Obstacles and Opportunities in Managing Coexisting Obesity and CKD: Report of a Scientific Workshop Cosponsored by the National Kidney Foundation and The Obesity Society

Obesity and its management in primary care setting

Obesity is a worldwide epidemic affecting adults and children, regardless of their socioeconomic status. Significant progress has been made in understanding the genetic causes contributing to obesity, shedding light on a portion of cases worldwide. In young children with severe obesity however, recessive mutations, i.e., leptin or leptin receptor deficiency should be sought. Much more has been learned about the far-reaching impact of obesity on complications, including cardiovascular disease, liver and kidney dysfunction, diabetes, inflammation, hypertension, sleep, cancer, and the eye. Preventive strategies, particularly in children, are crucial for reducing obesity rates and mitigating its long-term complications. While dietary modifications and lifestyle changes remain the cornerstone of obesity prevention or treatment, recent advancements have introduced highly effective pharmacological options complementing weight-reduction surgery. Newer medications, like incretin-based therapies including glucagon-like peptide-1 agonists (GLP-1RA), have demonstrated remarkable efficacy in promoting weight loss, offering new insights into margining obesity-related conditions. Primary care providers, whether treating adults or children, play a pivotal role in preventing obesity, initiating treatment, and making onward referrals to specialists to assist in managing obesity and obesity-related complications.

Clinical staging to guide management of metabolic disorders and their sequelae: a European Atherosclerosis Society consensus statement

Obesity rates have surged since 1990 worldwide. This rise is paralleled by increases in pathological processes affecting organs such as the heart, liver, and kidneys, here termed systemic metabolic disorders (SMDs). For clinical management of SMD, the European Atherosclerosis Society proposes a pathophysiology-based system comprising three stages: Stage 1, where metabolic abnormalities such as dysfunctional adiposity and dyslipidaemia occur without detectable organ damage; Stage 2, which involves early organ damage manifested as Type 2 diabetes, asymptomatic diastolic dysfunction, metabolic-associated steatohepatitis (MASH), and chronic kidney disease (CKD); and Stage 3, characterized by more advanced organ damage affecting multiple organs. Various forms of high-risk obesity, driven by maintained positive energy balance, are the most common cause of SMD, leading to ectopic lipid accumulation and insulin resistance. This progression affects various organs, promoting comorbidities such as hypertension and atherogenic dyslipidaemia. Genetic factors influence SMD susceptibility, and ethnic disparities in SMD are attributable to genetic and socioeconomic factors. Key SMD features include insulin resistance, inflammation, pre-diabetes, Type 2 diabetes, MASH, hypertension, CKD, atherogenic dyslipidaemia, and heart failure. Management strategies involve lifestyle changes, pharmacotherapy, and metabolic surgery in severe cases, with emerging treatments focusing on genetic approaches. The staging system provides a structured approach to understanding and addressing the multi-faceted nature of SMD, which is crucial for improving health outcomes. Categorization of SMD abnormalities by presence and progression is aimed to improve awareness of a multi-system trait and encourage a tailored and global approach to treatment, ultimately aiming to reduce the burden of obesity-related comorbidities.

A cross-sectional study investigating the L-shaped relationship between urinary albumin creatinine ratio and overweight/obesity in children and adolescents

Childhood and adolescent obesity has become one of the most serious public health problems worldwide, and obesity may have potential effects on kidney health. The urinary albumin creatinine ratio (UACR) is a sensitive indicator for assessing renal impairment. Relevant studies on pediatric and adolescent populations are more limited and controversial. This study aimed to clarify the relationship between UACR and overweight/obesity in children and adolescents in the United States, thereby providing new insights and recommendations for the clinical management and prevention of kidney disease. This study utilized data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2016. Variables were derived from demographic, examination, and laboratory data. Overweight/obesity status was assessed using BMI criteria, and random urine samples were used to measure UACR. The association between UACR and overweight/obesity was assessed using descriptive statistics, multivariate logistic regression analysis, subgroup analysis, and curve-fitting analysis. In this study of 4116 participants aged 8-19, multivariate logistic regression analysis revealed a significant negative association between UACR and overweight/obesity (OR = 0.32; 95% CI 0.26-0.38; P < 0.001). The interaction P-values were all greater than 0.05 in the interaction of subgroups, indicating that the findings were very stable and consistent between subgroups. In addition, smoothed curve fitting and threshold effect analyses revealed a nonlinear relationship between UACR and overweight/obesity, with an inflection point for log(UACR) determined to be 1.435 mg/g. The findings suggest a significant nonlinear negative correlation between UACR and overweight/obesity in the pediatric and adolescent populations. Until a precise mechanism of association is found, maintaining a standard range of BMI in all age groups may reduce the incidence of albuminuria in this population.

