Obesity and synergistic risk factors for chronic kidney disease in African American adults: the Jackson Heart Study

Risk factors of worsening kidney function and mortality in patients with renal vein thrombosis: a retrospective study

BACKGROUND

The outcome of renal vein thrombosis, in particular as for the long-term impact on kidney function, is not fully known. We aimed to study the natural course and outcomes of patients with renal vein thrombosis, in a large, single-center cohort.

METHODS

A single-center retrospective cohort study including patients who were diagnosed with renal vein thrombosis between January 2006 and September 2021 was analyzed. The main outcomes analyzed were worsening kidney function, defined as a decrease in eGFR of at least 40% from baseline, and all-cause mortality.

RESULTS

Eighty-seven patients were included, 56.3% were female, median age was 57 years. Malignancy was the most common cause of renal vein thrombosis (60.9%), followed by post-surgery and trauma (16.1%) and nephrotic syndrome (12.6%). At initial presentation, 65.5% of the patients were asymptomatic; the main signs and symptoms were gross hematuria (20.7%), flank pain (18.4%), and flank tenderness (9.2%). During follow-up, 18 (21.4%) patients experienced worsening kidney function and 57 (65.5%) died. Multivariable analyses showed that the risk of worsening kidney function was higher in patients with nephrotic syndrome (hazard ratio [HR] 18.41; 95% confidence interval [CI], 1.57-216.04), body weight ≥ 60 kg (HR 4.82; 95% CI 1.43-16.32), and malignancy (HR 9.10; 95% CI 1.05-78.63). Symptomatic acute renal vein thrombosis was associated with a lower risk of worsening kidney function compared to asymptomatic or symptomatic chronic renal vein thrombosis (HR 0.12; 95% CI 0.01-0.96). Malignancy (HR 5.45; 95% CI 2.58-11.54), age ≥ 75 years (HR 3.44; 95% CI 1.49-7.93), and serum albumin < 3.0 g/dL (HR 2.88; 95% CI 1.65-5.05) were associated with an increased mortality risk.

CONCLUSION

Renal vein thrombosis is associated with a high rate of worsening kidney function and mortality. It is crucial to promptly identify patients at high risk and initiate early treatment to prevent negative outcomes.

Body Fat Distribution Contributes to Defining the Relationship between Insulin Resistance and Obesity in Human Diseases

The risk for metabolic and cardiovascular complications of obesity is defined by body fat distribution rather than global adiposity. Unlike subcutaneous fat, visceral fat (including hepatic steatosis) reflects insulin resistance and predicts type 2 diabetes and cardiovascular disease. In humans, available evidence indicates that the ability to store triglycerides in the subcutaneous adipose tissue reflects enhanced insulin sensitivity. Prospective studies document an association between larger subcutaneous fat mass at baseline and reduced incidence of impaired glucose tolerance. Case-control studies reveal an association between genetic predisposition to insulin resistance and a lower amount of subcutaneous adipose tissue. Human peroxisome proliferator-activated receptorgamma (PPAR-γ) promotes subcutaneous adipocyte differentiation and subcutaneous fat deposition, improving insulin resistance and reducing visceral fat. Thiazolidinediones reproduce the effects of PPAR-γ activation and therefore increase the amount of subcutaneous fat while enhancing insulin sensitivity and reducing visceral fat. Partial or virtually complete lack of adipose tissue (lipodystrophy) is associated with insulin resistance and its clinical manifestations, including essential hypertension, hypertriglyceridemia, reduced HDL-c, type 2 diabetes, cardiovascular disease, and kidney disease. Patients with Prader Willi syndrome manifest severe subcutaneous obesity without insulin resistance. The impaired ability to accumulate fat in the subcutaneous adipose tissue may be due to deficient triglyceride synthesis, inadequate formation of lipid droplets, or defective adipocyte differentiation. Lean and obese humans develop insulin resistance when the capacity to store fat in the subcutaneous adipose tissue is exhausted and deposition of triglycerides is no longer attainable at that location. Existing adipocytes become large and reflect the presence of insulin resistance.

