Mechanisms of Disease: pathway-selective insulin resistance and microvascular complications of diabetes

New Perspectives on Obesity-Associated Nephropathy from Pathophysiology to Therapeutics: Revealing the Promise of GLP-1 RA Therapy

Obesity represents a substantial risk factor for a multitude of metabolic disorders, which seriously threatens human life and health. As the global obesity epidemic intensifies, obesity-related nephropathy (ORN) has attracted great attention. ORN arises from both physical/mechanical and non-physical insults to the glomerular and tubular structures precipitated by obesity, culminating in structural impairments and functional aberrations within the kidneys. Physical injury factors include changes in renal hemodynamics, renal compression, and mechanical stretching of podocytes. Non-physical injury factors include overactivation of the RAAS system, insulin resistance, lipotoxicity, inflammation, and dysregulation of bile acid metabolism. Exploring molecules that target modulation of physical or nonphysical injury factors is a potential approach to ORN treatment. ORN is characterized clinically by microproteinuria and pathologically by glomerulomegaly, which is atypical and makes early diagnosis difficult. Investigating early diagnostic markers for ORN thus emerges as a critical direction for future research. Additionally, there is no specific drug for ORN in clinical treatment, which mainly focuses on weight reduction, mitigating proteinuria, and preserving renal function. In our review, we delineate a progressive therapeutic approach involving enhancements in lifestyle, pharmacotherapy, and bariatric surgery. Our emphasis underscores glucagon-like peptide-1 receptor agonists (GLP-1 RAs) as poised to emerge as pivotal therapeutic modalities for ORN in forthcoming clinical avenues.

Triglyceride Glucose Index and the Risk of Diabetic Nephropathy in Patients with Type 2 Diabetes: A Meta-Analysis

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease in patients with type 2 diabetes mellitus (T2DM). This meta-analysis aims to evaluate the association between the triglyceride glucose (TyG) index, a novel marker reflecting insulin resistance, and the risk of developing DN in patients with T2DM. We conducted a comprehensive literature search in PubMed, Embase, and Web of Science databases up to May 12, 2024. Studies assessing the TyG index in relation to DN risk among T2DM patients were included. The pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. A total of eight longitudinal follow-up studies encompassing 15 889 patients with T2DM were included. The pooled analysis revealed a significant association between a higher TyG index and an increased risk of DN in patients with T2DM (RR=1.53, 95% CI: 1.37-1.71, p<0.001; I2=35%). The results of meta-regression analysis suggested that the cutoff of TyG index was positively associated with the RR for the association between TyG index and DN. Subgroup analyses demonstrated that the association was stronger in studies with cutoff of TyG index ≥9.5 as compared to those with the cutoff <9.5 (RR: 1.73 vs. 1.40, p for subgroup difference <0.05). The association was not significantly affected by study design, mean age of the patients, proportion of men, or follow-up durations. In conclusion, higher TyG index is significantly associated with an increased risk of DN in patients with T2DM.

A translational model of chronic diabetic nephropathy in the Nile grass rat

Diabetic nephropathy (DN) is a major healthcare challenge for individuals with diabetes and associated with increased cardiovascular morbidity and mortality. The existing rodent models do not fully represent the complex course of the human disease. Hence, developing a translational model of diabetes that reproduces both the early and the advanced characteristics of DN and faithfully recapitulates the overall human pathology is an unmet need. Here, we introduce the Nile grass rat (NGR) as a novel model of DN and characterize key pathologies underlying DN. NGRs spontaneously developed insulin resistance, reactive hyperinsulinemia, and hyperglycemia. Diabetic NGRs evolved DN and the key histopathological aspects of the human advanced DN, including glomerular hypertrophy, infiltration of mononuclear cells, tubular dilatation, and atrophy. Enlargement of the glomerular tufts and the Bowman's capsule areas accompanied the expansion of the Bowman's space. Glomerular sclerosis, renal arteriolar hyalinosis, Kimmelsteil-Wilson nodular lesions, and protein cast formations in the kidneys of diabetic NGR occurred with DN. Diabetic kidneys displayed interstitial and glomerular fibrosis, key characteristics of late human pathology as well as thickening of the glomerular basement membrane and podocyte effacement. Signs of injury included glomerular lipid accumulation, significantly more apoptotic cells, and expression of KIM-1. Diabetic NGRs became hypertensive, a known risk factor for kidney dysfunction, and showed decreased glomerular filtration rate. Diabetic NGRs recapitulate the breadth of human DN pathology and reproduce the consequences of chronic kidney disease, including injury and loss of function of the kidney. Hence, NGR represents a robust model for studying DN-related complications and provides a new foundation for more detailed mechanistic studies of the genesis of nephropathy, and the development of new therapeutic approaches.

Insulin resistance in the retina: possible implications for certain ocular diseases

Insulin resistance (IR) is becoming a worldwide medical and public health challenge as an increasing prevalence of obesity and metabolic disorders. Accumulated evidence has demonstrated a strong relationship between IR and a higher incidence of several dramatically vision-threatening retinal diseases, including diabetic retinopathy, age-related macular degeneration, and glaucoma. In this review, we provide a schematic overview of the associations between IR and certain ocular diseases and further explore the possible mechanisms. Although the exact causes explaining these associations have not been fully elucidated, underlying mechanisms of oxidative stress, chronic low-grade inflammation, endothelial dysfunction and vasoconstriction, and neurodegenerative impairments may be involved. Given that IR is a modifiable risk factor, it may be important to identify patients at a high IR level with prompt treatment, which may decrease the risk of developing certain ocular diseases. Additionally, improving IR through the activation of insulin signaling pathways could become a potential therapeutic target.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Association of sarcopenia with rapid kidney function decline and chronic kidney disease in adults with normal kidney function

The association between sarcopenia and kidney function remains poorly investigated. We aimed to evaluate the associations between sarcopenia status and kidney function (rapid kidney function decline and chronic kidney disease (CKD)) in middle-aged and older Chinese population. A total of 9375 participants from the China Health and Retirement Longitudinal Study 2011 were included in the cross-sectional analyses. A total of 5864 participants with eGFRcr-cys ≥ 60 ml/min per 1·73 m2 at baseline were included in the longitudinal analyses and were followed up in 2015. Sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 criteria. In the cross-sectional analyses, possible sarcopenia and sarcopenia were significantly associated with an increased risk of CKD. During the 4 years of follow-up, 359 (6·12 %) participants experienced rapid decline in kidney function and 126 (2·15 %) participants developed CKD. After multivariable adjustment of baseline eGFRcr-cys level and other risk factors, possible sarcopenia (OR, 1·33; 95 % CI 1·01, 2·12) and sarcopenia (OR, 1·49; 95 % CI 1·05, 2·12) were associated with an increased risk of primary outcome (composite of rapid decline in kidney function (annualised decline in eGFRcr-cys ≥ 5 ml/min per 1·73 m2) and progression to CKD (eGFRcr-cys < 60 ml/min per 1·73 m2). Individuals with low muscle mass or low muscle strength alone also had an increased risk of rapid decline in kidney function and progression to CKD.

Animal Models of Type 2 Diabetes Complications: A Review

Diabetes mellitus is a multifactorial metabolic disease, of which type 2 diabetes (T2D) is one of the most common. The complications of diabetes are far more harmful than diabetes itself. Type 2 diabetes complications include diabetic nephropathy (DN), diabetic heart disease, diabetic foot ulcers (DFU), diabetic peripheral neuropathy (DPN), and diabetic retinopathy (DR) et al. Many animal models have been developed to study the pathogenesis of T2D and discover an effective strategy to treat its consequences. In this sense, it is crucial to choose the right animal model for the corresponding diabetic complication. This paper summarizes and classifies the animal modeling approaches to T2D complications and provides a comprehensive review of their advantages and disadvantages. It is hopeful that this paper will provide theoretical support for animal trials of diabetic complications.

The Relationship Between Sarcopenia And Proteinuria, What Do We Know?

Sarcopenia is one of the most common geriatric syndromes in the elderly. It is defined as a decrease in muscle mass and function, and it can lead to physical disability, falls, poor quality of life, impaired immune system, and death. It is known that, the frequency of sarcopenia increases in the kidney patient population compared to healthy individuals. Although it is known that kidney disease can lead to sarcopenia; our knowledge of whether sarcopenia causes kidney disease is limited. Prior studies have suggested that protein energy wasting may be a risk of de novo CKD. Proteinuria is an important manifestation of kidney disease and there is a relationship between sarcopenia and proteinuria in diabetes, geriatric population, kidney transplant, and nephrotic syndrome. Does proteinuria cause sarcopenia or vice versa? Are they both the results of common mechanisms? This issue is not clearly known. In this review, we examined the relationship between sarcopenia and proteinuria in the light of other studies.

