Association and biomarker potential of elevated serum adiponectin with nephropathy among type 1 and type 2 diabetics: A meta-analysis

Childhood Obesity: Insight into Kidney Involvement

This review examines the impact of childhood obesity on the kidney from an epidemiological, pathogenetic, clinical, and pathological perspective, with the aim of providing pediatricians and nephrologists with the most current data on this topic. The prevalence of childhood obesity and chronic kidney disease (CKD) is steadily increasing worldwide, reaching epidemic proportions. While the impact of obesity in children with CKD is less pronounced than in adults, recent studies suggest a similar trend in the child population. This is likely due to the significant association between obesity and the two leading causes of end-stage renal disease (ESRD): diabetes mellitus (DM) and hypertension. Obesity is a complex, systemic disease that reflects interactions between environmental and genetic factors. A key mechanism of kidney damage is related to metabolic syndrome and insulin resistance. Therefore, we can speculate about an adipose tissue-kidney axis in which neurohormonal and immunological mechanisms exacerbate complications resulting from obesity. Adipose tissue, now recognized as an endocrine organ, secretes cytokines called adipokines that may induce adaptive or maladaptive responses in renal cells, leading to kidney fibrosis. The impact of obesity on kidney transplant-related outcomes for both donors and recipients is also significant, making stringent preventive measures critical in the pre- and post-transplant phases. The challenge lies in identifying renal involvement as early as possible, as it is often completely asymptomatic and not detectable through common markers of kidney function. Ongoing research into innovative technologies, such as proteomics and metabolomics, aims to identify new biomarkers and is constantly evolving. Many aspects of pediatric disease progression in the population of children with obesity still require clarification. However, the latest scientific evidence in the field of nephrology offers glimpses into various new perspectives, such as genetic factors, comorbidities, and novel biomarkers. Investigating these aspects early could potentially improve the prognosis of these young patients through new diagnostic and therapeutic strategies. Hence, the aim of this review is to provide a comprehensive exploration of the pathogenetic mechanisms and prevalent pathological patterns of kidney damage observed in children with obesity.

Serum Adiponectin Level in Different Stages of Type 2 Diabetic Kidney Disease: A Meta-Analysis

Background. Biomarkers in predicting the stages of nephropathy associated with type 2 diabetes mellitus are urgent, and adiponectin may be a promising biomarker. This meta-analysis examined the association of serum adiponectin level with the stages of type 2 diabetic nephropathy. Methods. Databases including PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure (CNKI), and Wan Fang were searched for published studies on adiponectin and type 2 diabetic kidney disease. The Newcastle-Ottawa scale was used to assess the quality of the literature. STATA 14.0 was used to conduct the statistical analysis. Results. Thirty-four studies with 5254 patients were included in this meta-analysis. The results of this study show that there was no significant difference in serum adiponectin level between normoalbuminuria and the control group ( $\text{mean}\text{difference}=-0.42$ , 95% CI [-1.23, 0.40]), while serum adiponectin level was positively correlated with the severity of type 2 diabetic kidney disease. The serum adiponectin level in type 2 diabetic kidney disease patients ranks as $\text{macroalbuminuria}>\text{microalbuminuria}>\text{normoalbuminuria}$ . Conclusions. Serum adiponectin level might be an important marker to predict the progression of type 2 diabetic kidney disease.

Obesity and chronic kidney disease: prevalence, mechanism, and management

The prevalence of childhood obesity is increasing worldwide at an alarming rate. While obesity is known to increase a variety of cardiovascular and metabolic diseases, it also acts as a risk factor for the development and progression of chronic kidney disease (CKD). During childhood and adolescence, severe obesity is associated with an increased prevalence and incidence of the early stages of kidney disease. Importantly, children born to obese mothers are also at increased risk of developing obesity and CKD later in life. The potential mechanisms underlying the association between obesity and CKD include hemodynamic factors, metabolic effects, and lipid nephrotoxicity. Weight reduction via increased physical activity, caloric restriction, treatment with angiotensin-converting enzyme inhibitors, and judicious bariatric surgery can be used to control obesity and obesity-related kidney disease. Preventive strategies to halt the obesity epidemic in the healthcare community are needed to reduce the widespread deleterious consequences of obesity including CKD development and progression.

