Association between insulin resistance and development of microalbuminuria in type 2 diabetes: a prospective cohort study

Metabolic syndrome as a risk factor for the development of kidney dysfunction: a meta-analysis of observational cohort studies

Background

Chronic kidney disease (CKD) is a major global health concern with increasing prevalence and associated complications. Metabolic syndrome (MetS) has been linked to CKD, but the evidence remains inconsistent. We conducted a systematic review and meta-analysis to investigate the association between MetS and kidney dysfunction.

Method

We conducted a comprehensive search of databases until December 2022 for cohort studies assessing the association between MetS and incident kidney dysfunction. Meta-analysis was performed using fixed and random effects models. Subgroup analyses were conducted to explore heterogeneity. Publication bias was assessed using Egger's and Begg's tests.

Result

A total of 24 eligible studies, involving 6,573,911 participants, were included in this meta-analysis. MetS was significantly associated with an increased risk of developing CKD (OR, 1.42; 95% CI, 1.28, 1.57), albuminuria or proteinuria (OR, 1.43; 95% CI, 1.10, 1.86), and rapid decline in kidney function (OR, 1.25; 95% CI, 1.07, 1.47). Subgroup analyses showed a stronger association as the number of MetS components increased. However, gender-specific subgroups demonstrated varying associations.

Conclusion

Metabolic syndrome is a significant risk factor for kidney dysfunction, requiring close renal monitoring. Lifestyle changes and targeted interventions may help reduce CKD burden. Further research is needed to understand the connection fully and assess intervention efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01348-5.

A Receptor Story: Insulin Resistance Pathophysiology and Physiologic Insulin Resensitization's Role as a Treatment Modality

Physiologic insulin secretion consists of an oscillating pattern of secretion followed by distinct trough periods that stimulate ligand and receptor activation. Apart from the large postprandial bolus release of insulin, β cells also secrete small amounts of insulin every 4-8 min independent of a meal. Insulin resistance is associated with a disruption in the normal cyclical pattern of insulin secretion. In the case of type-2 diabetes, β-cell mass is reduced due to apoptosis and β cells secrete insulin asynchronously. When ligand/receptors are constantly exposed to insulin, a negative feedback loop down regulates insulin receptor availability to insulin, creating a relative hyperinsulinemia. The relative excess of insulin leads to insulin resistance (IR) due to decreased receptor availability. Over time, progressive insulin resistance compromises carbohydrate metabolism, and may progress to type-2 diabetes (T2D). In this review, we discuss insulin resistance pathophysiology and the use of dynamic exogenous insulin administration in a manner consistent with more normal insulin secretion periodicity to reverse insulin resistance. Administration of insulin in such a physiologic manner appears to improve insulin sensitivity, lower HgbA1c, and, in some instances, has been associated with the reversal of end-organ damage that leads to complications of diabetes. This review outlines the rationale for how the physiologic secretion of insulin orchestrates glucose metabolism, and how mimicking this secretion profile may serve to improve glycemic control, reduce cellular inflammation, and potentially improve outcomes in patients with diabetes.

Triglyceride-glucose index is associated with the risk of chronic kidney disease progression in type 2 diabetes

OBJECTIVE

The study aimed to investigate the association of TyG index with chronic kidney disease (CKD) progression in type 2 diabetes mellitus (T2DM).

METHODS

A total of 179 T2DM patients with CKD were retrospectively included. CKD progression was defined as a doubling of baseline serum creatinine or onset of end-stage kidney disease (ESKD). Internal validation was performed by the Kidney Failure Risk Equation (KFRE) model and Net reclassification improvement (NRI).

RESULTS

The optimal cut-off value of the TyG index was 9.17. The cumulative incidence of kidney outcomes was significantly higher in the high-TyG group (v.s low-TyG group, P = 0.019). In addition, the high-TyG index was associated with a greater risk of CKD progression (HR 1.794, 95% CI 1.026-3.137, P = 0.040). And reclassification analyses confirmed the final adjusted model improved NRI (61.90% v.s model 2, 43.80% v.s model 1). The further RCS curves presented an inverted S-shaped relationship between the TyG index and the risk of CKD progression. Internal validation verified that a higher TyG index was associated with 2.10-fold increased odds of 2-year ESKD risk >10% (95% CI 1.82-8.21). Moreover, subgroup analysis suggested that the association was more pronounced in those at relatively early CKD stages (higher than stage 2) and with no medication history of oral hypoglycemic agents.

CONCLUSION

An elevated TyG index was associated with a higher risk of CKD progression in T2DM patients. Our findings suggested that timely targeting insulin sensitivity at the early stages of T2DM might be associated with declined future risk of CKD development.

Effect of clinical treatments for metabolic syndrome on albuminuria: a systematic review protocol

Introduction: Metabolic syndrome (MetS) predicts cardiovascular disease, and patients with this condition and type 2 diabetes have increased albuminuria, significantly impacting cardiovascular mortality and kidney disease progression. A considerable number of interventions to control MetS exist and are considered efficient, including the use of medication and changes in lifestyle. However, which approaches are effective in controlling albuminuria remains unclear. This systematic review protocol aims to map in the available literature whether lifestyle, medication, and surgical intervention for MetS have an impact on reducing albuminuria in adult patients. Methods: The Joanna Briggs Institute methodology for systematic reviews will be followed. Cochrane Database of Systematic Reviews, Scopus, Embase, and MEDLINE/PubMed databases will be used. For the Gray Literature, the DART-Europe E-theses Portal. There will be no language restriction. Studies written after 2009 will be included due to the consensus and definition of metabolic syndrome. This review will include studies considering pharmacological and non-pharmacological treatments for controlling albuminuria in patients with MetS. Studies where MetS is described in children and adolescents, animals, pregnant women, and patients with type 1 diabetes will be excluded. First, the selection will be based on reading the title and summary of the texts retrieved in the search strategy, followed by reading the relevant texts in full by two reviewers. After the selection of the studies, the extraction of the data, analysis, and synthesis will be conducted according to the JBI methodology.

Interaction among dietary n-3 and n-6 polyunsaturated fatty acid intake, fatty acid desaturase 2 genetic variants, and low-density lipoprotein cholesterol levels in type 2 diabetes patients

AIMS/INTRODUCTION

Fatty acid desaturase (FADS) genetic polymorphisms are strongly correlated with the risk of dyslipidemia and cardiovascular disease. In this study, we examined the impact of FADS1 and FADS2 genetic variants on plasma lipid status, and assessed interactions between FADS genetic polymorphisms and plasma n-3/n-6 fatty acids regarding lipid status within a population of 816 Taiwanese patients with type 2 diabetes.

MATERIALS AND METHODS

Selected tag single-nucleotide polymorphisms (FADS1 rs174546 [T/C]; FADS2 rs174602 [A/G] and rs2072114 [A/G]) were genotyped (n = 816).

RESULTS

The distribution of genotypes were compared with reports publicly available in the Genome Aggregation Database for East Asian populations (https://gnomad.broadinstitute.org). In the subgroup of patients not taking lipid-lowering medications (n = 192), we observed that the G allele of FADS2 rs174602 was statistically significantly correlated with lower low-density lipoprotein cholesterol (LDL-C) concentrations (P = 0.001), whereas the G allele of rs2072114 was marginally associated with LDL-C concentrations (P = 0.091). Using a general linear model adjusted for confounding factors, statistically significant interactions (P = 0.016) between single-nucleotide polymorphisms in rs2072114 and a low alpha-linolenic acid (18:3n-3)/linoleic acid (18:2n-6) ratio; the G allele correlated with lower LDL-C levels among individuals with a low alpha-linolenic acid/linoleic acid ratio. Interaction between rs174602 single-nucleotide polymorphisms and low alpha-linolenic acid/linoleic acid values on LDL-C was only marginally significant (P = 0.063).

CONCLUSIONS

Our results show the role of n-3/n-6 dietary polyunsaturated fatty acids in modifying the effects of genetic susceptibility on lipoprotein concentrations in patients with type 2 diabetes. Our findings highlight the potential of interventions with dietary polyunsaturated fatty acids regarding developing individualized prevention strategies for type 2 diabetes presenting with co-occurring dyslipidemia and cardiovascular diseases.

Association of microalbuminuria with serum lipids and inflammatory markers in an adult population in the Dikgale Health and Demographic Surveillance System site, South Africa

BACKGROUND

There is evidence that microalbuminuria (urinary albumin excretion) is an early sign of vascular damage and an established risk factor for cardiovascular morbidity and mortality. This study investigated the magnitude of microalbuminuria and its association with serum lipids and inflammatory markers among a rural black population residing in the Dikgale Health and Demographic Surveillance System site, South Africa.

METHODS

Data were collected from 602 presumably healthy participants (225 men and 377 women) aged ≥ 18 years. Biochemical data collection included serum lipids, glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), urine albumin and creatinine. Anthropometry and blood pressure were also measured. Microalbuminuria was diagnosed with an albumin-creatinine ratio of ≥ 2.5 mg/mmol in men and ≥ 3.5 mg/mmol in women. Data were analysed using SPSS version 22.0.