Ambient ozone pollution impairs glucose homeostasis and contributes to renal function decline: Population-based evidence

Particulate matter pollution could increase the risk of kidney disease, while evidence for ozone exposure is less well-established. Here, we aimed to evaluate the effect of ozone pollution on renal function and explore mechanisms. We first conducted a cross-sectional study based on Wuhan Chronic Disease Cohort Study baseline information. We recruited 2699 eligible participants, estimated their residential ozone concentrations, collected fasting peripheral blood samples for biochemical analysis and calculated the estimated glomerular filtration rate (eGFR). The linear regression model was applied to evaluate the long-term association between ozone pollution and eGFR. Then, we recruited another 70 volunteers as a panel with 8 rounds follow-up visits. We calculated the eGFR and measured fasting blood glucose and lipid levels. The linear mixed-effect model along with mediation analysis were performed to confirm the short-term association and explore potential mechanisms, respectively. For the long-term association, a 10.95 μg/m3 increment of 3-year ozone exposure was associated with 2.96 mL/min/1.73 m2 decrease in eGFR (95%CI: -4.85, -1.06). Furthermore, the drinkers exhibited a pronounced declination of eGFR (-7.46 mL/min/1.73 m2, 95%CI: -11.84, -3.08) compared to non-drinkers in relation to ozone exposure. Additionally, a 19.02 μg/m3 increase in 3-day ozone concentrations was related to 2.51 mL/min/1.73 m2 decrease in eGFR (95%CI: -3.78, -1.26). Hyperglycemia and insulin resistance mediated 12.2% and 16.5% of the aforementioned association, respectively. Our findings indicated that higher ozone pollution could affect renal function, and the hyperglycemia and insulin resistance linked to ozone might be the underlying mechanisms.

The progression from mild to severe hyperglycemia coupled with insulin resistance causes mitochondrial dysfunction and alters the metabolic secretome of epithelial kidney cells

Diabetic nephropathy (DN) and insulin resistance (IR) in kidney cells are considered main causes for end-stage renal failure. However, it is unclear how IR affects early stages of the disease. Here, we investigate the impact of mild (11 mM) and severe (22 mM) hyperglycemia, with and without induced IR, on cellular metabolism and mitochondrial bioenergetics in a human kidney cell line (HK-2). IR in HK-2 cells was induced with palmitic acid and cellular cytotoxicity was studied. We evaluated the impact of mild and severe hyperglycemia with and without IR on the metabolic secretome of the cells, their live-cell mitochondria function, mitochondrial membrane potential, and mitochondrial complex activities. Furthermore, we measured fatty acid oxidation and lipid accumulation. Cells cultured under mild hyperglycemic conditions exhibited increased mitochondrial bioenergetic parameters, such as basal respiration, ATP-linked production, maximal respiration capacity, and spare respiration capacity. However, these parameters decreased when cells were cultured under higher glucose concentrations when IR was induced. Our data suggests that progression from mild to severe hyperglycemia induces a metabolic shift, where gluconeogenic amino acids play a crucial role in supplying the energy requirements of HK-2. To our knowledge, this is the first study to evaluate the progression from mild to severe hyperglycemia allied to IR in human kidney cells. This work highlights that this progression leads to mitochondrial dysfunction and alters the metabolic profile of kidney cells. These results identify possible targets for early intervention in DN.

Exposure to ambient air pollution and metabolic kidney diseases: evidence from the Northeast China Biobank

BACKGROUND

At present, there is no epidemiological evidence of the association between metabolic kidney diseases (MKD) and exposure to air pollution.

METHODS

We investigated the association between exposure to long-term air pollution and the risk of developing MKD using samples from the Northeast China Biobank.

RESULTS

Data from 29 191 participants were analyzed. MKD prevalence was 3.23%. Every standard deviation increment in PM2.5 increased the risk of MKD [odds ratio (OR) = 1.37, 95% confidence interval (CI) 1.19-1.58), diabetic kidney disease (DKD) (OR = 2.03, 95% CI 1.52-2.73), hypertensive kidney disease (BKD) (OR = 1.31, 95% CI 1.11-1.56), hyperlipidemic kidney disease (PKD) (OR = 1.39, 95% CI 1.19-1.63) and obese kidney disease (OKD) (OR = 1.34, 95% CI 1.00-1.81). PM10 increased the risk of MKD (OR = 1.42, 95% CI 1.20-1.67), DKD (OR = 1.38, 95% CI 1.03-1.85), BKD (OR = 1.30, 95% CI 1.07-1.58) and PKD (OR = 1.50, 95% CI 1.26-1.80). Sulfur dioxide increased the risk of MKD (OR = 1.57, 95% CI 1.34-1.85), DKD (OR = 1.81, 95% CI 1.36-2.40), BKD (OR = 1.44, 95% CI 1.19-1.74) and PKD (OR = 1.72, 95% CI 1.44-2.04). Ozone decreased the risk of PKD (OR = 0.83, 95% CI 0.70-0.99). Age, ethnicity and air pollution interacted to affect the risk of MKD, BKD and PKD. Associations between air pollution and CKD or metabolic disease were weaker than those with MKD. The association between air pollution and MKD became stronger when compared with participants with non-metabolic disease.

CONCLUSIONS

Air pollution may cause MKD or facilitate the progression from metabolic disease to renal failure.

Association between triglyceride-glucose index and chronic kidney disease: A cohort study and meta-analysis

BACKGROUND AND AIMS

Nowadays, the relationship between triglyceride-glucose (TyG) index and chronic kidney disease (CKD) is still controversial. We aimed to prospectively investigate the relationship between TyG index and CKD in a cohort and meta-analysis.

METHODS AND RESULTS

A total of 10498 participants from the China Health and Retirement Longitudinal Study (CHARLS) were included. Participants were divided into four groups based on the quartiles of the TyG index. CKD was based on self-reported physicians' diagnosis or personal eGFR level. A cox regression model was established to analyze the correlation between TyG index and CKD. A meta-analysis was conducted to incorporate the results of the current study and previous studies on the association of TyG index with CKD. In multivariable-adjusted analyses, the adjusted hazard ratio (95% confidence interval) for the highest versus lowest quartile of TyG index was 1.30 (1.08-1.57). Each 1-SD higher TyG index was associated with an increased risk of 11% (HR 1.11, 95% CI 1.03-1.19). The meta-analysis further confirmed the significant associations between TyG and CKD and pooled relative risk for highest vs lowest TyG index quartile was 1.47 (1.32-1.63).

CONCLUSIONS

Higher TyG index was associated with increased risk of CKD, independently of established risk factors. The TyG index may be a predictor of incident CKD.

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.

Association of Non-Dipping Blood Pressure Patterns with Diabetic Peripheral Neuropathy: A Cross-Sectional Study among a Population with Diabetes in Greece

Diabetic peripheral neuropathy (DPN) is present in 20-50% of cases with diabetes. The pathophysiology of DPN is not yet clear regarding hypertension (HTN). The aim of this study was to assess the association between the stages of DPN and HTN in a Greek population with diabetes. We examined 102 adults for diabetic neuropathy (DPN) from November 2020 to December 2021, using the Toronto Clinical Neuropathy Scale System (TCNSS) to categorize them into two groups (no/mild DPN versus medium/severe DPN). Ambulatory blood pressure monitoring was performed to evaluate their hypertensive status. Univariate and multivariate logistic regression analyses were performed to assess the association between the stage of DPN and HTN. The multivariate analysis, considering sex, age, and dipping status, did not show statistically significant associations between stages of HTN and DPN. However, in contrast to dippers, non-dippers had an almost four-times higher risk of developing medium-to-severe DPN (odds ratio (OR) 3.93; 95% confidence interval (CI) [1.33-11.64]); females, in contrast to males, had a 65% lower risk of developing moderate/severe DPN (OR 0.35; 95%CI [0.14-0.92]). In conclusion, our findings showed no statistically significant associations between DPN and HTN; however, dipping status, hyperglycemia, and female sex were shown to play a role in the pathophysiology of DPN.

The presence of diabetic retinopathy closely associated with the progression of non-alcoholic fatty liver disease: A meta-analysis of observational studies

Background and Objective: Although growing evidence indicates that non-alcoholic fatty liver disease is related to diabetic retinopathy (DR), research results significantly vary. Therefore, we conducted a meta-analysis to assess the association between the progression of non-alcoholic fatty liver disease and the onset of DR. Methods: PubMed, Embase, and Cochrane databases were searched until 7 November 2021. Combined odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association. Results: We identified 18 studies involving 12,757 patients. The pooled effect assessment showed that liver fibrosis was positively correlated with DR (OR = 1.69, 95%CI 1.30-2.20; p < 0.0001); non-alcoholic fatty liver disease was not associated with the risk of DR (OR = 1.15, 95%CI 0.75-1.76; p = 0.51); non-alcoholic fatty liver disease was positively correlated with DR in patients with type 1 diabetes (OR = 2.96, 95%CI 1.48-5.94; p = 0.002). In patients with type 2 diabetes, there was no association between non-alcoholic fatty liver disease and DR (OR = 0.92, 95%CI 0.59-1.43; p = 0.70). Subgroup analysis showed no correlation in both Asian and Caucasian races. Conclusion: There is a significant correlation between liver fibrosis and DR. This suggests that the ocular examination of DR could be helpful in predicting whether patients with non-alcoholic fatty liver disease would progress to liver fibrosis.

