

Inflammation status (high-sensitivity C-reactive protein [hsCRP], glucose metabolism-glucose, insulin, and glycated hemoglobin [HbA1c], and homeostasis model assessment of insulin resistance [HOMA-IR]), LTL, FAs, and single nucleotide polymorphisms (SNPs) of the TERC gene (rs12696304, rs16847897, and rs3772190) were determined in 1,002 patients from the CORDIOPREV study (NCT00924937).

Results

We report an interaction of the TERC rs12696304 SNP with monounsaturated fatty acid (MUFA) affecting LTL (p interaction = .01) and hsCRP (p interaction = .03). Among individuals with MUFA levels above the median, CC individuals showed higher LTL and lower hsCRP than G-allele carriers. Moreover, MedDiet interacted with TERC rs12696304 SNP (p interaction = .03). Specifically, CC individuals displayed a greater decrease in hsCRP than G-allele carriers. These results were not adjusted for multiple statistical testing and p less than .05 was considered significant.

Conclusions

Our findings suggest that the TERC rs12696304 SNP interacts with MUFA improving inflammation status and telomere attrition related with CHD. Moreover, the MedDiet intervention improves the inflammatory profile in CC individuals compared with the G-allele carriers. These interactions could provide a right strategy for personalized nutrition in CHD patients.

miR-330-5p/Tim-3 axis regulates macrophage M2 polarization and insulin resistance in diabetes mice

Obesity is associated with a state of low-grade inflammatory response in adipose tissue, and contributes to the development of type 2 diabetes. Immune cells such as macrophages can infiltrate adipose tissue and are responsible for the majority of inflammatory cytokine production. Therefore, adipose tissue promotes macrophage infiltration, resulting in local inflammation and insulin resistance. Tim-3 negatively regulates IFN-γ secretion and influences the ability to induce T cell tolerance in diabetes. MicroRNA contributes to the development of immunological tolerance and involves in macrophage polarization. However, the potential of Tim-3 to regulate macrophage polarization and the related microRNA has not been reported. In this experiment, 8-week-old C57BL/6 mice were fed a high-fat diet for 8 weeks. The adipose tissue macrophages were isolated, miR-330-5p and Tim-3 levels, and M1/M2 polarization were analyzed. In addition, insulin tolerance tests was detected. The results demonstrated that miR-330-5p levels increased but Tim-3 levels decreased, leading to M1 polarization and insulin tolerance in diabetes mice. In addition, inhibition of miR-330-5p enhanced Tim-3 levels, leading to M2 polarization and insulin tolerance attenuation in diabetes mice. Furthermore, we detected the inverse relationship between miR-330-5p and Tim-3. We found that Tim-3 mRNA contained conserved miR-330-5p binding sites in its 3'UTR, and miR-330-5p could directly regulate Tim-3 expression through these 3'UTR sites. Our study demonstrated that miR-330-5p served as a regulator of the M2 polarization and miR-330-5p/Tim-3 axis potentially down-regulated insulin resistance in diabetes, probably through enhancing the M2 polarization of macrophage.

Passive smoking as an independent risk factor for gestational diabetes that synergizes with prepregnancy obesity in urban Chinese women

There are high-priority public health and legislative efforts around the world to reduce smoking and to reduce the spaces where smoking is allowable. These efforts are aimed at minimizing not only the adverse health effects of active smoking but also the adverse health effects of passive cigarette smoke exposure. While many cultures and societies make protection of a pregnant woman and her about-to-be-born-newborn a priority, the importance of protecting them from passive smoking that is prevalent in many modern societies has not been reported. The article by Leng et al, "Passive smoking increased risk of gestational diabetes mellitus independently and synergistically with prepregnancy obesity in Tianjin, China," newly published in Diabetes Metabolism Research and Reviews, provides evidence that passive smoke inhalation during pregnancy makes gestational diabetes more likely, bringing with it negative health consequences for the mother and her baby. This study will hopefully add support to public health officials' efforts to curb cigarette use, especially in public domains.

Health benefits of anthocyanins and molecular mechanisms: Update from recent decade

Anthocyanins are one of the most widespread families of natural pigments in the plant kingdom. Their health beneficial effects have been documented in many in vivo and in vitro studies. This review summarizes the most recent literature regarding the health benefits of anthocyanins and their molecular mechanisms. It appears that several signaling pathways, including mitogen-activated protein kinase, nuclear factor κB, AMP-activated protein kinase, and Wnt/β-catenin, as well as some crucial cellular processes, such as cell cycle, apoptosis, autophagy, and biochemical metabolism, are involved in these beneficial effects and may provide potential therapeutic targets and strategies for the improvement of a wide range of diseases in future. In addition, specific anthocyanin metabolites contributing to the observed in vivo biological activities, structure-activity relationships as well as additive and synergistic efficacy of anthocyanins are also discussed.

