Prognostic impact of renal sinus fat accumulation in patients with chronic kidney disease

Association of visceral adipose tissue with albuminuria and interaction between visceral adiposity and diabetes on albuminuria

AIMS

To explore the correlation between visceral adipose tissue and albuminuria, and whether there is interaction between visceral adipose tissue and diabetes on albuminuria.

METHODS

The study subjects were adult subjects (age ≥ 18 years) from the National Health and Nutrition Examination Surveys (NHANES) database of the USA in 2017-2018. Visceral fat area (VFA) was measured by dual-energy X-ray absorptiometry (DXA). Subjects were divided into three groups according to VFA: low (VFA 0-60cm2), medium (VFA 60-120 cm2) and high (VFA ≥ 120 cm2). Albuminuria was defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. The statistical analysis software used is STATA 17.0.

RESULTS

Data pertaining to 2965 participants (2706 without albuminuria) were included in the analysis. High VFA is an independent risk factor for albuminuria (OR 1.367, 95% CI 1.023-1.827). In the low-VFA group, there is no significant association between diabetes and albuminuria (OR 1.415, 95% CI 0.145-13.849). In the medium-VFA group, diabetes is an independent risk factor for albuminuria (OR 2.217, 95% CI 1.095-4.488). In the high-VFA group, diabetes is also an independent risk factor for albuminuria (OR 5.150, 95% CI 3.150-8.421). There is an additive interaction between high VFA (VFA ≥ 120 cm2) and diabetes on the effect of albuminuria (RERI 3.757, 95% CI 0.927-6.587, p = 0.009), while no multiplication interaction (OR 1.881, 95% CI 0.997-1.023, p = 0.141).

CONCLUSIONS

High VFA may represent an independent risk factor for albuminuria. The amount of visceral fat may affect the effect of diabetes on albuminuria. The higher the visceral fat, the stronger the correlation between diabetes and albuminuria should be present. We suppose an additive interaction between VFA and diabetes on the effect of albuminuria.

Renal sinus fat is associated with intrarenal hemodynamic abnormalities independent of visceral fat in patients with chronic kidney disease

OBJECTIVE

Obesity is a risk factor of chronic kidney disease (CKD), contributing to the rising incidence of cardiometabolic diseases. Renal sinus fat (RSF) is an ectopic fat depot located at the renal cavity that could impair renal function and hemodynamic through compression of renal structures. The major purpose of this study was to explore the relationship between RSF accumulation and renal dysfunction in CKD patients.

METHODS

We evaluated the associations between computed tomography measured RSF volume and key clinical and histologic parameters involved in renal function and hemodynamics in 132 well-characterized CKD patients who underwent renal biopsy (median age: 62 years; 63.6% men).

RESULTS

RSF volume normalized by renal volume (RSF%) positively correlated with obesity-related traits such body mass index and visceral fat volume (VFV) (all P < 0.001) whereas it negatively correlated with estimated glomerular filtration rate (eGFR) (ρ = -0.42, P < 0.001) and 24-h urinary creatinine clearance (CCr) (ρ = -0.34, P < 0.001). Notably, we found robust positive correlations between RSF% and renal resistive index (RRI) measured by the Doppler ultrasound (ρ = 0.40, P < 0.001), and the histological severity of global glomerular sclerosis (ρ = 0.48, P < 0.001) and interstitial fibrosis and tubular atrophy (IFTA) (ρ = 0.35, P < 0.001). In the multivariate linear regression models, after accounting for potential confounders including VFV, RSF% remained significantly associated with CCr (β = -0.26, P < 0.001), RRI (β = 0.17, P = 0.022), global glomerular sclerosis (β = 0.21, P = 0.002), and IFTA (β = 0.17, P = 0.012).

CONCLUSION

RSF accumulation is associated with renal dysfunction and hemodynamic abnormalities independent of visceral adiposity. Our results suggest that RSF may have a potential unique role in the pathogenesis of CKD.

Association Between Renal Sinus Fat and Cardiometabolic and Renin-Angiotensin System Parameters in Primary Aldosteronism

Context

Renal sinus fat (RSF) accumulation is associated with cardiometabolic diseases, such as obesity, diabetes, hypertension, and chronic kidney disease. However, clinical implications of RSF in primary aldosteronism (PA) remain unclear.

Objective

We aimed to investigate relationships between RSF volume and key cardiometabolic and renin-angiotensin system (RAS) parameters in PA patients and clarify the differences in these relationships between unilateral and bilateral subtypes.

Methods

We analyzed data obtained from well-characterized PA patients that involved 45 unilateral (median age: 52 years; 42.2% men) and 92 bilateral patients (51 years; 42.4% men).

Results

RSF volume normalized by renal volume (RSF%) was greater in the unilateral group than in the bilateral group (P < .05). RSF% was greater in men than in women (P < .05). RSF% positively correlated with parameters related to cardiometabolic risk, including age, body mass index, visceral fat volume, creatinine, triglycerides/high-density lipoprotein cholesterol ratio, uric acid, fasting glucose, and C-reactive protein regardless of PA subtypes (all P < .05). Intriguingly, RSF% positively correlated with plasma aldosterone concentration (PAC), aldosterone-to-renin ratio, and intact parathyroid hormone (iPTH) (all P < .05) in bilateral patients but did not correlate with RAS parameters and even showed an opposite trend in unilateral patients. In subgroup analyses by sex, these distinctions became more evident in women. After adjustment for potential confounders, RSF% remained positively correlated with PAC and iPTH in bilateral patients.

Conclusion

Our results indicate that RSF accumulation is involved in cardiometabolic dysfunction associated with PA. However, there were distinct correlations between RSF volume and RAS parameters according to sex and PA subtypes.

Obesity-Related Kidney Disease: Current Understanding and Future Perspectives

Obesity is a serious chronic disease and an independent risk factor for the new onset and progression of chronic kidney disease (CKD). CKD prevalence is expected to increase, at least partly due to the continuous rise in the prevalence of obesity. The concept of obesity-related kidney disease (OKD) has been introduced to describe the still incompletely understood interplay between obesity, CKD, and other cardiometabolic conditions, including risk factors for OKD and cardiovascular disease, such as diabetes and hypertension. Current therapeutics target obesity and CKD individually. Non-pharmacological interventions play a major part, but the efficacy and clinical applicability of lifestyle changes and metabolic surgery remain debatable, because the strategies do not benefit everyone, and it remains questionable whether lifestyle changes can be sustained in the long term. Pharmacological interventions, such as sodium-glucose co-transporter 2 inhibitors and the non-steroidal mineralocorticoid receptor antagonist finerenone, provide kidney protection but have limited or no impact on body weight. Medicines based on glucagon-like peptide-1 (GLP-1) induce clinically relevant weight loss and may also offer kidney benefits. An urgent medical need remains for investigations to better understand the intertwined pathophysiologies in OKD, paving the way for the best possible therapeutic strategies in this increasingly prevalent disease complex.