Adiponectin in renal fibrosis

Renal fibrosis is an inevitable consequence of parenchymal scarring and is the common final pathway that mediates almost all progressive renal diseases. Adiponectin, a hormone produced by adipose tissue, possesses potent anti-insulin, anti-inflammatory, and anti-fibrotic properties. Reportedly, adiponectin serves as an important messenger that facilitates complex interactions between adipose tissue and other metabolically related organs. In recent years, a growing body of evidence supports adiponectin involvement in renal fibrosis. These studies provide a deeper understanding of the molecular mechanism of action of adiponectin in renal fibrosis and also offer a potential preventive and therapeutic target for renal fibrosis. In this review, the physiological role of adiponectin is briefly introduced, and then the mechanism of adiponectin-mediated renal fibrosis and the related signaling pathways are described. Finally, we summarize the findings regarding the clinical value of adiponectin in renal fibrotic diseases and prospected its application potential.

ADIPOQ rs2241766 Gene Polymorphism and Predisposition to Diabetic Kidney Disease

BACKGROUND

This meta-analysis was performed to obtain a more comprehensive estimation of the role of the single nucleotide polymorphism (SNP) rs2241766 in the ADIPOQ gene in the occurrence of diabetic kidney disease (DKD).

METHODS

Relevant studies were identified from digital databases such as Embase, PubMed, Medline, Cochrane Library, Google Scholar, WanFang, and Chinese National Knowledge Infrastructure (CNKI). Odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs) were pooled by means of fixed- or random-effects models. Interstudy heterogeneity was examined using the Q test and I ² statistic, and sensitivity analysis was implemented to test the statistical stability of the overall estimates. Begg's funnel plot and Egger's test were applied to inspect potential publication bias among the included studies.

RESULTS

The overall ORs reflected a positive correlation between the ADIPOQ rs2241766 polymorphism and susceptibility to DKD in the GG vs. TT and GG vs. TT+TG comparisons (OR = 1.51, 95%CI = 1.16 - 1.95; OR = 1.43, 95%CI = 1.11 - 1.85). After stratification analyses by ethnicity and disease type, a similar trend was also revealed in the Caucasian and African subgroups as well as in the type 2 diabetes mellitus (T2DM) subgroup.

CONCLUSION

The ADIPOQ rs2241766 polymorphism may be associated with an increased risk of DKD, especially in Caucasian and African populations as well as in T2DM patients.

Serum cystatin C as an early marker of nephropathy among type 2 diabetics: A meta-analysis

AIM

The varying views as to the usefulness of serum cystatin C (CysC) as an early marker of diabetic nephropathy (DN) prompted us to investigate existing literature to determine whether serum CysC can be used as an early marker of DN using a meta-analysis approach.

MATERIALS AND METHODS

Twelve studies written in English were retrieved from PubMed using various key search terms. Data were extracted from the included studies by two of the authors and was subjected to statistical analysis using Review Manager 5.3 and Meta-Essentials. Levels of serum CysC were compared between the study groups using the standardized mean difference (SMD) and 95% confidence interval (CI).

RESULTS

Overall outcomes indicate that serum CysC levels are higher among those with microalbuminuria (MI) and macroalbuminuria (MA) than those in the control group (CN) and those with normoalbuminuria (NO). However, these findings were heterogeneous, which warranted an investigation using the Galbraith plot. Heterogeneity was either reduced or lost in the post-outlier outcomes indicating combinability of the studies.

CONCLUSION

Serum CysC is shown to be a superior biomarker in the early diagnosis of DN. However, further studies are still needed to verify our claims.