Peri-renal fat thickness is positively associated with the urine albumin excretion rate in patients with type 2 diabetes

The role of perirenal adipose tissue deposition in chronic kidney disease progression: Mechanisms and therapeutic implications

Chronic kidney disease (CKD) represents a significant and escalating global health challenge, with morbidity and mortality rates rising steadily. Evidence increasingly implicates perirenal adipose tissue (PRAT) deposition as a contributing factor in the pathogenesis of CKD. This review explores how PRAT deposition may exert deleterious effects on renal structure and function. The anatomical proximity of PRAT to the kidneys not only potentially causes mechanical compression but also leads to the dysregulated secretion of adipokines and inflammatory mediators, such as adiponectin, leptin, visfatin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and exosomes. Additionally, PRAT deposition may contribute to renal lipotoxicity through elevated levels of free fatty acids (FFA), triglycerides (TAG), diacylglycerol (DAG), and ceramides (Cer). PRAT deposition is also linked to the hyperactivation of the renin-angiotensin-aldosterone system (RAAS), which further exacerbates CKD progression. Recognizing PRAT deposition as an independent risk factor for CKD underscores the potential of targeting PRAT as a novel strategy for the prevention and management of CKD. This review further discusses interventions that could include measuring PRAT thickness to establish a baseline, managing metabolic risk factors that promote its deposition, and inhibiting key PRAT-induced signaling pathways.

Association between red cell distribution width/serum albumin ratio and diabetic kidney disease

BACKGROUND

Previous studies have shown that the red cell distribution width (RDW)/serum albumin ratio (RA) is an integrative and new inflammatory marker. RA is associated with clinical outcomes in a variety of diseases, but the clinical value of RDW/RA in the assessment of diabetic kidney disease (DKD) has not been elucidated. We examined the link between diabetic RA and DKD while controlling for a wide variety of possible confounders.

METHODS

Retrospective cohort analysis of the National Health and Nutrition Examination Survey (NHANES: 2009-2018) database from the Second Affiliated Hospital and Yuying Children's Hospital and the Wenzhou Medical University (WMU) database was conducted. Multivariate logistic regression analysis was used to assess the association between RA and DKD.

RESULTS

Overall, 4513 diabetic patients from the NHANES database (n = 2839) and the WMU (n = 1412) were included in this study; 974 patients were diagnosed with DKD in NHANES and 462 in WMU. In the NHANES cohort, diabetes mellitus (DM) patients with higher RA level had a higher risk of DKD (odds ratio = 1.461, 95% confidence interval: 1.250-1.707, p < 0.00001). After adjusting for confounders and propensity score-matched (PSM) analysis, both shown RA levels were independently linked to DKD (pAdjust = 0.00994, pPSM = 0.02889). Similar results were also observed in the WMU cohort (p < 0.00001).

CONCLUSIONS

The study observes that the RA was an independent predictor of DKD in DM patients. The RA, a biomarker that is cost-effective and easy-to-access, may have potential for risk stratification of DKD.

Renal fat deposition measured on dixon-based MRI is significantly associated with early kidney damage in obesity

PURPOSE

To investigate the renal fat deposition on Dixon-based magnetic resonance imaging (MRI) and to explore the predictive value of renal fat biomarkers of magnetic resonance (MR-RFBs) for early kidney damage in obesity.

METHODS

This prospective study included 56 obese volunteers and 47 non-obese healthy volunteers. All volunteers underwent renal magnetic resonance examinations. The differences in MR-RFBs [including renal proton density fat fraction (PDFF), renal sinus fat volume (RSFV), and perirenal fat thickness (PRFT)] measured on Dixon-based MRI between the obese and non-obese volunteers were analyzed using a general linear model, taking sex, age, diabetes, and hypertension as covariates. The relationship between estimated glomerular filtration rate (eGFR) and demographic, laboratory, and imaging parameters in obese volunteers was examined by correlation analysis.

RESULTS

Obese volunteers had higher MR-RFBs than non-obese volunteers after controlling for confounders (all p < 0.001). Renal PDFF (r = - 0.383; p = 0.004), RSFV (r = - 0.368; p = 0.005), and PRFT (r = - 0.451; p < 0.001) were significantly negatively correlated with eGFR in obesity. After adjusting for age, sex, body mass index, diabetes, hypertension, visceral adipose tissue, subcutaneous adipose tissue, renal PDFF, and RSFV, PRFT remained independently negatively associated with eGFR (β = - 0.587; p = 0.003).