The association between visceral adiposity index and chronic kidney disease in the elderly: A cross-sectional analysis of NHANES 2011-2018

Visceral adiposity index (VAI) is a new metric for evaluating visceral adiposity dysfunction. The aim of the present study was to explore the association between VAI and incident chronic kidney disease (CKD) in the American elderly population. We included 6085 participants aged 60 years or older with available data on renal function and VAI from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018 and divided them into four groups according to the VAI quartiles. VAI values were ln-transformed to reduce skewness. We conducted multivariable logistic regression analyses and spline smoothing plot analyses to evaluate the association between VAI and CKD. After fully adjusting for confounding factors, higher lnVAI was associated with a higher risk of CKD (OR, 1.23; 95 %CI, 1.02, 1.48). Compared to the Q1 group (VAI < 1.1), The third and fourth VAI quartiles were associated with a higher prevalence of CKD (Q3: VAI, 1.8-3.0; Q4: VAI > 3.0). The adjusted ORs (95% CI) in Q3 and Q4 were 1.74 (1.24, 2.42) and 1.59 (1.08, 2.33). Adjusted smoothed plots suggested a nonlinear relationship between lnVAI and CKD. The development of CKD increased with increasing VAI among participants with a lnVAI between -0.6 and 1.6 (VAI: 0.5-5.0). In conclusion, VAI is significantly associated with the risk of CKD in the US elderly population aged 60 years or older.

Combination of Risks of BMI and Health-Related Lifestyles on Kidney Function in the Prediabetic Japanese Population: A Prospective Cohort Study

Diabetic overweight patients are more likely to show the progression of kidney damage than the general population. The majority of people in the early stages of kidney damage do not recognize the importance of risk modification, mainly due to the asymptomatic nature of the disease. This study aimed to examine specific risk combinations of lifestyle and BMI regarding the deterioration of kidney function and to explore whether there are gender-based differences among the prediabetic population. Prediabetic participants with normal kidney function were identified via annual health examination from April 2016 to March 2019. The information on health status and lifestyle was collected at enrollment. The study subjects were followed until March 2021 to observe the progression of kidney damage. There were 2241 participants enrolled in this study. Smoking (HR = 3.5, p < 0.001), eating snacks (HR = 3.2, p < 0.001), not engaging in regular exercise (HR = 2.9, p < 0.001), and not having adequate sleep (HR = 3.0, p < 0.001) showed accelerated risks for kidney damage progression among the prediabetic population in males. These lifestyle effects were not observed in females. In conclusion, risk-based modification of lifestyle behavior is important to prevent kidney function damage among the overweight prediabetic population in males.

The Effect of Metabolic Syndrome and Its Individual Components on Renal Function: A Meta-Analysis

BACKGROUND

Observational studies have reported inconsistent findings in the relationship between metabolic syndrome (MetS), its components, and loss of renal function, mainly including eGFR decline, new-onset CKD, and ESRD. This meta-analysis was performed to investigate their potential associations.

METHODS

PubMed and EMBASE were systematically searched from their inception to 21 July 2022. Observational cohort studies in English assessing the risk of renal dysfunction in individuals with MetS were identified. Risk estimates and their 95% confidence intervals (CIs) were extracted and pooled using the random-effects approach.

RESULTS

A total of 32 studies with 413,621 participants were included in the meta-analysis. MetS contributed to higher risks of renal dysfunction (RR = 1.50, 95% CI = 1.39-1.61) and, specifically, rapid decline in eGFR (RR 1.31, 95% CI 1.13-1.51), new-onset CKD (RR 1.47, 95% CI 1.37-1.58), as well as ESRD (RR 1.55, 95% CI 1.08-2.22). Moreover, all individual components of MetS were significantly associated with renal dysfunction, while elevated BP conveyed the highest risk (RR = 1.37, 95% CI = 1.29-1.46), impaired fasting glucose with the lowest and diabetic-dependent risk (RR = 1.20, 95% CI = 1.09-1.33).

