Compliance with a structured weight loss program is associated with reduced systolic blood pressure in obese patients with chronic kidney disease

Probiotics and Fecal Transplant: An Intervention in Delaying Chronic Kidney Disease Progression?

Chronic kidney disease (CKD) is a global health challenge affecting nearly 700 million people worldwide. In the United States alone, the Medicare costs for CKD management has reached nearly USD 80 billion per year. While reversing CKD may be possible in the future, current strategies aim to slow its progression. For the most part, current management strategies have focused on employing Renin Angiotensin Aldosterone (RAS) inhibitors and optimizing blood pressure and diabetes mellitus control. Emerging data are showing that a disruption of the gut-kidney axis has a significant impact on delaying CKD progression. Recent investigations have documented promising results in using microbiota-based interventions to better manage CKD. This review will summarize the current evidence and explore future possibilities on the use of probiotics, prebiotics, synbiotics, and fecal microbial transplant to reduce CKD progression.

The Feasibility and User-Experience of a Digital Health Intervention Designed to Prevent Weight Gain in New Kidney Transplant Recipients-The ExeRTiOn2 Trial

Half of kidney transplant recipients (KTRs) gain more than 5% of their body weight in the first year following transplantation. KTRs have requested support with physical activity (PA) and weight gain prevention, but there is no routine care offered. There are few high-quality studies investigating the clinical value of diet, PA or combined interventions to prevent weight gain. The development and evaluation of theoretically informed complex-interventions to mitigate weight gain are warranted. The aims of this mixed-methods randomized controlled trial (RCT) were to explore the feasibility, acceptability and user-experience of a digital healthcare intervention (DHI) designed to prevent post-transplant weight gain, in preparation for a large multi-center trial. New KTRs (<3 months) with access to an internet compatible device were recruited from a London transplant center. The usual care (UC) group received standard dietary and PA advice. The intervention group (IG) received access to a 12-week DHI designed to prevent post-transplant weight gain. Primary feasibility outcomes included screening, recruitment, retention, adherence, safety and hospitalizations and engagement and experience with the DHI. Secondary outcomes (anthropometrics, bioimpedance, arterial stiffness, 6-minute walk distance and questionnaires) were measured at baseline, 3- and 12-months. 38 KTRs were screened, of which 32 (84.2%) were eligible, and of those 20 (62.5%) consented, with 17 participants (85%) completing baseline assessment (Median 49 years, 58.8% male, Median 62 days post-transplant). Participants were randomized using a computer-generated list (n = 9 IG, n = 8 UC). Retention at 12-months was 13 (76.4%) (n = 6 IG, n = 7 UC). All a priori progression criteria were achieved. There were no associated adverse events. Reflexive thematic analysis revealed four themes regarding trial participation and experience whilst using the DHI. Halting recruitment due to COVID-19 resulted in the recruitment of 40% of the target sample size. Mixed-methods data provided important insights for future trial design. A definitive RCT is warranted and welcomed by KTRs.

Clinical Trial Registration

www.clinicalTrials.gov, identifier: NCT03996551.

Synbiotics Easing Renal Failure by Improving Gut Microbiology II (SYNERGY II): A Feasibility Randomized Controlled Trial

Synbiotics have emerged as a therapeutic strategy for modulating the gut microbiome and targeting novel cardiovascular risk factors, including uremic toxins indoxyl sulfate (IS) and p-cresyl sulfate (PCS). This study aims to evaluate the feasibility of a trial of long-term synbiotic supplementation in adults with stage 3-4 chronic kidney disease (CKD). Adult participants with CKD and estimated glomerular filtration rate (eGFR) of 15-60 mL/min/1.73 m²) were recruited between April 2017 and August 2018 to a feasibility, double-blind, placebo-controlled, randomized trial of synbiotic therapy or matched identical placebo for 12 months. The primary outcomes were recruitment and retention rates as well as acceptability of the intervention. Secondary outcomes were treatment adherence and dietary intake. Exploratory outcomes were evaluation of the cardiovascular structure and function, serum IS and PCS, stool microbiota profile, kidney function, blood pressure, and lipid profile. Of 166 potentially eligible patients, 68 (41%) were recruited into the trial (synbiotic n = 35, placebo n = 33). Synbiotic and placebo groups had acceptable and comparable 12-month retention rates (80% versus 85%, respectively, p = 0.60). Synbiotic supplementation altered the stool microbiome with an enrichment of Bifidobacterium and Blautia spp., resulting in a 3.14 mL/min/1.73 m² (95% confidence interval (CI), -6.23 to -0.06 mL/min/1.73 m², p < 0.01) reduction in eGFR and a 20.8 µmol/L (95% CI, 2.97 to 38.5 µmol/L, p < 0.01) increase in serum creatinine concentration. No between-group differences were observed in any of the other secondary or exploratory outcomes. Long-term synbiotic supplementation was feasible and acceptable to patients with CKD, and it modified the gastrointestinal microbiome. However, the reduction in kidney function with synbiotics warrants further investigation.