Perspectives on the profiling of renal risk in obesity

With the formal designation of obesity as a primary disease process, early detection of its end-organ consequences and the prognostication of long-term risk will become an important aspect of its clinical management. Obesity is increasingly recognized as a treatable risk factor for chronic kidney disease. However, profiling of kidney health and estimation of renal risk remain relatively underemphasized in obesity and nephrology care guidelines. The establishment of clinical protocols that facilitate the detection of early-stage renal impairment in obesity and incorporate profiling of an individual's risk of progression, could help guide strategies to break the causal association between obesity and chronic kidney disease. Currently, checks on kidney health in patients with obesity are prompted due to the presence of obesity complications such as cardiovascular and/or metabolic disease and routine screening relies upon the use of estimated glomerular filtration rate equations. Ample evidence exists to demonstrate that these equations are of limited utility in the setting of excess body weight and intentional weight loss. The present article presents the case that an expanded model of renal risk profiling should be developed for obesity medicine, suggesting feasible means of incorporating important risk factors and biomarker profiling alongside a more targeted assessment of directly measured GFR and renal functional reserve in at risk patients. The development of such a model or variation thereof should be prioritized to guide the targeted deployment of obesity treatments with proven reno-protective effects.

Economic evaluation of weight loss and transplantation strategies for kidney transplant candidates with obesity

Novel antiobesity medications, particularly glucagon-like peptide-1 receptor agonists (GLP-1RAs), have expanded weight loss (WL) options for kidney transplantation (KT) candidates with obesity beyond lifestyle modifications and bariatric surgery. However, varying effectiveness, risk profiles, and costs make strategy choices challenging. To aid decision-making, we used a Markov model to examine the cost-effectiveness of different WL strategies over a 10-year horizon. A target WL of 15% of total body weight was used for the base case scenario, and we compared these strategies to a "liberal" KT strategy of transplanting candidates with obesity. Outcomes included costs (2023 US dollars), quality-adjusted life years, and incremental cost-effectiveness ratios. In analysis, a liberal KT strategy was favored over lifestyle modifications and GLP-1RAs. Among WL strategies, bariatric surgery was the most effective and cost the least, whereas lifestyle modification had the highest cumulative costs and was the least effective. Compared to liberal KT, bariatric surgery costs $45 859 per quality-adjusted life year gained. GLP-1RAs were favored over bariatric surgery only when drug costs were below $5000 per year (base cost $12 077). In conclusion, for KT candidates with obesity, a liberal KT strategy and bariatric surgery are preferred over lifestyle modifications alone and GLP-1RAs based on outcomes and cost-effectiveness.

Amelioration impact of gut-brain communication on obesity control by regulating gut microbiota composition through the ingestion of animal-plant-derived peptides and dietary fiber: can food reward effect as a hidden regulator?

Various roles of intestinal flora in the gut-brain axis response pathway have received enormous attention because of their unique position in intestinal flora-derived metabolites regulating hormones, inducing appetite, and modulating energy metabolism. Reward pathways in the brain play a crucial role in gut-brain communications, but the mechanisms have not been methodically understood. This review outlined the mechanisms by which leptin, ghrelin, and insulin are influenced by intestinal flora-derived metabolites to regulate appetite and body weight, focused on the significance of the paraventricular nucleus and ventromedial prefrontal cortex in food reward. The vagus nerve and mitochondria are essential pathways of the intestinal flora involved in the modulation of neurotransmitters, neural signaling, and neurotransmission in gut-brain communications. The dynamic response to nutrient intake and changes in the characteristics of feeding activity requires the participation of the vagus nerve to transmit messages to be completed. SCFAs, Bas, BCAAs, and induced hormones mediate the sensory information and reward signaling of the host in the complex regulatory mechanism of food selection, and the composition of the intestinal flora significantly impacts this process. Food reward in the process of obesity based on gut-brain communications expands new ideas for the prevention and treatment of obesity.

