Prevalence of Chronic Kidney Disease in Morbidly Obese Japanese and the Impact of Bariatric Surgery on Disease Progression

Association between weight change across adulthood and risk of chronic kidney disease: NHANES 1999-2020

BACKGROUND

Obesity is a recognized risk factor for chronic kidney disease (CKD), but whether weight change is associated with CKD remains unclear. This research aimed to investigate the relationship between weight change patterns across adulthood and the risk of CKD.

METHODS

Data for 34,187 adults participating in the National Health and Nutrition Examination Survey 1999-2020 were analyzed. The weight change patterns of participants were assessed across different time intervals, including transitions from obesity to non-obesity, non-obesity to obesity, and remaining stable obesity. Absolute weight changes were also analyzed, categorizing participants into various weight gain and loss groups. Furthermore, stratified analyses were conducted to explore potential interactions between age, sex, and smoking status about CKD risk.

RESULTS

The study found that individuals transitioning from obesity to non-obesity, non-obesity to obesity, and remaining stable obesity had an elevated risk of developing CKD throughout adulthood compared to those maintaining stable non-obesity weight patterns. Moreover, a J-shaped or U-shaped relationship was observed between CKD risk and absolute weight changes, with both extreme weight gain (≥20 kg) and substantial weight loss (>2.5 kg) associated with increased CKD risk. Stratified analyses revealed that age and sex played significant roles in these associations, with stronger effects observed among participants under 60 years at baseline.

CONCLUSIONS

This study underscores the link between weight change across adulthood and the risk of CKD. Maintaining a stable weight and avoiding extreme weight fluctuations may reduce CKD risk. These insights can be considered when developing CKD prevention and management strategies.

A Case of Bariatric Surgery for a Japanese Kidney Transplant Recipient With Diabetes Mellitus: A Case Report

The patient, a 54-year-old woman, underwent a living donor kidney transplant at Osaka City University Hospital 7 years before the bariatric surgery. Her comorbidities were diabetes, sleep apnea, and severe obesity (weight 103 kg, body mass index [BMI] 36 kg/m2), and her diabetes was poorly controlled with an HbA1c of 8.5%. On admission, she weighed 99 kg, BMI was 34 kg/m2, Serum creatinine (S-Cre) was 1.54 mg/dL, and HbA1c was 7.1%. A laparoscopic sleeve gastrectomy was performed, and her weight decreased without complications during the perioperative period. She was discharged on postoperative day 28. Two months after surgery, her weight was 87 kg, BMI 30 kg/m2, S-Cre 1.34 mg/dL, HbA1c 6.7 %, renal function improved, urine protein decreased, and insulin dosage decreased dramatically. We report this valuable case because there are no reports of bariatric surgery in Japanese renal transplant recipients.

Improvement of kidney function in patients with chronic kidney disease and severe obesity after bariatric surgery: A systematic review and meta-analysis

The general management for chronic kidney disease (CKD) includes treating reversible causes, including obesity, which may be both a driver and comorbidity for CKD. Bariatric surgery has been shown to reduce the likelihood of CKD progression and improve kidney function in observational studies. We performed a systematic review and meta-analysis of patients with at least stage 3 CKD and obesity receiving bariatric surgery. We searched Embase, MEDLINE, CENTRAL and identified eligible studies reporting on kidney function outcomes in included patients before and after bariatric surgery with comparison to a medical intervention control if available. Risk of bias was assessed with the Newcastle-Ottawa Risk of Bias score. Nineteen studies were included for synthesis. Bariatric surgery showed improved eGFR with a mean difference (MD) of 11.64 (95%CI: 5.84 to 17.45, I²  = 66%) ml/min/1.73m² and reduced SCr with MD of -0.24 (95%CI -0.21 to -0.39, I²  = 0%) mg/dl after bariatric surgery. There was no significant difference in the relative risk (RR) of having CKD stage 3 after bariatric surgery, with a RR of -1.13 (95%CI: -0.83 to -2.07, I²  = 13%), but there was reduced likelihood of having uACR >30 mg/g or above with a RR of -3.03 (95%CI: -1.44 to -6.40, I²  = 91%). Bariatric surgery may be associated with improved kidney function with the reduction of BMI and may be a safe treatment option for patients with CKD. Future studies with more robust reporting are required to determine the feasibility of bariatric surgery for the treatment of CKD.