RESULTS

The mean age of participants was 48.63 ± 20.89 years. High percentages of microalbuminaria (35.7%), high levels of interleukin 6 (17.8%), hs-CRP (32.9%), triglycerides (TG) (26.1%), low-density lipoprotein cholesterol (52.2%) and total cholesterol (32.0%), and low levels of high-density lipoprotein cholesterol (29.1%) were observed in the population. Increased glucose levels (32.8%), insulin resistance (27.6%), hypertension (45.8%), overweight (26.8%) and obesity (25.4%) were also prevalent. Microalbuminuria was associated with high hs-CRP and TG levels in the men (adjusted odds ratios = 9.434, 95% confidence interval: 1.753 - 50.778, p = 0.01).

CONCLUSIONS

High prevalence of microalbuminuria, hypertension, insulin resistance, overweight and obesity, as well as abnormal levels of serum lipids and inflammatory markers were observed in the population. Microalbuminuria was associated with high hs-CRP and TG levels among men.

Association of Longitudinal Trajectories of Insulin Resistance With Adverse Renal Outcomes

OBJECTIVE

To analyze the relationship between time-serial changes in insulin resistance and renal outcomes.

RESEARCH DESIGN AND METHODS

A prospective cohort of subjects from the general population without chronic kidney disease (CKD) underwent a biennial checkup for 12 years (n = 5,347). The 12-year duration was divided into a 6-year exposure period, where distinct HOMA for insulin resistance (HOMA-IR) trajectories were identified using latent variable mixture modeling, followed by a 6-year event accrual period, from which the renal outcome data were analyzed. The primary end point was adverse renal outcomes, defined as a composite of estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 in two or more consecutive checkups or albumin ≥1+ on urine strip.

RESULTS

Two distinct groups of HOMA-IR trajectories were identified during the exposure period: stable (n = 4,770) and increasing (n = 577). During the event accrual period, 449 patients (8.4%) developed adverse renal outcomes, and the risk was higher in the increasing HOMA-IR trajectory group than in the stable group (hazard ratio 2.06, 95% CI 1.62-2.60, P < 0.001). The results were similar after adjustment for baseline clinical characteristics, comorbidities, anthropometric and laboratory findings, eGFR, and HOMA-IR. The clinical significance of increasing HOMA-IR trajectory was similar in three or four HOMA-IR trajectories. The increasing tendency of HOMA-IR was persistently associated with a higher incidence of adverse renal outcomes, irrespective of the prevalence of diabetes.

CONCLUSIONS

An increasing tendency of insulin resistance was associated with a higher risk of adverse renal outcomes. Time-serial tracking of insulin resistance may help identify patients at high risk for CKD.

MicroRNAs and their delivery in diabetic fibrosis

The global prevalence of diabetes mellitus was estimated to be 463 million people in 2019 and is predicted to rise to 700 million by 2045. The associated financial and societal costs of this burgeoning epidemic demand an understanding of the pathology of this disease, and its complications, that will inform treatment to enable improved patient outcomes. Nearly two decades after the sequencing of the human genome, the significance of noncoding RNA expression is still being assessed. The family of functional noncoding RNAs known as microRNAs regulates the expression of most genes encoded by the human genome. Altered microRNA expression profiles have been observed both in diabetes and in diabetic complications. These transcripts therefore have significant potential and novelty as targets for therapy, therapeutic agents and biomarkers.

Insulin Resistance is Associated with Clinical Manifestations of Diabetic Kidney Disease (Glomerular Hyperfiltration, Albuminuria, and Kidney Function Decline)

Clinical features of diabetic kidney disease include glomerular hyperfiltration, albuminuria, and kidney function decline towards End-Stage Kidney Disease (ESKD). There are presently neither specific markers of kidney involvement in patients with diabetes nor strong predictors of rapid progression to ESKD. Serum-creatinine-based equations used to estimate glomerular filtration rate are notoriously unreliable in patients with diabetes. Early kidney function decline, reduced glomerular filtration rate, and proteinuria contribute to identifying diabetic patients at higher risk for rapid kidney function decline. Unlike proteinuria, the elevation of urinary albumin excretion in the range of microalbuminuria is frequently transient in patients with diabetes and does not always predict progression towards ESKD. Although the rate of progression of kidney function decline is usually accelerated in the presence of proteinuria, histological lesions of diabetes and ESKD may occur with normal urinary albumin excretion. No substantial reduction in the rate of ESKD associated with diabetes has been observed during the last decades despite intensified glycemic control and reno-protective strategies, indicating that existing therapies do not target underlying pathogenic mechanisms of kidney function decline. Very long-term effects of sodium-glucose transporters- 2 inhibitors and glucagon-like peptide-1 analogs remain to be defined. In patients with diabetes, glucagon secretion is typically elevated and induces insulin resistance. Insulin resistance is consistently and strongly associated with clinical manifestations of diabetic kidney disease, suggesting that reduced insulin sensitivity participates in the pathogenesis of the disease and may represent a therapeutic objective. Amelioration of insulin sensitivity in patients with diabetes is associated with cardioprotective and kidney-protective effects.

Potential screening indicators for early diagnosis of NAFLD/MAFLD and liver fibrosis: Triglyceride glucose index-related parameters

IMPORTANCE

Homeostatic model assessment for insulin resistance (HOMA-IR) and triglyceride glucose (TyG) index-related parameters [TyG index, triglyceride glucose-waist circumference (TyG-WC), triglyceride glucose-waist-to-height ratio (TyG-WHtR), and triglyceride glucose-body mass index (TyG-BMI)] are gradually considered as convenient and alternative indicators for insulin resistance in various metabolic diseases, but the specific diagnostic capacity and the comparison of the parameters in non-alcoholic fatty liver disease (NAFLD), metabolic-associated fatty liver disease (MAFLD), and liver fibrosis remain uncertain.

OBJECTIVE

To comprehensively assess and compare the diagnostic accuracy of the above parameters in NAFLD, MAFLD, and liver fibrosis and identify the appropriate indicators.

METHODS

A total of 1,727 adults were enrolled from the 2017-2018 National Health and Nutrition Examination Surveys. Logistic regressions were used to identify the parameters significantly associated with NAFLD, MAFLD, and liver fibrosis; receiver operating characteristic (ROC) curves were used to evaluate and compare their diagnostic capacity. Subgroup analyses were conducted to validate the concordance, and the optimal cutoff values were determined according to the Youden's indexes.

RESULTS

Significant differences were observed between quartile-stratified HOMA-IR and TyG index-related parameters across the NAFLD, MAFLD, and liver fibrosis (P < 0.05). All variables were significantly predictive of different disease states (P < 0.05). The top three AUC values are TyG-WC, TyG-WHtR, and TyG-BMI with AUCs of 0.815, 0.809, and 0.804 in NAFLD. The optimal cutoff values were 822.34, 4.94, and 237.77, respectively. Similar values and the same trend of the above three indexes could be observed in MAFLD and liver fibrosis. Subgroup analyses showed consistent results with the primary research, despite some heterogeneity.

CONCLUSIONS

TyG-WC, TyG-WHtR, and TyG-BMI can be used for early screening of NAFLD and MAFLD. These three parameters and HOMA-IR were more suitable for assessing metabolic risks and monitoring disease progression in patients with NAFLD.

The association between EKG abnormalities and the development of microalbuminuria in type 2 diabetes

Microalbuminuria is associated with both with chronic kidney disease and various cardiovascular abnormalities. Given the common use of electrocardiograms (EKGs) in diagnosing cardiovascular dysfunction, this study is analyzing the relationship between EKG abnormalities and diabetic nephropathy in type 2 diabetes mellitus (DM) patients. The enrollments of this study were from the 10-year follow-up data (2003-2012) of the Diabetes Management through an Integrated Delivery System project. All study subjects underwent at least 1 EKG measurement. The urinary microalbuminuria was recorded annually. The logistic regression model was used to evaluate the association between EKG abnormalities and the occurrence of diabetic nephropathy in type 2 DM patients. The total of 1189 patients with type 2 DM are included in this study and a total of 552 patients had microalbuminuria during a 10-year follow-up. A significantly higher odds ratio of microalbuminuria occurrence (4.85) was found in the patients with premature supraventricular contraction or tachycardia compared to those without EKG abnormalities. The odds ratios of microalbuminuria occurrence were 1.00, 2.43, 2.64, and 2.98, respectively, for patients with insulin resistance in the Q (quartile) 1(as the reference), Q2, Q3, and Q4, respectively. Our findings can serve as a reference for the association between EKG abnormalities and the development of microalbuminuria in type 2 diabetes.