Case Study: The Weighty Issue of Treatment Options for Obese Dialysis Patients

Obesity is a complex chronic disease and common comorbidity in kidney failure and is the leading causes of death and disability in this population. Guidelines do not specifically address the preferred weight management option(s) for obesity while on dialysis. Large body size is a limiting factor for consideration of a kidney transplantation. We report on a successful bariatric surgery with a young adult after 5.5 years on dialysis with hope for a future transplant. Success was demonstrated with progressive weight loss without adverse changes in renal clinical markers accompanied by improvements in exercise tolerance and health status thereby improving her suitability for a kidney transplant. Further studies and guidelines are needed to address weight loss options for those with obesity on dialysis and want to lose weight.

Ten tips on how to manage obesity in the presence of CKD

Patients with chronic kidney disease are frequently facing the challenge of weight reduction. Finding a weight loss strategy is on the one hand essential to reduce the co-morbidity risks in CKD but remains complex due to the metabolic abnormalities with declining renal function. Here, we provide ten tips to support our CKD patients on their journey, focussing on dietary and behavioural habits and health professional supportive therapies.

Obesity, kidney and metabolic bariatric surgery: a surgeon’s narrative review

Excess body weight impacts kidney function in individuals with severe obesity, primarily through metabolic alterations in adipocytes, especially in visceral adipose tissue. The relationship between persistent sterile inflammation associated with obesity and the progression of obesity-related kidney disease to chronic kidney disease (CKD) is an area of growing interest. The beneficial effects of weight loss on the prevention of kidney disease and the improvement of kidney function in individuals with obesity have been well documented. Currently, the most effective weight loss strategy is metabolic bariatric surgery (MBS), which has been proven to not only prevent the progression of CKD but also reverse it. However, awareness and understanding of the impact of obesity on the kidney should also extend to the severely obese population with clinically normal renal function. The purpose of this review is to outline the current knowledge on the pathophysiology of obesity-induced kidney damage, the effects of MBS on renal function in severely obese individuals with or without CKD, and provide the current evidence on perioperative management strategies for CKD patients, including diet and nutrition.

Approach to weight management in patients with advanced chronic kidney disease in a real-life clinical setting

Objective

Excess adiposity represents a risk factor for chronic kidney disease (CKD) and progression to end-stage kidney disease. Anti-Obesity Medications (AOMs) are vastly underutilized in patients with advanced CKD because of concerns related to safety and efficacy. This study was conducted to evaluate the real-world approach to weight management and the efficacy and safety of AOMs in people with advanced CKD.

Methods

This is a retrospective analysis of individuals with Body Mass Index (BMI) ≥ 27 kg/m2 and eGFR ≤ 30 mL/min/1.73 m2 referred to an academic medical weight-management program between 01/2015 and 09/2022. Evaluation of weight-management approaches, body weight change, treatment-related side effects, and reasons for treatment discontinuation were reported.

Results

Eighty-nine patients met inclusion criteria, 16 were treated with intensive lifestyle modifications (ILM) alone and 73 with AOMs (all treated with glucagon-like peptide-1 receptor agonist [GLP1-RA] +/- other AOMs) along with ILM. Patients treated with AOMs had a longer duration of on-treatment follow-up (median 924 days) compared to (93 days) the ILM group. Over 75% of patients treated with AOMs lost ≥5% body weight versus 25% of those treated with ILM. Only 15% of patients treated with AOMs discontinued therapy due to treatment-related side effects.

Conclusion

In patients with obesity and advanced CKD, GLP-1RA-based anti-obesity treatment was well-tolerated, effective, and led to durable weight reduction.

