Impact of visceral fat area in patients with chronic kidney disease

Exploring Adiposity and Chronic Kidney Disease: Clinical Implications, Management Strategies, Prognostic Considerations

Obesity poses a significant and growing risk factor for chronic kidney disease (CKD), requiring comprehensive evaluation and management strategies. This review explores the intricate relationship between obesity and CKD, emphasizing the diverse phenotypes of obesity, including sarcopenic obesity and metabolically healthy versus unhealthy obesity, and their differential impact on kidney function. We discuss the epidemiological evidence linking elevated body mass index (BMI) with CKD risk while also addressing the paradoxical survival benefits observed in obese CKD patients. Various measures of obesity, such as BMI, waist circumference, and visceral fat assessment, are evaluated in the context of CKD progression and outcomes. Mechanistic insights into how obesity promotes renal dysfunction through lipid metabolism, inflammation, and altered renal hemodynamics are elucidated, underscoring the role of adipokines and the renin-angiotensin-aldosterone system. Furthermore, the review examines current strategies for assessing kidney function in obese individuals, including the strengths and limitations of filtration markers and predictive equations. The management of obesity and associated comorbidities like arterial hypertension, type 2 diabetes mellitus, and non-alcoholic fatty liver disease in CKD patients is discussed. Finally, gaps in the current literature and future research directions aimed at optimizing the management of obesity-related CKD are highlighted, emphasizing the need for personalized therapeutic approaches to mitigate the growing burden of this intertwined epidemic.

Exploring the nexus: The place of kidney diseases within the cardiovascular-kidney-metabolic syndrome spectrum

Cardiovascular-kidney-metabolic (CKM) syndrome and chronic kidney disease (CKD) are two significant comorbidities affecting a large proportion of the general population with considerable crosstalk. In addition to substantial co-incidence of CKD and CKM syndrome in epidemiological studies, clinical and pre-clinical studies have identified similar pathophysiological pathways leading to both entities. Patients with CKM syndrome are more prone to develop acute kidney injury and CKD, while therapeutic alternatives and their success rates are considerably lower in such patient groups. Nevertheless, the association between CKM syndrome and CKD or ESKD is bidirectional rather than being a cause-effect relationship as patients with CKD are also prone to develop peripheral insulin resistance, high blood pressure, and dyslipidemia. Furthermore, such patients are less likely to receive kidney transplantation in addition to the higher allograft dysfunction risk. We hereby aim to evaluate the association in-between kidney diseases and CKM syndrome, including epidemiological data, pre-clinical studies with pathophysiological pathways, and potential therapeutic perspectives.

Factors associated with early-onset intracranial aneurysms in patients with autosomal dominant polycystic kidney disease

BACKGROUND

Recently, the importance of attribute-based medicine has been emphasized. The effects of early-onset intracranial aneurysms on patients can be significant and long-lasting. Herein, we compared the factors associated with intracranial aneurysms in patients with autosomal dominant polycystic kidney disease (ADPKD) according to age categories (≥ 50 years, < 50 years).

METHODS

We included 519 ADPKD patients, with a median age of 44 years, estimated glomerular filtration rate of 54.5 mL/min/1.73 m2, and total follow-up duration of 3104 patient-years. Logistic regression analyses were performed to determine factors associated with intracranial aneurysms.

RESULTS

Regarding the presence of intracranial aneurysm, significant interactions were identified between the age category (age ≥ 50 years), female sex (P = 0.0027 for the interaction) and hypertension (P = 0.0074 for the interaction). Female sex and hypertension were associated with intracranial aneurysm risk factors only in patients aged ≥ 50 years. The presence of intracranial aneurysm was significantly associated with chronic kidney disease (CKD) stages 4-5 (odds ratio [OR] = 3.87, P = 0.0007) and family history of intracranial aneurysm or subarachnoid hemorrhage (OR = 2.30, P = 0.0217) in patients aged < 50 years. For patients aged ≥ 50 years, in addition to the abovementioned factors [OR = 2.38, P = 0.0355 for CKD stages 4-5; OR = 3.49, P = 0.0094 for family history of intracranial aneurysm or subarachnoid hemorrhage], female sex (OR = 4.51, P = 0.0005), and hypertension (OR = 5.89, P = 0.0012) were also associated with intracranial aneurysm.