Gender-specific and age-specific associations of the homoeostasis model assessment for IR (HOMA-IR) with albuminuria and renal function impairment: a retrospective cross-sectional study in Southeast China

OBJECTIVES

The study aimed to investigate the association of insulin resistance (IR), which was estimated by the homoeostasis model assessment for IR (HOMA-IR), with albuminuria and renal function impairment in a general Chinese population.

DESIGN

A retrospective cross-sectional study.

SETTING AND PARTICIPANTS

A total of 13 742 adults (age: ≥18 years) who underwent a health check-up at a hospital in Southeast China during 2013-2014 were enrolled. 216 subjects were excluded due to lack of enough fasting time, be pregnant, have chronic diseases influencing metabolic functions or have glomerulonephritis, renal cancer, kidney transplant. Eventually, 7552 men and 5974 women were included for the present analysis.

PRIMARY OUTCOME MEASURES

The association of HOMA-IR with albuminuria and renal function impairment were analysed. The HOMA-IR cut-off value for detecting albuminuria and renal function impairment were determined.

RESULTS

An increase in the HOMA-IR quartile was significantly associated with the prevalence of albuminuria and renal function impairment in all men and women aged >45 years. The multivariable logistic regression analyses revealed a significant association of the HOMA-IR with albuminuria and renal function impairment in subjects aged >45 years of the fourth quartiles compared with those of the first quartile after adjusting for potential confounders (albuminuria: men OR, 2.39; 95% CI 1.51 to 3.79, p<0.001; women OR, 2.40; 95% CI 1.44 to 4.01; p=0.001; renal function impairment: men OR, 2.30; 95% CI 1.50 to 3.51; p<0.001; women OR, 2.20; 95% CI 1.35 to 3.58; p=0.002). The optimal cut-off value of HOMA-IR for detecting albuminuria and renal function impairment was 2.69 in men aged ≤45 years, 1.60 in men aged >45 years and 1.86 in women aged >45 years.

CONCLUSIONS

Our study revealed that HOMA-IR was significantly associated with albuminuria and renal function impairment in individuals aged >45 years.

Epidemiological characteristics of diabetic kidney disease in Taiwan

Diabetic kidney disease (DKD) is a critical microvascular complication of diabetes. With the continuous increase in the prevalence of diabetes since 2000, the prevalence of DKD has also been increasing in past years. The prevalence of DKD among individuals with type 2 diabetes in Taiwan increased from 13.32% in 2000 to 17.92% in 2014. The cumulative incidence of DKD among individuals with type 1 diabetes in Taiwan was higher than 30% during 1999-2012. DKD is the leading cause of end-stage renal disease (ESRD), with a prevalence of approximately 45% in a population on chronic dialysis in Taiwan. Among individuals with type 2 diabetes, the prevalence of ESRD in the receipt of dialysis also increased from 1.32% in 2005 to 1.47% in 2014. Risk factors for DKD development are age, race, family history, hyperglycemia, hypertension, dyslipidemia, dietary patterns, and lifestyles. Prognostic factors that aggravate DKD progression include age, family history, sex, glycemic control, blood pressure (BP), microvascular complications, and atherosclerosis. This review summarizes updated information on the onset and progression of DKD, particularly in the Taiwanese population. Translating these epidemiological features is essential to optimizing the kidney care and improving the prognosis of DKD in Asian populations.

The relationship between resting heart rate and new-onset microalbuminuria in people with type 2 diabetes: An 8-year follow-up study

AIMS

Microalbuminuria is an indicator of adverse cardiovascular events and chronic kidney disease. Studies have described an elevated resting heart rate as a risk factor for microalbuminuria in people with cardiovascular disease, but none have clarified its role in microalbuminuria development in people with type 2 diabetes. Therefore, this study investigated the relationship between resting heart rate and new-onset microalbuminuria in type 2 diabetes.

METHODS

A total of 788 people from a glycaemic control trial in Taiwan were enrolled. Microalbuminuria was defined as a fasting urine albumin-to-creatinine ratio ≥30 mg/g in two consecutive urine tests. Resting heart rate and other covariates were measured at baseline. The quartile of resting heart rates, categorized as <70, 70-74, 75-80 and >80 beats/min, was used for analysis. Cox proportional hazard models were used to evaluate the association between resting heart rate and risk of microalbuminuria.

RESULTS

During the follow-up period, 244 people (31%) developed microalbuminuria. Those who developed microalbuminuria had a longer diabetes duration (median = 3.0 vs. 2.0 years, p < 0.001), higher rate of hypertension (77% vs. 66%, p = 0.003), higher rate of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker treatment (50% vs. 38%, p = 0.001) and higher baseline HbA_1c level (70 vs. 64 mmol/mol, 8.6 vs. 8.0%, p < 0.001). After adjusting for demographics, metabolic profiles and inflammatory markers, developing microalbuminuria was significantly associated with baseline resting heart rate of 70-74, 75-80 and >80 beats/min (with hazard ratios [95% CI] of 2.05 [1.32, 3.18], 2.10 [1.32, 3.32] and 1.62 [1.01, 2.59], respectively) compared to resting heart rates <70 beats/min. An average increased risk of microalbuminuria for increment of 10 beats/min was about 24% among those with hypertension (with hazard ratios of 1.24 [1.05, 1.47] in the multivariable Cox model).

CONCLUSIONS

This prospective cohort study showed that resting heart rate may be an associative risk factor for developing microalbuminuria in type 2 diabetes.

Association between the triglyceride-glucose index and diabetic nephropathy in patients with type 2 diabetes: A cross-sectional study

Aims/Introduction

The triglyceride–glucose (TyG) index has been proposed as a reliable and simple marker of insulin resistance. We investigated the association between TyG index and diabetic nephropathy (DN) in patients with type 2 diabetes.

Materials and Methods

A consecutive case series of 682 adult patients with type 2 diabetes hospitalized in the Department of Endocrinology at the Tongji Hospital (Wuhan, Hubei, China) from January 2007 to December 2009 was included in this cross‐sectional analysis. Receiver operating characteristics curve analysis, correlation analysis and multiple logistic regression analysis were carried out.

Results

A total of 232 (34.0%) participants were identified with DN. Compared with the non‐DN group, the DN group had longer disease duration, and higher bodyweight, systolic blood pressure, diastolic blood pressure, glycated hemoglobin, triglycerides, total cholesterol, serum uric acid, 24 h‐urinary albumin, TyG index and homeostasis model assessment 2 estimates for insulin resistance (HOMA2‐IR; P < 0.05 for each). The TyG index with an optimal cut‐off point >9.66 showed a higher area under the receiver operating characteristic curve of 0.67 (P = 0.002) than HOMA2‐IR (area under the curve 0.61, P = 0.029) on receiver operating characteristic curve analysis for DN identification. Additionally, the TyG index positively correlated with the levels of metabolic indicators (bodyweight, glycated hemoglobin, triglycerides, total cholesterol, serum uric acid, fasting glucose and HOMA2‐IR) and natural logarithmic 24 h‐urinary albumin (P < 0.05 for each), but not natural logarithm of estimated glomerular filtration rate. On multiple regression analysis, an increased TyG index was shown to be an independent risk factor (odds ratio 1.91, P = 0.001) for DN.

Conclusions

The TyG index was independently associated with DN in patients with type 2 diabetes, and was a better marker than HOMA2‐IR for identification of DN in type 2 diabetes patients.

Differential Network Analysis Reveals Metabolic Determinants Associated with Mortality in Acute Myocardial Infarction Patients and Suggests Potential Mechanisms Underlying Different Clinical Scores Used To Predict Death

We present here the differential analysis of metabolite–metabolite association networks constructed from an array of 24 serum metabolites identified and quantified via nuclear magnetic resonance spectroscopy in a cohort of 825 patients of which 123 died within 2 years from acute myocardial infarction (AMI). We investigated differences in metabolite connectivity of patients who survived, at 2 years, the AMI event, and we characterized metabolite–metabolite association networks specific to high and low risks of death according to four different risk parameters, namely, acute coronary syndrome classification, Killip, Global Registry of Acute Coronary Events risk score, and metabolomics NOESY RF risk score. We show significant differences in the connectivity patterns of several low-molecular-weight molecules, implying variations in the regulation of several metabolic pathways regarding branched-chain amino acids, alanine, creatinine, mannose, ketone bodies, and energetic metabolism. Our results demonstrate that the characterization of metabolite–metabolite association networks is a promising and powerful tool to investigate AMI patients according to their outcomes at a molecular level.