Guidelines on Models of Diabetic Heart Disease

Diabetes is a major risk factor for cardiovascular diseases, including diabetic cardiomyopathy, atherosclerosis, myocardial infarction, and heart failure. As cardiovascular disease represents the number one cause of death in people with diabetes, there has been a major emphasis on understanding the mechanisms by which diabetes promotes cardiovascular disease, and how antidiabetic therapies impact diabetic heart disease. With a wide array of models to study diabetes (both type 1 and type 2), the field has made major progress in answering these questions. However, each model has its own inherent limitations. Therefore, the purpose of this guidelines document is to provide the field with information on which aspects of cardiovascular disease in the human diabetic population are most accurately reproduced by the available models. This review aims to emphasize the advantages and disadvantages of each model, and to highlight the practical challenges and technical considerations involved. We will review the preclinical animal models of diabetes (based on their method of induction), appraise models of diabetes-related atherosclerosis and heart failure, and discuss in vitro models of diabetic heart disease. These guidelines will allow researchers to select the appropriate model of diabetic heart disease, depending on the specific research question being addressed.

Visit-to-Visit Fasting Glucose Variability in Young Adulthood and Nonalcoholic Fatty Liver Disease in Middle Age

CONTEXT

Diabetes has a bidirectional association with nonalcoholic fatty liver disease (NAFLD) and increases the risk of cirrhosis and related complications.

OBJECTIVE

To investigate the association between visit-to-visit fasting glucose (FG) variability in early adulthood and NAFLD in middle age.

METHODS

This prospective cohort study included 2467 Black and White adults aged 18 to 30 years at baseline (1985-1986) who were followed over 25 years in the Coronary Artery Risk Development in Young Adults Study. FG variability measures included coefficient of variation about the mean FG (CV-FG), the SD of FG (SD-FG), and the average real variability of FG (ARV-FG) across 25 years (year 0, 7, 10, 15, 20, and 25 examinations). NAFLD was defined as liver attenuation ≤ 40 Hounsfield units on computed tomography scan at year 25 examination after excluding other causes of hepatic steatosis.

RESULTS

Of the 2467 participants, 241 (9.8%) had NAFLD at year 25. In multivariate analysis, the odds ratio for NAFLD was 2.80 (95% CI, 1.69-4.64; P trend < 0.001) for the fourth quartile vs first quartile of CV-FG after adjusting for confounding variables, including mean FG. Similar results were observed for SD-FG and ARV-FG.

CONCLUSION

Greater visit-to-visit FG variability in early adulthood was associated with higher risk of NAFLD in middle age independent of mean FG level. FG variability may help identify individuals at high risk for NAFLD.

Pathophysiology and Treatment of Diabetic Cardiomyopathy and Heart Failure in Patients with Diabetes Mellitus

There is a close relationship between diabetes mellitus and heart failure, and diabetes is an independent risk factor for heart failure. Diabetes and heart failure are linked by not only the complication of ischemic heart disease, but also by metabolic disorders such as glucose toxicity and lipotoxicity based on insulin resistance. Cardiac dysfunction in the absence of coronary artery disease, hypertension, and valvular disease is called diabetic cardiomyopathy. Diabetes-induced hyperglycemia and hyperinsulinemia lead to capillary damage, myocardial fibrosis, and myocardial hypertrophy with mitochondrial dysfunction. Lipotoxicity with extensive fat deposits or lipid droplets is observed on cardiomyocytes. Furthermore, increased oxidative stress and inflammation cause cardiac fibrosis and hypertrophy. Treatment with a sodium glucose cotransporter 2 (SGLT2) inhibitor is currently one of the most effective treatments for heart failure associated with diabetes. However, an effective treatment for lipotoxicity of the myocardium has not yet been established, and the establishment of an effective treatment is needed in the future. This review provides an overview of heart failure in diabetic patients for the clinical practice of clinicians.

Biomarkers of non-communicable chronic disease: an update on contemporary methods

Chronic diseases constitute a major global burden with significant impact on health systems, economies, and quality of life. Chronic diseases include a broad range of diseases that can be communicable or non-communicable. Chronic diseases are often associated with modifications of normal physiological levels of various analytes that are routinely measured in serum and other body fluids, as well as pathological findings, such as chronic inflammation, oxidative stress, and mitochondrial dysfunction. Identification of at-risk populations, early diagnosis, and prediction of prognosis play a major role in preventing or reducing the burden of chronic diseases. Biomarkers are tools that are used by health professionals to aid in the identification and management of chronic diseases. Biomarkers can be diagnostic, predictive, or prognostic. Several individual or grouped biomarkers have been used successfully in the diagnosis and prediction of certain chronic diseases, however, it is generally accepted that a more sophisticated approach to link and interpret various biomarkers involved in chronic disease is necessary to improve our current procedures. In order to ensure a comprehensive and unbiased coverage of the literature, first a primary frame of the manuscript (title, headings and subheadings) was drafted by the authors working on this paper. Second, based on the components drafted in the preliminary skeleton a comprehensive search of the literature was performed using the PubMed and Google Scholar search engines. Multiple keywords related to the topic were used. Out of screened papers, only 190 papers, which are the most relevant, and recent articles were selected to cover the topic in relation to etiological mechanisms of different chronic diseases, the most recently used biomarkers of chronic diseases and finally the advances in the applications of multivariate biomarkers of chronic diseases as statistical and clinically applied tool for the early diagnosis of chronic diseases was discussed. Recently, multivariate biomarkers analysis approach has been employed with promising prospect. A brief discussion of the multivariate approach for the early diagnosis of the most common chronic diseases was highlighted in this review. The use of diagnostic algorithms might show the way for novel criteria and enhanced diagnostic effectiveness inpatients with one or numerous non-communicable chronic diseases. The search for new relevant biomarkers for the better diagnosis of patients with non-communicable chronic diseases according to the risk of progression, sickness, and fatality is ongoing. It is important to determine whether the newly identified biomarkers are purely associations or real biomarkers of underlying pathophysiological processes. Use of multivariate analysis could be of great importance in this regard.

Association of metabolic syndrome traits with urinary biomarkers in Japanese adults

BACKGROUND

Although metabolic syndrome traits are risk factors for chronic kidney disease, few studies have examined their association with urinary biomarkers.

METHODS

Urinary biomarkers, including A-megalin, C-megalin, podocalyxin, albumin, α₁-microglobulin, β₂-microglobulin, and N-acetyl-β-D-glucosaminidase, were cross-sectionally assessed in 347 individuals (52.7% men) with a urine albumin-to-creatinine ratio (ACR)  < 300 mg/g in a health checkup. Metabolic syndrome traits were adopted from the National Cholesterol Education Program (third revision) of the Adult Treatment Panel criteria modified for Asians.

RESULTS

Participants had a mean body mass index, estimated glomerular filtration rate (eGFR), and median ACR of 23.0 kg/m², 74.8 mL/min/1.73 m², and 7.5 mg/g, respectively. In age- and sex-adjusted logistic regression analysis, A-megalin and albumin were significantly associated with the clustering number of metabolic syndrome traits (3 or more). After further adjustment with eGFR, higher quartiles of A-megalin and albumin were each independently associated with the clustering number of metabolic syndrome traits (adjusted odds ratio for A-megalin: 1.30 per quartile, 95% CI 1.03-1.64; albumin: 1.42 per quartile, 95% CI 1.12-1.79).

CONCLUSIONS

Both urinary A-megalin and albumin are associated with the clustering number of metabolic syndrome traits. Further research on urinary A-megalin is warranted to examine its role as a potential marker of kidney damage from metabolic risk factors.

Association between the metabolic score for insulin resistance (METS-IR) and estimated glomerular filtration rate (eGFR) among health check-up population in Japan: A retrospective cross-sectional study

AIM

This study aimed to investigate the relationship between a new metric-metabolic score for insulin resistance (METS-IR)-and estimated glomerular filtration rate (eGFR) among Japanese participants who underwent health check-ups.

METHODS

We conducted a cross-sectional study that involved participants in a medical health screening program, which was conducted at the Medical Health Check-up Center in Japan. This retrospective study examined the relationship between METS-IR and eGFR among 881 individuals that joined the program between March 1, 2004, and December 31, 2012. Covariates consisted of serum laboratory tests and lifestyle questionnaires. Multivariate linear regression analysis was used to explore the association between METS-IR and eGFR. In addition, subgroup and interaction analyses were done based on age, sex, body mass index (BMI), alcohol use, smoking status, and hyperuricemia.