CONCLUSION

Kidney dysfunction and family history of intracranial aneurysm or subarachnoid hemorrhage are risk factors for early-onset intracranial aneurysm. Patients aged < 50 years with a family history of intracranial aneurysm or subarachnoid hemorrhage or with CKD stages 4-5 may be at an increased risk of early-onset intracranial aneurysm.

Myosteatosis and aortic calcium score on abdominal CT as prognostic markers in non-dialysis chronic kidney disease patients

We aimed to examine the relationship between abdominal computed tomography (CT)-based body composition data and both renal function decline and all-cause mortality in patients with non-dialysis chronic kidney disease (CKD). This retrospective study comprised non-dialysis CKD patients who underwent consecutive unenhanced abdominal CT between January 2010 and December 2011. CT-based body composition was measured using semiautomated method that included visceral fat, subcutaneous fat, skeletal muscle area and density, and abdominal aortic calcium score (AAS). Sarcopenia and myosteatosis were defined by decreased skeletal muscle index (SMI) and decreased skeletal muscle density, respectively, each with specific cutoffs. Risk factors for CKD progression and survival were identified using logistic regression and Cox proportional hazard regression models. Survival between groups based on myosteatosis and AAS was compared using the Kaplan-Meier curve. 149 patients (median age: 70 years) were included; 79 (53.0%) patients had sarcopenia and 112 (75.2%) had myosteatosis. The median AAS was 560.9 (interquartile range: 55.7-1478.3)/m2. The prognostic factors for CKD progression were myosteatosis [odds ratio (OR) = 4.31, p = 0.013] and high AAS (OR = 1.03, p = 0.001). Skeletal muscle density [hazard ratio (HR) = 0.93, p = 0.004] or myosteatosis (HR = 4.87, p = 0.032) and high AAS (HR = 1.02, p = 0.001) were independent factors for poor survival outcomes. The presence of myosteatosis and the high burden of aortic calcium were significant factors for CKD progression and survival in patients with non-dialysis CKD.

Health effects of the New Nordic Renal Diet in patients with stage 3 and 4 chronic kidney disease, compared with habitual diet: a randomized trial

BACKGROUND

Chronic kidney disease (CKD) leads to an accumulation of waste products and causes adverse cardiometabolic effects.

OBJECTIVES

We investigated the health effects of the New Nordic Renal Diet (NNRD), a novel meal pattern reduced in phosphorus, protein, and sodium.

METHODS

A 26-wk randomized trial compared the NNRD with a habitual diet. The NNRD group received weekly home deliveries of food and recipes. Monthly study visits included fasting blood samples, 24-h urine samples, blood pressure, and anthropometric measurements. Intention-to-treat analysis used linear mixed-effects models.

RESULTS

Sixty patients, mean estimated glomerular filtration rate (eGFR) 34 mL/min/1.73 m2 and body mass index of 25-27 kg/m2, were included and 58 completed. Metabolic syndrome was present in 53% (NNRD group) and 57% (control group). The NNRD group (n = 30) reduced their 24-h urine phosphorus excretion by 19% (-153 mg; 95% confidence interval [CI]: -210, -95), control group (n = 30) (no change), between-group difference -171 mg (95% CI: -233, -109; P < 0.001). Proteinuria was reduced by 39% in the NNRD group (-0.33 g/d; 95% CI: -0.47, -0.18), control group (no change), between-group difference -0.34 g/d (95% CI: -0.52, -0.17; P < 0.001). Plasma urea was reduced by -1.5 mmol/L in the NNRD group (95% CI: -2.1, -0.9), control group (no change), between-group difference -1.4 mmol/L (95% CI: -2.0, -0.7; P < 0.001). Systolic blood pressure fell by -5.2 mmHg in the NNRD group (95% CI: -8.4, -2.1), control group (no change), between-group difference -3.9 mmHg (95% CI; -7.6, -0.2; P = 0.04). The NNRD group lost -1.7 kg (95% CI: -2.6, -0.8), control group (no change), between-group difference -2.0 kg (95% CI: -3.0, -1.0; P < 0.001). There were no effects on eGFR during the 26-wk intervention.