Proinsulin/insulin ratio as a predictor of insulin resistance in patients with diabetic nephropathy

Patients with Diabetic nephropathy (DN) have an increase in cardiovascular mortality, and since IR may be a contributing factor. Therefore, the aim of this study was to assess the role of pro insulin/insulin ratio as a predictor of insulin resistance in patients with diabetic nephropathy PATIENTS AND METHODS: A Case-control study was conducted in a total of 50 patients who diagnosed with type 2 diabetes mellitus from July 2017 to March 2018. The patients were divided into 2 groups according to presence of diabetic nephropathy. Demographic and clinical data were collected. RESULTS: There is a significant increase in serum pro insulin/insulin ratio in patients with diabetic nephropathy patients compared to patients without diabetic nephropathy An association was found between increase serum pro insulin/insulin ratio and increase predicting of insulin resistance. Cut-off value of serum pro insulin/insulin ratio ≥0.1145 with sensitivity and specificity of 92.3 and 60.3 respectively as a predictor for insulin resistance CONCLUSION: This study demonstrate a strong relationship between insulin resistance and CKD and this relationship was stronger in the presence of obesity. Pro insulin/insulin ratio was found to be a significant predictor for insulin resistance.

Body-mass index and the risk of albuminuria in hypertensive patients with a poor estimated glomerular filtration rate and the potential role of diabetes mellitus

BACKGROUND

Obesity-related to metabolic syndrome was associated with a greater risk for development of chronic kidney disease (CKD). We aimed to assess the association between obesity and micro/macroalbuminuria in hypertensive patients with a poor estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m².

METHODS

One hundred old patients (median age 79 years ± inter-quartile range 68-84.7) with manifested hypertension (systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 85 mmHg) and a permanently poor eGFR for a duration time more than 3 months were enclosed. Albuminuria was defined as urinary albumin-to-creatinine ratio (ACR) ≥ 30 mg/gr and it was classified according to KDIGO 2012. The obesity was defined by a high body mass index (BMI>30 kg/m²). The waist circumference, HDL-C, triglycerides and serum glucose were measured. Chi-square tests and an adjusted model were performed.

RESULTS

Chi-square tests showed significant association between classified albuminuria and both obesity and high serum triglycerides (x² = 7.2, p = 0.02 and x² = 8.3, p = 0.01 respectively). However, the adjusted model for the prediction of albuminuria showed that the presence of a high BMI was a non-significant risk factor, although diabetes mellitus and eGFR value were found to be significant risk factors (p = 0.03, OR = 4.3, 1.2-22.07 and p = 0.04, OR = 0.9, 0.9-1.007 respectively) adjusting to covariates including the high waist circumference.

CONCLUSION

Obesity defined by a high BMI was not found to be a significant risk factor for micro/macroalbuminuria in hypertensive patients with a poor estimated glomerular filtration rate, when diabetes mellitus and the low eGFR value act as confounders.

Narrative review of the effects of antidiabetic drugs on albuminuria

Diabetes mellitus is the most prevalent metabolic disorder worldwide. Glycemic control is the main focus of antidiabetic therapy. However, there are data suggesting that some antidiabetic drugs may have intrinsic beneficial renal effects and protect against the development and progression of albuminuria, thus minimizing the risk of diabetic nephropathy. These pharmacological agents can suppress upstream molecular pathways involved in the pathophysiology of diabetes-induced renal dysfunction such as oxidative stress, inflammatory responses, and apoptosis. In this narrative review, the pathophysiology of albuminuria in patients with diabetic nephropathy is discussed. Furthermore, the renoprotective effects of antidiabetic drugs, focusing on albuminuria, are reviewed.

Association of serum high-density lipoprotein cholesterol with microalbuminuria in type 2 diabetes patients

BACKGROUND

The association of serum high-density lipoprotein cholesterol (HDL-C) with microalbuminuria in type 2 diabetes mellitus (T2DM) remains controversial. Therefore, a cross-sectional study was conducted on patients with T2DM to investigate the relationship of HDL-C with microalbuminuria.

METHODS

A total of 524 participants with T2DM were recruited in this cross-sectional study. The patients were divided into four groups according to serum HDL-C quartile. A nonparametric test was employed to assess the relationships across quartiles with clinical parameters and demographics. Multivariate logistic regression analysis was further performed.

RESULTS

Of the 524 patients, 138 (26.3%) were found to have microalbuminuria by urinary albumin excretion rate determination. Serum HDL-C levels in microalbuminuria group were significantly lower than those in non-microalbuminuria group (1.04 (0.90-1.21) vs. 1.10 (0.94-1.31) mmol/L, P = 0.002). The nonparametric test for trend showed that the prevalence of microalbuminuria was significantly reduced for subjects of the fourth quartile of HDL-C compared to the first to third quartile (13.5% vs. 33.1%, 28.6%, 29.4%, P = 0.001). Multivariate logistic regression showed that subjects within the highest quartile of HDL-C had lower odds of microalbuminuria than those within the lowest quartile of HDL-C (OR = 0.17, 95% CI 0.15-0.52, P = 0.004).

CONCLUSIONS

Higher levels of serum HDL-C were associated with decreased rates of microalbuminuria in T2DM patients.

Effects of long-term exposure to CO and PM2.5 on microalbuminuria in type 2 diabetes

OBJECTIVE

No study has examined the effects of air pollutants on albuminuria in type 2 diabetes. Therefore, the present study investigated this association.

METHODS

This follow-up study enrolled 812 patients with type 2 diabetes between 2003 and 2012. The urinary albumin-to-creatinine ratio (ACR) was recorded annually. Exposure to the air pollutants CO, NO₂, O₃, SO₂, and PM_2.5 was interpolated from 72 air-quality monitoring stations to residences by using the kriging method. The association between air pollutants and ACR increase was assessed using mixed-effect model with random intercepts for 36 clinics.

RESULTS

The study objects (mean age: 55.4 years) were followed for 3 or more years (average period: 5.4 years). ACR increase was found to be positively associated with the male sex, baseline hemoglobin A1c, and exposure to CO and PM_2.5, and negatively associated with waist circumference through multiple linear regression. Annually urine albumin/creatinine ratio increase was estimated by the final model, Patients exposed to higher levels of CO (e.g., third quartile, 1025 ppb) and lower levels of CO (e.g., first quartile, 850 ppb) had an annual ACR increase of 3.73 and 3.54 mg/g, respectively. Patients exposed to higher levels of PM_2.5 (e.g., third quartile, 38.8 μg/M3) and lower levels of PM_2.5 (e.g., first quartile, 27.7 μg/M3) had an annual ACR increase of 3.96 and 3.17 mg/g, respectively.

CONCLUSIONS

Exposure to high CO and PM_2.5 levels increased albuminuria in type 2 diabetes.

Metabolic Syndrome and Chronic Renal Disease

Background: The influence of metabolic syndrome (MetS) on kidneys is related to many complications. We aimed to assess the association between MetS and chronic renal disease defined by a poor estimated glomerular filtration rate (eGFR) and/or the presence of microalbuminuria/macroalbuminuria.

METHODS

149 patients (77 males/72 females) were enrolled in the study. Chronic renal disease was defined according to KDIGO 2012 criteria based on eGFR category and classified albuminuria. MetS was studied as a dichotomous variable (0 to 5 components) including hypertension, waist circumference, low HDL-cholesterol, high triglycerides, and high glucose. Results: The association between clustering MetS and both classified eGFR and classified albuminuria (x² = 50.3, p = 0.001 and x² = 26.9, p = 0.003 respectively) was found to be significant. The MetS presence showed an odds 5.3-fold (1.6-17.8) higher for low eGFR and 3.2-fold (1.2-8.8) higher for albuminuria in combination with the presence of diabetes mellitus, which also increased the risk for albuminuria by 3.5-fold (1.1-11.3). Albuminuria was significantly associated with high triglycerides, hypertension, high glucose (x² = 11.8, p = 0.003, x² = 11.4, p = 0.003 and x² = 9.1, p = 0.01 respectively), and it was mildly associated with a low HDL-C (x² = 5.7, p = 0.06). A significant association between classified eGFR and both high triglycerides and hypertension (x² = 9.7, p = 0.04 and x² = 16.1, p = 0.003 respectively) was found. Conclusion: The clustering of MetS was significantly associated with chronic renal disease defined by both classified eGFR and albuminuria. The definition of impaired renal function by classified albuminuria was associated with more MetS components rather than the evaluation of eGFR category. MetS may contribute to the manifestation of albuminuria in patients with diabetes mellitus.

Metabolic Syndrome and Chronic Renal Disease

Background: The influence of metabolic syndrome (MetS) on kidneys is related to many complications. We aimed to assess the association between MetS and chronic renal disease defined by a poor estimated glomerular filtration rate (eGFR) and/or the presence of microalbuminuria/macroalbuminuria.

