Insulin resistance, hyperinsulinemia, and renal injury: mechanisms and implications

Association between the combination of the triglyceride-glucose index and obesity-related indices with hyperuricemia among children and adolescents in China

BACKGROUND

The prevalence of hyperuricemia (HUA) among Chinese children and adolescents is a significant public health concern. Triglyceride-glucose (TyG) is recognized as a reliable biomarker in predicting insulin resistance, a condition associated with various metabolic disorders. Nevertheless, research on the association between TyG and its obesity-related indices with HUA among children and adolescents in China is limited.

METHODS

This study utilized data from the 2017 Chinese National Nutrition and Health Surveillance of Children and Lactating Mothers. TyG, TyG-BMI, TyG-WC, and TyG-WHtR were calculated based on participants' fasting blood glucose, triglycerides, and measured height, weight, and waist circumference. Multivariable logistic regressions were used to assess the relationships between TyG and its obesity-related indices with HUA in children and adolescents. Receiver Operating Characteristic curves were constructed to compare the predictive power of these indicators. Furthermore, we conducted a stratified analysis based on sex and age. Restricted cubic spline curves were used to illustrate the dose-response relationship of TyG, TyG-BMI, TyG-WC, and TyG-WHtR with HUA in children and adolescents. The sensitivity analysis included 1:1 propensity score matching with a caliper value of 0.02 and adjustments to the diagnostic criteria for HUA.

RESULTS

After adjusting for all covariables, multivariable logistic regression analysis indicated that the fourth quartiles of TyG (OR: 1.33, 95% CI: 1.14-1.54, P < 0.001), TyG-BMI (OR: 1.43, 95% CI: 1.14-1.79, P = 0.002), TyG-WC (OR: 1.76, 95% CI: 1.42-2.19, P < 0.001), and TyG-WHtR (OR: 1.92, 95% CI: 1.66-2.21, P < 0.001) were significantly associated with higher odds of HUA, compared to the lowest quartile. Stratified analyses identified a significant interaction between sex and TyG-BMI, TyG-WC, and TyG-WHtR. Compared to the first quartile, the highest quartile of TyG-BMI, TyG-WC and TyG-WHtR among male participants exhibited a stronger association with HUA(Male: TyG-BMI: OR = 1.82, 95%CI: 1.28-2.59; TyG-WC: OR = 1.87, 95%CI: 1.31-2.67; TyG-WHtR: OR = 2.07, 95%CI: 1.68-2.54).

CONCLUSIONS

This study identified a significant association between TyG and related obesity indices with HUA in children and adolescents in China. Furthermore, stronger associations of TyG-BMI, TyG-WC, and TyG-WHtR with HUA were observed, particularly in males.

Association of Obesity, Visceral Fat Accumulation, and Dyslipidemia with the Risk of Chronic Kidney Disease

Objective Although chronic kidney disease (CKD) is independently associated with hypertension or hyperglycemia, there is no consensus on the thresholds of obesity, dyslipidemia, or visceral fat accumulation to predict CKD onset and progression. Methods We performed a multivariable logistic regression analysis for the association of the subsequent rate of estimated glomerular filtration rate (eGFR) decline with body mass index (BMI), blood high-density lipoprotein (HDL) cholesterol and triglycerides (TG) levels on 308,174 subjects who underwent health examinations conducted by the Public Health Research Center Foundation from 2015 to 2022. In addition, a Poisson regression analysis was used to evaluate the association between the appearance of urinary protein in participants without baseline urinary protein levels and eGFR decline. Results The median age of the subjects was 46 years old, and the median observation period was approximately 3 years. An eGFR decline rate of ≥5%/year was significantly associated with low HDL-cholesterol levels (<40 mg/dL), independent of the BMI and TG levels. A high baseline BMI (≥25 kg/m2) or waist circumference (≥85 cm for men and ≥90 cm for women), high TG levels (≥150 mg/dL), and low HDL-cholesterol levels were significantly associated with new-onset proteinuria. Furthermore, the higher the baseline BMI, the higher the incidence rate ratio of new-onset proteinuria. Conclusion Independent of hyperglycemia and hypertension, dyslipidemia according to the Japanese metabolic syndrome criteria and an elevated BMI were associated with a high risk of new-onset proteinuria, and a low HDL-cholesterol level was significantly associated with a rapid eGFR decline.

Predictive risk factors for early-stage renal dysfunction: An analysis of specific health checkup data for the general Japanese population

BACKGROUND AND AIMS

Early prevention of chronic kidney disease is critical. We aimed to identify predictive risk factors for early-stage renal dysfunction.

METHODS AND RESULTS

This retrospective study analyzed specific health checkup data from the general Japanese population. We included 1385 adults who underwent a specific health checkup in 2013 and 2019 and had an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 in 2013. The composite endpoint was the progression of renal dysfunction for 6 years, including doubling of serum creatinine levels, ≥30 % decline in eGFR, and ≥30 % increase in the urine albumin-to-creatinine ratio (UACR) for individuals with UACR ≥30 mg/gCre at baseline or progression to ≥30 mg/gCre for those with UACR <30 mg/gCre at baseline. Participants were categorized into groups with and without progression of renal dysfunction. Univariate analysis of health checkup data and questionnaire data collected in 2013 was conducted, followed by multiple logistic regression analyses. Significant between-group differences were observed in age, body weight, body mass index (BMI), waist circumference, medication for hypertension and hyperlipidemia, systolic and diastolic blood pressure, high-density lipoprotein cholesterol, diabetes, glycated hemoglobin (HbA1c), urine glucose qualitative, UACR, urine protein-to-creatinine ratio, current smoking, weight gain, and walking habits. Logistic regression analysis showed that BMI (odds ratio [95 % confidence interval]: 1.14 [1.07-1.24], P < 0.001), HbA1c (1.57 [1.24-1.98], P < 0.001), and walking habits (0.51 [0.33-0.80], P = 0.003) were significantly associated with renal dysfunction progression.

CONCLUSIONS

Higher BMI and HbA1c and lower walking habits were associated with early-stage renal dysfunction, even in the general population.

Ultra-processed foods and risk of declined renal function: a dose-response meta-analysis of 786,216 participants

OBJECTIVES

Earlier investigations have documented an association between elevated consumption of Ultra-Processed Foods (UPFs) and adverse renal outcomes. To explore this relationship further, we executed a comprehensive dose-response meta-analysis to examine the link between UPFs intake and the risk of declined renal function.

SETTING

A systematic search was completed utilizing the ISI Web of Science, Scopus, Embase as well as PubMed/MEDLINE databases (without any restrictions), up until September 5, 2024. Effect sizes of declined renal function were recalculated by applying a random effects model. The GRADE tool was adopted to assess the certainty of the evidence, while study quality and potential publication bias were examined via validated methods such as the Newcastle-Ottawa Scale, Egger's regression asymmetry and Begg's rank correlation test.

RESULTS

Thirty-three studies (comprising 786,216 participants) were incorporated in the quantitative analysis. The results demonstrated that a greater UPFs intake was significantly associated with an enhanced risk of declined renal function (RR = 1.16; 95% CI: 1.09, 1.23; I2 = 68.8%; p < 0.001; n = 37). Additionally, we observed that each 1-serving-per-day increase in UPFs consumption was associated to a 5% greater risk of reduced renal function (RR = 1.05; 95% CI: 1.02, 1.09; I2 = 80.9%; p = 0.013; n = 9). A positive, linear association between UPF intake and the risk of declined renal function (Pnonlinearity = 0.107, Pdose-response < 0.001) was further displayed in the non-linear dose-response analysis.

CONCLUSION

Greater exposure to UPFs is positively associated with the risk of declined renal function. The information emphasizes the importance of considering UPFs in the prevention and management of adverse renal outcomes.

Association between triglyceride-glucose related indices and all-cause and cardiovascular mortality among the population with cardiovascular-kidney-metabolic syndrome stage 0-3: a cohort study

BACKGROUND

Cardiovascular-Kidney-Metabolic (CKM) syndrome typically commences with the interaction of insulin resistance (IR), excessive or dysfunctional obesity, and the consequent systemic inflammatory response and oxidative stress. The relationship between the triglyceride-glucose (TyG) index and TyG-related indices that may simply assess IR and obesity, as well as the mortality risk in the CKM syndrome population, remains ambiguous.

METHODS

This study included 6,383 participants from the National Health and Nutrition Examination Survey (NHANES) 2009-2018. The TyG index, TyG-waist-to-height ratio (TyG-WHtR), TyG-waist circumference (TyG-WC), and TyG-body mass index (TyG-BMI) were developed. Cox proportional hazards models, smooth curve fitting, and two-stage Cox proportional hazards models were employed to examine the association of TyG and TyG-related indices with all-cause and cardiovascular mortality in the CKM syndrome population. Subgroup analyses and interaction tests were conducted to evaluate the risk within various demographics.