CONCLUSIONS

All MR-RFBs are negatively correlated with eGFR in obesity. The MR-RFBs, especially PRFT, may have predictive value for early kidney damage in obesity.

The potential mechanisms underlying the modulating effect of perirenal adipose tissue on hypertension: Physical compression, paracrine, and neurogenic regulation

Hypertension, a prevalent global cardiovascular disease, affects approximately 45.4 % of adults worldwide. Despite advances in therapy, hypertension continues to pose a significant health risk due to inadequate management. It has been established that excessive adiposity contributes majorly to hypertension, accounting for 65 to 75 % of primary cases. Fat depots can be categorised into subcutaneous and visceral adipose tissue based on anatomical and physiological characteristics. The metabolic impact and the risk of hypertension are determined more significantly by visceral fat. Perirenal adipose tissue (PRAT), a viscera enveloping the kidney, is known for its superior vascularisation and abundant innervation. Although traditionally deemed as a mechanical support tissue, recent studies have indicated its contributing potential to hypertension. Hypertensive patients tend to have increased PRAT thickness compared to those without, and there is a positive correlation between PRAT thickness and elevated systolic blood pressure. This review encapsulates the anatomical characteristics and biogenesis of PRAT. We provide an overview of the potential mechanisms where PRAT may modulate blood pressure, including physical compression, paracrine effects, and neurogenic regulation. PRAT has become a promising target for hypertension management, and continuous effort is required to further explore the underlying mechanisms.

Role of perirenal adiposity in renal dysfunction among CKD individuals with or without diabetes: a Japanese cross-sectional study

INTRODUCTION

It remains unclear whether increased perirenal fat (PRF) accumulation is equally related to renal involvement in patients with and without diabetes mellitus (DM). We evaluated the association between PRF volume (PRFV) and low glomerular filtration rate (GFR) and proteinuria in people with or without type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We performed a cross-sectional analysis of 473 individuals without T2DM (non-DM, n=202) and with T2DM (DM, n=271). PRFV (cm3), obtained from non-contrast CT, was indexed as PRF index (PRFV/body surface area, cm3/m2). Multivariate-adjusted models were used to determine the ORs of PRFV and PRFV index for detecting estimated GFR (eGFR) decrease of <60 mL/min/1.73 m2 proteinuria onset, or both.

RESULTS

Although body mass index (BMI), visceral fat area, and waist circumference were comparable between the non-DM and DM groups, kidney volume, PRFV, and PRFV index were higher in individuals with T2DM than in those without T2DM. In the multivariate analysis, after adjusting for age, sex, BMI, hypertension, smoking history, and visceral fat area ≥100 cm2, the cut-off values of PRFV index were associated with an eGFR<60 in individuals with DM (OR 6.01, 95% CI 2.20 to 16.4, p<0.001) but not in those without DM.

CONCLUSIONS

PRFV is associated with low eGFR in patients with T2DM but not in those without T2DM. This suggests that PRF accumulation is more closely related to the onset and progression of diabetic kidney disease (DKD) than non-DKD. Clarifying the mechanisms through which PRF influences DKD development could pave the way for novel prevention and treatment strategies.

Abdominal adipose tissue and type 2 diabetic kidney disease: adipose radiology assessment, impact, and mechanisms

Diabetic kidney disease (DKD) is a significant healthcare burden worldwide that substantially increases the risk of kidney failure and cardiovascular events. To reduce the prevalence of DKD, extensive research is being conducted to determine the risk factors and consequently implement early interventions. Patients with type 2 diabetes mellitus (T2DM) are more likely to be obese. Abdominal adiposity is associated with a greater risk of kidney damage than general obesity. Abdominal adipose tissue can be divided into different fat depots according to the location and function, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), perirenal adipose tissue (PAT), and renal sinus adipose tissue (RSAT), which can be accurately measured by radiology techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI). Abdominal fat depots may affect the development of DKD through different mechanisms, and radiologic abdominal adipose characteristics may serve as imaging indicators of DKD risk. This review will first describe the CT/MRI-based assessment of abdominal adipose depots and subsequently describe the current studies on abdominal adipose tissue and DKD development, as well as the underlying mechanisms in patients of T2DM with DKD.