CONCLUSIONS

Individuals with MetS and its components are at higher risk of renal dysfunction.

Association of intraabdominal fat with the risk of incident chronic kidney disease according to body mass index among Korean adults

BACKGROUND

The association between abdominal visceral adipose tissue and the risk of incident chronic kidney disease according to body mass index in the Asian population, remains unclear. We evaluated the impact of abdominal adiposity stratified by body mass index on the risk of incident chronic kidney disease.

METHODS

A cohort study included 11,050 adult participants who underwent health check-ups and re-evaluated the follow-up medical examination at a single university-affiliated healthcare center. Cross-sectional abdominal adipose tissue areas were measured using computed tomography. The primary outcome was progression to chronic kidney disease (estimated glomerular filtration rate <60 ml/min/1.73m2). The highest quartile of visceral adipose tissue was used for the cut-off of central obesity.

RESULTS

During the mean of 5.6 follow-up years, 104 incident chronic kidney disease cases were identified. The risk for chronic kidney disease incidence was significantly increased in the 3rd and 4th quartile ranges of visceral adipose tissue [hazard ratio (95% confidence interval)]: 4.59 (1.48-14.30) and 7.50 (2.33-24.20), respectively. In the analysis stratified by body mass index, the chronic kidney disease incidence risk was increased in the highest quartile range of visceral adipose tissue in the normal weight group: 7.06 (1.35-37.04). However, there was no significant relationship between visceral adipose tissue and chronic kidney disease in the obese group. Compared to the subjects with normal weight and absent central obesity, the hazard ratio for chronic kidney disease incidence was 2.32 (1.26-4.27) among subjects with normal weight and central obesity and 1.81 (1.03-3.15) among subjects with obesity and central obesity.

CONCLUSION

Visceral adipose tissue was a significant risk factor for subsequent chronic kidney disease progression, and the association was identified only in the normal weight group. Normal-weight central obesity was associated with excess risk of chronic kidney disease, similar to the risk in the group with obesity and central obesity.

Obesity Pillars Roundtable: Body mass index and body composition in Black and Female individuals. Race-relevant or racist? Sex-relevant or sexist?

Background

Body mass index (BMI or weight in kilograms/height in meters2) is the most common metric to diagnose overweight and obesity. However, a body composition analysis more thoroughly assesses adiposity, percent body fat, lean body mass (i.e., including skeletal muscle), and sometimes bone mineral density. BMI is not an accurate assessment of body fat in individuals with increased or decreased muscle mass; the diagnostic utility of BMI in individuals is also influenced by race and sex.

Methods

Previous Obesity Pillars Roundtables addressed the diagnostic limitations of BMI, the importance of android and visceral fat (especially among those with South and East Asian ancestry), and considerations of obesity among individuals who identify as Hispanic, diverse in sexual-orientation, Black, Native American, and having ancestry from the Mediterranean and Middle East regions. This roundtable examines considerations of BMI in Black and female individuals.

Results

The panelists agreed that body composition assessment was a more accurate measure of adiposity and muscle mass than BMI. When it came to matters of race and sex, one panelist felt: "race is a social construct and not a defining biology." Another felt that: "BMI should be a screening tool to prompt further evaluation of adiposity that utilizes better diagnostic tools for body composition." Regarding bias and misperceptions of resistance training in female individuals, another panelist stated: "I have spent my entire medical career taking care of women and have never seen a woman unintentionally gain 'too much' muscle mass and bulk up from moderate strength training."

Conclusions

Conveying the importance of race and sex regarding body composition has proven challenging, with the discussion sometimes devolving into misunderstandings or misinformation that may be perceived as racist or sexist. Body composition analysis is the ultimate diagnostic equalizer in addressing the inaccuracies and biases inherent in the exclusive use of BMI.