RESULTS

In survey-weighted multifactorial regression analyses, a significant positive association existed between TyG, TyG-related indices, and both all-cause mortality and cardiovascular mortality, except for the TyG index, which did not demonstrate a significant link with all-cause mortality. Of these indices, the TyG-WC index exhibited the strongest correlation with all-cause mortality, with a hazard ratio (HR) of 1.50 and a 95% confidence interval (CI) of 1.18-1.92, followed by the TyG-WHtR index (HR: 1.45, 95%CI 1.13-1.85). The TyG-WHtR index demonstrated the strongest correlation with cardiovascular mortality (HR: 1.85, 95% CI 1.19-2.86), followed by the TyG-WC index(HR: 1.83, 95%CI 1.21-2.78). An L-shaped association was identified between TyG-WHtR, TyG-BMI, and all-cause mortality in CKM syndrome during the examination of nonlinear relationships (both P for log-likelihood ratio < 0.05). The TyG-WHtR, TyG-WC, and TyG-BMI indices exhibited a more pronounced correlation with all-cause mortality in those with CKM syndrome stages 1 and 3 (P value < 0.05, P for interaction < 0.05).

CONCLUSION

Our study emphasizes the association between TyG and TyG-related indices and mortality in individuals with CKM syndrome stages 0-3. Individuals with CKM syndrome stages 1 and 3 should be more vigilant to abnormal alterations in TyG-related indices.

The effect of the endothelin receptor antagonist atrasentan on insulin resistance in phenotypic clusters of patients with type 2 diabetes and chronic kidney disease

AIMS

Type 2 diabetes (T2D) patients with a clinical phenotype characterized by a high degree of insulin resistance are at increased risk of chronic kidney disease (CKD). We previously demonstrated that the endothelin receptor antagonist (ERA) atrasentan reduced insulin resistance in T2D. In this study, we compared the effect of atrasentan on insulin resistance across different phenotypic clusters of patients with T2D.

MATERIALS AND METHODS

We performed a post hoc analysis of the SONAR trial, a randomized, placebo-controlled trial of the ERA atrasentan in patients with T2D and CKD. Patients were stratified into four previously identified phenotypic clusters: severe insulin-deficient diabetes (SIDD), severe insulin-resistant diabetes (SIRD), mild obesity-related diabetes (MOD) and mild age-related diabetes (MARD). Changes in insulin resistance, assessed by HOMA-IR, were compared between the phenotypic clusters using a mixed effects model.

RESULTS

In total, 931 patients were included in the analysis. In the overall population, atrasentan compared to placebo reduced HOMA-IR by 12.9% [95%CI 3.5,21.4]. This effect of atrasentan was more pronounced in clusters characterized by insulin resistance or deficiency: (SIRD cluster 26.2% [95% CI 3.8,43.3] and SIDD cluster 18.5% [95%CI -3.8,35.9]), although the latter did not reach statistical significance. The effect of atrasentan compared to placebo was less pronounced in the other two clusters (MARD 12.2% [95% CI -1.7,24.12] and MOD -5.3% [95% CI -28.9,13.9]).

CONCLUSIONS

Atrasentan significantly improved insulin sensitivity in patients with T2D and CKD, especially in those characterized by high insulin resistance (SIRD cluster). Further studies are warranted to investigate the long-term clinical outcomes of atrasentan treatment in these distinct phenotypic clusters.

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.

Diabetes and its Silent Partner: A Critical Review of Hyperinsulinemia and its Complications

In this complex realm of diabetes, hyperinsulinemia is no longer regarded as just a compensatory response to insulin resistance but rather has evolved into an integral feature. This comprehensive review provides a synthesis of the current literature, including various aspects associated with hyperinsulinemia in diabetic complications. Hyperinsulinemia has been shown to be more than just a compensatory mechanism, and the key findings demonstrate how hyperinsulinism affects the development of cardiovascular events as well as microvascular complications. Additionally, recognizing hyperinsulinemia as a modifiable factor, the diabetes management paradigm shifts towards cognitive ones that consider the use of lifestyle modifications in combination with newer pharmacotherapies and precision medicine approaches. These findings have crucial implications for the clinical work, requiring a careful appreciation of hyperinsulinemia's changing aspects as well as incorporation in personalized treatment protocol. In addition, the review focuses on bigger issues related to public health, showing that prevention and early diagnosis will help reduce the burden of complications. Research implications favor longitudinal studies, biomarker discovery, and the study of emerging treatment modalities; clinical practice should adopt global evaluations, patient education, and precision medicine adaptation. Finally, this critical review provides an overview of the underlying processes of hyperinsulinemia in diabetes and its overall health effects.

Vitamin B1 and calcitriol enhance glibenclamide suppression of diabetic nephropathy: Role of HMGB1/TLR4/NF-κB/TNF-α/Nrf2/α-SMA trajectories

Glibenclamide is one of the most prescribed insulin secretagogues in diabetes due to its low cost, but its efficacy on suppressing diabetic complications is limited. Here, we examine whether addition of either vitamin B1 or calcitriol to glibenclamide could produce more suppression of diabetic nephropathy. Type 2 diabetes was induced by high fructose (10 % in drinking water), high salt (3 % in diet), and high fat diet (25 % in diet) for 3 weeks, followed by single dose of STZ (40 mg/kg, i.p.). Diabetic rats were treated with either glibenclamide (0.6 mg/kg), vitamin B1 (70 mg/kg), glibenclamide/vitamin B1, calcitriol (0.1 μg/kg), or glibenclamide/calcitriol. Addition of either vitamin B1 or calcitriol to glibenclamide therapy enabled more suppression of diabetic nephropathy development as evidenced by more preserved creatinine clearance and less renal damage scores. Combination therapy resulted in mild enhancement in the effect of glibenclamide on glucose tolerance without affecting the area under the curve. Combination therapy was associated with more suppression of inflammatory cascades as evidenced by reducing the expression of high mobility group box-1 (HMGB1), toll-like receptor-4 (TLR4), nuclear factor-kappa B (NF-κB), and tumor necrosis factor-α (TNF-α). In addition, combination therapy enhanced the antioxidant mechanisms as evidenced by increased expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione content and reducing malondialdehyde and nitric oxide levels. Furthermore, combination therapy provided more suppression of fibrotic pathways as appear from reducing collagen deposition and the expression of α- smooth muscle actin (α-SMA). In conclusion, addition of vitamin B1 or calcitriol to glibenclamide therapy can enhance the therapeutic efficiency of glibenclamide in suppressing diabetic nephropathy progression to the same extend, the protective effect is mediated through modulating HMGB1/TLR4/NF-κB/TNF-α/Nrf2/α-SMA trajectories.

New Markers of Early Kidney Damage in Children and Adolescents with Simple Obesity

The impact of obesity on kidney injury and the development of chronic kidney disease (CKD) is well documented. Unfortunately, the early stages of CKD are asymptomatic, leading to a delayed diagnosis and a worse prognosis. There is a need for more sensitive indicators of kidney damage than those currently used. We aimed to assess the usefulness of serum t-CAF, urinary netrin-1, α-GST, π-GST, calbindin, and calprotectin as biomarkers of early kidney damage in obese children and to investigate the relationship between these indicators and the degree of obesity. A total of 125 simple obese, normoalbuminuric children and 33 non-obese children as controls were selected. Patients were divided into 2 subgroups according to SDS BMI (I: 2 ≤ 4, II: >4). Serum t-CAF was significantly higher in the obese group compared to the controls, as were urinary α-GST, netrin-1, π-GST, and calprotectin. No difference was found between the two obese groups. In normoalbuminuric obese children and adolescents without significant metabolic disorders, serum t-CAF may be a new biomarker for the early detection of renal dysfunction, and urinary netrin-1, α-GST, π-GST, and calprotectin may be better indicators for the detection of early tubular damage, independent of the severity of obesity.

Association of obesity severity and duration with incidence of chronic kidney disease

INTRODUCTION

Obesity is a known risk factor for chronic kidney disease (CKD), but the impact of obesity severity and duration on CKD incidence is unclear.

METHODS

Cumulative Excess Weight (CEW) and Cumulative Excess Waist Circumference (CEWC) scores were calculated, which represent the accumulation of deviations from expected body mass index and waist circumference values over time until the development of CKD or the end of the follow-up period. Time-dependent Cox models were used to investigate the sex-stratified association of CEW and CEWC with CKD incidence while controlling for confounding variables.

RESULTS

Out of the 8697 participants who were evaluated in this study, 56% (4865) were women and the mean age was 40 ± 14. During the 15-year follow-up period, 41.7% (3629) of the participants developed CKD. Among the CKD patients, 65.4% (829) of men and 77.9% (1839) of women had a BMI higher than 25, and high WC was found to be 73.7% (934) and 55.3% (1306) for men and women, respectively. We found a significant association between one standard deviation change of CEW and the development of CKD in both sexes (fully adjusted hazard ratios and 95% CI of CEW in men and women were 1.155 [1.081-1.232) and 1.105 (1.047-1.167)]. However, the association between CEWC and CKD development was only significant among men participants [HR = 1.074 (1.006-1.147)].

CONCLUSION

Over a 15-year follow-up, the accumulation of general and central obesity was associated with an increased incidence of CKD development.