METHODS

149 patients (77 males/72 females) were enrolled in the study. Chronic renal disease was defined according to KDIGO 2012 criteria based on eGFR category and classified albuminuria. MetS was studied as a dichotomous variable (0 to 5 components) including hypertension, waist circumference, low HDL-cholesterol, high triglycerides, and high glucose. Results: The association between clustering MetS and both classified eGFR and classified albuminuria (x² = 50.3, p = 0.001 and x² = 26.9, p = 0.003 respectively) was found to be significant. The MetS presence showed an odds 5.3-fold (1.6-17.8) higher for low eGFR and 3.2-fold (1.2-8.8) higher for albuminuria in combination with the presence of diabetes mellitus, which also increased the risk for albuminuria by 3.5-fold (1.1-11.3). Albuminuria was significantly associated with high triglycerides, hypertension, high glucose (x² = 11.8, p = 0.003, x² = 11.4, p = 0.003 and x² = 9.1, p = 0.01 respectively), and it was mildly associated with a low HDL-C (x² = 5.7, p = 0.06). A significant association between classified eGFR and both high triglycerides and hypertension (x² = 9.7, p = 0.04 and x² = 16.1, p = 0.003 respectively) was found. Conclusion: The clustering of MetS was significantly associated with chronic renal disease defined by both classified eGFR and albuminuria. The definition of impaired renal function by classified albuminuria was associated with more MetS components rather than the evaluation of eGFR category. MetS may contribute to the manifestation of albuminuria in patients with diabetes mellitus.

The Saudi Diabetic Kidney Disease study (Saudi-DKD): clinical characteristics and biochemical parameters

BACKGROUND

Saudi Arabia is facing an epidemic of type 2 diabetes that is complicated by a high rate of chronic complications such as kidney disease, which have a major impact on the healthcare system and economy. The Saudi diabetic kidney disease (SAUDI-DKD) study was launched to understand the implications of chronic diabetic kidney disease .

OBJECTIVES

Examine the hematological, biochemical and metabolic parameters of the selected cohorts to look for biomarkers of diabetic nephropathy.

DESIGN

Cross-sectional, hospital-based.

SETTING

Four general hospitals and two dialysis centers in Riyadh.

PATIENTS AND METHODS

We recruited adult type 2 diabetic patients aged between 35 and 70 years, with a duration of diabetes > 10 years, including subjects with microalbuminuria, macroalbuminuria and end stage renal disease (ESRD). They were compared with subjects with normal albumin excretion classified according to American Diabetes Association (ADA) criteria.

MAIN OUTCOME MEASURES

The effect of different stages of diabetic nephropathy on hematological and biochemical parameters.

RESULTS

Of 427 subjects with nephropathy, 184 (43%) had microalbuminuria, 83 (19%) had macroalbu.minuria and 160 (37%) had end stage renal disease (ESRD). The remaining 213 (50%) subjects did not have nephropathy. Patients with nephropathy were older with a mean age (SD) of 55.62 (6.00) years and had a longer duration of diabetes (mean [SD], 19.04 [6.33]) years), and had a lower monthly income and body mass index (BMI) than patients without nephropathy. Insulin resistance, elevated uric acid level, low red blood cells (RBCs) count and low hemoglobin level were associated with significantly increased risk of macroalbuminuria and ESRD. Elevated uric acid and LDH were associated with significantly increased risk of microalbuminuria and ESRD, while elevated red blood cell distribution width was significantly associated with an increased risk of ESRD.

CONCLUSION

Diabetic nephropathy is associated with insulin resistance, changes in liver enzymes and uric acid in addition to abnormalities in the red blood cell count and red blood cell shape that warrant frequent monitoring among patients with diabetic kidney disease.

LIMITATIONS

Cross-sectional study design and exclusion of patients with some risk factors.

Insulin Sensitivity and Diabetic Kidney Disease in Children and Adolescents With Type 2 Diabetes: An Observational Analysis of Data From the TODAY Clinical Trial

BACKGROUND

Diabetic kidney disease is a major cause of premature mortality in type 2 diabetes mellitus (T2DM). Worsening insulin sensitivity independent of glycemic control may contribute to the development of diabetic kidney disease. We investigated the longitudinal association of insulin sensitivity with hyperfiltration and increased albumin excretion in adolescents with T2DM.

STUDY DESIGN

Observational prospective cohort study.

SETTING & PARTICIPANTS

532 TODAY (Treatment Options for Type 2 Diabetes in Adolescents and Youth) participants aged 12 to 17 years with T2DM duration less than 2 years at baseline. The TODAY Study was a multicenter randomized clinical trial that examined the efficacy of 3 treatment regimens (metformin monotherapy, metformin plus rosiglitazone, or metformin plus an intensive lifestyle intervention program) to achieve durable glycemic control.

PREDICTORS

Natural log-transformed estimated insulin sensitivity (reciprocal of fasting insulin), hemoglobin A_1c concentration, age, race-ethnicity, treatment group, body mass index, loss of glycemic control, and hypertension.

OUTCOMES

Hyperfiltration was defined as 99th percentile or higher of estimated glomerular filtration rate (≥140mL/min/1.73m²) when referenced to healthy adolescents (NHANES 1999-2002) and albumin-creatinine ratio ≥ 30μg/mg at 3 consecutive annual visits.

RESULTS

Hyperfiltration was observed in 7.0% of participants at baseline and in 13.3% by 5 years, with a cumulative incidence of 5.0% over 5 years. The prevalence of increased albumin excretion was 6% at baseline and 18% by 5 years, with a cumulative incidence of 13.4%. There was an 8% increase in risk for hyperfiltration per 10% lower estimated insulin sensitivity in unadjusted and adjusted models (P=0.01). Increased albumin excretion was associated with hemoglobin A_1c concentration, but not estimated insulin sensitivity.

LIMITATIONS

Longer follow-up is needed to capture the transition from hyperfiltration to rapid glomerular filtration rate decline in youth-onset T2DM.

CONCLUSIONS

Lower estimated insulin sensitivity was associated with risk for hyperfiltration over time, whereas increased albumin excretion was associated with hyperglycemia in youth-onset T2DM.

Obesity, weight change, and chronic kidney disease in patients with type 2 diabetes mellitus: A longitudinal study in Taiwan

BACKGROUND

The aim of the present study was to investigate relationships between the risk of chronic kidney disease (CKD) and obesity and weight changes in Asian patients with type 2 diabetes.

METHODS

At baseline (2003-05), 1187 diabetic patients aged 30-70 years were recruited to the study, with follow-up surveys completed in 2008, 2009, and 2010. Chronic kidney disease was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m² ; body mass index (BMI) was categorised as normal (18.5-22.9 kg/m² ), overweight (23-27.4 kg/m² ), or obese (≥27.5 kg/m² ); waist circumference (WC) ≥80 cm for women and ≥90 cm for men was taken to indicate abdominal obesity. Changes in weight and WC were calculated from baseline to each follow-up survey. Relative risk (RR) and 95% confidence intervals (CIs) of CKD were estimated. To estimate the risk for incident CKD, associations were examined in patients without CKD at baseline (n = 881).

RESULTS

Over 7 years of follow-up, obesity (RR 1.48; 95% CI 1.08-2.04; P = 0.015) and high WC (RR 1.23; 95% CI 1.00-1.52; P = 0.049) were associated with CKD after adjusting for covariates. Among participants without CKD at baseline, those who gained >10% weight (RR 1.43; 95% CI 1.07-1.90; P = 0.015) and in whom WC increased >15% (RR 1.37; 95% CI 1.01-1.85; P = 0.045) had a higher risk of incident CKD than those who remained stable (±5% changes in weight or WC).

CONCLUSIONS

Diabetic patients who are obese and those with excessive central fat were more likely to have CKD. Large weight gain (>10%) and increases in WC (>15%) independently predicted incident CKD.

Decreased serum extracellular superoxide dismutase activity is associated with albuminuria in Chinese patients with type 2 diabetes mellitus

AIMS

The aim of this study was to determine the activity of serum extracellular superoxide dismutase (ecSOD) in patients with type 2 diabetes mellitus (T2DM) and healthy subjects, and to determine the prospective association between baseline serum ecSOD activity and the subsequent risk of albuminuria progression in a cohort of Chinese T2DM patients.

METHODS

A total of 458 T2DM patients and 100 healthy subjects were assessed. After a median follow-up of 7.7 months, 319 patients with baseline normoalbuminuria (urinary albumin-to-creatinine ratio [UACR] <30 mg/g) and 77 patients with baseline microalbuminuria (UACR = 30-299 mg/g) were divided into progression and non-progression groups according to UACR changes. Serum ecSOD activity was determined by the autoxidation of pyrogallol method. Multivariate Cox regression analysis was used for investigating the predictors for albuminuria progression.

RESULTS

Compared with healthy controls (174.5 ± 25.1 U/mL), serum ecSOD activity significantly decreased in T2DM patients with normoalbuminuria (114.9 ± 13.2 U/mL), with microalbuminuria (106.6 ± 16.3 U/mL), and with macroalbuminuria (97.1 ± 18.2 U/mL) (all P < 0.001). Serum ecSOD activity was associated with albuminuria (odds ratio [OR] = 1.028, P = 0.004) in T2DM patients. Baseline serum ecSOD activity (hazard ratio [HR] = 0.902, 95% CI 0.877-0.928, P < 0.001) was an independent predictor for albuminuria progression.

CONCLUSION

Serum ecSOD activity may be useful for predicting the future risk of albuminuria progression in Chinese T2DM patients.