RESULTS

A total of 881 individuals participated in this study. High METS-IR was highly linked with reduced eGFR (adjusted β = -5.04, 95% confidence interval (CI): -7.65 to -2.43), while METS-IR was utilized as a categorical variable inside the multiple regression analysis. A decrease in eGFR of 2.54 units was reported for every 10-unit rise in METS-IR (adjusted β = -2.54, 95% CI: -4.04 to -1.05, P-value = 0.001). Stratified analysis suggested no marked interaction between METS-IR and eGFR across age, sex, BMI, and alcohol consumption groups. However, there was an indication of interaction between METS-IR level, smoking status (P-value = 0.001), and uric level (P-value = 0.011) on eGFR decrease.

CONCLUSIONS

METS-IR is remarkably associated with eGFR among the participants who underwent health check-ups in Gifu, Japan. Although more studies are required to prove it, METS-IR could be applied as a monitoring index for early screening, primary prevention, and diagnostic and treatment management strategies for chronic kidney disease.

Usefulness of metabolic score for insulin resistance index in estimating the risk of mildly reduced estimate glomerular filtration rate: a cross-sectional study of rural population in China

OBJECTIVES

This study aimed to reveal the association between metabolic score for insulin resistance (MetS-IR) and the risk of mildly decreased estimated glomerular filtration rate (eGFR), and explore the evaluation effect of MetS-IR on the progress of eGFR decline.

STUDY DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

A total of 11 956 rural participants (aged ≥35 years) from northeastern China were enrolled in the study. After excluding the subjects whose data were not integrated or who met the exclusion criteria, we finally obtained 11 042 participants in the present study.

MAIN OUTCOME MEASURES

Mildly decreased eGFR was defined as 60-90 mL/min/1.73 m².

RESULTS

The prevalence of mildly decreased eGFR in the general population was 36.9%. After adjustment of covariates, each SD increment of MetS-IR could bring 26.3% additional risk of mildly decreased eGFR (OR: 1.263, 95% CI: 1.066 to 1.497, p=0.007). When MetS-IR was classified into four levels by quartile, we observed participants in the top level had 3.032-fold risk of mildly decreased eGFR (OR: 3.032, 95% CI: 1.841 to 4.991, p<0.001) compared with those from the bottom level. Further, we found the participants with higher MetS-IR score were more likely to aggravate into a worse renal state which presented as higher risk of accelerated decline of eGFR, by additional 28.3% risk in whole participants (OR: 1.283, 95% CI: 1.150 to 1.430, p<0.001) and 41.9% in men (OR: 1.419, 95% CI: 1.183 to 1.701, p<0.001).

CONCLUSION

High MetS-IR was associated with high risk of mildly reduced eGFR and often accompanied by a high risk of accelerated decline in eGFR. Hence, we believed MetS-IR was a suitable indicator to evaluate the risk of early-stage renal dysfunction.

Impact of Obesity in Kidney Diseases

The clinical consequences of obesity on the kidneys, with or without metabolic abnormalities, involve both renal function and structures. The mechanisms linking obesity and renal damage are well understood, including several effector mechanisms with interconnected pathways. Higher prevalence of urinary albumin excretion, sub-nephrotic syndrome, nephrolithiasis, increased risk of developing CKD, and progression to ESKD have been identified as being associated with obesity and having a relevant clinical impact. Moreover, renal replacement therapy and kidney transplantation are also influenced by obesity. Losing weight is key in limiting the impact that obesity produces on the kidneys by reducing albuminuria/proteinuria, declining rate of eGFR deterioration, delaying the development of CKD and ESKD, and improving the outcome of a renal transplant. Weight reduction may also contribute to appropriate control of cardiometabolic risk factors such as hypertension, metabolic syndrome, diabetes, and dyslipidemia which may be protective not only in renal damage but also cardiovascular disease. Lifestyle changes, some drugs, and bariatric surgery have demonstrated the benefits.

[Triglyceride-glucose product is an independent risk factor for predicting chronic kidney disease in middle-aged and elderly population: a prospective cohort study]

OBJECTIVE

To explore the correlation of triglyceride-glucose product (TyG) index with chronic kidney disease (CKD) in elderly population in Lanzhou (Gansu Province, China).

METHODS

From May to September, 2011, a total of 3868 middleaged and elderly individuals without CKD from 3 communities in Lanzhou were selected as the cohort study population and were followed for an average of 3.1 years (from June, 2014 to August, 2015). After excluding those with missing follow-up data, a total of 3439 individuals were included for analysis, who were divided according to the quartile of TyG index into Q1 group (TyG≤8.47), Q2 group (TyG 8.48-8.84), Q3 group (TyG 8.85-9.20) and Q4 group (TyG>9.20). The estimated glomerular filtration rate (eGFR) and urinary albumin/creatinine ratio (UACR) were used to evaluate the renal function of the participants.

RESULTS

In this cohort, a high TyG index was found to correlate with a high risk of CKD (P < 0.05). Analysis of the follow-up data showed that the TyG index was significantly higher in patients who developed CKD during the follow-up than in those without CKD (P < 0.05). Logistic regression analysis showed that TyG index was an independent risk factor for abnormal eGFR and CKD (P < 0.05).

CONCLUSION

A high TyG index is an independent risk factor for CKD in middle-aged and elderly population.

The association of glucose metabolism and kidney function in middle-aged adults

BACKGROUND

Previous clinical studies have shown that various measures of glucose metabolism are associated with a risk of chronic kidney disease in different populations, but results were not consistent. In this study we assessed measures of glucose metabolism and their association with kidney function in a population-based study.

METHODS

The Netherlands Epidemiology of Obesity study is a population-based cohort study of middle-aged men and women. We categorized the study population according to glycaemic levels into normoglycaemia (reference group), pre-diabetes mellitus (pre-DM), known DM and newly diagnosed DM. Outcome variables were serum creatinine, estimated glomerular filtration rate (eGFR), glomerular hyperfiltration (defined as an eGFR >90th percentile; >102 mL/min/1.73 m2) and micro-albuminuria. We examined the association between measures of glucose metabolism [fasting glucose, haemoglobin A1c (HbA1c), fasting insulin, glucose area under the curve (AUC), insulin AUC, Homoeostatic Model Assessment of Insulin Resistance (HOMA-IR), HOMA of β-cell function (HOMA-B) and disposition index] and measures of kidney function.

RESULTS

Of the total population (N = 6338), 55% of participants were classified as normoglycaemic (reference), 35% as pre-DM, 7% as DM and 4% as newly diagnosed DM. Compared with the reference group, diagnosed and newly diagnosed DMs were associated with a slightly higher trend in eGFR {+2.1 mL/min/1.73 m2 [95% confidence interval (CI) -0.2-4.4] and +2.7 mL/min/1.73 m2 [95% CI -0.3-5.7], respectively}. A 1% higher HbA1c was associated with increased odds of hyperfiltration [odds ratio (OR) 1.41 (95% CI 1.06-1.88)]. Higher levels of fasting plasma glucose, AUC glucose and HOMA-B were associated with hyperfiltration. Fasting insulin, AUC insulin and HOMA-IR were not associated with hyperfiltration. The OR of microalbuminuria was 1.21 (95% CI 1.04-1.42) per mmol/L higher fasting glucose concentrations.

CONCLUSIONS

Both fasting and post-prandial glucose and HOMA-B, but not measures of insulin resistance, were associated with glomerular hyperfiltration, while fasting glucose was also associated with microalbuminuria.

A Comprehensive, Multidisciplinary, Personalized, Lifestyle Intervention Program Is Associated with Increased Leukocyte Telomere Length in Children and Adolescents with Overweight and Obesity

Leucocyte telomere length (LTL) is a robust marker of biological aging and is associated with obesity and cardiometabolic risk factors in childhood and adolescence. We investigated the effect of a structured, comprehensive, multidisciplinary, personalized, lifestyle intervention program of healthy diet and physical exercise on LTL in 508 children and adolescents (239 males, 269 females; 282 prepubertal, 226 pubertal), aged 10.14 ± 0.13 years. Participants were classified as obese (n = 267, 52.6%), overweight (n = 174, 34.2%), or of normal BMI (n = 67, 13.2%) according to the International Obesity Task Force (IOTF) cutoff points and were studied prospectively for one year. We demonstrated that LTL increased significantly after 1 year of the lifestyle interventions, irrespective of gender, pubertal status, or body mass index (BMI). Waist circumference was the best negative predictor of LTL at initial assessment. The implementation of the lifestyle interventions also resulted in a significant improvement in clinical (BMI, BMI z-score and waist to height ratio) and body composition indices of obesity, inflammatory markers, hepatic enzymes, glycated hemoglobin (HbA1C), quantitative insulin sensitivity check index (QUICKI), and lipid profile in all participants. These findings indicate that the increased LTL may be associated with a more favorable metabolic profile and decreased morbidity later in life.