Association between insulin resistance and vascular damage in an adult population in China: a cross-sectional study

There is a relative scarcity of large-scale population studies investigating the relationship between the insulin resistance index of homeostasis model assessment (HOMA-IR) and vascular damage. Therefore, we assessed the association between HOMA-IR and vascular damage in adults aged 18 years and older in China. A total of 17,985 research subjects were included. Vascular damage markers and relevant laboratory tests were measured. HOMA-IR was calculated as (fasting insulin * fasting blood glucose)/22.5. Vascular damage included arteriosclerosis (ba-PWV > 1800 cm/s), peripheral artery disease (ABI < 0.9), and microalbuminuria (UACR > 30 mg/g). The relationship between HOMA-IR and vascular damage was analyzed using the RCS. The restricted cubic spline (RCS) analysis suggested that HOMA-IR was nonlinearly associated with arteriosclerosis (P for no-liner < 0.01), peripheral artery disease (P for no-liner < 0.01), and microalbuminuria (P for no-liner < 0.01). Further segmented regression analyses revealed that in study subjects with HOMA-IR < 5, we found that HOMA-IR was associated with an increased OR for arteriosclerosis (OR: 1.36, 95% CI (1.28, 1.45), P < 0.01), peripheral artery disease (OR: 1.33, 95% CI (1.10, 1.60), P < 0.01) and microalbuminuria (OR: 1.59, 95% CI (1.49, 1.70), P < 0.01). HOMA-IR is an independent risk factor for vascular damage, both macrovascular and microvascular. The phenomenon of saturation of HOMA-IR with vascular damage needs further investigation.

The association between Chinese visceral adiposity index and cardiometabolic multimorbidity among Chinese middle-aged and older adults: a national cohort study

Objective

This study aimed to explore the association between the Chinese visceral adiposity index (CVAI) and cardiometabolic multimorbidity in middle-aged and older Chinese adults.

Methods

The data used in this study were obtained from a national cohort, the China Health and Retirement Longitudinal Study (CHARLS, 2011-2018 wave). The CVAI was measured using previously validated biomarker estimation formulas, which included sex, age, body mass index, waist circumference, triglycerides, and high-density lipoprotein cholesterol. The presence of two or more of these cardiometabolic diseases (diabetes, heart disease, and stroke) is considered as cardiometabolic multimorbidity. We used Cox proportional hazard regression models to examine the association between CVAI and cardiometabolic multimorbidity, adjusting for a set of covariates. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used to show the strength of the associations. We also conducted a subgroup analysis between age and sex, as well as two sensitivity analyses. Receiver operator characteristic curves (ROC) were used to test the predictive capabilities and cutoff value of the CVAI for cardiometabolic multimorbidity.

Results

A total of 9028 participants were included in the final analysis, with a mean age of 59.3 years (standard deviation: 9.3) and women accounting for 53.7% of the sample population. In the fully-adjusted model, compared with participants in the Q1 of CVAI, the Q3 (HR = 2.203, 95% CI = 1.039 - 3.774) and Q4 of CVAI (HR = 3.547, 95% CI = 2.100 - 5.992) were associated with an increased risk of cardiometabolic multimorbidity. There was no evidence of an interaction between the CVAI quartiles and sex or age in association with cardiometabolic multimorbidity (P >0.05). The results of both sensitivity analyses suggested that the association between CVAI and cardiometabolic multimorbidity was robust. In addition, the area under ROC and ideal cutoff value for CVAI prediction of cardiometabolic multimorbidity were 0.685 (95% CI = 0.649-0.722) and 121.388.

Conclusion

The CVAI is a valid biomarker with good predictive capability for cardiometabolic multimorbidity and can be used by primary healthcare organizations in the future for early warning, prevention, and intervention with regard to cardiometabolic multimorbidity.

Metabolic health's central role in chronic kidney disease progression: a 20-year study of obesity-metabolic phenotype transitions

This study investigates the risk of chronic kidney disease (CKD) across four metabolic phenotypes: Metabolically Healthy-No Obesity (MH-NO), Metabolically Unhealthy-No obesity (MU-NO), Metabolically Healthy-Obesity (MH-O), and Metabolically Unhealthy-Obesity (MU-O). Data from the Tehran Lipid and Glucose Study, collected from 1999 to 2020, were used to categorize participants based on a BMI ≥ 30 kg/m2 and metabolic health status, defined by the presence of three or four of the following components: high blood pressure, elevated triglycerides, low high-density lipoprotein, and high fasting blood sugar. CKD, characterized by a glomerular filtration rate < 60 ml/min/1.72 m2. The hazard ratio (HR) of CKD risk was evaluated using Cox proportional hazard models. The study included 8731 participants, with an average age of 39.93 years, and identified 734 incidents of CKD. After adjusting for covariates, the MU-O group demonstrated the highest risk of CKD progression (HR 1.42-1.87), followed by the MU-NO group (HR 1.33-1.67), and the MH-O group (HR 1.18-1.54). Persistent MU-NO and MU-O posed the highest CKD risk compared to transitional states, highlighting the significance of exposure during early adulthood. These findings emphasize the independent contributions of excess weight and metabolic health, along with its components, to CKD risk. Therefore, preventive strategies should prioritize interventions during early-adulthood.

Hepatitis C virus antibody seropositivity is associated with albuminuria but not peripheral artery disease in patients with type 2 diabetes

Hepatitis C virus (HCV) infection is prevalent in patients with type 2 diabetes mellitus (DM). We aimed to investigate whether HCV antibody (Ab) seropositivity is associated with diabetic micro- and macro-vascular diseases. In this hospital-based cross-sectional study, we retrospectively collected data from patients who participated in the diabetes pay-for-performance program and underwent HCV Ab screening in the annual comprehensive assessment between January 2021 and March 2022. We examined the relationships of HCV Ab seropositivity with the spot urinary albumin-to-creatinine ratio (UACR) and ankle-brachial index (ABI) in patients aged ≥ 50 years with type 2 DM. A total of 1758 patients were enrolled, and 85 (4.83%) of the enrolled patients had HCV Ab seropositivity. Multivariable regression analyses revealed that albuminuria showed a dose-dependent association with HCV Ab seropositivity (UACR [30-299 mg/g]: odds ratio [OR] = 1.463, 95% confidence interval [CI] 0.872‒2.456); UACR [≥ 300 mg/g]: OR = 2.300, 95% CI 1.160‒4.562; P for trend = 0.015) when compared with normal albuminuria (UACR < 30 mg/g). However, the proportion of patients with peripheral arterial disease, defined as an ABI ≤ 0.9, was not significantly different between the groups with and without HCV Ab seropositivity (3.5% vs. 3.9%, P = 0.999). In conclusion, severely increased albuminuria, but not the ABI, showed a significant association with HCV Ab seropositivity in patients aged ≥ 50 years with type 2 DM.

Predictors of survival among patients with chronic hepatitis C at a tertiary care center in Oman

BACKGROUND

Chronic hepatitis C (CHC) is a leading cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide. This study aimed to determine rates and predictors of survival among Omani patients with CHC at a tertiary hospital in Muscat, Oman.

METHODS

This ambidirectional cohort study included all CHC patients who presented to the Sultan Qaboos University Hospital between January 2009 and December 2017. Baseline demographic, clinical, laboratory, and radiological data were analyzed. Patients were followed-up until death or the endpoint of the study (April 2022) to determine survival and associations with other parameters.

RESULTS

A total of 702 CHC patients were included, of which 398 (56.7%) were under 50 years of age and 477 (67.9%) were male. Overall, 180 patients (25.6%) died by the study endpoint. The mean duration of follow-up was 93.3 ± 48.0 months. The 5-year survival rate was estimated to be 80.5%, while the 10-year survival was 73%. Sustained virological response and the absence of diabetes mellitus, chronic kidney disease, HCC, or other malignancies were associated with significantly better overall survival. The 3- and 5-year survival rate of patients with hepatitis C virus (HCV)-related HCC was 46.5% and 27.6%, respectively, with a median survival of 29.5 months. Co-infection with hepatitis B was associated with poor survival among this subgroup; conversely, early HCV screening and the presence of a single HCC lesion were associated with better overall survival.

CONCLUSIONS

National policies for early CHC screening and rapid treatment are needed to improve survival rates in this population.

Visceral fat and its dynamic change are associated with renal damage: Evidence from two cohorts

BACKGROUND AND AIMS

To evaluate the association of Chinese visceral adiposity index (CVAI) and its dynamic trends with risk of renal damage, and to compare its prediction performance with that of other obesity indices.

METHODS AND RESULTS

A community-based population with 23 905 participants from Shantou city was included in the cross-sectional analysis. A total of 9,778 individuals from two separated cohort were included in the longitudinal portion. Five patterns of CVAI change were predefined (low-stable, decreasing, moderate, increasing, and persistent-high). Logistic and Cox regressions were used to evaluate the association between CVAI and renal damage. We explored potential mechanisms using the mediating effect method, and the prediction performance was determined by receiver operating characteristic curve analysis. Results from both cross-sectional and longitudinal data revealed a positive and linear association between CVAI and risk of renal damage. Pooled analysis of the two cohorts showed that per unit increase in Z score of CVAI induced 18% increased risk of renal damage (P = .008). Longitudinal trends of CVAI were also associated with renal damage, and the moderate, increasing, and persistent-high patterns showing a higher risk. Blood pressure and glucose had a mediating effect on renal damage induced by CVAI. Among several obesity indices, CVAI was the optimal for predicting renal damage.

CONCLUSION

A higher level of immediate CVAI and longitudinal increasing and persistent-high patterns of CVAI were independently associated with increased risk of renal damage. Monitoring immediate level and long-term trend of CVAI may contribute to the prevention of renal damage.