Low dose doxycycline decreases systemic inflammation and improves glycemic control, lipid profiles, and islet morphology and function in db/db mice

The aim of this study was to determine whether low dose doxycycline as an anti-inflammatory agent could improve glucose metabolism in diabetic animals. Therefore, doxycycline was supplemented in drinking water to 6-week-old male db/db mice for 10 weeks. Doxycycline reduced perirenal/epididymal fat, Lee's index, and liver cholesterol. Blood HDL-cholesterol increased, but total cholesterol and aspartate transaminase decreased. Glucose and insulin tolerances were improved, accompanying with reduced fasting blood glucose, insulin, HOMA-IR and advanced glycation end products. Islet number, β-cell percentage and mass increased, while islet size decreased. Consistently, less apoptosis but more β-cell proliferation were found in islets of treated mice. Freshly isolated islets from treated mice showed higher insulin content and enhanced glucose stimulated insulin secretion (GSIS). In addition, purified islets of Balb/c mice showed increased GSIS after cultivation in vitro with doxycycline, but not with chloramphenicol and levofloxacin. Inflammation markers, including lipopolysaccharides (LPS) and C-reactive protein (CRP) in serum as well as CD68-positive cells in treated islets, decreased significantly. Finally, LPS stimulated the production of inflammatory factors but inhibited GSIS of MIN6 cells; however, the effects were completely reversed by doxycycline. The results support further study of possible long-term usage of sub-antimicrobial doxycycline in diabetic patients.

Plasma Mannose Levels Are Associated with Incident Type 2 Diabetes and Cardiovascular Disease

Plasma mannose levels are elevated in subjects with insulin resistance independently of obesity. Here, we found that elevated plasma mannose levels are strong markers of future risk of several chronic diseases including T2D, CVD, and albuminuria, and that it may contribute to their development rather than just being a novel biomarker.

FADS Gene Polymorphisms, Fatty Acid Desaturase Activities, and HDL-C in Type 2 Diabetes

Polyunsaturated fatty acids (PUFA) correlate with risk of dyslipidemia and cardiovascular diseases. Fatty acid desaturase (FADS) single nucleotide polymorphisms (SNPs) modulate circulating PUFA concentrations. This study examined influence of FADS1 and FADS2 genetic variants on desaturase activities and blood lipid concentrations in type 2 diabetes patients, and further assessed their interrelationships. Selected SNPs (FADS1: rs174547, rs174548, rs174550; FADS2: rs174575, rs174576, rs174583, rs498793 and rs2727270) were genotyped in 820 type 2 diabetes patients and compared with those reported in the HapMap. Patient subgroups (n = 176) without taking lipid-lowering medicine were studied to assess influence of tag SNPs including rs174547, rs174575, rs498793 and rs2727270 on delta-5 desaturase (D5D: 20:4 (n-6)/20:3 (n-6)) and delta-6 desaturase (D6D:18:3 (n-6)/18:2 (n-6)) activities, and blood lipids. FADS1 rs174547 TT/TC/CC and FADS2 rs2727270 CC/CT/TT were significantly (p for trend < 0.05) associated with reduced HDL-C, D5D and D6D activities. Upon adjustment for confounders, D5D (p = 0.006) correlated significantly and D6D marginally (p = 0.07) correlated with increased HDL-C levels, whereas rs174547 and rs2727270 polymorphisms were not associated. D6D andD5D activities may play a role in modulating HDL-C levels in type 2 diabetes. Future studies with larger sample sizes are needed to investigate how FADS genetic variations interact with desaturase activities or PUFAs in the metabolism of lipoproteins in diabetic patients.

Relationships of pancreatic beta-cell function with microalbuminuria and glomerular filtration rate in middle-aged and elderly population without type 2 diabetes mellitus: a Chinese community-based analysis

BACKGROUND

Relationships of pancreatic beta-cell function abnormality with microalbuminuria (MA) and glomerular filtration rate (GFR) may differ by age, ethnicity and accompanied diseases. Previous studies were generally conducted in Western adult patients with type 2 diabetes mellitus (T2DM), and it is uncertain whether pancreatic beta-cell function is associated with MA and GFR in Chinese community-dwelling middle-aged and elderly population without T2DM. We therefore examined the relationships of pancreatic beta-cell function with two indices of renal damage, MA and GFR, in Chinese community-dwelling middle-aged and elderly population without T2DM.

METHODS

This analysis focused on 380 Beijing residents older than 45 years who were free of T2DM and completed the evaluation of pancreatic beta-cell function.

RESULTS

Median age was 67 (49-80) years. Levels of triglyceride, diastolic blood pressure and homeostasis model assessment-beta (HOMA-beta) index were positively related to urine microalbumin (P<0.05 for all). Age, low-density lipoprotein cholesterol levels and HOMA-beta index were inversely correlated with GFR, while high-density lipoprotein cholesterol levels were positively correlated with GFR (P<0.05 for all). In all three adjustment models, there was a significant positive association between HOMA-beta index and MA; subjects with higher beta-cell function had higher odds of MA (P<0.05 for all). There was no association between HOMA-beta index and GFR <60 mL/min/1.73 m² in any model (P>0.05 for all).

CONCLUSION

Modeling the pancreatic beta-cell function with different adjusted variables provided the same conclusion of association with MA; beta-cell function was positively associated with MA. Additionally, there was a specific difference in the adjusted associations of pancreatic beta-cell function with MA and GFR <60 mL/min/1.73 m²; beta-cell function was not independently associated with GFR <60 mL/min/1.73 m². This result indicated that abnormal pancreatic beta-cell function plays an important role in the development of MA.

Contribution of serum adipocyte fatty acid-binding protein levels to the presence of microalbuminuria in a Chinese hyperglycemic population

AIMS/INTRODUCTION

Individuals with type 2 diabetes mellitus are vulnerable to micro- and macrovascular complications in the presence of microalbuminuria. Adipocyte fatty acid-binding protein (A-FABP) was proposed as an indicator for albuminuria in patients with diabetes. The present study aimed to explore the associations between serum A-FABP levels and microalbuminuria in the hyperglycemic population.

MATERIALS AND METHODS

Serum A-FABP levels were detected using sandwich enzyme-linked immunosorbent assay. Microalbuminuria was identified by urinary albumin-to-creatinine ratio (UACR), when the value was between 30-300 mg/g. The participants were divided into the subgroups based on sex and the status of impaired glucose regulation or newly diagnosed type 2 diabetes mellitus.

RESULTS

A total of 939 participants, consisting of 436 men and 503 women, were enrolled. Serum levels of A-FABP were much higher in participants with microalbuminuria than those without microalbuminuria. This result held true for all subgroups (all P < 0.05). For Spearman's correlation analyses, serum A-FABP levels showed a positive relationship with the UACR in men and women (both P < 0.01). Multiple stepwise regression analysis showed that serum A-FABP levels were independently and positively correlated with UACR in both sexes (men: standardized β = 0.256, P < 0.001; women: standardized β = 0.155, P = 0.001). This relationship remained significant in every subgroup (all P < 0.01).

CONCLUSIONS

For hyperglycemic individuals, serum A-FABP levels increased in the presence of microalbuminuria. Serum A-FABP levels were identified as an independent factor positively associated with the UACR.

DBA2J db/db mice are susceptible to early albuminuria and glomerulosclerosis that correlate with systemic insulin resistance

Diabetic nephropathy (DN) is the leading cause of kidney failure in the world. To understand important mechanisms underlying this condition, and to develop new therapies, good animal models are required. In mouse models of type 1 diabetes, the DBA/2J strain has been shown to be more susceptible to develop kidney disease than other common strains. We hypothesized this would also be the case in type 2 diabetes. We studied db/db and wild-type (wt) DBA/2J mice and compared these with the db/db BLKS/J mouse, which is currently the most widely used type 2 DN model. Mice were analyzed from age 6 to 12 wk for systemic insulin resistance, albuminuria, and glomerular histopathological and ultrastructural changes. Body weight and nonfasted blood glucose were increased by 8 wk in both genders, while systemic insulin resistance commenced by 6 wk in female and 8 wk in male db/db DBA/2J mice. The urinary albumin-to-creatinine ratio (ACR) was closely linked to systemic insulin resistance in both sexes and was increased ~50-fold by 12 wk of age in the db/db DBA/2J cohort. Glomerulosclerosis, foot process effacement, and glomerular basement membrane thickening were observed at 12 wk of age in db/db DBA/2J mice. Compared with db/db BLKS/J mice, db/db DBA/2J mice had significantly increased levels of urinary ACR, but similar glomerular histopathological and ultrastructural changes. The db/db DBA/2J mouse is a robust model of early-stage albuminuric DN, and its levels of albuminuria correlate closely with systemic insulin resistance. This mouse model will be helpful in defining early mechanisms of DN and ultimately the development of novel therapies.