Measuring Albuminuria in Individuals With Obesity: Pitfalls of the Urinary Albumin-Creatinine Ratio

An increased urinary albumin excretion rate is an important early risk factor for chronic kidney disease and other major outcomes and is usually measured using the urinary albumin-creatinine ratio (ACR). Obesity is highly prevalent in the general and chronic kidney disease populations and is an independent risk factor for moderately increased albuminuria (henceforth, moderate albuminuria). In this review, we describe how the ACR was developed and used to define moderate albuminuria. We then investigate how biases related to urinary creatinine excretion are introduced into the ACR measurement and how the use of the 30-mg/g threshold decreases the performance of the test in populations with higher muscle mass, with a primary focus on why and how this occurs in the obese population. The discussion then raises several strategies that can be used to mitigate such bias. This review provides a comprehensive overview of the medical literature on the uses and limitations of ACR in individuals with obesity and critically assesses related issues. It also raises into question the widely accepted 30-mg/g threshold as universally adequate for the diagnosis of moderate albuminuria. The implications of our review are relevant for clinicians, epidemiologists, and clinical trialists.

Insulin Secretion, Sensitivity, and Kidney Function in Young Individuals With Type 2 Diabetes

OBJECTIVE

β-Cell dysfunction and insulin resistance magnify the risk of kidney injury in type 2 diabetes. The relationship between these factors and intraglomerular hemodynamics and kidney oxygen availability in youth with type 2 diabetes remains incompletely explored.

RESEARCH DESIGN AND METHODS

Fifty youth with type 2 diabetes (mean age ± SD 16 ± 2 years; diabetes duration 2.3 ± 1.8 years; 60% female; median HbA1c 6.4% [25th, 75th percentiles 5.9, 7.6%]; BMI 36.4 ± 7.4 kg/m2; urine albumin-to-creatinine ratio [UACR] 10.3 [5.9, 58.0] mg/g) 21 control participants with obesity (OCs; age 16 ± 2 years; 29% female; BMI 37.6 ± 7.4 kg/m2), and 20 control participants in the normal weight category (NWCs; age 17 ± 3 years; 70% female; BMI 22.5 ± 3.6 kg/m2) underwent iohexol and p-aminohippurate clearance to assess glomerular filtration rate (GFR) and renal plasma flow, kidney MRI for oxygenation, hyperglycemic clamp for insulin secretion (acute C-peptide response to glucose [ACPRg]) and disposition index (DI; ×103 mg/kg lean/min), and DXA for body composition.

RESULTS

Youth with type 2 diabetes exhibited lower DI (0.6 [0.0, 1.6] vs. 3.8 [2.4, 4.5] × 103 mg/kg lean/min; P < 0.0001) and ACPRg (0.6 [0.3, 1.4] vs. 5.3 [4.3, 6.9] nmol/L; P < 0.001) and higher UACR (10.3 [5.9, 58.0] vs. 5.3 [3.4, 14.3] mg/g; P = 0.003) and intraglomerular pressure (77.8 ± 11.5 vs. 64.8 ± 5.0 mmHg; P < 0.001) compared with OCs. Youth with type 2 diabetes and OCs had higher GFR and kidney oxygen availability (relative hyperoxia) than NWCs. DI was associated inversely with intraglomerular pressure and kidney hyperoxia.

CONCLUSIONS

Youth with type 2 diabetes demonstrated severe β-cell dysfunction that was associated with intraglomerular hypertension and kidney hyperoxia. Similar but attenuated findings were found in OCs.

Anti-obesity pharmacotherapy in adults with chronic kidney disease

Obesity is a leading risk factor for the development and progression of kidney disease and a major barrier to optimal management of patients with chronic kidney disease. While in the past anti-obesity drugs offered only modest weight loss efficacy in exchange for various safety and tolerability risks, a wave of safer, more tolerable, and more effective treatment options is transforming the management of obesity. This review evaluates current and future pharmacologic anti-obesity therapy in adults through a kidney-oriented lens. It also explores the goals of anti-obesity treatment, describes the underlying putative mechanisms of action, and raises important scientific questions that deserve further exploration in people with chronic kidney disease.