The association between skipping breakfast and chronic kidney disease

BACKGROUND/OBJECTIVES

There are few reports on the relationship between skipping breakfast and chronic kidney disease (CKD). We examined the skipping breakfast-CKD relationship and the mediation effects of metabolic diseases (obesity, hypertension, and diabetes) on this relationship.

SUBJECTS/METHODS

We analyzed the data of 21,138 participants aged ≥ 40 years from the Korea National Health and Nutrition Examination Survey 2013-2018. Skipping breakfast was defined as rarely eating breakfast over the past year. CKD was defined as decreased kidney function expressed by an estimated glomerular filtration rate of < 60 mL/min/1.73 m2. We used a complex sample logistic regression model to examine the relationship between skipping breakfast and CKD. We used Baron and Kenny's approach to examine whether metabolic diseases work as a mediator within the skipping breakfast-CKD relationships.

RESULTS

About 7.6% of participants skipped breakfast, and 5.5% had CKD. After adjusting for confounders, participants who skipped breakfast were at higher odds of having CKD (odds ratio 1.61; 95% confidence interval 1.07-2.42; p value 0.021) compared to those who did not skip breakfast. With full adjustments for confounders, skipping breakfast was not significantly associated with any metabolic diseases, while CKD was significantly associated with diabetes and hypertension.

CONCLUSION

We found that middle-aged or older people who skipped breakfast had a significantly higher odds of having CKD compared to those who did not skip breakfast. However, metabolic diseases did not mediate the relationship between skipping breakfast and CKD.

Metabolic health status and renal disorders: a cross-sectional study

Previous surveys suggests that body mass index (BMI) may be positively related to development of chronic kidney disease (CKD). However, this association might be altered by metabolic syndrome. Therefore, we aimed to evaluate the association of metabolic health status with CKD. The present cross-sectional study was carried out on 3322 representative sample of Iranian adults. Metabolic syndrome was identified based on the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) and BMI was assessed by anthropometric measurements. Estimated glomerular filtration rate (eGFR) was calculated by modification of diet in renal disease-Chronic Kidney Disease Epidemiology Collaboration (MDRD-EPI) formula. Subjects were categorized into four phenotypes: metabolically healthy normal weight (MHNW), metabolically healthy overweight and obesity (MHO), metabolically unhealthy normal weight (MUHNW), and metabolically unhealthy overweight and obesity (MUHO). Based on multivariate-adjusted models, the risk of CKD was significantly higher in MUHO compared with MHNW (OR: 1.48; p < 0.05). Although MUHNW and MUHO were associated with lower eGFR and albuminuria, the significant association was not observed in case of hematuria. Furthermore, subjects with kidney stones tended to be in MHO (OR: 1.42; p < 0.05) and MUHO phenotypes (OR: 1.64; p < 0.05), in comparison to the MHNW phenotype. The odds of kidney disorders were higher in adults with metabolic syndrome, regardless of BMI. However, this relationship might be strengthened by the concomitance of metabolic syndrome and obesity. To verify our findings, clarify the causality, and elucidate the underlying mechanisms, further research are warranted.

Kidney Considerations in Pediatric Obesity

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is a common condition and a major cause of morbidity and mortality in adults, but children and adolescents are also at risk for early kidney injury and development of CKD. Obesity contributes both directly and indirectly to the development of CKD. The purpose of this review is to describe obesity-related kidney disease (ORKD) and diabetic kidney disease (DKD) and their impact in the pediatric population.

RECENT FINDINGS

Although obesity-related CKD in childhood and adolescence is uncommon, nascent kidney damage may magnify the lifetime risk of CKD. Glomerular hyperfiltration is an early phenotype of both ORKD and DKD and typically manifests prior to albuminuria and progressive decline in GFR. Novel treatments for obesity and type 2 diabetes exerting protective effects on the kidneys are being investigated for use in the pediatric population. It is important to understand the impact of obesity on the kidneys more fully in the pediatric population to help detect injury earlier and intervene prior to the onset of irreversible progression of disease and to guide future research in this area.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease Cross Talk

Nonalcoholic fatty liver disease is a multisystem condition with effects beyond the liver. The identification of chronic kidney disease as an independent mediator of nonalcoholic fatty liver disease or associated entity with shared cardiometabolic risk factors remains controversial and continues to draw scientific interest. With increasing prevalence of nonalcoholic fatty liver disease and lack of Food and Drug Administration approved therapies, these shared cardiometabolic risk factors have drawn significant attention. In this article, we review shared pathophysiological mechanisms between nonalcoholic fatty liver disease and chronic kidney disease along with current treatment strategies that might be useful for both disease processes.

Metabolic-Related Index to Predict Post-Transplantation Diabetes Mellitus After Kidney Transplantation

Metabolic-related markers are novel tools for assessing insulin resistance. Early identification of post-transplantation diabetes mellitus (PTDM) before hyperglycemia can be helpful to attenuate the rapid development of diabetic complications. This article aims to explore the convenient and inexpensive values of metabolic-related markers, including TyG, TyG-BMI, TG/HDL-C, and non-HDL-C/HDL-C for predicting PTDM. The data of 191 kidney transplant recipients in our center were collected retrospectively. The association between TyG, TyG-BMI, TG/HDL-C, non-HDL-C/HDL-C and the risk of PTDM was examined by the area under the curve and logistic regression analyses. During 6 months follow-up, 12.04% of KT recipients developed PTDM, and significantly higher values of TyG-BMI, TyG, and non-HDL-C/HDL-C was found in patients with PTDM than in nondiabetic patients, especially among the recipients taking tacrolimus, regardless of gender. The incidence of PTDM increased along with the values of TyG or TyG-BMI. After adjusting for multiple potential factors, recipients with the highest trisector of TyG or TyG-BMI still had a higher risk of PTDM morbidity. In conclusion, TyG, TyG-BMI, TG/HDL-C and non-HDL-C/HDL-C can be used as cost-effective and promising monitors to identify individuals at high risk of PTDM, and TyG-BMI was the best alternative marker among the four markers.

Obesity and chronic kidney disease

The prevalence of obesity has increased dramatically during the past decades, which has been a major health problem. Since 1975, the number of people with obesity worldwide has nearly tripled. An increasing number of studies find obesity as a driver of chronic kidney disease (CKD) progression, and the mechanisms are complex and include hemodynamic changes, inflammation, oxidative stress, and activation of the renin-angiotensin-aldosterone system (RAAS). Obesity-related kidney disease is characterized by glomerulomegaly, which is often accompanied by localized and segmental glomerulosclerosis lesions. In these patients, the early symptoms are atypical, with microproteinuria being the main clinical manifestation and nephrotic syndrome being rare. Weight loss and RAAS blockers have a protective effect on obesity-related CKD, but even so, a significant proportion of patients eventually progress to end-stage renal disease despite treatment. Thus, it is critical to comprehend the mechanisms underlying obesity-related CKD to create new tactics for slowing or stopping disease progression. In this review, we summarize current knowledge on the mechanisms of obesity-related kidney disease, its pathological changes, and future perspectives on its treatment.

Insulin Resistance and Type 2 Diabetes Mellitus: An Ultimatum to Renal Physiology

Insulin resistance (IR) is stated as diminished insulin action regardless of hyperinsulinemia. The usual target organs for insulin activities are the liver, skeletal muscle, and adipose tissue. Hence, the vasculature and kidneys are nonconventional target organs as the impacts of insulin on these are comparatively separate from other conventional target organs. Vasodilation is achieved by raising endothelial nitric oxide (NO) generation by initiating the phosphoinositide 3-kinase (PI3K) pathway. In insulin-nonresponsive conditions, this process is defective, and there is increased production of endothelin-1 through the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway, which predominates the NO effects, causing vasoconstriction. Renal tubular cells and podocytes have insulin receptors, and their purposeful importance has been studied, which discloses critical acts of insulin signaling in podocyte survivability and tubular action. Diabetic nephropathy (DN) is a prevalent problem in individuals with hypertension, poor glycemic management, hereditary susceptibility, or glomerular hyperfiltration. DN could be a significant contributing factor to end-stage renal disease (ESRD) that results from chronic kidney disease (CKD). IR and diabetes mellitus (DM) are the constituents of syndrome X and are accompanied by CKD progression. IR performs a key part in syndrome X leading to CKD. However, it is indistinct whether IR individually participates in enhancing the threat to CKD advancement rather than CKD complexity. CKD is an extensive public health problem affecting millions of individuals worldwide. The tremendous spread of kidney disease intensifies people’s health impacts related to communicable and noncommunicable diseases. Chronic disease regulator policies do not include CKD at global, local, and/or general levels. Improved knowledge of the character of CKD-associated problems might aid in reforming diagnosis, prevention, and management.