Association between Use of Nutrition Labels and Risk of Chronic Kidney Disease: The Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2019

Nutrition labeling on food packages is increasingly found to promote healthier food choices associated with lower risk of chronic kidney disease (CKD). To examine associations between nutrition labels use and CKD risk, we conducted a nationally representative cross-sectional study of 32,080 adults from the 2008−2019 Korean National Health and Nutrition Examination Survey. Nutrition labels use was collected via self-reported questionnaires. Ascertainment and severity of CKD was determined by estimated glomerular filtration rate or proteinuria. In multivariable-adjusted (MV) logistic regression models, increasing awareness and use of nutrition labels was significantly associated with lower CKD risk (MV-adjusted OR “nutrition labels aware and use” group vs. “nutrition labels unaware” group [95% CIs]: 0.75 [0.59−0.95], Ptrend:0.03). This inverse association varied with CKD’s risk of progression, with 21% and 42% reduced risk observed for CKD subtypes with “moderate” and “high” risk of progression, respectively (all Ptrend ≤ 0.04). Furthermore, the nutrition labels use and CKD risk association significantly differed by age, with 35% reduced risk observed in the older group aged 49 years or older, but not in the younger group (Pinteraction < 0.001). Our results suggest increasing perception and use of nutrition labels may contribute to CKD prevention and its early asymptomatic progression, especially in older adults.

Effect of Normalizing eGFR to Standard Body Surface Area on Rates of Obesity-Related Hyperfiltration among Diverse Female Adolescents

INTRODUCTION

Obesity is more prevalent among African American individuals, increasing the risk for cardiorenal morbidity. We explored interactions between race, BMI, and the risk of hyperfiltration associated with obesity-related glomerulopathy (ORG).

METHODS

We created a cohort of female adolescents from electronic health records. Glomerular filtration rate (GFR) was estimated in two ways: (A) using standard age recommended formulae and (B) absolute eGFR - adjusted to individual body surface area (BSA). Multivariate logistic regression was used to analyze the contribution of risk factors for ORG-associated hyperfiltration defined as 135 mL/min/1.73 m2 or 135 mL/min, according to BMI group. Pearson's coefficient was used to assess correlation with creatinine clearance (CrCl).

RESULTS

The final cohort included 7,315 African American and 15,102 non-African American adolescent females, with CrCl available for internal validation in 207 non-African American and 107 African American individuals. Compared with non-African American ethnicity, African American ethnicity was independently associated with a lower risk of hyperfiltration with standard eGFR calculations (odds ratio [OR] = 0.57, 95% confidence intervals [CIs] 0.45-0.71), associations were enhanced for absolute eGFR (OR = 0.81, 95% CI 0.69-0.95). Absolute eGFR values agreed better with CrCl (r = 0.63), compared to standard indexed eGFR formulae. Proportions classified as hyperfiltration changed with standard versus absolute eGFR; they were similar across BMI groups with the first and reflected obesity with the later.

CONCLUSION

Adjusting to individual BSA improves estimation of GFR and identification of obesity-related hyperfiltration. More accurate and earlier ascertainment of obesity-related hyperfiltration may have important consequences for preservation of kidney function.

Obesity and CKD in Sub-Saharan Africa: A Narrative Review

Obesity is a major public health problem in the developed world, where it has reached an epidemic status over the last few decades. In parallel with this, the prevalence of chronic kidney disease (CKD) has increased. Although obesity is a risk factor for hypertension and diabetes, it is also independently associated with the development and progression of CKD. Two-third of patients with CKD worldwide will be residents of developing countries by the year 2030. Risk factors for CKD are prevalent in the sub-Saharan Africa region; this review discusses the available data regarding the relationship between obesity and CKD. The prevalence of CKD appears to correlate with increasing adiposity in sub-Saharan Africa; however, limited data are currently available, and the analysis of this association is further complicated by a variety of parameters used to define obesity. (eg, body mass index vs waist circumference). Longer, large-scale studies are needed to inform the prevalence and kidney implications of obesity in sub-Saharan Africa.