Range of adiposity and cardiorenal syndrome

Obesity and obesity-related co-morbidities, diabetes mellitus, and hypertension are among the fastest-growing risk factors of heart failure and kidney disease worldwide. Obesity, which is not a unitary concept, or a static process, ranges from alterations in distribution to the amount of adiposity. Visceral adiposity, which includes intraabdominal visceral fat mass and ectopic fat deposition such as hepatic, cardiac, or renal, was robustly associated with a greater risk for cardiorenal morbidity than subcutaneous adiposity. In addition, morbid obesity has also demonstrated a negative effect on cardiac and renal functioning. The mechanisms by which adipose tissue is linked with the cardiorenal syndrome (CRS) are hemodynamic and mechanical changes, as well neurohumoral pathways such as insulin resistance, endothelial dysfunction, nitric oxide bioavailability, renin-angiotensin-aldosterone, oxidative stress, sympathetic nervous systems, natriuretic peptides, adipokines and inflammation. Adiposity and other associated co-morbidities induce adverse cardiac remodeling and interstitial fibrosis. Heart failure with preserved ejection fraction has been associated with obesity-related functional and structural abnormalities. Obesity might also impair kidney function through hyperfiltration, increased glomerular capillary wall tension, and podocyte dysfunction, which leads to tubulointerstitial fibrosis and loss of nephrons and, finally, chronic kidney disease. The development of new treatments with renal and cardiac effects in the context of type 2 diabetes, which improves mortality outcome, has highlighted the importance of CRS and its prevalence. Increased body fat triggers cellular, neuro-humoral and metabolic pathways, which create a phenotype of the CRS with specific cellular and biochemical biomarkers. Obesity has become a single cardiorenal umbrella or type of cardiorenal metabolic syndrome. This review article provides a clinical overview of the available data on the relationship between a range of adiposity and CRS, the support for obesity as a single cardiorenal umbrella, and the most relevant studies on the recent therapeutic approaches.

The impact of sleeve gastrectomy on renal function in patients with chronic kidney disease varies with severity of renal insufficiency

BACKGROUND

Although laparoscopic sleeve gastrectomy is known, in general, to improve renal function in patients with obesity and chronic kidney disease (CKD), its effect on estimated glomerular filtration rate (eGFR) stratified by the stage of CKD is less clear.

OBJECTIVES

We aimed to evaluate the impact of sleeve gastrectomy on renal function in a stratified cohort of patients with CKD.

SETTING

University Hospital.

METHODS

We performed a retrospective review of 1932 patients who met National Institutes of Health's guidelines for metabolic surgery and underwent laparoscopic sleeve gastrectomy performed by 1 of 3 surgeons. One hundred sixty-four patients with CKD stages 1 through 4 were identified.

RESULTS

Mean follow-up period was 1.57 ± 1.0 years. Mean age was 56.4 ± 9.9 years with a preoperative body mass index of 47 ± 9 kg/m², which decreased to 38.9 ± 8.7 kg/m² at most recent follow-up (P < .001). In the cohort of patients with diabetes, significant decreases were observed in mean glycated hemoglobin level, daily number of oral hypoglycemics, and daily long acting insulin use (P < .001 each). Of 67 patients with diabetes, 34.3% (n = 24) achieved complete remission. In patients with hypertension, average daily number of antihypertensives decreased (P < .001) and 22.3% (n = 31) of 133 patients with hypertension discontinued all antihypertensives. Patients with CKD stages 2, 3a, and 3b showed significant improvement in eGFR. Reinforcing this evidence of improvement, patients with CKD 3a and 3b were more likely to downstage disease compared with those with CKD 4 (58.1% versus 73.1% versus 22.7%, respectively) (P < .001).