Albuminuria Is Associated with Hepatic Iron Load in Patients with Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome

Background: Increased albuminuria is associated with increased serum ferritin, insulin resistance, and non-alcoholic fatty liver disease (NAFLD). Liver iron accumulation is also related to hyperferritinemia, insulin resistance, and NAFLD; however, there is no evidence on its relationship with albuminuria. Aims: To assess the relationship between hepatic iron load and urine albumin-to-creatinine ratio (UACR) in patients with metabolic syndrome (MetS) and NAFLD. Methods: In total, 75 MetS and NAFLD patients (aged 40–60 years, BMI 27–40 kg/m²) were selected from a cohort according to available data on hepatic iron load (HepFe) by magnetic resonance imaging (MRI). Subjects underwent anthropometric measurements, biochemistry testing, and liver MRI. Increased albuminuria was defined by UACR. Results: UACR correlated with NAFLD, HepFe, triglycerides, serum ferritin, fasting insulin, insulin resistance (calculated using the homeostatic model assessment for insulin resistance—HOMA-IR- formula), and platelets (p < 0.05). Multiple regression analysis adjusted for gender, age, eGFR, HbA1c, T2DM, and stages of NAFLD, found that HepFe (p = 0.02), serum ferritin (p = 0.04), fasting insulin (p = 0.049), and platelets (p = 0.009) were associated with UACR (R² = 0.370; p = 0.007). UACR, liver fat accumulation, serum ferritin, and HOMA-IR increased across stages of HepFe (p < 0.05). Patients with severe NAFLD presented higher HepFe, fasting insulin, HOMA-IR, and systolic blood pressure as compared to patients in NAFLD stage 1 (p < 0.05). Conclusion: Hepatic iron load, serum ferritin, fasting insulin, and platelets were independently associated with albuminuria. In the context of MetS, increased stages of NAFLD presented higher levels of HepFe. Higher levels of HepFe were accompanied by increased serum ferritin, insulin resistance, and UACR. The association between iron accumulation, MetS, and NAFLD may represent a risk factor for the development of increased albuminuria.

Incidence and Predictive Factors for Amputations Derived From Charcot's Neuroarthropathy in Persons With Diabetes

Charcot's neuroarthropathy (CN) is the progressive destruction of the bones and joints of the feet, as a consequence of severe peripheral neuropathy, which predisposes patients to amputations. The purpose of this study was to measure the cumulative incidence of amputations resulting from CN and risk factors among amputated people with diabetes mellitus (DM). This was an epidemiological, observational, and retrospective study of 114 patients with DM who had an amputation involving the lower limbs. Data were collected from 2 specialized outpatient clinics between 2015 and 2019, including socio-demographic and clinical variables (cause of amputation: CN, peripheral arterial disease [PAD], infected ulcers, fracture, osteomyelitis, and others; body mass index [BMI]; 1 or 2 DM, time since DM diagnosis, insulin treatment, glycated hemoglobin; creatinine; smoking and drinking; systemic arterial hypertension, diabetic retinopathy, diabetic kidney disease, diabetic peripheral neuropathy, acute myocardial infarction, PAD, and stroke; characteristics of amputation [level and laterality], in addition to the specific variables related to CN [time of amputation in relation to the diagnosis of CN, diagnosis of CN in the acute phase, and treatment implemented in the acute phase]). We compared socio-demographic and clinical characteristics, including types of amputation, between patients with and without CN. Statistical analyses were performed using the 2 sample t-test or Wilcoxon-Mann-Whitney test, for quantitative variables, and the Pearson's χ² test or Fisher's exact test for categorical variables. The investigation of the possible association of predictive factors for a CN amputation was carried out through logistic regression. The amputation caused by CN was present in 27 patients with a cumulative incidence of 23.7% in 5 years. There was a statistically significant association between BMI and the occurrence of CN (odds ratio: 1.083; 95% confidence interval: 1.001-1.173; P = .048); higher values of BMI were associated with a higher occurrence of amputations secondary from CN.

Endothelial Glycocalyx Disorders May Be Associated With Extended Inflammation During Endotoxemia in a Diabetic Mouse Model

In diabetes mellitus (DM) patients, the morbidity of infectious disease is increased, and these infections can easily progress from local to systemic infection. Sepsis is a characteristic of organ failure related to microcirculation disorders resulting from endothelial cell injury, whose most frequent comorbidity in patients is DM. The aim of the present study was to evaluate the influence of infection on DM-induced microvascular damage on inflammation and pulmonary endothelial structure using an experimental endotoxemia model. Lipopolysaccharide (LPS; 15 mg/kg) was injected intraperitoneally into 10-week-old male C57BLKS/J Iar- + lepr db /lepr db (db/db) mice and into C57BLKS/J Iar-m + / + lepr db (db/ +) mice, which served as the littermate non-diabetic control. At 48 h after LPS administration, the survival rate of db/db mice (0%, 0/10) was markedly lower (P < 0.05) than that of the db/ + mice (75%, 18/24), whereas the survival rate was 100% in both groups 24 h after LPS administration. In control mice, CD11b-positive cells increased at 6 h after LPS administration; by comparison, the number of CD11b-positive cells increased gradually in db/db mice until 12 h after LPS injection. In the control group, the number of Iba-1-positive cells did not significantly increase before and at 6, 12, and 24 h after LPS injection. Conversely, Iba-1-positive cells continued to increase until 24 h after LPS administration, and this increase was significantly greater than that in the control mice. Expression of Ext1, Csgalnact1, and Vcan related to endothelial glycocalyx synthesis was significantly lower in db/db mice than in the control mice before LPS administration, indicating that endothelial glycocalyx synthesis is attenuated in db/db/mice. In addition, ultrastructural analysis revealed that endothelial glycocalyx was thinner in db/db mice before LPS injection. In conclusion, in db/db mice, the endothelial glycocalyx is already injured before LPS administration, and migration of inflammatory cells is both delayed and expanded. This extended inflammation may be involved in endothelial glycocalyx damage due to the attenuation of endothelial glycocalyx synthesis.

Low muscle mass is associated with progression of chronic kidney disease and albuminuria - An 8-year longitudinal study in Asians with Type 2 Diabetes

AIMS

We examined the longitudinal relationship between baseline skeletal muscle mass and its change over time with eGFR decline and albuminuria progression among Asians with type 2 diabetes(T2D).

METHODS

This was a prospective cohort study of 1272 T2D patients. Skeletal muscle mass was estimated using tetra-polar multi-frequency bio-impedance analysis and Skeletal Muscle Mass Index(SMI) was defined as skeletal muscle mass/weight * 100.

RESULTS

After up to 8 years of follow-up, 33.3% of participants had CKD progression and 28.3% albuminuria progression. Every 1-SD above baseline SMI was associated with 18% lower risk of CKD progression[Hazards Ratio(HR)0.82; 95%CI 0.70-0.97; p = 0.018] and 17% lower risk of albuminuria progression [HR 0.83 (95%CI 0.71-0.97; p = 0.017)]. The largest decrease in SMI over time was associated with 67% higher risk of CKD progression, compared to those with the smallest change from baseline SMI tertile 2[HR 1.67 (95%CI 1.10-2.55); p = 0.016]. Pigment epithelium-derived factor(PEDF) and plasma leucine-rich α-2-glycoprotein (LRG1) accounted for 40.1% of the association between SMI and CKD progression.

CONCLUSIONS

Low baseline skeletal muscle mass and its reduction over time is associated with increased risk of progression of CKD among Asians with T2D. PEDF and LRG1 mediated the inverse relationship between SMI and CKD progression.

Periodontitis and its higher levels of severity are associated with the triglyceride/high density lipoprotein cholesterol (TG/HDL-C) ratio

BACKGROUND

Periodontitis and the Triglyceride/High Density Lipoprotein Cholesterol (TG/HDL-C) ratio have both been associated with cardiovascular disease, metabolic syndrome, and obesity. Additionally, the ratio is a possible substitute for predicting insulin resistance. This study investigated the association between periodontitis, its severity levels (exposures), and the TG/HDL-C ratio (outcome).

METHODS

A cross-sectional study of public health service users in Brazil considered socioeconomic-demographic characteristics, lifestyle behavior, and general and oral health conditions. Anthropometric measurements and blood pressure were also measured. Systemic biomarker data were obtained, as well as assessment of periodontal diagnosis and its severity. The TG/HDL-C ratio was calculated using the serum triglyceride level over HDL cholesterol and the cut-off point, TG/HDL-C ≥2.3 serving as the cutoff indicting dyslipidemia. Logistic and linear regressions were used to statistically analyze the data.