CONCLUSION

NNRD in moderate CKD reduces phosphorus excretion, proteinuria, systolic blood pressure, and weight, mainly by reducing abdominal fat. This trial was registered at clinicaltrials.gov as NCT04579315.

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

BACKGROUND

Obesity is associated with the development and progression of chronic kidney disease (CKD). In the general population, the amount of renal sinus fat was associated with hypertension and renal impairment. However, its impact upon those with CKD remains uncertain.

METHODS

We prospectively included CKD patients who underwent renal biopsy and simultaneously measured their renal sinus fat volume. The association between the percentage of renal sinus fat volume, which was adjusted by kidney volume, and renal outcomes was investigated.

RESULTS

A total of 56 patients (median 55 years old, 35 men) were included. Among baseline characteristics, age and visceral fat volume were positively correlated with the percentage of renal sinus fat volume (p < 0.05). The percentage of renal sinus fat volume was associated with hypertension (p < 0.01) and tended to be associated with max glomerular diameter (p = 0.078) and urine angiotensinogen creatinine ratio (p = 0.064) after adjustment with several clinical factors. The percentage of renal sinus fat volume was significantly associated with a future > 50% decline in estimated glomerular filtration rate (p < 0.05).

CONCLUSIONS

Among those with CKD who required renal biopsy, the amount of renal sinus fat was associated with poor renal outcomes accompanied by systemic hypertension.

Role of Machine Learning-Based CT Body Composition in Risk Prediction and Prognostication: Current State and Future Directions

CT body composition analysis has been shown to play an important role in predicting health and has the potential to improve patient outcomes if implemented clinically. Recent advances in artificial intelligence and machine learning have led to high speed and accuracy for extracting body composition metrics from CT scans. These may inform preoperative interventions and guide treatment planning. This review aims to discuss the clinical applications of CT body composition in clinical practice, as it moves towards widespread clinical implementation.

Visceral fat and attribute-based medicine in chronic kidney disease

Visceral adipose tissue plays a central role in obesity and metabolic syndrome and is an independent risk factor for both cardiovascular and metabolic disorders. Increased visceral adipose tissue promotes adipokine dysregulation and insulin resistance, leading to several health issues, including systemic inflammation, oxidative stress, and activation of the renin-angiotensin-aldosterone system. Moreover, an increase in adipose tissue directly and indirectly affects the kidneys by increasing renal sodium reabsorption, causing glomerular hyperfiltration and hypertrophy, which leads to increased proteinuria and kidney fibrosis/dysfunction. Although the interest in the adverse effects of obesity on renal diseases has grown exponentially in recent years, the relationship between obesity and renal prognosis remains controversial. This may be attributed to the long clinical course of obesity, numerous obesity-related metabolic complications, and patients' attributes. Multiple individual attributes influencing the pathophysiology of fat accumulation make it difficult to understand obesity. In such cases, it may be effective to elucidate the pathophysiology by conducting research tailored to individual attributes from the perspective of attribute-based medicine/personalized medicine. We consider the appropriate use of clinical indicators necessary, according to attributes such as chronic kidney disease stage, level of visceral adipose tissue accumulation, age, and sex. Selecting treatments and clinical indicators based on individual attributes will allow for advancements in the clinical management of patients with obesity and chronic kidney disease. In the clinical setting of obesity-related nephropathy, it is first necessary to accumulate attribute-based studies resulting from the accurate evaluation of visceral fat accumulation to establish evidence for promoting personalized medicine.