CONCLUSION

Renal function, as measured by eGFR, in patients with stages 1 and 4 CKD did not improve after laparoscopic sleeve gastrectomy; in contrast, eGFR in patients with CKD stages 2 and 3 significantly improved. Early surgical referral and intervention may be important in achieving the greatest improvement in eGFR and possibly delaying or reversing progression to end-stage renal disease.

Physical Exercise and Grip Strength in Patients Intervened through Bariatric Surgery

Objective: This work sought to evaluate a physical exercise program of moderate intensity in patients operated of bariatric surgery and its influence on muscle strength. Method: Randomized clinical trial, with an intervention group and a control group. Forty-three patients were operated of bariatric surgery. The intervention group was applied a program of moderate physical activity during six months. Grip strength and bioimpedance were measured at their baseline form, at one month, and six months after surgery. A bivariate study was conducted to observe variable changes. Results: Upon conducting Student´s t for independent samples in all the variables (weight, body mass index, grip strength, lean mass, fat mass, and metabolism), the result is that no significant differences exist between the intervention group and the control group with p > 0.05. Conclusion: A program of moderate physical activity lasting six months in patients intervened of bariatric surgery has no significant result in the development of muscle mass evaluated through manual dynamometry and bioimpedance.

Nutritional Management for Chronic Kidney Disease Patients who Undergo Bariatric Surgery: A Narrative Review

Bariatric surgery (BS) may be effective for chronic kidney disease (CKD) patients by reducing microalbuminuria and proteinuria, and by facilitating their meeting inclusion criteria for kidney transplantation. However, nutritional management for this population is complex and specific guidelines are scarce. A literature search was performed to create dietetic practice for these patients based on the most recent evidence. For the purposes of nutritional recommendations, we divided the patients into 2 subgroups: 1) patients with CKD and dialysis, and 2) patients after kidney transplantation. Before surgery, nutritional care includes nutritional status evaluation and adjusting doses of supplements to treat deficiencies and daily nutrient intake according to the dietary restrictions derived from kidney disease, including quantities of fluids, protein, phosphorus, potassium, and vitamins. After BS, these patients are at major risk for lean body mass loss, malnutrition and dehydration because of fluid restriction and diuretics. Postoperative nutritional recommendations should be carefully tailored according to CKD nutritional limitations and include specific considerations regarding protein, fluids, and supplementation, in particular calcium, vitamin A, and vitamin D. Nutritional management of CKD and kidney transplant patients undergoing BS is challenging and future studies are required to establish uniform high-level evidence-based guidelines.

Longitudinal assessment of renal function in native kidney after bariatric surgery

The epidemic of obesity parallels that of chronic kidney disease (CKD). Obesity worsens the course of CKD, mainly defined by an abnormal glomerular filtration rate (GFR). Patients with severe obesity stages (II and III with body mass index >35 kg/m²) are eligible for bariatric surgery (BS), which is the most efficient method of achieving durable weight loss. BS may reverse glomerular hyperfiltration and albuminuria, improve adipocytokine profile, and relieve diabetes and hypertension. Obesity remission after BS might prevent the progression of renal failure in populations with morbid obesity. However, evidence for the beneficial effect of BS on renal function is scant. This lack of knowledge is mainly due to methodologic reasons, which are addressed in this review. The reversibility of hyperfiltration due to the presence of functional renal reserve hampers the interpretation of changes in true GFR after BS. This true GFR is only obtained with the renal clearance of an exogenous filtration marker. Estimation of GFR is generally provided by prediction equations, namely by modification of diet in renal diseases or by chronic kidney disease-epidemiology collaborative group. These equations are not accurate because the serum levels of both creatinine and cystatin C depend on extrarenal factors, which are modified by BS. Comparing the slopes of measured GFR according to various durations of exposure with morbid obesity would be critical in providing reliable data. Herein, we review the current knowledge on the effects of BS on kidney function; we specify the methodologic issues and particularities of the dietary management of CKD patients to propose reliable directions for future clinical research.