RESULTS

A total of 1011 participants were included, with 84.17% having periodontitis and 49.85% having a TG/HDL-C ratio ≥2.3. For individuals with periodontitis, the odds of TG/HDL-C ratio ≥2.3 were 1.47 times greater than in those without periodontitis (OR_Adjusted  = 1.47, 95% CI: 1.02-2.14). Similar results were found for those with moderate and severe periodontitis, with a slight increase in the measurement magnitude with disease severity.

CONCLUSION

A positive relationship between periodontitis and the TG/HDL-C ratio ≥2.3 was found, suggesting a possible association with periodontal disease severity.

Comprehensive elaboration of glycemic variability in diabetic macrovascular and microvascular complications

Diabetes mellitus is the major risk factor for the development of macrovascular and microvascular complications. It is increasingly recognized that glycemic variability (GV), referring to oscillations in blood glucose levels and representing either short-term or long-term GV, is involved in the pathogenesis of diabetic complications and has emerged as a possible independent risk factor for them. In this review, we summarize the metrics and measurement of GV in clinical practice, as well as comprehensively elaborate the role and related mechanisms of GV in diabetic macrovascular and microvascular complications, aiming to provide the mechanism-based therapeutic strategies for clinicians to manage diabetes mellitus.

Dapagliflozin improves cardiovascular risk factors in Emirati patients with T2DM

BACKGROUND

Dapagliflozin is a sodium-glucose co transporter-2 inhibitor that proved efficacy in reduction of blood glucose level through extrusion of glucose in urine. It is used in treatment of type 2 diabetes mellitus (T2DM). It also has reported cardiovascular and renal benefits in patients with T2DM. Data are very limited about its effects in Emirati patients with diabetes. Our aim was to evaluate dapagliflozin treatment in Emirati patients with T2DM.

PATIENTS AND METHODS

This is a retrospective study involving 89 diabetes patients who were using dapagliflozin 10 mg once daily as add-on therapy for 12 months. All patients had T2DM, aged over 18 years and had an estimated glomerular filtration rate (eGFR) over 60 ml/min/1.73 m². Body weight, height, body mass index, sitting blood pressure and heart rate were collected. Fasting plasma glucose, glycosylated hemoglobin (HbA1c), lipid profile and other available biochemical parameters, for example, creatinine, blood urea nitrogen, and urine albumin/creatinine ratio were traced from medical records and eGFR was calculated.

RESULTS

Patients were aged 62.3 ± 9.4 years with a median duration of diabetes of 15 (10-20) years. Data were analyzed before, at 6 months and 12 months of treatment. Fasting plasma glucose, HbA1c, body mass index, systolic and diastolic blood pressure significantly decreased (p = 0.002, p < 0.0005, p < 0.002, p < 0.0005, p < 0.0005, respectively). The median reduction of HbA1c was 0.7% (0.2-1.2) and 0.9% (0.5-1.8) at 6 and 12 months, respectively. Systolic blood pressure decreased by a median of 7 mmHg (4-20 mmHg) and 9 mmHg (1-10 mmHg) on the 6th and 12th month of treatment, respectively, while the diastolic decreased by a median of 3 mmHg (4 to 10 mmHg) and 6 mmHg (1-10 mmHg); without increase in heart rate (p = 0.188). A significant reduction of body mass index, C-reactive protein and rate pressure product was noticed (p = 0.002, p = 0.001, p < 0.0005, respectively). No decline in eGFR or microalbuminuria was noticed. Stage I chronic kidney disease with eGFR < 90 ml/min/1.73 m² showed continuous progressive reduction of HbA1c without a significant change in other variables.

CONCLUSION

Our data indicate improved cardiovascular risk profile in dapagliflozin-treated Emirati patients with T2DM.

Recombinant Spidroin Films Attenuate Individual Markers of Glucose Induced Aging in NIH 3T3 Fibroblasts

The effect of bioresorbable materials on aging in cultured mouse NIH 3T3 fibroblasts treated with elevated glucose concentration was investigated. The cells were grown on films produced from the silkworm fibroin and rS1/9, a recombinant analog of Nephila clavipes spidroin 1. Exposure to 50 mM glucose of the cells grown on uncoated glass support resulted in the cell growth retardation. The average areas of the cells and nuclei and the percentage of apoptotic cells increased, whereas the amount of soluble collagen decreased. In contrast, on the fibroin and spidroin films, the cell density and the percentage of 5-bromo-2'-deoxyuridine (BrdU)-positive cells were higher vs. the cells grown on the glass support. The films protected NIH 3T3 fibroblasts from the glucose-induced death. The most prominent effects on the cell density, BrdU incorporation, and apoptosis prevention were observed in the cells cultured on spidroin films. Unlike the cells grown on glass support (decrease in the soluble collagen production) or fibroin (no effect), production of soluble collagen by the cells grown on spidroin films increased after cell exposure to 50 mM glucose. Molecular analysis demonstrated that 50 mM glucose upregulated phosphorylation of the NFκB heterodimer p65 subunit in the cells grown on the glass support. The treatment of cells grown on fibroin films with 5.5 mM or 50 mM glucose had no effect on p65 phosphorylation. The same treatment decreased p65 phosphorylation in the cells on the spidroin films. These results demonstrate the anti-aging efficacy of biomaterials derived from the silk proteins and suggest that spidroin is more advantageous for tissue engineering and therapy than fibroin.

Short adult height increases the risk of end-stage renal disease in type 2 diabetes

OBJECTIVE

Although short adult height has been associated with an increasing variety of diseases and all-cause death, no reliable data exist on the association between adult height and end-stage renal disease (ESRD) in diabetic patients. We investigated the relationship between short adult height, development of ESRD, and mortality in type 2 diabetes mellitus (DM).

METHODS

This nationwide population-based cohort study analyzed clinical data from a total of 2,621,907 subjects aged ≥30 years with type 2 DM between January 1, 2009 and December 31, 2012, using the National Health Insurance Database in Korea.

RESULTS

During a 6.9-year follow-up period, 220,457 subjects (8.4%) died, and 28,704 subjects (1.1%) started dialysis. Short adult height significantly increased the incidence of ESRD and all-cause mortality in the overall cohort analysis. In multivariable Cox models, hazard ratios (HR) for the development of ESRD comparing the highest and lowest quartiles of adult height were 0.86 (95% CI 0.83-0.89). All-cause mortality also decreased with the highest height compared to patients with the lowest height, after fully adjusting for confounding variables (HR 0.79, 95% CI 0.78-0.81). Adult height had an inverse relationship to newly diagnosed ESRD (male: HR 0.86, 95% CI 0.83-0.90, female: HR 0.84, 95% CI 0.79-0.90) and all-cause mortality (male: HR 0.81, 95% CI 0.79-0.82, female: HR 0.80, 95% CI 0.78-0.82).

CONCLUSIONS

Short adult height is strongly associated with the increased risk of ESRD development and all-cause mortality in type 2 DM.

Sphingomyelin and progression of renal and coronary heart disease in individuals with type 1 diabetes

AIMS/HYPOTHESIS

Lipid abnormalities are associated with diabetic kidney disease and CHD, although their exact role has not yet been fully explained. Sphingomyelin, the predominant sphingolipid in humans, is crucial for intact glomerular and endothelial function. Therefore, the objective of our study was to investigate whether sphingomyelin impacts kidney disease and CHD progression in individuals with type 1 diabetes.

METHODS

Individuals (n = 1087) from the Finnish Diabetic Nephropathy (FinnDiane) prospective cohort study with serum sphingomyelin measured using a proton NMR metabolomics platform were included. Kidney disease progression was defined as change in eGFR or albuminuria stratum. Data on incident end-stage renal disease (ESRD) and CHD were retrieved from national registries. HRs from Cox regression models and regression coefficients from the logistic or linear regression analyses were reported per 1 SD increase in sphingomyelin level. In addition, receiver operating curves were used to assess whether sphingomyelin improves eGFR decline prediction compared with albuminuria.

RESULTS

During a median (IQR) 10.7 (6.4, 13.5) years of follow-up, sphingomyelin was independently associated with the fastest eGFR decline (lowest 25%; median [IQR] for eGFR change: <-4.4 [-6.8, -3.1] ml min^-1 [1.73 m^-2] year^-1), even after adjustment for classical lipid variables such as HDL-cholesterol and triacylglycerols (OR [95% CI]: 1.36 [1.15, 1.61], p < 0.001). Similarly, sphingomyelin increased the risk of progression to ESRD (HR [95% CI]: 1.53 [1.19, 1.97], p = 0.001). Moreover, sphingomyelin increased the risk of CHD (HR [95% CI]: 1.24 [1.01, 1.52], p = 0.038). However, sphingomyelin did not perform better than albuminuria in the prediction of eGFR decline.