Finerenone protects against progression of kidney and cardiovascular damage in a model of type 1 diabetes through modulation of proinflammatory and osteogenic factors

The non-steroidal mineralocorticoid receptor antagonist (MRA) finerenone (FIN) improves kidney and cardiovascular outcomes in patients with chronic kidney disease (CKD) in type 2 diabetes (T2D). We explored the effect of FIN in a novel model of type 1 diabetic Munich Wistar Frömter (MWF) rat (D) induced by injection of streptozotocin (15 mg/kg) and additional exposure to a high-fat/high-sucrose diet. Oral treatment with FIN (10 mg/kg/day in rat chow) in diabetic animals (D-FIN) was compared to a group of D rats receiving no treatment and a group of non-diabetic untreated MWF rats (C) (n = 7-10 animals per group). After 6 weeks, D and D-FIN exhibited significantly elevated blood glucose levels (271.7 ± 67.1 mg/dl and 266.3 ± 46.8 mg/dl) as compared to C (110.3 ± 4.4 mg/dl; p < 0.05). D showed a 10-fold increase of kidney damage markers Kim-1 and Ngal which was significantly suppressed in D-FIN. Blood pressure, pulse wave velocity (PWV) and arterial collagen deposition were lower in D-FIN, associated to an improvement in endothelial function due to a reduction in pro-contractile prostaglandins, as well as reactive oxygen species (ROS) and inflammatory cytokines (IL-1, IL-6, TNFα and TGFβ) in perivascular and perirenal adipose tissue (PVAT and PRAT, respectively). In addition, FIN restored the imbalance observed in CKD between the procalcifying BMP-2 and the nephroprotective BMP-7 in plasma, kidney, PVAT, and PRAT. Our data show that treatment with FIN improves kidney and vascular damage in a new rat model of DKD with T1D associated with a reduction in inflammation, fibrosis and osteogenic factors independently from changes in glucose homeostasis.

Upregulation in Inflammation and Collagen Expression in Perirenal but Not in Mesenteric Adipose Tissue from Diabetic Munich Wistar Frömter Rats

Perirenal adipose tissue (PRAT) surrounding the kidney is emerging as a player and novel independent risk factor in diabetic kidney disease (DKD); DKD is a complication of diabetes and is a major cause of increased cardiovascular (CV) risk and CV mortality in affected patients. We determined the effect of diabetes induction on (i) kidney and CV damage and (ii) on the expression of proinflammatory and profibrotic factors in both the PRAT and the mesenteric adipose tissue (MAT) of Munich Wistar Frömter (MWF) rats. The 16-week-old male MWF rats (n = 10 rats/group) were fed standard chow (MWF-C) or a high-fat/high-sucrose diet for 6 weeks together with low-dose streptozotocin (15 mg/kg i.p.) at the start of dietary exposure (MWF-D). Phenotyping was performed at the end of treatment through determining water intake, urine excretion, and oral glucose tolerance; use of the homeostatic model assessment-insulin resistance index (HOMA-IR) evidenced the development of overt diabetes manifestation in MWF-D rats. The kidney damage markers Kim-1 and Ngal were significantly higher in MWF-D rats, as were the amounts of PRAT and MAT. A diabetes-induced upregulation in IL-1, IL-6, Tnf-α, and Tgf-β was observed in both the PRAT and the MAT. Col1A1 was increased in the PRAT but not in the MAT of MWF-D, whereas IL-10 was lower and higher in the PRAT and the MAT, respectively. Urinary albumin excretion and blood pressure were not further increased by diabetes induction, while heart weight was higher in the MWF-D. In conclusion, our results show a proinflammatory and profibrotic in vivo environment in PRAT induced by diabetes which might be associated with kidney damage progression in the MWF strain.