Visceral fat area and body fat percentage measured by bioelectrical impedance analysis correlate with glycometabolism

BACKGROUND

Adiposity evaluated by body mass index (BMI) is associated with glycometabolism. The aim of the investigation was to explore the correlation of visceral fat area (VFA), body fat percentage (BFP), BMI and waist circumference (WC) with type 2 diabetes mellitus (T2DM) and pre-diabetes.

METHODS

A total of 18,458 participates underwent physical examination in Nanjing Drum Tower Hospital from January 2018 to April 2022 was included in this study. Data were collected retrospectively. Regression analysis was used to evaluate the relationship of VFA, BFP, WC and BMI with diabetes status, fasting blood glucose (FBG) and glycohemoglobin (HbA1c).

RESULTS

After fully adjusted for multiple covariates, VFA, BFP, WC and BMI in T2DM and pre-diabetes group exceeded compared with normal group. FBG was positively correlated with VFA, BFP, WC and BMI with βs of 2.221,0.306,0.606 and 0.175(p < 0.001). HbA1c was also positively correlated with the four indexes with βs of 2.645, 0.328, 0.685 and 0.255(p < 0.001). Subgroup analysis shown that FBG and HbA1c were positively correlated with VFA, BFP, BMI and WC in normal and pre-diabetes group (p < 0.001). FBG was negatively correlated with BMI in T2DM group (p = 0.023). In T2DM, there were non-linear relationships of HbA1c with VFA, BFP, WC and BMI with the inflection points for about 7%. Before the inflection point, HbA1c was positively correlated with obesity-related indicators, and it was reversed after the inflection point. In the individuals with excessive VFA and normal BMI, the risk for glycometabolism disorder exceed compared with normal VFA and normal BMI. Every per-standard deviation increasing in VFA, BFP, WC and BMI, the corresponding risk increasing of glycometabolism disorder was 16.4, 14.6, 22.6 and 22.2%.

CONCLUSION

The study demonstrated that in adults with T2DM or prediabetes, the VFA, BFP, WC and BMI were higher than with normal glycometabolism. In pre-diabetes and normal population, there were positive correlations of HbA1c and FBG with obesity-related indicators. In T2DM with poor glycemic control (HbA1c > 7%), there might be a trend of fat loss. VFA could negatively affect glycometabolism independently from BMI. The optimum to evaluate the risk of glycometabolism disorder was WC.

Differences by age in the obesity paradox in severe burns

BACKGROUND

Many studies show a "obesity paradox", which seems to protect against death. Whether an obesity paradox space is present in severe burn patients remains a matter of great debate. Most research on the obesity paradox of burn injuries is classified by body mass index (BMI) rather than by age.

OBJECTIVE

To investigate whether the obesity paradox exists in severe burn patients stratified by age.

METHODS

Retrospective analysis was performed on 490 patients with severe burns who were ≥ 18 years of age and were admitted to Fujian Medical University Union Hospital from January 2005 to December 2020. Demographic and clinical characteristics were collected, including age, BMI, total body surface area (TBSA), presence of inhalation injury, abbreviated burn severity index (ABSI) score, diabetes comorbidities, hypertension comorbidities, and in-hospital mortality. The patients were divided into the younger group (18 ≤ age<65 years) and the older group (age ≥ 65 years). The important variables of the two groups were compared. The predictive value of BMI stratified by age on in-hospital mortality was evaluated by binary logistic regression analysis and the Cochran's and Mantel-Haenszel statistics.

RESULTS

A total of 490 patients were selected for this study, and were divided into the younger group (413) and the elderly group (77) according to their ages. In the younger group, logistic regression analyses indicated that high BMI remained significantly and independently associated with decreased in-hospital mortality (P = 0.021). That is, in-hospital mortality decreased by 17.8% when BMI increased by 1 kg/m². In the older group, BMI was not associated with in-hospital mortality (P = 0.808). In the younger group, the results of Pearson's chi-square test was less than 0.05, indicating a correlation between BMI and prognosis. In the older group, the conclusion was contrary with, no correlation between BMI and prognosis. If the confounding factors of age were not considered, this results in no correlation between BMI and prognosis. In the younger group, the survival/death ratio of patients with overweight and obesity was 2.078 times that of patients with normal weight.