CONCLUSIONS/INTERPRETATION

This study demonstrates for the first time in a prospective setting that sphingomyelin is associated with the fastest eGFR decline and progression to ESRD in type 1 diabetes. In addition, sphingomyelin is a risk factor for CHD. These data suggest that high sphingomyelin level, independently of classical lipid risk factors, may contribute not only to the initiation and progression of kidney disease but also to CHD. Graphical abstract.

Sweet dreams: therapeutic insights, targeting imaging and physiologic evidence linking sleep, melatonin and diabetic nephropathy

Melatonin is the main biochronologic molecular mediator of circadian rhythm and sleep. It is also a powerful antioxidant and has roles in other physiologic pathways. Melatonin deficiency is associated with metabolic derangements including glucose and cholesterol dysregulation, hypertension, disordered sleep and even cancer, likely due to altered immunity. Diabetic nephropathy (DN) is a key microvascular complication of both type 1 and 2 diabetes. DN is the end result of a complex combination of metabolic, haemodynamic, oxidative and inflammatory factors. Interestingly, these same factors have been linked to melatonin deficiency. This report will collate in a clinician-oriented fashion the mechanistic link between melatonin deficiency and factors contributing to DN.

Dietary zinc intake and incident chronic kidney disease

BACKGROUND & AIMS

Previous studies have shown that dietary zinc intake is closely related to cardiovascular complications and metabolic derangements. However, the effect of dietary zinc intake on renal function is not fully elucidated.

METHODS

Data from the Korean Genome and Epidemiology Study were used. Dietary zinc intake was assessed by a Food Frequency Questionnaire and dietary zinc density was calculated as absolute zinc intake amount per daily energy intake (mg/1000 kcal day). The participants were categorized into quartiles according to dietary zinc density. The primary end point was incident chronic kidney disease (CKD), defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m².

RESULTS

A total of 7735 participants with normal renal function was included in the final analysis. The mean age was 52.0 ± 8.8 years, 47.5% were male, and mean eGFR was 92.1 ± 16.1 ml/min/1.73 m². The mean daily zinc intake and zinc intake density were 8.6 ± 3.4 mg and 4.4 ± 0.9 mg/1000 kcal, respectively. During a median follow up of 11.5 (1.7-12.5) years and 70,617 person-years of observation, CKD developed in 1409 (18.2%) participants. Multivariable cox hazard analysis revealed that risk for CKD development was significantly higher in the quartile with a mean zinc intake density of 3.6 ± 0.2 mg/1000 kcal compared with the quartile with a mean zinc intake density of 5.6 ± 1.0 mg/1000 kcal (Hazard ratio; 1.36; 95% Confidence Interval 1.18-1.58; P < 0.001). This relationship remained significant even after adjustments for confounding factors.

CONCLUSION

Low dietary zinc intake may increase the risk of CKD development in individuals with normal renal function.

High-fat diet pre-conditioning improves microvascular remodelling during regeneration of ischaemic mouse skeletal muscle

AIM

Critical limb ischaemia (CLI) is characterized by inadequate angiogenesis, arteriolar remodelling and chronic myopathy, which are most severe in type 2 diabetic patients. Hypertriglyceridaemia, commonly observed in these patients, compromises macrovascular function. However, the effects of high-fat diet-induced increases in circulating lipids on microvascular remodelling are not established. Here, we investigated if high-fat diet would mimic the detrimental effect of type 2 diabetes on post-ischaemia vascular remodelling and muscle regeneration, using a mouse model of hindlimb ischaemia.

METHODS

Male C57Bl6/J mice were fed with normal or high-fat diets for 8 weeks prior to unilateral femoral artery ligation. Laser doppler imaging was used to assess limb perfusion recovery. Vascular recovery, inflammation, myofibre regeneration and fibrosis were assessed at 4 or 14 days post-ligation by histology and RNA analyses. Capillary-level haemodynamics were assessed by intravital microscopy of control and regenerating muscles 14 days post-ligation.

RESULTS

High-fat diet increased muscle succinate dehydrogenase activity and capillary-level oxygen supply. At 4 days post-ligation, no diet differences were detected in muscle damage, inflammatory infiltration or capillary activation. At 14 days post-ligation, high fat-fed mice displayed accelerated limb blood flow recovery, elevated capillary and arteriole densities as well as greater red blood cell supply rates and capillary-level oxygen supply. Regenerating muscles from high fat-fed mice displayed lower interstitial fat and collagen deposition.

CONCLUSION

The muscle-level adaptations to high-fat diet improved multiple aspects of muscle recovery in response to ischaemia and did not recapitulate the worse outcomes seen in diabetic CLI patients.

[Correlation between sarcopenia and albuminuria in patients with type 2 diabetes]

OBJECTIVE

To investigate the correlation between sarcopenia and albuminuria in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 360 T2DM patients (including 206 male and 154 female patients) hospitalized in our hospital between January, 2015 and December, 2018 were enrolled. According to their medical history and laboratory test results, the patients were divided into albuminuria group (n=122) and non-albuminuria group (n=238). The clinical and anthropological data were collected and skeletal muscle index (SMI), appendage lean mass, muscle index, total body fat, bone mineral capacity and bone mineral density were measured using dual-energy X-ray absorptiometry. Logistic regression was used to analyze the correlation of these body composition parameters with albuminuria or chronic kidney disease (CKD) in the diabetic patients.

RESULTS

The disease course of T2DM, history of hypertension, age, systolic blood pressure, low density lipoprotein cholesterol, triglyceride, uric acid, waistline, Urinary albumin creatinine ratio, serum creatinine, and glomerular filtration rate differed significantly between the diabetic patients with albuminuria and those without albuminuria (P < 0.05). The prevalence rate of sarcopenia was significantly higher in patients with albuminuria (31.4% vs 13.1%, P < 0.01). Compared with those without albuminuria, the patients with albuminuria had significantly decreased SMI (t=-2.304, P=0.021) and body mass index (Z=- 5.534, P < 0.01) and significantly increased total body fat (Z=- 2.838, P=0.005). Multivariate logistic regression analysis showed that after adjustment for age, gender, total body fat, smoking history, drinking history, duration of diabetes, HbA1c, history of hypertension, systolic blood pressure, low density lipoprotein cholesterol, body mass index, and triglyceride, the patients with a decreased SMI had a significantly increased risk of albuminuria (P=0.011 and 0.010), but SMI was not correlated with the risk of CKD in patients with T2DM (P > 0.05).

CONCLUSIONS

Sarcopenia is probably an independent risk factor for albuminuria in patients with T2DM.

Infliximab ameliorates tumor necrosis factor-alpha exacerbated renal insulin resistance induced in rats by regulating insulin signaling pathway

Infliximab (IFX), a monoclonal antibody for tumor necrosis factor-alpha (TNF-α), is known to restore blood glucose homeostasis. However, its effects on improving renal insulin resistance (IR) are not yet studied. So we investigate the impact of infliximab on renal insulin signaling pathway in IR rat model regarding to metformin (MET). The induced IR was confirmed by a high oral glucose tolerance test, an elevation of lipid profile and the homeostatic model assessment of insulin resistance 2 (HOMA-IR 2) values. Subsequently, IR rats were concurrently treated with either MET (100 mg/kg/day) or IFX (one dose 5 mg/kg) besides IR and normal control (NC) groups. Four weeks later, IR control rats displayed hyperglycemia, hyperinsulinemia and elevation in HOMA-IR 2, renal function markers and renal tissue TNF-α, interleukins-1β and 6 (Il-1β, IL-6) and suppressor of cytokines signaling 3 (SOCS3) contents as well as glomerulosclerosis when compared to NC group. Additionally, the phosphorylation of renal insulin receptor substrate 1 (IRS1), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) were markedly impaired. Treatment with either MET or IFX significantly improved IR and kidney functions. The effects of the drugs were achieved by the downregulation of renal inflammatory cytokines and SOCS3 levels and the amelioration of the renal IRS1/PI3K/Akt pathway. In conclusion, MET and IFX ameliorated the TNF-α worsening effect on IR in rat renal tissues by regulating insulin signaling. Interestingly, infliximab was superior to metformin in regulating insulin signaling pathway. Therefore, infliximab could be used as an adjuvant therapy in improving renal IR.