Optimizing Diet to Slow CKD Progression

Due to the unique role of the kidney in the metabolism of nutrients, patients with chronic kidney disease (CKD) lose the ability to excrete solutes and maintain homeostasis. Nutrient intake modifications and monitoring of nutritional status in this population becomes critical, since it can affect important health outcomes, including progression to kidney failure, quality of life, morbidity, and mortality. Although there are multiple hemodynamic and metabolic factors involved in the progression and prognosis of CKD, nutritional interventions are a central component of the care of patients with non-dialysis CKD (ND-CKD) and of the prevention of overweight and possible protein energy-wasting. Here, we review the reno-protective effects of diet in adults with ND-CKD stages 3-5, including transplant patients.

Conservative Management of Obesity in Kidney Transplant Candidates

OBJECTIVE

Obesity is prevalent in patients with chronic kidney disease and is associated with increased complications after kidney transplantation (KT). A body mass index limit is used in most transplant programs, though few studies have focused on conservative weight loss in KT candidates. The objective of this retrospective study is to evaluate the efficacy of a basic conservative weight management program in morbidly obese KT candidates and to perform a comprehensive nutritional evaluation.

METHODS

This retrospective study included patients with a body mass index (BMI) >35 kg/m^2, with grade IV or V chronic kidney disease. The conservative weight loss program consisted of anthropometric measurements every 3 months, consultation with a nutritionist, daily exercise, and counseling for healthier eating habits. Overall and quarterly BMI targets were defined. A subset of patients further underwent a comprehensive nutritional evaluation to measure socioeconomic characteristics, food intake behavior, motivation for change, and a 4-day food diary.

RESULTS

Eighty patients were observed for a mean of 24 months. Successful weight loss (BMI < 35 kg/m²) was achieved in 26.3%, associated with women and those already close to the limit. The mean 1-year excess body weight loss was 8.4%. No patient with a BMI >40 kg/m² was successful. The comprehensive nutritional evaluation was performed with 44 patients and found that only 14.6% had previously received nutritional counseling for weight loss. Cognitive restraint scored highest in the food-intake behavior. Most patients were motivated to lose weight with 66% in the action phase. There was little evidence of overeating with a recommended mean calculated daily caloric intake of 82.9%.

CONCLUSION

The conservative weight loss program can have limited but non-negligible, success. Future successful nutritional interventions should take into consideration this surprising comprehensive profile of morbidly obese KT candidates.

Usability and experience testing to refine an online intervention to prevent weight gain in new kidney transplant recipients

OBJECTIVES

Weight gain in the first year following kidney transplantation increases the risk of adverse health outcomes. Currently, there is no recognized intervention available to prevent weight gain after kidney transplantation. An online kidney transplant-specific resource, entitled Exercise in Renal Transplant Online (ExeRTiOn), has been co-created by a multi-professional team, including patients, to assist with weight prevention. This study aimed to evaluate patient and health care professional usability and experience of the ExeRTiOn online resource.

DESIGN

Qualitative study utilizing 'Think-Aloud' and semi-structured interviews.

METHODS

Participants (n = 17) were purposively sampled to include new kidney transplant recipients (n = 11) and transplant health care professionals (n = 6). Kidney transplant recipient participants were from a spread of physical activity levels based on scores from the General Practice Physical Activity Questionnaire (GPPAQ). 'Think-Aloud' interviews assessed the usability of ExeRTiOn. Semi-structured interviews explored participants' experience of ExeRTiOn, weight gain, and physical activity. The data set were analysed thematically. Participant characteristics, including login data and self-reported body weight, were collected.