C-Reactive Protein Promotes Diabetic Kidney Disease in db/db Mice via the CD32b-Smad3-mTOR signaling Pathway

C-reactive protein (CRP) is associated with progressive diabetic nephropathy in patients with type-2 diabetes (T2DN). However, role of CRP in T2DN remains unclear. We report here that CRP is pathogenic in T2DN in db/db mice that express human CRP (CRPtg-db/db). Compared to the littermate db/db mice, CRPtg-db/db developed more severe T2DN, showing higher levels of fasting blood glucose and microalbuminuria and more progressive renal inflammation and fibrosis. Enhanced T2DN in CRPtg-db/db mice were associated with over-activation of CRP-CD32b, NF-κB, TGF-β/Smad3, and mTOR signaling. Further studies in vitro defined that CRP activated Smad3 directly at 15 mins via the CD32b- ERK/p38 MAP kinase crosstalk pathway and indirectly at 24 hours through a TGF-β1-dependent mechanism. Importantly, CRP also activated mTOR signaling at 30 mins via a Smad3-dependent mechanism as Smad3 bound mTOR physically and CRP-induced mTOR signaling was abolished by a neutralizing CD32b antibody and a specific Smad3 inhibitor. Finally, we also found that CRP induced renal fibrosis through a CD32b-Smad3-mTOR pathway because blocking mTOR signaling with rapamycin inhibited CRP-induced CTGF and collagen I expression. Thus, CRP is pathogenic in T2DN. CRP may promote CD32b- NF-κB signaling to mediate renal inflammation; whereas, CRP may enhance renal fibrosis in T2DN via CD32b-Smad3-mTOR signaling.

C-reactive protein inhibits high-molecular-weight adiponectin expression in 3T3-L1 adipocytes via PI3K/Akt pathway

Adiponectin, an adipose-specific protein hormone, is secreted from white adipose tissue and involved in glucose and lipid metabolism. It is assembled into low-molecular-weight trimer (LMW), middle-molecular-weight hexameric (MMW) and high-molecular-weight (HMW), among which HMW exhibits higher activity. In this study, we proved that C-reactive protein (CRP), an inflammatory marker, inhibited adiponectin expression, especially HMW in time-and dose-dependent manners. Furthermore, CRP decreased the HMW/total adiponectin ration and reduced adiponectin assembly by increasing ERp44, and decreasing Ero1-α and DsbA-L. CRP activated pAkt, the downstream of PI3K. Inhibition of PI3K or pAkt abolished the effect of CRP. Our study suggested that CRP decreased adiponectin expression and multimerization, while CRP-induced decline in adiponectin might be mediated through the PI3K/Akt pathway.

Genetic and baseline metabolic factors for incident diabetes and HbA(1c) at follow-up: the healthy twin study

BACKGROUND

We investigated baseline anthropometric/metabolic traits predicting incident diabetes, genetic/environmental relationships between these traits and HbA1c at follow-up and the contribution of genetics, covariates and environments to variance in HbA(1c) at follow-up and incident diabetes.

METHODS

Nondiabetic twins (n = 869) and their family members (n = 949) were followed over 3.7 ± 1.4 years (44.3 ± 12.8 years of age); baseline anthropometric/metabolic traits were measured. Fasting plasma glucose and HbA(1c) were measured at follow-up. Incident diabetes was defined as HbA(1c) ≥6.5% or fasting plasma glucose ≥7 mmol/L.

RESULTS

Age-adjusted incident diabetes was 4.9% in men and 4.1% in women. Odd ratio for incident diabetes was 2.34-2.40, 1.25-1.28, 1.22-1.27 and 1.89 per standard deviation of baseline fasting plasma glucose, white blood cell (WBC), triglycerides and waist circumference, respectively, in multivariate generalized estimating equation models (p < 0.05). Age-adjusted and sex-adjusted heritability was 0.85 for diabetes and 0.72 for HbA(1c). In bivariate analyses adjusted for age, sex and body mass index at baseline, HbA1c at follow-up showed significant genetic and environmental correlations with baseline glucose (0.44, 0.17), significant genetic correlation with baseline waist circumference (0.16) and triglycerides (0.30) and significant environmental correlation with baseline WBC (0.09). Variance in HbA1c at follow-up and incident diabetes was explained by genetics (33% and 28%, respectively), covariates (36% and 48%, respectively), shared environments (7% and 0%, respectively) and errors (24% and 24%, respectively).