Inhibition of tumor necrosis factor-α enhanced the antifibrotic effect of empagliflozin in an animal model with renal insulin resistance

Insulin resistance (IR) has emerged as one of the main risk factors for renal fibrosis (RF) that represents a common stage in almost all chronic kidney disease. The present study aims to investigate the inhibitory effect of empagliflozin (EMPA "a sodium-glucose co-transporter 2 inhibitor") and infliximab [IFX "a tumor necrosis factor-α (TNF-α) antibody"] on RF in rats with induced IR. IR was induced by adding 10% fructose in drinking water for 20 weeks. Thereafter, fructose-induced IR rats were concurrently treated with EMPA (30 mg/kg), IFX (1 dose 5 mg/kg), or EMPA + IFX for 4 weeks, in addition to IR control group (received 10% fructose in water) and normal control (NC) group. Rats with IR displayed hyperglycemia, deterioration in kidney functions, glomerulosclerosis, and collagen fiber deposition in renal tissues as compared to NC. This was associated with downregulation of the renal sirtuin 1 (Sirt 1) expression along with higher renal tissue TNF-α and transforming growth factor-β1 (TGF-β1) levels. Both EMPA and IFX significantly modulated the aforementioned fibrotic cytokines, upregulated the renal Sirt 1 expression, and attenuated RF compared to IR control group. Of note, IFX effect was superior to that of EMPA. However, the combination of EMPA and IFX alleviated RF to a greater extent surpassing the monotherapy. This may be attributed to the further upregulation of renal Sirt 1 in addition to the downregulation of fibrotic cytokines. These findings suggest that the combination of EMPA and IFX offers additional benefits and may represent a promising therapeutic option for RF.

A Novel Indoline Derivative Ameliorates Diabesity-Induced Chronic Kidney Disease by Reducing Metabolic Abnormalities

Both diabetes and obesity (diabesity) contribute significantly to the development of chronic kidney disease (CKD). In search of new remedies to reverse or arrest the progression of CKD, we examined the therapeutic potential of a novel compound, AN1284, in a mouse model of CKD induced by type 2 diabetes with obesity. Six-week-old BKS Cg-Dock 7^m+/+ Lepr^db/J mice with type 2 diabetes and obesity were treated with AN1284 (2.5 or 5 mg kg^-1 per day) via micro-osmotic pumps implanted subcutaneously for 3 months. Measures included renal, pancreatic, and liver assessment as well as energy utilization. AN1284 improved kidney function in BSK-db/db animals by reducing albumin and creatinine and preventing renal inflammation and morphological changes. The treatment was associated with weight loss, decreased body fat mass, increased utilization of body fat toward energy, preservation of insulin sensitivity and pancreatic β cell mass, and reduction of dyslipidemia, hepatic steatosis, and liver injury. This indoline derivative protected the kidney from the deleterious effects of hyperglycemia by ameliorating the metabolic abnormalities of diabetes. It could have therapeutic potential for preventing CKD in human subjects with diabesity.

Insulin resistance and chronic kidney disease progression, cardiovascular events, and death: findings from the chronic renal insufficiency cohort study

BACKGROUND

Insulin resistance contributes to the metabolic syndrome, which is associated with the development of kidney disease. However, it is unclear if insulin resistance independently contributes to an increased risk of chronic kidney disease (CKD) progression or CKD complications. Additionally, predisposing factors responsible for insulin resistance in the absence of diabetes in CKD are not well described. This study aimed to describe factors associated with insulin resistance and characterize the relationship of insulin resistance to CKD progression, cardiovascular events and death among a cohort of non-diabetics with CKD.

METHODS

Data was utilized from Chronic Renal Insufficiency Cohort Study participants without diabetes (N = 1883). Linear regression was used to assess associations with insulin resistance, defined using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The relationship of HOMA-IR, fasting glucose, hemoglobin A1c (HbA1c), and C-peptide with CKD progression, cardiovascular events, and all-cause mortality was examined with Cox proportional hazards models.

RESULTS

Novel positive associations with HOMA-IR included serum albumin, uric acid, and hemoglobin A1c. After adjustment, HOMA-IR was not associated with CKD progression, cardiovascular events, or all-cause mortality. There was a notable positive association of one standard deviation increase in HbA1c with the cardiovascular endpoint (HR 1.16, 95% CI: 1.00-1.34).

CONCLUSION

We describe potential determinants of HOMA-IR among a cohort of non-diabetics with mild-moderate CKD. HOMA-IR was not associated with renal or cardiovascular events, or all-cause mortality, which adds to the growing literature describing an inconsistent relationship of insulin resistance with CKD-related outcomes.

The Efficacy and Mechanism of Chinese Herbal Medicine on Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common microvascular complication of diabetes and is one of the main causes of end-stage renal disease (ESRD) in many countries. The pathological features of DKD are the hypertrophy of mesangial cells, apoptosis of podocytes, glomerular basement membrane (GBM) thickening, accumulation of extracellular matrix (ECM), glomerular sclerosis, and tubulointerstitial fibrosis. The etiology of DKD is very complicated and many factors are involved, such as genetic factors, hyperglycemia, hypertension, hyperlipidemia, abnormalities of renal hemodynamics, and metabolism of vasoactive substances. Although some achievements have been made in the exploration of the pathogenesis of DKD, the currently available clinical treatment methods are still not completely effective in preventing the progress of DKD to ESRD. CHM composed of natural products has traditionally been used for symptom relief, which may offer new insights into therapeutic development of DKD. We will summarize the progress of Chinese herbal medicine (CHM) in the treatment of DKD from two aspects. In clinical trials, the Chinese herbal formulas were efficacy and safety confirmed by the randomized controlled trials. In terms of experimental research, studies provided evidence for the efficacy of CHM from the perspectives of balancing metabolic disorders, reducing inflammatory response and oxidative stress, antifibrosis, protecting renal innate cells, and regulating microRNA and metabolism. CHM consisting of different ingredients may play a role in synergistic interactions and multiple target points in the treatment of DKD.

Evaluating All Potential Oral Complications of Diabetes Mellitus

Diabetes mellitus (DM) is associated with several microvascular and macrovascular complications, such as retinopathy, nephropathy, neuropathy, and cardiovascular diseases. The pathogenesis of these complications is complex, and involves metabolic and hemodynamic disturbances, including hyperglycemia, insulin resistance, dyslipidemia, hypertension, and immune dysfunction. These disturbances initiate several damaging processes, such as increased reactive oxygen species (ROS) production, inflammation, and ischemia. These processes mainly exert their damaging effect on endothelial and nerve cells, hence the susceptibility of densely vascularized and innervated sites, such as the eyes, kidneys, and nerves. Since the oral cavity is also highly vascularized and innervated, oral complications can be expected as well. The relationship between DM and oral diseases has received considerable attention in the past few decades. However, most studies only focus on periodontitis, and still approach DM from the limited perspective of elevated blood glucose levels only. In this review, we will assess other potential oral complications as well, including: dental caries, dry mouth, oral mucosal lesions, oral cancer, taste disturbances, temporomandibular disorders, burning mouth syndrome, apical periodontitis, and peri-implant diseases. Each oral complication will be briefly introduced, followed by an assessment of the literature studying epidemiological associations with DM. We will also elaborate on pathogenic mechanisms that might explain associations between DM and oral complications. To do so, we aim to expand our perspective of DM by not only considering elevated blood glucose levels, but also including literature about the other important pathogenic mechanisms, such as insulin resistance, dyslipidemia, hypertension, and immune dysfunction.

Monotherapy with Metformin versus Sulfonylureas and Risk of Cancer in Type 2 Diabetic Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Accumulating evidence suggests that patients with type 2 diabetes mellitus and hyperinsulinemia are at an increased risk of developing malignancies. It remains to be fully elucidated whether the use of metformin, an insulin sensitizer, and/or sulfonylureas, insulin secretagogues, affects cancer incidence in subjects with type 2 diabetes mellitus.

OBJECTIVE

A systematic review and meta-analysis was performed to compare the risk of cancer incidence associated with monotherapy with metformin compared with monotherapy with sulfonylureas in type 2 diabetes mellitus patients.

METHODS

Search was performed throughout MEDLINE/PubMed, EMBASE, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov up until December 2018. In this meta-analysis, each raw data (unadjusted) and study-specific (adjusted) relative risks (RRs) was combined and the pooled unadjusted and adjusted RRs with the 95% CI were calculated using the random-effects model with inverse-variance weighting. Heterogeneity among the studies was evaluated using I ² statistics. Publication bias was evaluated using the funnel plot asymmetry test. The Newcastle-Ottawa scale (NOS) was used to assess the study quality.

RESULTS

A total of 8 cohort studies were included in the meta-analysis. Obvious heterogeneity was noted, and monotherapy with metformin was associated with a lower risk of cancer incidence (unadjusted RR = 0.74, 95% CI: 0.55-0.99, I ² = 97.89%, p < 0.00001; adjusted RR = 0.76, 95% CI: 0.54-1.07, I ² = 98.12%, p < 0.00001) compared with monotherapy with sulfonylurea, using the random-effects model with inverse-variance weighting.

CONCLUSIONS

According to this review, the monotherapy with metformin appears to be associated with a lower risk of cancer incidence than monotherapy with sulfonylurea in patients with type 2 diabetes. This analysis is mainly based on cohort studies, and our findings underscore the need for large-scale randomized controlled trials to establish the effect of metformin monotherapy, relative to sulfonylureas monotherapy on cancer.