A Synopsis of the Evidence for the Science and Clinical Management of Cardiovascular-Kidney-Metabolic (CKM) Syndrome: A Scientific Statement From the American Heart Association

A growing appreciation of the pathophysiological interrelatedness of metabolic risk factors such as obesity and diabetes, chronic kidney disease, and cardiovascular disease has led to the conceptualization of cardiovascular-kidney-metabolic syndrome. The confluence of metabolic risk factors and chronic kidney disease within cardiovascular-kidney-metabolic syndrome is strongly linked to risk for adverse cardiovascular and kidney outcomes. In addition, there are unique management considerations for individuals with established cardiovascular disease and coexisting metabolic risk factors, chronic kidney disease, or both. An extensive body of literature supports our scientific understanding of, and approach to, prevention and management for individuals with cardiovascular-kidney-metabolic syndrome. However, there are critical gaps in knowledge related to cardiovascular-kidney-metabolic syndrome in terms of mechanisms of disease development, heterogeneity within clinical phenotypes, interplay between social determinants of health and biological risk factors, and accurate assessments of disease incidence in the context of competing risks. There are also key limitations in the data supporting the clinical care for cardiovascular-kidney-metabolic syndrome, particularly in terms of early-life prevention, screening for risk factors, interdisciplinary care models, optimal strategies for supporting lifestyle modification and weight loss, targeting of emerging cardioprotective and kidney-protective therapies, management of patients with both cardiovascular disease and chronic kidney disease, and the impact of systematically assessing and addressing social determinants of health. This scientific statement uses a crosswalk of major guidelines, in addition to a review of the scientific literature, to summarize the evidence and fundamental gaps related to the science, screening, prevention, and management of cardiovascular-kidney-metabolic syndrome.

Patient and Health Care Professional Perspectives on Addressing Obesity in ESKD

RATIONALE & OBJECTIVE

Obesity is common among patients with end-stage kidney disease (ESKD) and is a pervasive barrier to kidney transplantation. Patient perspectives about barriers to weight loss and patient and health care professionals' viewpoints about optimal obesity management in ESKD are needed.

STUDY DESIGN

Qualitative study using a descriptive phenomenological approach to understand ESKD patients' lived experiences with obesity and weight loss and patients' and health professionals' perceptions about optimal obesity care for ESKD patients.

SETTING & PARTICIPANTS

Between October 2020 and December 2021, we conducted 90-minute semistructured interviews with 40 ESKD patients with obesity (body mass index [BMI] ≥30kg/m2) and 60-minute interviews with 20 ESKD health care professionals.

ANALYTICAL APPROACH

Deductive and inductive thematic analysis of interviews.

RESULTS

Among patients with ESKD, the median age was 55 (IQR, 46-63) years, median BMI was 39.5 (IQR, 35.3-41.6) kg/m2, and median dialysis vintage was 5 (IQR, 3-8) years; 58% were female, and 46% were non-Hispanic White. Among health care professionals, 50% were renal dietitians, 20% were nephrologists, and the remainder were transplant professionals (surgeons, nephrologists, and dietitians). ESKD patients described unique weight loss challenges, including (1) conflicting tenets of "kidney-friendly" versus popular diets, (2) fatigue due to dialysis that affects dietary choices, and (3) perceived pressure and unrealistic expectations from health professionals to lose weight for kidney transplantation. Professionals and patients described a lack of transparent and honest communication about obesity and unclear roles and responsibilities for obesity counseling.

LIMITATIONS

Lack of caregiver perspectives and potential lack of transferability to overall dialysis population given overrepresentation of patients with severe obesity and previous weight loss surgery.

CONCLUSIONS

Obesity interventions for ESKD patients should be tailored to meet the unique challenges reported by patients with ESKD. Clarifying ESKD health professionals' roles and responsibilities for obesity care would help to ensure that patients have consistent and effective support to manage obesity.

PLAIN-LANGUAGE SUMMARY

Adults with coexisting obesity and end-stage kidney disease (ESKD) are often required to lose weight for kidney transplantation. Yet there is little knowledge about barriers to healthy weight loss in this population. In this study, we conducted interviews with 40 ESKD patients with coexisting obesity and 20 ESKD health care professionals to learn about opportunities to improve obesity-related health care in ESKD. Patients reported that fatigue and dialysis affected dietary choices, and fluid and food restrictions hampered weight loss. Professionals described a lack of training, comfort, and time to address obesity. Patients and professionals reported a lack of open communication about obesity management. Improving obesity-related education and clinical communication should be prioritized to improve care for patients with ESKD and obesity.