The Fatty Kidney and Beyond: A Silent Epidemic

As the prevalence of obesity rises in the United States, so does the incidence of obesity-related kidney disease. Obesity itself is an independent risk factor for chronic kidney disease where the pathophysiology is complex, involving altered hemodynamics, renin-angiotensin-aldosterone system overactivation, and adipokines leading to inflammation and fibrosis. Obesity-related kidney disease comprises both obesity-related glomerulopathy and fatty kidney disease. Obesity-related glomerulopathy is a consequence of glomerular hyperfiltration and often presents clinically with subnephrotic proteinuria and pathologically with glomerulomegaly with or without focal glomerulosclerosis. Fatty kidney disease is the effect of renal ectopic fat contributing to chronic kidney disease. Whether the renal ectopic fat is a distinct clinical entity or a pathologic mechanism contributing to obesity-related glomerulopathy, the treatment paradigm of weight and proteinuria reduction remains the same. We present the pathophysiology behind obesity-related kidney disease, clinical outcomes, and treatment strategies, which include lifestyle interventions, use of renin-angiotensin-aldosterone system inhibitors, glucagon-like peptide 1 receptor agonists, sodium-glucose co-transporter-2 inhibitors, and bariatric surgery. With old and novel therapeutics, we are attempting to stave off the silent epidemic that obesity-related kidney disease is becoming.

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.

Pararenalfat Tissue: Rate of Pararenal Obesity and Relation with Anthropometric Indices of Obesity

Aim. To study a rate of excessive pararenal fat tissue (PRFT) thickness and its relationship with anthropometric obesity indices.Material and methods. 372 patients (152 men and 220 women) were included in the study, the average age was 63.5±13.3 years. There were measured: height, weight, waist circumference (WC), hip circumference (HC), body mass index (BMI), WC/height ratio, sagittal abdominal diameter (SAD), body fat percentage (BFP), body surface area (BSA), body adiposity index (BAI) and visceral obesity index (VAI). All subjects underwent abdominal multispiral computed tomography. PRFT thickness was detected on a single slice at the level of the left renal vein.Results. 27% of the examined group had BMI<25 kg/m2, 28% – excessive body mass, 45% – obesity. The median PRFT thickness was 1.61 (1.03; 2.46) cm. There were correlations between PRFT thickness and glucose (r=0,64, p<0,05) and uric acid (r=0,46, p<0,05) levels. The threshold of referential PRFT thickness was 1,91cm. The rate of pararenal obesity was 9,9% among those with normal body mass, 29,3% in excessive body mass, 66,1% – in 1 class obesity, 67,7% – in 2 class, and 90,1% – in 3 class. The correlation analysis revealed a significant positive correlation between the PRFT thickness and obesity indices with exception of VAI and BAI: with BMI (r=0.43, p<0.05), WC (r=0.57, p<0.05), SAD (r=0.58, p<0.05), BFP (r=0.48, p<0.05), WC/height ratio (r=0.46, p<0.05), and BSA (r=0.58, p<0.05).Conclusion. Excessive PRFT may be detected isolated without any external anthropometric signs of obesity, wherein it is an active component of metabolic disorders typical for obesity. The most significant indices for the detection of pararenal obesity may be WC, SAD, and BSA.

Obesity-related glomerulopathy: Current approaches and future perspectives

Obesity-related glomerulopathy (ORG) is a silent comorbidity which is increasing in incidence as the obesity epidemic escalates. ORG is associated with serious health consequences including chronic kidney disease, end-stage renal disease (ESRD), and increased mortality. Although the pathogenic mechanisms involved in the development of ORG are not fully understood, glomerular hemodynamic changes, renin-angiotensin-aldosterone system (RAAS) overactivation, insulin-resistance, inflammation and ectopic lipid accumulation seem to play a major role. Despite albuminuria being commonly used for the non-invasive evaluation of ORG, promising biomarkers of early kidney injury that are emerging, as well as new approaches with proteomics and metabolomics, might permit an earlier diagnosis of this disease. In addition, the assessment of ectopic kidney fat by renal imaging could be a useful tool to detect and evaluate the progression of ORG. Weight loss interventions appear to be effective in ORG, although large-scale trials are needed. RAAS blockade has a renoprotective effect in patients with ORG, but even so, a significant proportion of patients with ORG will eventually progress to ESRD despite therapeutic efforts. It is noteworthy that certain antidiabetic agents such as sodium-glucose cotransporter 2 inhibitors (SGLT2i) or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) could be useful in the treatment of ORG through different pleiotropic effects. In this article, we review current approaches and future perspectives in the care and treatment of ORG.