Predictive Value of HbA1c and Metabolic Syndrome for Renal Outcome in Non-Diabetic CKD Stage 1-4 Patients

Glycated hemoglobin (HbA1c) levels are commonly used to indicate long-term glycemic control. An HbA1c level of 6.5−5.7% is defined as pre-diabetes and is proposed as a criterion for diagnosing metabolic syndrome (MetS). However, HbA1c levels can be affected by chronic kidney disease (CKD). Whether HbA1c is associated with clinical outcomes in nondiabetic CKD patients with or without MetS is still unknown. This study included 1270 nondiabetic CKD stage 1−4 Asian patients, divided by HbA1c and MetS. Through linear regression, HbA1c was positively associated with age, waist circumference, hemoglobin levels, and C-reactive protein and was negatively associated with malnutrition−inflammation. HbA1c levels were 5.5% (0.6%) and 5.7% (0.6%) in non-MetS and MetS, respectively (p < 0.001). In Cox regression, higher-level HbA1c was associated with worse composite renal outcome in MetS patients, but with better renal outcome in non-MetS patients: Hazard ratio (HR) (95% confidence interval [CI]) of HbA1c ≥5.7%, compared with HbA1c <5%, was 2.00 (1.06−3.78) in MetS and 0.25 (0.14−0.45) in non-MetS. An association between HbA1c and all-cause mortality was not found. In conclusion, higher HbA1c levels are associated with worse renal outcomes in nondiabetic CKD stage 1−4 patients modified by the presence of MetS.

Association between metabolic phenotype and urinary albumin-creatinine ratio in Chinese community adults: A cross-sectional study

BACKGROUND

Urinary albumin-creatinine ratio (UACR) is a sensitive marker of kidney injury. This study analyzed the prevalence of different metabolic phenotypes and investigated their relationship with UACR in Chinese community adults.

METHODS

This study involved 33 303 participants over 40 years old from seven centers across China. They were stratified into six groups according to their body mass index (BMI) and metabolic status: metabolically healthy normal weight (MHNW), metabolically healthy overweight (MHOW), metabolically healthy obesity (MHO), metabolically unhealthy normal weight (MUNW), metabolically unhealthy overweight (MUOW), and metabolically unhealthy obesity (MUO). Increased albuminuria was defined as a UACR ≥30 mg/g.

RESULTS

The percentages of MHNW, MHOW, MHO, MUNW, MUOW, and MUO were 27.6%, 15.9%, 4.1%, 19.8%, 22.5%, and 9.6%, respectively. Multiple logistic regression analysis showed that the MHO group (odds ratio [OR] 1.205; 95% CI, 1.081-1.343), MUNW group (OR 1.232; 95% CI, 1.021-1.486), MUOW group (OR 1.447; 95% CI, 1.303-1.607), and MUO group (OR 1.912; 95% CI, 1.680-2.176) were at higher risk of increased albuminuria compared to the MHNW group. Subgroup analysis indicated that the risk of increased albuminuria was further elevated among regular smokers in men aged 40 to 55 years old with abdominal obesity.

CONCLUSIONS

Among Chinese community adults, increased albuminuria was associated with increased BMI whether metabolism was normal or not, and those with abnormal metabolism were at greater risk of increased albuminuria than those with normal metabolism. These findings suggest that overweight or obesity or metabolic abnormalities are risk factors for chronic kidney disease.

Metabolic Syndrome and Obesity-Related Indices Are Associated with Rapid Renal Function Decline in a Large Taiwanese Population Follow-Up Study

A rapid decline in renal function can cause many complications, and therefore it is important to detect associated risk factors. Few studies have evaluated the associations among obesity-related indices and metabolic syndrome (MetS) with renal function decline. This longitudinal study aimed to explore these relationships in a large cohort of Taiwanese participants. The studied obesity-related indices were waist-to-height ratio (WHtR), A body shape index (ABSI), visceral adiposity index (VAI), lipid accumulation product (LAP), waist-to-hip ratio (WHR), body roundness index (BRI), conicity index (CI), body mass index (BMI), body adiposity index (BAI) and abdominal volume index (AVI). We included 122,068 participants in the baseline study, of whom 27,033 were followed for a median of four years. The baseline prevalence of MetS was 17.7%. Multivariable analysis showed that the participants with MetS and high VAI, WHtR, WHR, LAP, CI, BRI, BMI, BAI, AVI, and ABSI values were significantly associated with a high baseline estimated glomerular filtration rate (eGFR) (all p < 0.001). In addition, the participants with MetS (p < 0.001), high WHtR (p = 0.007), low LAP (p < 0.001), high BRI (p = 0.002), high CI (p = 0.002), high AVI (p = 0.001), high VAI (p = 0.017), and high ABSI (p = 0.013) were significantly associated with a low △eGFR, indicating a rapid decline in renal function. These results showed associations between MetS and high values of obesity-related indices except LAP with high baseline eGFR and rapid decline in kidney function. These findings suggest that screening for MetS and obesity may help to slow the decline in renal function in high-risk populations.

Obesity and Chronic Kidney Disease A Current Review

Background

Obesity poses significant challenges to healthcare globally, particularly through its bi-directional relationship with co-morbid metabolic conditions such as type 2 diabetes and hypertension. There is also emerging evidence of an association between obesity and chronic kidney disease (CKD) which is less well characterized.

Methods

A literature search of electronic libraries was conducted to identify and present a narrative review of the interplay between obesity and CKD.

Findings

Obesity may predispose to CKD directly as it is linked to the histopathological finding of obesity-related glomerulopathy and indirectly through its widely recognized complications such as atherosclerosis, hypertension, and type 2 diabetes. The biochemical and endocrine products of adipose tissue contribute to pathophysiological processes such as inflammation, oxidative stress, endothelial dysfunction, and proteinuria. The prevention and management of obesity may prove critical in counteracting both the development and advancement of CKD. Moreover, measures of abdominal adiposity such as waist circumference, are generally associated with worse morbidity and mortality in individuals receiving maintenance hemodialysis.

Conclusion

Obesity is a risk factor for the onset and progression of CKD and should be recognized as a potential target for a preventative public health approach to reduce CKD rates within the general population. Future research should focus on the use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors in patients with CKD and obesity due to their multi-faceted actions on major outcomes.

Hepatitis Status and its Effect upon the Progression of Chronic Kidney Disease: Presentations, Associations and Complications

Chronic kidney disease (CKD), hepatitis B virus (HBV), and hepatitis C virus (HCV) have a high prevalence in Oman. This study aimed to examine the association between CKD and viral hepatitis through an observational cohort study conducted at the Royal Hospital of the Sultanate of Oman to evaluate the relationship of HBV and HCV with CKD. During the study, 233 patients were identified, 112 with chronic HBV (Group 1), 112 with chronic HCV (Group 2), and nine with HBV and HCV coinfection (Group 3). The population was predominantly male, especially in Groups 1 and 3. The difference in age between Groups 1 and 2 was significant, with the mean age being 48 ± 14.6 years and 55 ± 12.6 years, respectively (P <0.05). This study revealed that the prevalence of CKD in Group 1 is 51%, in Group 2 was 78%, and in Group 3 was 56%. The mean estimated glomerular filtration rate (eGFR) was 79.7 mL/min/1.73 m2 in Group 1, 73.2 mL/min/1.73 m2 in Group 2, and 57.6 mL/min/1.73 m2 in Group 3. CKD had the highest prevalence in Group 2. The lowest eGFR was found in Group 3. Group 2 showed the highest rate of declining renal function over time despite treatment. This study found a significant and independent association between viral hepatitis and the risk of CKD, especially in cases of coinfection and HCV infection. This warrants close monitoring of kidney function during screening and follow-up. Patients with CKD should be screened for viral hepatitis.

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.

Elevated TyG Index Predicts Incidence of Contrast-Induced Nephropathy: A Retrospective Cohort Study in NSTE-ACS Patients Implanted With DESs

BACKGROUND

Triglyceride-glucose (TyG) index is a reliable and specific biomarker for insulin resistance and is associated with renal dysfunction. The present study sought to explore the relationship between TyG index and the incidence of contrast-induced nephropathy (CIN) in non-ST elevation acute coronary syndrome (NSTE-ACS) patients implanted with drug-eluting stents (DESs).

METHODS

A total of 1108 participants were recruited to the study and assigned to two groups based on occurrence of CIN. TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting blood glucose (mg/dL)/2]. Baseline characteristics and incidence of CIN were compared between the two groups. Logistic regression analysis was performed to evaluate the relationship between TyG index and CIN.

RESULTS

The results showed that 167 participants (15.1%) developed CIN. Subjects in the CIN group had a significantly higher TyG index compared with subjects in the non-CIN group (8.9 ± 0.7 vs. 9.3 ± 0.7, P<0.001). TyG index was significantly correlated with increased risk of CIN after adjusting for confounding factors irrespective of diabetes mellitus status and exhibited a J-shaped non-linear association. Subgroup analysis showed a significant gender difference in the relationship between TyG index and CIN. Receiver operating characteristic (ROC) curve analysis indicated that the risk assessment performance of TyG index was superior compared with other single metabolic indexes. Addition of TyG index to the baseline model increased the area under the curve from 0.713 (0.672-0.754) to 0.742 (0.702-0.782) and caused a reclassification improvement of 0.120 (0.092-0.149).

CONCLUSION

The findings from the present study show that a high TyG index is significantly and independently associated with incidence of CIN in NSTE-ACS patients firstly implanted with DESs. Routine preoperative assessment of TyG index can alleviate CIN and TyG index provides a potential target for intervention in prevention of CIN.