CONCLUSIONS

High values for baseline fasting plasma glucose, WBC, triglycerides and waist circumference are independent risk factors for incident diabetes. While genetic influences strongly contribute to variance in HbA1c at follow-up and incident diabetes, these risk factors significantly contribute to the remaining variance.

The update of anthocyanins on obesity and type 2 diabetes: experimental evidence and clinical perspectives

With the dramatically increasing prevalence of obesity and type 2 diabetes mellitus (T2DM) worldwide, there is an urgent need for new strategies to combat the growing epidemic of these metabolic diseases. Diet is an essential factor affecting the development of and risk for obesity and T2DM and it can either help or hurt. In searching for preventative and therapeutic strategies, it is therefore advantageous to consider the potential of certain foods and their bioactive compounds to reverse or prevent the pathogenic processes associated with metabolic disease. Anthocyanins are naturally occurring polyphenolic compounds abundant in dark-colored fruits, vegetables and grains. Epidemiological studies suggest that increased consumption of anthocyanins lowers the risk of T2DM. Many in vitro and in vivo studies also reveal an array of mechanisms through which anthocyanins could prevent or reverse obesity- and T2DM-related pathologies including promotion of antioxidant and anti-inflammatory activities, improvement of insulin resistance, and hypolipidemic and hypoglycemic actions. Here, we summarize the data on anthocyanin-mediated protection against obesity and T2DM and the underlying mechanisms. Further population-based and long-term human intervention studies are necessary to ultimately evaluate the use of anthocyanins for protection/prevention against the development of obesity and T2DM.

Effect of whey supplementation on circulating C-reactive protein: a meta-analysis of randomized controlled trials

Whey supplementation is beneficial for human health, possibly by reducing the circulating C-reactive protein (CRP) level, a sensitive marker of inflammation. Thus, a meta-analysis of randomized controlled trials was conducted to evaluate their relationship. A systematic literature search was conducted in July, 2014, to identify eligible studies. Either a fixed-effects model or a random-effects model was used to calculate pooled effects. The meta-analysis results of nine trials showed a slight, but no significant, reduction of 0.42 mg/L (95% CI −0.96, 0.13) in CRP level with the supplementation of whey protein and its derivates. Relatively high heterogeneity across studies was observed. Subgroup analyses showed that whey significantly lowered CRP by 0.72 mg/L (95% CI −0.97, −0.47) among trials with a daily whey dose ≥20 g/day and by 0.67 mg/L (95% CI −1.21, −0.14) among trials with baseline CRP ≥3 mg/L. Meta-regression analysis revealed that the baseline CRP level was a potential effect modifier of whey supplementation in reducing CRP. In conclusion, our meta-analysis did not find sufficient evidence that whey and its derivates elicited a beneficial effect in reducing circulating CRP. However, they may significantly reduce CRP among participants with highly supplemental doses or increased baseline CRP levels.

Short duration of sleep is associated with elevated high-sensitivity C-reactive protein level in Taiwanese adults: a cross-sectional study

BACKGROUND

Elevated plasma levels of high-sensitivity C-reactive protein (hs-CRP) have been associated with increased adverse health outcomes. The aim of this study was to investigate the association of sleep duration with risk of elevated hs-CRP levels in Taiwanese adults.

METHODS

We examined the association between sleep duration and hs-CRP in 353 healthy adults recruited from the physical examination center at a regional hospital in southern Taiwan. Elevated hs-CRP was defined as a plasma level ≥ 0.20 mg/dL. Short sleep duration was defined as ≤ 5.5 h per day. Multiple logistic regression analysis was used to assess the association of short duration of sleep with elevated hs-CRP levels.

RESULTS

In this study, short duration of sleep (odds ratio [OR] = 2.20; 95% confidence interval [CI]: 1.11-4.30), aged 70 years or older (OR = 4.58; 95% CI: 1.70-12.66), menopause (OR = 2.81; 95% CI: 1.52-5.3), higher heart rate (OR = 1.38; 95% CI: 1.10-1.75), higher body mass index (OR = 1.20; 95% CI: 1.09-1.34), higher white blood cell count (OR = 1.38; 95% CI: 1.14-1.66), and higher uric acid level (OR = 1.31; 95% CI: 1.06-1.63) were significantly associated with an increased risk of elevated hs-CRP levels.

CONCLUSIONS

In this study of healthy Taiwanese adults, short duration of sleep was significantly associated with elevated hs-CRP levels. Activation of pro-inflammatory pathways might represent a mechanism by which short sleep duration affects health.