Perirenal Fat Thickness: A Surrogate Marker for Metabolic Syndrome in Chinese Newly Diagnosed Type 2 Diabetes

OBJECTIVE

Increasing evidence suggested that perirenal fat thickness (PrFT) was associated with metabolic risk factors. This study aimed to assess the association between PrFT and metabolic syndrome (MetS) in Chinese newly diagnosed type 2 diabetes (T2DM), further evaluating the ability of PrFT in identifying MetS.

METHOD

A total of 445 Chinese newly diagnosed T2DM were enrolled in this study from January to June 2021. Demographic and anthropometric information were collected. PrFT was evaluated by CT scan on Revolution VCT 256. MetS was based on the Chinese Diabetes Society definition. Receiver operating characteristic (ROC) curve was conducted to assess the optimal cutoff value of PrFT in identifying MetS.

RESULTS

Overall, the prevalence of MetS was 57.5% (95% CI: 54.0-64.0%) in men and 58.9% (95% CI: 52.3-65.5%) in women separately. The correlation analysis showed that PrFT was significantly correlated with metabolic risk factors like body mass index, waist circumference, triglycerides, high-density lipoprotein cholesterol, systolic blood pressure, diastolic blood pressure, uric acid, and insulin resistance. PrFT was also shown to be independently associated with MetS after adjustment for other confounders. The odds ratios (ORs, 95% CI) were 1.15 (1.03-1.38) in men and 1.31 (1.08-1.96) in women (P < 0.05). The ROC curves showed a good predictive value of PrFT for MetS. The areas under the curve of PrFT identifying MetS were 0.895 (95% CI: 0.852-0.939) in men and 0.910 (95% CI: 0.876-0.953) in women (P < 0.001). The optimal cutoff values of PrFT were 14.6 mm (sensitivity: 83.8%, specificity: 89.6%) for men and 13.1 mm (sensitivity: 87.6%, specificity: 91.1%) for women.

CONCLUSIONS

PrFT was significantly associated with MetS and showed a powerful predictive value for it, which suggested that PrFT can be an applicable surrogate marker for MetS in Chinese newly diagnosed T2DM.

CLINICAL TRIAL REGISTRATION

This study was registered in clinicaltrials.gov (ChiCTR2100052032).

The Perirenal Fat Thickness Was Associated with Nonalcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus

PURPOSE

Obesity is an important risk factor for nonalcoholic fatty liver disease (NAFLD). Perirenal fat and paranephric fat were seldom studied in NAFLD. We aimed to explore the relationship between perirenal fat thickness (PrFT) and paranephric fat thickness (PnFT) and NAFLD in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

A total of 493 diabetic patients including 231 NAFLD patients were enrolled in our study from September 2019 to December 2020. Patients with NAFLD were categorized into three subgroups according to the severity and fibrosis risk of NAFLD. Anthropometric indices and clinical characteristics were collected from clinical records. PrFT and PnFT were measured via ultrasound. Multivariate logistic regression analysis was used to assess the association between PrFT, PnFT and presence, severity and advanced fibrosis risk of NAFLD.

RESULTS

Compared with non-NAFLD patients, those with NAFLD had significantly higher PrFT and PnFT. The PrFT and PnFT were independently associated with presence of NAFLD and the PrFT was independently associated with the advanced fibrosis risk of NAFLD after adjusting confounding factors.

CONCLUSION

The PrFT was independently associated with the presence and advanced fibrosis risk of NAFLD in patients with T2DM.

The Utility of Perirenal Fat in Determining the Risk of Onset and Progression of Diabetic Kidney Disease

BACKGROUND

Perirenal fat (PRF) has multiple effects on the kidney through its physical structure and adipocytokine-secreting ability. The present study explored the relationship between PRF thickness and the onset and progression of albuminuria in patients with diabetes.

METHODS

In the cross-sectional analysis, we screened 959 patients from 8764 subjects with type 2 diabetes mellitus (T2DM) who met the inclusion criteria and measured their perirenal fat thickness (PFT) using color Doppler ultrasound. A group of laboratory indexes were included in the analysis models. In a longitudinal study, a total of 218 patients with a baseline UACR <30 mg/g were included in the follow-up study.