The association between a body shape index and elevated urinary albumin-creatinine ratio in Chinese community adults

BACKGROUND

Obesity, especially visceral obesity, seems to be one of the most decisive risk factors for chronic kidney disease. A Body Shape Index (ABSI) is an emerging body size measurement marker of visceral obesity. This study aimed to explore whether ABSI is associated with albuminuria in Chinese community adults.

METHODS

This cross-sectional study enrolled 40,726 participants aged 40 or older from seven provinces across China through a cluster random sampling method. ABSI was calculated by body mass index, waist circumference, and height. Increased albuminuria was defined as urinary albumin-creatinine ratio (UACR) ≥ 30 mg/g, indicating kidney injury. For ABSI, we divided it by quartile cutoff points and tried to determine the association between ABSI levels and UACR by multiple regression analysis. DAG (Directed Acyclic Graph) was plotted using literature and expert consensus to identify potential confounding factors.

RESULTS

The average age of subjects with elevated UACR was 61.43 ± 10.07, and 26% were men. The average age of subjects with normal UACR was 57.70 ± 9.02, and 30.5% were men. Multiple logistic regression analysis was conducted and demonstrated that the ABSI quartiles were related to elevated UACR positively (OR [95% CI] Q2 vs. Q1: 1.094 [1.004, 1.197]; OR [95% CI] Q3 vs. Q1: 1.126 [1.030, 1.231]; OR [95% CI] Q4 vs. Q1: 1.183 [1.080, 1.295], p for trend < 0.001) after adjustments for confounding factors. The stratified analysis further showed that with the mounting for ABSI levels, elevated UACR more easily occurred in the people characterized by the elderly, men, and hypertension.

CONCLUSIONS

In Chinese community adults, people with higher ABSI levels can be deemed as high-risk individuals with UACR elevation, and it will be beneficial for them to lose weight and significantly reduce visceral fat.

Update on pathogenesis and diagnosis flow of normoalbuminuric diabetes with renal insufficiency

In recent decades, the prevalence of diabetic kidney disease has remained stable and appears to be a wide heterogeneity. Normoalbuminuric diabetes with renal insufficiency, which is characterized by a decline in the glomerular filtration rate in the absence of albuminuria, has been identified as an albuminuria-independent phenotype of diabetic kidney disease. Epidemiological data demonstrate that normoalbuminuric phenotype is prevalent. Compared to albuminuric phenotype, normoalbuminuric phenotype has distinct clinical characteristics and a wide heterogeneity of pathological features. Currently, the pathogenesis of normoalbuminuric phenotype remains unclear. Additionally, the flow of diagnosing normoalbuminuric phenotype is not perfect. In this article, we review the latest studies addressing the epidemiology, clinical characteristics, and pathology of normoalbuminuric phenotype. Based on the studies of clinical features and renal histopathologic changes, we attempt to propose an underlying pathogenesis model and a flow chart for diagnosing normoalbuminuric phenotype.

Urinary NGAL is a Potential Biomarker for Early Renal Injury in Insulin Resistant Obese Non-diabetic Children

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) is one of the new biomarkers for detecting acute renal injury. There are studies showing the relationship between NGAL and renal injury in obese children. The aim of this study was to investigate whether urinary levels of NGAL, kidney injury molecule-1, and serum cystatin C are increased in insulin resistance (IR) patients before the development of diabetes.

METHODS

Cross-sectional, case-controlled study that included non-diabetic obese children and adolescent patients with IR and a non-diabetic obese control group with no IR, who attended a tertiary center pediatric endocrinology outpatient clinic between 2016-2018. Those with diabetes mellitus and/or known renal disease were excluded. NGAL and creatinine (Cr) levels were evaluated in the morning spot urine from all participants. Serum renal function was evaluated.

RESULTS

Thirty-six control and 63 IR patients were included in the study, of whom 68 (68.7%) were girls. The mean age of all participants was 13.12±2.64 years and no statistically significant difference was found between the two groups in terms of age or gender distribution. Median (range) spot urinary NGAL (u-NGAL) values in the IR group were significantly higher at 26.35 (7.01-108.7) ng/mL than in the control group at 19.5 (3.45-88.14) ng/mL (p=0.018). NGAL/Cr ratio was also significantly higher in the IR group compared to the control group (p=0.018).

CONCLUSION

Obese pediatric patients with IR were shown to have elevated levels of u-NGAL, a marker of renal injury. u-NGAL examination may show early renal injury before development of diabetes.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: A Review of Links and Risks

Nonalcoholic fatty liver disease and chronic kidney disease are both chronic conditions with rapidly increasing prevalence and incidence worldwide that have led to a significant burden on health-care systems. The association between these two disease entities is partly attributed to shared cardiometabolic comorbidities including diabetes, hypertension, obesity, and metabolic syndrome. However, independent of these overlapping risks, there are increased rates and more severe CKD in NAFLD patients. Conversely, more progressive NAFLD is seen with advanced stages of kidney injury. In addition to overlapping risk factors, shared pathogenic mechanisms suggest these two disease entities may resemble different manifestations of a single underlying disease process.

Recent therapeutic targets in diabetic nephropathy

BACKGROUND

The prevalence of diabetes mellitus has been increased dramatically which in turn leads to complications including cardiovascular diseases, diabetic kidney disease, and substantially end-stage renal disease.

METHODS

We reviewed articles discussing the pathophysiology of diabetic nephropathy with new agents that may be useful in the management of the disease. We used PubMed, Scopus, Google Scholar and the Open-access searching engines.

RESULTS

The recent recommendations primarily depend on glycaemic and blood pressure control and the use of standard renin-angiotensin system blockade. Currently, the use of agents with nephroprotective effects beyond the hyperglycaemic lowering effect has been evidenced clinically.

CONCLUSIONS

In his review, the pathophysiology, clinical manifestations, and lines of treatment of diabetic nephropathy are discussed. In addition, a focus on the clinical role and nephroprotective effects of the emerging therapeutic class, dipeptidyl peptidase IV (DPP-4) inhibitors, is addressed in detail.

Relation of glomerular filtration to insulin resistance and related risk factors in obese children

BACKGROUND AND OBJECTIVE

Childhood obesity is associated with later development of significant renal morbidity. We evaluated the impact of the degree of insulin sensitivity on estimated glomerular filtration rate (eGFR) and determined the factors associated with eGFR in obese children. We further tested the relation of eGFR to clinical outcomes such as blood pressure and microalbuminuria.

MATERIALS AND METHODS

We evaluated the relation of whole body insulin sensitivity and estimated glomerular filtration rate (eGFR) across the spectrum of obesity in children and adolescents. eGFR was calculated using the iCARE formula, which has been validated in obese children with varying glucose tolerance.

RESULTS

1080 children and adolescents with overweight and obesity (701 females and 379 males) participated. Insulin sensitivity was a strongly negatively associated with (B = -2.72, p < 0.001) eGFR), even after adjustment for potential confounders. Male sex emerged to be significantly associated with eGFR with boys having greater values than girls (B = 18.82, p < 0.001). Age was a positively associated (B = 2.86, p < 0.001) with eGFR. Whole body and hepatic insulin sensitivity decreased across eGFR quartiles. Adjusted eGFR was tightly positively associated with systolic blood pressure (B = 0.09, p = 0.003) and negatively associated with the presence of microalbuminuria (B = -2.18, p = 0.04).

CONCLUSIONS

eGFR tends to increase with greater degrees of insulin resistance in children and adolescents representing hyperfiltration and is associated with cardiovascular risk factors. Longitudinal studies are needed to determine the natural history of childhood insulin resistance related hyperfiltration in regards to future kidney disease.

Retrospective cohort study of changes in estimated glomerular filtration rate for patients prescribed a low carb diet

PURPOSE OF REVIEW

Obesity and diabetes contribute to chronic kidney disease (CKD) and accelerate the loss of kidney function. Low carbohydrate diets (LCDs) are associated with weight loss and improved diabetes control. Compared to the typical Western diet, LCDs contain more protein, so individuals with CKD are not included in studies of LCDs. Therefore, there are no studies of LCDs for weight loss and their effects on kidney function.

RECENT FINDINGS

Obesity, hyperglycemia, and hyperinsulinemia can be detrimental to kidney function. LCDs may improve kidney function in patients with obesity and diabetes because they are associated with weight loss, improve blood sugar control, and decrease endogenous insulin production and exogenous insulin requirements.

SUMMARY

In this study, for patients with mildly reduced and moderately to severely reduced kidney function who were prescribed an LCD, their estimated glomerular filtration rate (eGFR) was either unchanged or improved. For those with normal or elevated eGFR, their kidney function was slightly decreased. For those without diabetes, greater weight loss was associated with improved eGFR. Future studies should prospectively measure low carbohydrate dietary adherence and physical activity and directly measure changes in GFR and albuminuria for participants with CKD before and during that diet.

The association between hepatitis C virus infection and renal function

BACKGROUND

The association between hepatitis C virus (HCV) infection and chronic kidney disease (CKD) still remains controversial. We aimed to investigate whether HCV really affects renal function, and to analyze the association between clinical effects of CHC and decreased kidney function (assessed by glomerular filtration rate (eGFR) level).