Proof of Concept for the FLEX Intervention: Feasibility of Home Based Coaching to Improve Physical Activity Outcomes and Viral Load Suppression among African American Youth Living with HIV

FLEX is a Motivational Interviewing, home-based coaching program that concurrently targets HIV-related and physical activity goals among African American youth living with HIV in the United States. To create and pilot test FLEX, we leveraged a 2-step exploratory sequential mixed methods design informed by the ORBIT model with initial qualitative work followed by pre-post analysis of quantitative outcomes, concluding with qualitative exit surveys. Data were evaluated pre- and 3-months post-intervention. Recruitment was 90%. Participants reported high program satisfaction and program adherence (76% completion rate). Preliminary findings indicate reductions in participants’ viral loads and improvements across 4 measures of physical activity.

Obesity as a predictive factor for chronic kidney disease in adults: systematic review and meta-analysis

Chronic kidney disease (CKD) is one of the main chronic diseases affecting the world population due to its high prevalence and increasing morbidity. Similarly, obesity gained the interest of the scientific community as it directly or indirectly increases mortality from cardiovascular causes, and its prevalence characterizes a pandemic. The objective of this study was to investigate obesity measured by body mass index as a predictor for end-stage renal disease in the general adult population. A systematic review and meta-analysis was carried out by searching 10 databases for prospective or retrospective cohort studies, with no restrictions on the language of publication, including adults with obesity without previous renal disease and who evolved to CKD (diagnosed by estimated glomerular filtration rate below 60 mL&mac_middot;min^-1&mac_middot;(1.73 m²)^-1 over the follow-up period. The R software and Meta package were used for data analysis. After removing duplicates, 5431 studies were submitted to the steps of the systematic review, and 21 articles were included in the data analysis. In total, 3,504,303 patients, 521,216 with obesity, and an average follow-up time of 9.86 years were included. The relative risk of obese people for developing CKD in the random effects model was 1.81 (95%CI: 1.52-2.16). The evidence found in this meta-analysis confirmed that obese people are at higher risk of developing CKD that the non-obese population (1.81 times higher), with obesity being a priority risk factor in preventive actions.

Probiotic Lactobacillus paracasei HII01 protects rats against obese-insulin resistance-induced kidney injury and impaired renal organic anion transporter 3 function

The relationship between gut dysbiosis and obesity is currently acknowledged to be a health topic which causes low-grade systemic inflammation and insulin resistance and may damage the kidney. Organic anion transporter 3 (Oat3) has been shown as a transporter responsible for renal handling of gut microbiota products which are involved in the progression of metabolic disorder. The present study investigated the effect of probiotic supplementation on kidney function, renal Oat3 function, inflammation, endoplasmic reticulum (ER) stress, and apoptosis in obese, insulin-resistant rats. After 12 weeks of being provided with either a normal or a high-fat diet (HF), rats were divided into normal diet (ND); ND treated with probiotics (NDL); HF; and HF treated with probiotic (HFL). Lactobacillus paracasei HII01 1 × 108 colony forming unit (CFU)/ml was administered to the rats daily by oral gavage for 12 weeks. Obese rats showed significant increases in serum lipopolysaccharide (LPS), plasma lipid profiles, and insulin resistance. Renal Oat 3 function was decreased along with kidney dysfunction in HF-fed rats. Obese rats also demonstrated the increases in inflammation, ER stress, apoptosis, and gluconeogenesis in the kidneys. These alterations were improved by Lactobacillus paracasei HII01 treatment. In conclusion, probiotic supplementation alleviated kidney inflammation, ER stress, and apoptosis, leading to improved kidney function and renal Oat3 function in obese rats. These benefits involve the attenuation of hyperlipidemia, systemic inflammation, and insulin resistance. The present study also suggested the idea of remote sensing and signaling system between gut and kidney by which probiotic might facilitate renal handling of gut microbiota products through the improvement of Oat3 function.