Microalbuminuria predicts the recurrence of cardiovascular events in patients with essential hypertension

OBJECTIVES

Microalbuminuria (MAU) is associated with an enhanced risk of cardiovascular events. The prevalence of MAU and its prognostic impact has an important role in the stratification of cardiovascular risk in patients with essential hypertension. This is an observational, prospective study performed by 13 general practitioners aiming at assessing the prevalence and prognostic relevance of MAU in essential hypertension.

METHODS

Patients with essential hypertension and with recent determination of MAU were enrolled into the study by general practitioners, and were followed up for 3 years. Primary end point was the occurrence of major cardiovascular events during the follow-up.

RESULTS

Out of 1024 unselected patients, consecutively enrolled from January 2009 to March 2010, 804 completed the 3-year follow-up. Patients were categorized into two groups according to the absence (n = 523, 65%) or presence (n = 281, 35%) of MAU. During the follow-up, 41 cardiovascular events (1.69 events/100 patient-years) were reported. The presence of MAU was not associated with increased risk of cardiovascular events (adjusted hazard ratio = 1.32; 95% confidence interval 0.290-4.340, P = 0.097). When the analysis was restricted to the patients with previous cardiovascular event, MAU (adjusted hazard ratio = 2.18; 95% confidence interval 0.42-2.43, P = 0.031), together with age, metabolic syndrome, diabetes, and smoking, independently predicted the occurrence of cardiovascular events.

CONCLUSION

Presence of MAU in patients with essential hypertension is not associated with increased risks of cardiovascular events. At the variance, in patients with previous cardiovascular events, MAU was found to predict recurrent events. Thus, the assessment of MAU could be considered a useful tool in secondary prevention.

Interleukin-6 gene polymorphisms correlate with the progression of nephropathy in Chinese patients with type 2 diabetes: A prospective cohort study

AIMS

Interleukin-6 (IL-6), an inflammatory cytokine, is considered a candidate gene possibly involved in susceptibility to nephropathy in diabetes. This study aimed to examine whether IL-6 polymorphisms predict the progression of nephropathy in a prospective Chinese cohort of patients with type 2 diabetes.

METHODS

A total of 568 type 2 diabetic patients with normoalbuminuria at baseline were followed up for a mean of 5.3±1.5years. Urinary albumin-to-creatinine ratio (ACR) ⩾30mg/g in two consecutive urine tests were defined as progression to diabetic nephropathy (n=143). Five polymorphisms of IL-6 gene, rs1800795, rs1800796, rs1524107, rs2069837, and rs2069840, were genotyped. Cox proportional hazard models were used to estimate hazard ratio (HR) and 95% CI of progression to diabetic nephropathy under different genetic models.

RESULTS

Almost all patients (99.6%) carried the rs1800795 GG homozygous genotypes. In the Cox proportional models adjusted for multiple covariates, the HR under recessive model was 2.02 for rs1800796 GG (vs. CC+CG, 95% CI: 1.08-3.75, p=0.027), 2.37 for rs2069837 GG (vs. AA+AG, 95% CI: 1.15-4.87, p=0.019), and 2.08 for rs1524107 CC (vs. TT+TC, 95% CI: 1.12-3.89, p=0.021). These associations remained significant for rs1800796 and rs1524107 after correction for multiple testing (α=0.017). Overall, our results suggest that rs1800796 GG and rs1524107 CC homozygous genotypes may confer a greater risk for development of nephropathy in type 2 diabetes.

CONCLUSIONS

IL-6 gene polymorphisms rs1800796 and rs1524107 may serve as predictors of progression of nephropathy in Chinese patients with type 2 diabetes.

The dose-response effect of insulin sensitivity on albuminuria in children according to diabetes type

BACKGROUND

Insulin resistance is associated with microalbuminuria among youth with diabetes mellitus. We sought to determine the dose-response effect of insulin sensitivity (IS) on the magnitude of albuminuria and whether there is a threshold below which urine albumin excretion increases.

METHODS

These analyses included participants from the SEARCH for Diabetes in Youth Study with incident diabetes who completed a baseline study visit (n = 2988). We estimated IS using a validated equation incorporating waist circumference, HbA1C, and fasting serum triglycerides. Multivariate regression analyses were performed to assess the effect of IS on urine albumin creatinine ratio (UACR), stratified by diabetes type. The IS threshold was then determined using segmented regressions within each diabetes type and incorporated into the multivariate model.

RESULTS

There was an association between IS and UACR in type 2 diabetes only (beta = -0.39; p < 0.001). There was strong statistical evidence for a threshold effect of IS score on UACR in the group of youth with type 2 (beta = 0.40; p < 0.001) but not type 1 diabetes (p = 0.3).

CONCLUSIONS

In cross-sectional analyses, there is a negative association between IS and UACR in youth with type 2 but not type 1 diabetes, and this association likely includes a threshold effect of IS on UACR.

12-Lipoxygenase Inhibition on Microalbuminuria in Type-1 and Type-2 Diabetes Is Associated with Changes of Glomerular Angiotensin II Type 1 Receptor Related to Insulin Resistance

(1) BACKGROUND: 12-lipoxygenase (12-LO) is involved in the development of diabetic nephropathy (DN). In the present study, we investigated whether 12-LO inhibition may ameliorate type-2 DN (T2DN) by interfering with insulin resistance (IR); (2) METHODS: Rat glomerular mesangial cells, glomeruli and skeletal muscles were isolated and used in this study. Kidney histological changes were confirmed by periodic-acid Schiff staining; mRNA expression was detected by competitive reverse transcription polymerase chain reaction; and the protein level was determined by Western blot and the enzyme-linked immunosorbent assay, respectively; (3) RESULTS: The inhibition of 12-LO attenuated microalbuminuria (MAU) increases in type-2 diabetic rats, but not in type-1 diabetic rats. Infusion of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) significantly increased the expression of angiotensin II (Ang II) and Ang II type 1 receptor (AT1R), but decreased the expression of AT1R-associated protein (ATRAP) in rat glomeruli, compared to the control. An in vitro study revealed that both 12(S)-HETE and insulin upregulated AT1R expression in rat mesangial cells. In the presence of p38 mitogen-activated protein kinase (MAPK) inhibitor, SB202190, the 12(S)-HETE-induced ATRAP reduction was significantly abolished. Interestingly, 12-LO inhibition did not influence AT1R expression in type-1 diabetic rats, but significantly abolished the increased AT1R and Ang II expression in glomeruli of type-2 diabetic rats. Furthermore, the inhibition of 12-LO significantly corrected impaired insulin sensitivity and fast serum insulin level, as well as the p-AMP-activated protein kinase (AMPK) reduction in skeletal muscle of type-2 diabetic rats; (4) CONCLUSION: The inhibition of 12-LO potentially ameliorated MAU by preventing IR through the downregulation of glomerular AT1R expression in T2DN.

Comparison of Acarbose and Metformin on Albumin Excretion in Patients With Newly Diagnosed Type 2 Diabetes: A Randomized Controlled Trial

Increased urinary albumin excretion in diabetes not only signals nephropathy but also serves as a risk marker for cardiovascular disease. The data of MARCH (Metformin and AcaRbose in Chinese as the initial Hypoglycaemic treatment) trial demonstrated that acarbose and metformin were similarly efficacious at lowering blood glucose and blood pressure, as well as improving insulin sensitivity in Chinese patients newly diagnosed with type 2 diabetes mellitus. The purpose of this study was to identify the effects of acarbose and metformin therapy on albumin excretion in MARCH study.Baseline urine albumin/creatinine ratio (ACR) of 762 newly diagnosed, drug-naïve patients with type 2 diabetes mellitus was measured. Included patients were randomized to receive either acarbose or metformin and followed for 48 weeks. In addition to change in ACR, the estimated glomerular filtration rates (eGFR) and frequency of metabolic syndrome (MetS) were also assessed.Elevated ACR levels (≥30 mg/g) were present at baseline in 21.9% of all participants. A significant decline in urine ACR was observed in both the acarbose and metformin groups at week 24 and 48 (all P < 0.001). The proportion of patients with elevated ACRs was also reduced in both treatment groups at week 24 and 48 compared with baseline values (all P < 0.05). The change in urine ACR at week 48 was significantly greater in patients prescribed acarbose than in those prescribed metformin (P = 0.01). Both acarbose and metformin significantly decreased the frequency of MetS at week 24 and 48 (both P < 0.05). Neither treatment affected eGFR.In sum, both acarbose and metformin decreased urine ACR levels and reduced the frequency of elevated ACR and MetS in Chinese patients with newly diagnosed type 2 diabetes mellitus without affecting eGFR. After 48 weeks' intervention, acarbose therapy resulted in a greater reduction in urine ACR compared with metformin.

Altered serum levels of FGF-23 and magnesium are independent risk factors for an increased albumin-to-creatinine ratio in type 2 diabetics with chronic kidney disease

AIMS

To investigate the role of FGF-23 and magnesium in relation to the albumin-to-creatinine ratio in type 2 diabetics with chronic kidney disease (CKD) stages 2-4.