METHODS

An estimated 3360 patients with HCV infection and 3360 age- and sex-matched community-based control individuals without HCV were enrolled (1:1, case and control ratio) in this study between 2004 and 2016. We used the modification of diet in renal diseases to calculate eGFR. Demographic and laboratory parameters were assessed, and appropriate statistical methods were performed for the analysis.

RESULTS

Multivariate logistic regression analysis revealed that serum alanine aminotransferase level (odds ratio [OR] 0.998; 95% confidence interval [CI] 0.997-0.999; P = 0.001), platelet count (OR 0.997; 95% CI 0.995-0.999; p = 0.002), and hypertension (OR 1.31; 95% CI 1.03-1.66; P = 0.027) were significantly associated with HCV infection and serum triglyceride levels (OR 1.001; 95% CI 1.00-1.002; p = 0.005), platelet count (OR 0.996; 95% CI 0.995-0.997; p < 0.001), body mass index (BMI) >25 (OR 1.43; 95% CI 1.23-1.67; p < 0.001), hypertension (OR 1.69; 95% CI 1.42-1.99; p < 0.001), hyperlipidemia (OR 1.32; 95% CI 1.02-1.71; p = 0.035), and diabetes (OR 1.33; 95% CI 1.03-1.71; p = 0.032) were significantly associated with a low eGFR (<90 mL/min/m3) in control subjects. The BMI >25 kg/m2, hypertension, and diabetes were found to be associated with low eGFR interaction with the HCV infection, via a multivariate analysis.

CONCLUSION

Our study found that the patients with HCV infection are associated with a low eGFR compared with non-HCV-infected patients. This association is consistent in obese, diabetic, and hypertensive patients.

Obesity Without Metabolic Abnormality and Incident CKD: A Population-Based British Cohort Study

RATIONALE & OBJECTIVE

Metabolically healthy obesity (obesity without any metabolic abnormality) is not considered to be associated with increased risk of morbidity and mortality. We examined and quantified the association between metabolically healthy overweight/obesity and the risk of incident chronic kidney disease (CKD) in a British primary care population.

STUDY DESIGN

Retrospective population-based cohort study.

SETTING & PARTICIPANTS

4,447,955 of the 5,182,908 adults in The Health Improvement Network (THIN) database (United Kingdom, 1995-2015) with a recorded body mass index (BMI) at the time of registration date who were free of CKD and cardiovascular disease.

EXPOSURE

11 body size phenotypes were created, defined by BMI categories (underweight, normal weight, overweight, and obesity) and 3 metabolic abnormalities (diabetes, hypertension, and dyslipidemia).

OUTCOME

Incident CKD defined as a recorded code for kidney replacement therapy, a recorded diagnosis of CKD, or by an estimated glomerular filtration rate of<60mL/min/1.73m² for≥90 days, or a urinary albumin-creatinine ratio>3mg/mmol for≥90 days.

RESULTS

Of the 4.5 million individuals, 1,040,921 (23.4%) and 588,909 (13.2%) had metabolically healthy overweight and metabolically healthy obesity, respectively. During a mean follow-up interval of 5.4±4.3 (SD) years, compared with individuals with a metabolically healthy normal weight (n=1,656,231), there was a higher risk of incident CKD among those who had metabolically healthy overweight (adjusted HR, 1.30 [95% CI, 1.28-1.33]) and metabolically healthy obesity (adjusted HR, 1.66 [95% CI, 1.62-1.70]). The association was stronger in those younger than 65 years of age. In all BMI categories, there was greater risk of incident CKD with a greater number of metabolic abnormalities in a graded manner.

LIMITATIONS

Potential misclassification of metabolic status due to delayed diagnosis and residual confounding due to unmeasured factors.

CONCLUSIONS

Overweight and obesity without metabolic abnormality are associated with a higher risk of incident CKD compared with those with normal body weight and no metabolic abnormality.

Pathological Hyperinsulinemia and Hyperglycemia in the Impaired Glucose Tolerance Stage Mediate Endothelial Dysfunction Through miR-21, PTEN/AKT/eNOS, and MARK/ET-1 Pathways

BACKGROUND

Impaired glucose tolerance (IGT) is an important prediabetic stage characterized by elevated concentrations of glucose and insulin in the blood. The pathological hyperglycemia and hyperinsulinemia in IGT may regulate the expression of microRNA-21 (miR-21) and affect the downstream insulin signaling pathways, leading to endothelial cell dysfunction and early renal damage.

METHODS

The individual and combined effects of insulin and glucose were investigated using human glomerular endothelial cells (HGECs). The expression levels of miR-21, and PTEN/AKT/eNOS and MAPK/ET-1 pathway proteins in the treated cells were measured. The levels of nitric oxide (NO) and endothelin-1 (ET-1) secreted by the cells were also measured. The role of miR-21 in mediating the regulatory effects of insulin and glucose was assessed by overexpression/inhibition of this miRNA using mimics/inhibitor.

RESULTS

High (>16.7 mmol/L) concentration of glucose upregulated the expression of miR-21, leading to the activation and inhibition of the PTEN/AKT/eNOS and MAPK/ET-1 pathways, and upregulation of NO and downregulation of ET-1 secretion, respectively. High (>25 ng/mL) concentration of insulin downregulated the expression of miR-21, and lead to the activation of the MAPK/ET-1 and inhibition of the PTEN/AKT/eNOS pathway, thereby upregulating the expression of ET-1 and downregulating the secretion of NO. MiR-21 was observed to play a key role by directly controlling the activation of the insulin signaling pathways when the cells were cotreated with different concentrations of insulin and glucose. The expression of miR-21 was found to be dependent on the relative concentration of insulin and glucose. Under simulated conditions of the IGT stage (8.3 mmol/L glucose + 50 ng/mL insulin), the inhibitory effect of high insulin concentration on miR-21 expression in the cells attenuated the activation by high glucose concentration, resulting in the downregulation of miR-21, upregulation of ET-1 and downregulation of NO secretion.

CONCLUSION

Taken together, these results indicate that high insulin and glucose concentrations regulate the secretory function of glomerular endothelial cells in opposite ways by regulating the expression of miRNA-21. Pathological concentrations of insulin and glucose in the IGT stage may lead to a decrease in miR-21 expression, thereby disordering the secretion of vasoactive factors, resulting in renal tubule ischemia.

Association between weight status, metabolic syndrome, and chronic kidney disease among middle-aged and elderly Chinese

BACKGROUND AND AIMS

Obesity often initiates or coexists with certain metabolic abnormalities. This study sought to examine the independent and joint relations of weight and metabolic syndrome (MetS) with incident chronic kidney disease (CKD) among Chinese elderly people.

METHODS AND RESULTS

A total of 15,229 participants (mean age: 62.8 years) from the Dongfeng-Tongji cohort with complete baseline questionnaire and medical examination data were followed from 2008 to 2010 to 2013. All participants were categorized into four phenotypes: metabolically healthy non-overweight/obesity (MHNO), metabolically healthy overweight/obesity (MHO), metabolically unhealthy non-overweight/obesity (MUNO), metabolically unhealthy overweight/obesity (MUO). Multivariable-adjusted logistic regression models were applied to estimate the odds ratios (ORs) and confidence intervals (CIs) of four phenotypes with the risk of incident CKD, which was defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m². A total of 1151 CKD cases were identified during a mean of 4.6-year follow-up. After adjusting for potential confounders, both overweight/obesity and MetS were associated with higher risk of CKD, and the ORs (95% CI) were 1.32 (1.15-1.52) and 1.50 (1.31-1.73), respectively. The risk of CKD was progressively higher in MHO (1.31, 1.09-1.57), MUNO (1.54, 1.22-1.93), and MUO (2.05, 1.73-2.42) as compared with MHNO phenotype, without significant multiplicative interaction between overweight/obesity and MetS (P_interaction = 0.906). These associations were slightly stronger among those aged >60 years or with baseline diabetes.

CONCLUSION

Both overweight/obesity and MetS were associated with an increased risk of CKD. It is worth noting that MHO and MUNO also have an elevated risk. Maintaining both normal weight and healthy metabolic profile is recommended.

Ameliorative Effects of Bredemolic Acid on Markers Associated with Renal Dysfunction in a Diet-Induced Prediabetic Rat Model

Recently, studies have shown that renal dysfunction is associated not only with overt diabetes but also with the preceding stage known as prediabetes. Diet and pharmacological interventions are the therapeutic approaches to managing prediabetes, but the compliance in combining the two interventions is low. Hence, the efficacy of pharmacological intervention is reduced without diet modification. In our previous study, we established that bredemolic acid (BA) ameliorated glucose homeostasis via increased GLUT 4 expression in the skeletal muscle of prediabetic rats in the absence of diet intervention. However, the effects of bredemolic acid on renal function in prediabetic condition are unknown. Therefore, this study was aimed at investigating the ameliorative effects of bredemolic acid on renal dysfunction in a diet-induced prediabetic rat model. Thirty-six Sprague-Dawley male rats (150-180 g) were divided into two groups: the nonprediabetic (n = 6) and prediabetic (n = 30) groups which were fed normal diet (ND) and high-fat high-carbohydrate (HFHC) diet, respectively, for 20 weeks. After the 20^th week, the prediabetic groups were subdivided into prediabetic control (PD) and 4 other prediabetic groups which were treated with either BA (80 mg/kg) or metformin (MET, 500 mg/kg) for further 12 weeks (21^st to 32^nd). Plasma, urine, and kidney samples were collected for biochemical analysis. The untreated prediabetic (PD) rats presented increased fluid intake and urine output; increased creatinine, urea, and uric acid plasma concentrations; albuminuria; proteinuria; sodium retention; potassium loss; increased aldosterone and kidney injury molecule (KIM-1) concentration; and increased urinary podocin mRNA expression. However, BA administration attenuated the renal markers and oxidative stress and decreased the urinary podocin mRNA expression. In conclusion, BA administration, regardless of diet modification, attenuates renal dysfunction in an experimentally induced prediabetic state.