RESULTS

In a cross-sectional analysis, patients with diabetes and higher PFT presented with higher albuminuria. Multiple logistic regression analysis indicated that PFT was an independent risk factor for the degree of albuminuria in patients with T2DM (odds ratio = 4.186, 95%CI: 2.290-7.653, P < 0.001). In a longitudinal study, 218 albuminuria-free patients with T2DM at the baseline were followed up for a mean of 12.3 months. Based on the cutoff value from the ROC diagnostic test in the cross-sectional study, patients were divided into two groups: higher PFT (H-PFT) and lower PFT (L-PFT). Kaplan-Meier survival curve analysis showed that H-PFT was associated with a higher incidence of albuminuria than L-PFT (log-rank test, χ2 = 4.522, P = 0.033). Cox regression analysis showed that PFT was a risk factor for the earlier onset of albuminuria (hazard ratio 2.83, 95% CI: 1.34-4.88, P < 0.001).

CONCLUSIONS

PRF evaluated by color Doppler ultrasound is an easy and reliable tool for predicting the onset and progression of albuminuria in patients with T2DM.

Cardiorenal Fat: A Cardiovascular Risk Factor With Implications in Chronic Kidney Disease

There is a growing interest in the potential role of adipose tissues in cardiac and renal pathophysiology, and determining the mechanisms by which fat compartments around the heart and kidneys influence cardiovascular disease is of clinical importance in both general and high-risk populations. Epicardial fat and perirenal fat have been associated with adverse outcomes in chronic kidney disease (CKD) patients. Epicardial fat is a rich source of free fatty acids and is capable of secreting inflammatory and pro-atherogenic cytokines that promote atherosclerosis through a local paracrine effect. Recent evidence has demonstrated that perirenal fat has a closer correlation with kidney diseases than other visceral fat deposits in obesity or metabolic disturbances. Moreover, perirenal fat has been reported as an independent risk factor for CKD progression and even associated with cardiorenal dysfunction. Accordingly, these forms of organ-specific fat deposits may act as a connecter between vascular and cardiorenal disease. This review explores the possible links between epicardial and perirenal fat and its significant role as a modulator of cardiorenal dysfunction in CKD patients.

Ectopic Fat Accumulation in Pancreas and Heart

Ectopic fat is found in liver, muscle, and kidney and is known to accumulate as visceral fat. In recent years, ectopic fat has also been observed in the pancreas, and it has been said that pancreatic fat accumulation is related to the pathophysiology of diabetes and the onset of diabetes, but the relationship has not yet been determined. In the heart, epicardium fat is another ectopic fat, which is associated with the development of coronary artery disease. Ectopic fat is also observed in the myocardium, and diabetic patients have more fat accumulation in this tissue than nondiabetic patients. Myocardium fat is reported to be related to diastolic cardiac dysfunction, which is one of the characteristics of the complications observed in diabetic patients. We recently reported that ectopic fat accumulation was observed in coronary arteries of a type 2 diabetic patient with intractable coronary artery disease, and coronary artery is attracting attention as a new tissue of ectopic fat accumulation. Here, we summarize the latest findings focusing on the relationship between ectopic fat accumulation in these organs and diabetic pathophysiology and complications, then describe the possibility of future treatments targeting these ectopic fat accumulations.

Perirenal Adipose Tissue-Current Knowledge and Future Opportunities

The perirenal adipose tissue (PRAT), a component of visceral adipose tissue, has been recently recognized as an important factor that contributes to the maintenance of the cardiovascular system and kidney homeostasis. PRAT is a complex microenvironment consisting of a mixture of white adipocytes and dormant and active brown adipocytes, associated with predipocytes, sympathetic nerve endings, vascular structures, and different types of inflammatory cells. In this review, we summarize the current knowledge about PRAT and discuss its role as a major contributing factor in the pathogenesis of hypertension, obesity, chronic renal diseases, and involvement in tumor progression. The new perspectives of PRAT as an endocrine organ and recent knowledge regarding the possible activation of dormant brown adipocytes are nowadays considered as new areas of research in obesity, in close correlation with renal and cardiovascular pathology. Supplementary PRAT complex intervention in tumor progression may reveal new pathways involved in carcinogenesis and, implicitly, may identify additional targets for tailored cancer therapy.