METHODS

In a cross-sectional study we included all eligible type 2 diabetic patients with CKD stages 2-4, followed in our outpatient Diabetic Kidney clinic. We used descriptive statistics, the Student'st-test, ANOVA and the chi-square tests. Our population was divided according to the UACR (G1 30-300 mg/g and G2≥300 mg/g), and compared these groups regarding several biological and laboratorial parameters. We employed a multiple regression model to identify risk factors of increased UACR.

RESULTS

The patients in G2 displayed a lower eGFR (p=0.0001) and, had lower levels of magnesium (p=0.004) as well as higher levels of FGF-23 (p=0.043) compared to patients in G1. FGF-23 (β=0.562, P=0.0001) and the magnesium (β=- 8.916, p=0.0001) were associated with increased UACR.

CONCLUSIONS

A dysregulation of mineral metabolism, reflected by altered levels of magnesium and FGF-23, correlates with an increased UACR in type 2 diabetic patients with CKD stages 2-4.

Diabetic Kidney Disease in Adolescents With Type 2 Diabetes: New Insights and Potential Therapies

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD) and dialysis in the Western world. Early DKD, including microalbuminuria and renal hyperfiltration, is common in adolescents with type 2 diabetes (T2D). Furthermore, youth-onset T2D carries a higher risk of progressive DKD than adult-onset T2D of similar diabetes duration. DKD is characterized by a long clinically silent period without signs of disease. Therefore, a major challenge in preventing DKD is the difficulty in identifying high-risk T2D patients at an early stage. The Type 2 Diabetes in Adolescents and Youth (TODAY) study demonstrated a high initial prevalence that increased over time, irrespective of treatment arm. This key observation underscores the importance of discovering new therapeutic targets to supplement conventional management, in order to reduce DKD risk. In this review, we focus on early DKD in T2D and summarize potential novel biomarkers and therapeutic targets.

The Association between Obstructive Sleep Apnea on Diabetic Kidney Disease: A Systematic Review and Meta-Analysis

STUDY OBJECTIVE

This systematic review aims to investigate the association between obstructive sleep apnea (OSA) and diabetic kidney disease (DKD).

METHODS

MeSH terms and free text searches were performed on MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception to April 2015. Zetoc and OpenGrey databases were queried for grey literature, and lastly, hand searches were carried out. Study selection and quality assessment were conducted by two authors. One author carried out data extraction, which was checked by other authors. The relationships between apneahypopnea index (AHI), oxygen desaturation index (ODI), time spent under 90% oxygen saturation (%TST < 90), and minimum and mean oxygen saturation (O2) on DKD were examined.

RESULTS

Two longitudinal and ten cross-sectional studies were included for our narrative synthesis, and seven studies for meta-analysis. Studies that performed multi-variable analysis demonstrated significant associations between OSA (assessed using either apnea-hypopnea index or ODI) and DKD in type 2 diabetes mellitus (T2DM). This was confirmed by meta-analysis (pooled OR 1.73, 95% CI: 1.13-2.64). There was some evidence to suggest that %TST < 90 may have an association with DKD. There was insufficient evidence to conclude on the relationship between minimum and mean oxygen saturation on DKD. There was no evidence available on the associations between OSA and other respiratory parameters in type 1 diabetes mellitus populations.

CONCLUSIONS

There is moderate evidence that OSA is associated with DKD in patients with T2DM. Large prospective studies with long-term follow up are needed to assess the possible bi-directional mechanisms between OSA and DKD.

Associations of pancreatic β-cell function and insulin resistance with microalbuminuria in type 2 diabetes

We investigate the relationships of pancreatic β-cell function and insulin resistance with microalbuminuria in a cross-sectional study of patients with type 2 diabetes. The study suggests insulin resistance is associated with an increased prevalence of microalbuminuria, while improved pancreatic β-cell function is linked to decreased rates of microalbuminuria for those patients.

Factors associated with no apparent coronary artery disease in patients with type 2 diabetes mellitus for more than 10 years of duration: a case control study

BACKGROUND

Type 2 diabetes mellitus is an important risk factor in the development of coronary artery disease (CAD) and is often associated with severe disease. However, this risk is not uniform, some patients remain free of CAD even after many years of treatment for diabetes. The present study was aimed to identify the factors that are associated with a favorable CAD profile.

METHODS

A case-control study of 76 patients with type 2 diabetes mellitus who were on treatment for more than 10 years duration and undergoing a coronary angiogram for the evaluation of clinically suspected CAD at a tertiary care hospital were recruited for the study. The presence and absence of significant CAD was determined after a coronary angiogram. Clinical history, and anthropometric and biochemical parameters were analyzed. Insulin resistance was determined by the Homeostasis Model Assessment. Multiple logistic regressions were done to find out the factors associated for a favorable CAD profile.

RESULTS

The difference in HOMA-IR (2.37 ± 0.69 VS 3.77 ± 1.64, p < 0.001) and urine microalbumin (24.15 ± 32.16 VS 82.72 ± 117.70, p = 0.004) were found to be statistically significant among those who did not have CAD when compared to those who had CAD. The difference in lipid profile, HbA1C, fasting blood sugar, BMI, waist hip ratio, waist and hip circumference was not significant. The adjusted odds ratio for insulin resistance less than 2.5 (OR 9.09, 95 % CI 1.91-41.83, p = 0.005), females (OR 7.91, 95% CI 1.55-40.38, p = 0.013) and microalbumin <20 mg/l (OR 4.57, 95% CI 1.17-17.85, p = 0.029) were independently associated with normal coronaries. The adjusted odds ratio for lipid profile, BMI, blood pressure and HbA1C were not significant.

CONCLUSIONS

HOMA-IR less than 2.5, microalbuminuria less than 20 mg/l and females are the factors appear to be associated with no apparent CAD.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Insulin resistance is associated with the development of albuminuria in Korean subjects without diabetes

Previous studies have shown that insulin resistance is associated with the development of albuminuria. However, most studies are done on a background of diabetes or metabolic syndrome and there is little data from general population. The aim of this study is to define the effect of insulin resistance on the development of albuminuria in healthy individuals without diabetes. We analyzed 60,047 participants without baseline diabetes or chronic kidney disease, who underwent at least two health maintenance visits at a 2-year interval between 2002 and 2009 at a tertiary hospital in Korea. We measured the incidence of albuminuria at the second examination and calculated the odds ratio for the development of albuminuria according to the quintile of the homeostasis model assessment of insulin resistance (HOMA-IR). After 2 years, 880 cases of incident albuminuria were observed. The cumulative incidences of albuminuria were 1.08, 1.50, 1.35, 1.47, and 1.92% for the 1st to 5th quintiles of HOMA-IR. On multivariate logistic analysis, the odds ratios for incident albuminuria compared to those in the 1st quintile were 1.38 (95% CI 1.10-1.73; P=0.006), 1.23 (95% CI 0.97-1.55; P=0.087), 1.32 (95% CI 1.04-1.67; P=0.020), and 1.66 (95% CI 1.31-2.09; P<0.001) in the 2nd, 3rd, 4th, and 5th quintiles, respectively. A high level of insulin resistance assessed with HOMA-IR was associated with the development of albuminuria in relatively healthy subjects without diabetes. Further research is needed to verify the role of insulin resistance in the development of albuminuria and renal injury.

Increased prevalence of albuminuria in individuals with higher range of impaired fasting glucose: the 2011 Korea National Health and Nutrition Examination Survey

AIMS

We investigated the prevalence of albuminuria across a range of fasting plasma glucose (FPG), including normal fasting glucose (NFG), impaired fasting glucose (IFG), and diabetes.

METHODS

A total of 5202 subjects who participated in the fifth Korea National Health and Nutrition Examination Survey were enrolled. Spot urine samples were taken and the albumin-creatinine ratio was calculated for each patient. Subjects were divided into five groups according to FPG levels: <5.0 (NFG1, n=1,905), 5.0-5.5 (NFG2, n=1,784), 5.6-6.0 (IFG1, n=727), 6.1-6.9 (IFG2, n=268), and ≥7.0 (diabetes, n=518) mmol/L. Analysis of covariance tests and logistic regression were used.

RESULTS

The rates of albuminuria were 4.1%, 6.0%, 7.6%, 12.3%, and 23.4% in the NFG1, NFG2, IFG1, IFG2 and diabetes groups, respectively (P<0.01 for the trend). The rate of albuminuria in the IFG2 group was significantly higher than in the IFG1 group, even after adjustment for age, gender, hypertension, and obesity. The odds ratio for the presence of albuminuria in the IFG2 group was 1.87 (95% CI, 1.19-2.94), using the NFG1 group as a control in logistic regression analyses.

CONCLUSIONS

Albuminuria is more prevalent in subjects in the higher range of IFG. Therefore, strategies to reduce albuminuria should be emphasized especially in these subjects.