Metabolic Syndrome Rather than Obesity Alone Is More Significant for Kidney Disease

INTRODUCTION

Obesity is associated with metabolic syndrome, nonalcoholic steatohepatitis, and kidney disease. BMI may not be the ideal measure of obesity when used to assess its effect on kidney disease as it does not discriminate for age, sex, ethnicity, muscle, bone, or fat mass.

OBJECTIVES

To assess the prevalence microalbuminuria and identify independent risk factors for development of kidney disease in the obese Indian population.

METHODS

Age, weight, BMI, total body fat percentage, waist-to-hip ratio, hypertension, urinary albumin-to-creatinine ratio (UACR), and HbA1c were collected from 568 obese patients, presenting for bariatric surgery. Multivariate binary logistic regression was used to identify independent risk factors for kidney disease.

RESULTS

A total of 114 out of 568 (20.07%) obese patients had microalbuminuria (UACR range 30-283 μg/mg). HbA1C levels ≥ 6 (p = 0.01) and hypertension (p = 0.03) were the strongest independent variables for microalbuminuria. 14.67% with a BMI < 35 kg/m², 21.30% with a BMI 35-50 kg/m², and 19.44% with a BMI > 50 kg/m² had microalbuminuria. Increasing BMI however was not statistically significant (p = 0.75). Total body fat percentage (p = 0.51), waist-to-hip ratio (p = 0.96), age (p = 0.30), sex (p = 0.38), and BMI (p = 0.75) were found to be statistically insignificant.

CONCLUSIONS

Kidney disease afflicts 1/5th of the obese Indian patients studied. Diabetes and hypertension remained as the most significant risk factors, while age, weight, increasing BMI, waist-to-hip ratio, or increasing body fat were found to be statistically insignificant for development and progression of kidney disease.

Associations between hepatitis B infection and chronic kidney disease: 10-Year results from the U.S. National Inpatient Sample

INTRODUCTION

Viral hepatitis infection is associated with negative impacts on renal function that may lead to nephropathy. We investigated associations between chronic hepatitis B virus (HBV) infection and chronic kidney disease (CKD) and/or end-stage renal disease (ESRD) in a large, representative sample from a nationwide U.S.

DATABASE

METHODS

This population-based, retrospective observational study extracted data from the U.S. Nationwide Inpatient Sample (NIS) database, including adults ≥18 years old admitted to U.S. hospitals between 2005 and 2014 with records of chronic HBV infection in medical history. The final analytic sample included 70,674 HBV-infected patients and 282,696 matched non-HBV controls. Study endpoints were prevalent CKD and ESRD. Associations between CKD/ESRD and HBV and patients' clinical characteristics were determined by logistic regression analysis.

RESULTS

HBV infection was associated with slightly increased risk of prevalent CKD (OR: 1.06, 95% CI: 1.004-1.119) and an approximate 2-times risk of prevalent ESRD (OR: 1.98, 95% CI: 1.880-2.086). HBV infection in both genders was associated with slightly increased risk of CKD (males, OR: 1.09, 95% CI: 1.02-1.16; females, OR: 1.07, 95% CI: 0.98,1.17), and significantly associated with increased risk for CKD among non-diabetic patients (OR: 1.23, 95% CI: 1.15-1.32), white patients (OR: 1.14, 95% CI: 1.06-1.23) and Asian/Pacific Islanders (OR: 1.13, 95% CI: 0.98-1.30).

CONCLUSIONS

Chronic HBV infection is associated with slightly increased risk for CKD and greater risk for ESRD in males and females, Whites and Asian/Pacific Islanders and non-diabetic patients.

The Iberian pig fed with high-fat diet: a model of renal disease in obesity and metabolic syndrome

BACKGROUND

The pathogenesis of renal disease in the context of overweight/obesity, metabolic syndrome, and insulin resistance is not completely understood. This may be due to the lack of a definitive animal model of disease, which limits our understanding of obesity-induced renal damage. We evaluated the changes in renal histology and lipid deposits induced by obesity in a model of insulin resistance: the Iberian swine fed with fat-enriched food.

METHODS

Twenty-eight female sows were randomized to standard (SD) or high-fat diet (HFD: 6.8% of saturated fat) for 100 days. Weight, adiposity, analytics, oral glucose tolerance tests, and measured renal function were determined. Renal histology and lipid deposits in renal tissue were analyzed.

RESULTS

Animals on HFD developed obesity, hypertension, high levels of LDL cholesterol, triglycerides, insulin resistance, and glomerular hyperfiltration. No animal developed overt diabetes. Animals on HFD showed "diabetoid changes", including mesangial expansion [21.40% ± 4 vs.13.20% ± 4.0, p < 0.0001], nodular glomerulosclerosis [7.40% ± 7, 0.75 vs. 2.40% ± 4.7, p = 0.02], and glomerulomegaly (18% vs. 10%, p = 0.010) than those on SD. Tubular atrophy, interstitial fibrosis, inflammation, arteriolar hyalinosis, or fibrointimal thickening were mild and similar between groups. Triglyceride content in renal tissue was higher in animals on HFD than in SD (15.4% ± 0.5 vs. 12.7% ± 0.7; p < 0.01).

CONCLUSIONS

Iberian pigs fed with fat-enriched food showed diabetoid changes and glomerulomegaly as observed in obese humans making this model suitable to study obesity-induced renal disease.

Effect of imidazoline-1 receptor agonists on renal dysfunction in rats associated with chronic, sequential fructose and ethanol administration

Insulin resistance and chronic alcoholism are risk factors for renal dysfunction. This study investigated the therapeutic effects of two imidazoline-1 receptor (I1R) agonists on renal dysfunction in rats after chronic, sequential fructose and ethanol administration. Daily drinking water was supplemented with fructose (10%, w/v) for 12 weeks and then with ethanol (20%, v/v) for another 8 weeks. Rats were treated with rilmenidine and clonidine in the last two weeks of the study. Blood glucose and serum insulin (sIns) levels, lipid profiles, kidney function and renal histopathology were evaluated at the end of the experiment. Additionally, renal gene expression of nischarin, phosphatidylcholine-specific phospholipase C (PC-PLC) and prostaglandin E2 (PGE2) were measured. Renal levels of superoxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and total NO (tNO) were detected, and we determined the relative renal gene expression levels of alpha smooth muscle actin (α-SMA), hydroxyproline, interleukin 10 (IL-10), tumour necrosis factor alpha (TNF-α) and caspase-3. The results showed significant deterioration of blood glucose, sIns, lipid profiles, kidney function and renal histopathology in fructose/ethanol-fed rats. Additionally, markers of inflammation, fibrosis, apoptosis and oxidative stress were upregulated. The administration of rilmenidine or clonidine significantly improved blood glucose and sIns levels and reduced renal dysfunction. Our work showed that chronic, sequential fructose and ethanol administration induced fasting hyperglycaemia and renal impairment, and these effects were ameliorated by I1R agonists.

The impact of antiviral therapy for HCV on kidney disease: a systematic review and meta-analysis

BACKGROUND

Controversy persists about the role of hepatitis C as a risk factor for developing kidney disease in the general population. Some authors have evaluated the effect of antiviral therapy for HCV on the risk of kidney disease.

STUDY AIMS AND DESIGN

A systematic review of the published medical literature was performed to assess whether antiviral therapy for HCV has an independent impact on kidney survival in the adult general population. A random effects model was used to generate an overall estimate of the risk of kidney disease after anti-HCV therapy across the published studies. Meta-regression and stratified analysis were also carried out.

RESULTS

Fifteen studies were eligible (n=356, 285 patients) and separate meta-analyses were conducted according to the outcome. Pooling studies based on viral responses (n=7; 34,763 individual patients) demonstrated a relationship between sustained viral response and lower frequency of kidney disease; the overall estimate for adjusted risk of kidney disease was 2.50 (95% CI, 1.41; 4.41) (p=0.0016) and between-study heterogeneity was found (p-value by Q test=0.004). Aggregation of studies comparing treated vs untreated cohorts (n=8, n=333,312 patients) revealed an association between anti-HCV therapy and lower risk of kidney disease. The overall estimate for adjusted risk of kidney disease across the eight studies was 0.39 (95% CI, 0.25; 0.612) (p=0.0001). Meta-regression showed that the effectiveness of antiviral therapy in reducing the frequency of kidney disease diminishes as cirrhosis (p=0.02) and HBV infection (p=0.0001) increase among HCV-infected individuals.

CONCLUSIONS

Antiviral therapy for HCV lowers the risk of kidney disease among HCV-infected individuals. Studies to understand the mechanisms underlying this association are ongoing.