CONCLUSION

In this study of patients with severe burns, overweight and obesity had protective effect on burn injury in the younger group (18 ≤ age<65 years), but not in the older group (age ≥ 65 years). Investigating the obesity paradox in burn patients needs to consider age differences. However, multicentre clinical trials are needed to verify the results.

The Association Between Visceral Adiposity Index and Worsening Renal Function in the Elderly

Background

Visceral adiposity index (VAI) is an indicator of visceral fat accumulation and dysfunction. However, little is known about whether VAI is associated with worsening renal function (WRF) in the elderly. Therefore, our study aimed to explore the association between VAI and WRF among the elderly population.

Methods

In total, 5,583 elderly participants (aged ≥ 65 years) who participated in the annual health checkups at least twice between January 2017 and July 2021 were enrolled and divided into four groups according to the VAI quartiles. The primary endpoint was incident chronic kidney disease (CKD), defined as incident estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m². The secondary endpoint was rapid kidney function decline (RKFD), defined as decline in eGFR of 40%. To evaluate the association between VAI and WRF, three Cox regression models were conducted, where VAI was treated as a continuous variable and a categorical variable (Q1 as reference), respectively. Subgroup analysis in participants with different baseline characteristics was also performed.

Results

During a median of 2.46 year follow-up, 931 (16.68%) participants developed CKD. After fully adjusting for confounding factors, VAI was significantly associated with incident CKD (HR, 1.052; 95% CI: 1.029–1.076, p < 0.001), and RKFD (HR, 1.077; 95% CI: 1.041–1.114, p < 0.001). Moreover, compared to those with the lowest VAI quartiles, subjects with the highest quartiles had a higher risk of incident CKD (HR, 1.286; 95% CI: 1.033–1.601, p = 0.024), and RKFD (HR, 1.895; 95% CI: 1.086–3.307, p = 0.025). The risk of incident CKD also tended to increase with elevated VAI quartiles (all p-values for trend <0.05). This positive association remained consistent among participants with different genders, baseline weights, or kidney functions.

Conclusion

In our study, elevated VAI was associated with increased risk of incident CKD and RKFD in the elderly population.

Effects of Artificial Intelligence-Derived Body Composition on Kidney Graft and Patient Survival in the Eurotransplant Senior Program

The Eurotransplant Senior Program allocates kidneys to elderly transplant patients. The aim of this retrospective study is to investigate the use of computed tomography (CT) body composition using artificial intelligence (AI)-based tissue segmentation to predict patient and kidney transplant survival. Body composition at the third lumbar vertebra level was analyzed in 42 kidney transplant recipients. Cox regression analysis of 1-year, 3-year and 5-year patient survival, 1-year, 3-year and 5-year censored kidney transplant survival, and 1-year, 3-year and 5-year uncensored kidney transplant survival was performed. First, the body mass index (BMI), psoas muscle index (PMI), skeletal muscle index (SMI), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) served as independent variates. Second, the cut-off values for sarcopenia and obesity served as independent variates. The 1-year uncensored and censored kidney transplant survival was influenced by reduced PMI (p = 0.02 and p = 0.03, respectively) and reduced SMI (p = 0.01 and p = 0.03, respectively); 3-year uncensored kidney transplant survival was influenced by increased VAT (p = 0.04); and 3-year censored kidney transplant survival was influenced by reduced SMI (p = 0.05). Additionally, sarcopenia influenced 1-year uncensored kidney transplant survival (p = 0.05), whereas obesity influenced 3-year and 5-year uncensored kidney transplant survival. In summary, AI-based body composition analysis may aid in predicting short- and long-term kidney transplant survival.