RESULTS

Data analyses identified valued intervention content and usability aspects which were summarized by two themes. The first theme 'You need to know how to manage yourself' included subthemes: (1) the resource filled a guidance gap, (2) expert patient content resonated, and (3) the importance of goal setting and monitoring progress. The second theme 'room for improvement' included subthemes: (2) web support and (2) content and operational change suggestions.

CONCLUSIONS

Results have allowed for identification of potential areas for resource refinement. This has facilitated iterative enhancement of ExeRTiOn in preparation for a randomized controlled feasibility trial.

Moderate Protein Restriction in Advanced CKD: A Feasible Option in An Elderly, High-Comorbidity Population. A Stepwise Multiple-Choice System Approach

Background: Protein restriction may retard the need for renal replacement therapy; compliance is considered a barrier, especially in elderly patients. Methods: A feasibility study was conducted in a newly organized unit for advanced kidney disease; three diet options were offered: normalization of protein intake (0.8 g/kg/day of protein); moderate protein restriction (0.6 g/kg/day of protein) with a “traditional” mixed protein diet or with a “plant-based” diet supplemented with ketoacids. Patients with protein energy wasting (PEW), short life expectancy or who refused were excluded. Compliance was estimated by Maroni-Mitch formula and food diary. Results: In November 2017–July 2018, 131 patients started the program: median age 74 years (min–max 24-101), Charlson Index (CCI): 8 (min-max: 2–14); eGFR 24 mL/min (4–68); 50.4% were diabetic, BMI was ≥ 30 kg/m² in 40.4%. Normalization was the first step in 75 patients (57%, age 78 (24–101), CCI 8 (2–12), eGFR 24 mL/min (8–68)); moderately protein-restricted traditional diets were chosen by 24 (18%, age 74 (44–91), CCI 8 (4–14), eGFR 22 mL/min (5–40)), plant-based diets by 22 (17%, age 70 (34–89), CCI 6.5 (2–12), eGFR 15 mL/min (5–46)) (p < 0.001). Protein restriction was not undertaken in 10 patients with short life expectancy. In patients with ≥ 3 months of follow-up, median reduction of protein intake was from 1.2 to 0.8 g/kg/day (p < 0.001); nutritional parameters remained stable; albumin increased from 3.5 to 3.6 g/dL (p = 0.037); good compliance was found in 74%, regardless of diets. Over 1067 patient-months of follow-up, 9 patients died (CCI 10 (6–12)), 7 started dialysis (5 incremental). Conclusion: Protein restriction is feasible by an individualized, stepwise approach in an overall elderly, high-comorbidity population with a baseline high-protein diet and is compatible with stable nutritional status.

Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation

BACKGROUND

Adults with severe obesity [body mass index (BMI) of ≥ 35 kg/m2] have an increased risk of comorbidities and psychological, social and economic consequences.

OBJECTIVES

Systematically review bariatric surgery, weight-management programmes (WMPs) and orlistat pharmacotherapy for adults with severe obesity, and evaluate the feasibility, acceptability, clinical effectiveness and cost-effectiveness of treatment.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials and the NHS Economic Evaluation Database were searched (last searched in May 2017).

REVIEW METHODS

Four systematic reviews evaluated clinical effectiveness, cost-effectiveness and qualitative evidence for adults with a BMI of ≥ 35 kg/m2. Data from meta-analyses populated a microsimulation model predicting costs, outcomes and cost-effectiveness of Roux-en-Y gastric bypass (RYGB) surgery and the most effective lifestyle WMPs over a 30-year time horizon from a NHS perspective, compared with current UK population obesity trends. Interventions were cost-effective if the additional cost of achieving a quality-adjusted life-year is < £20,000-30,000.

RESULTS

A total of 131 randomised controlled trials (RCTs), 26 UK studies, 33 qualitative studies and 46 cost-effectiveness studies were included. From RCTs, RYGB produced the greatest long-term weight change [-20.23 kg, 95% confidence interval (CI) -23.75 to -16.71 kg, at 60 months]. WMPs with very low-calorie diets (VLCDs) produced the greatest weight loss at 12 months compared with no WMPs. Adding a VLCD to a WMP gave an additional mean weight change of -4.41 kg (95% CI -5.93 to -2.88 kg) at 12 months. The intensive Look AHEAD WMP produced mean long-term weight loss of 6% in people with type 2 diabetes mellitus (at a median of 9.6 years). The microsimulation model found that WMPs were generally cost-effective compared with population obesity trends. Long-term WMP weight regain was very uncertain, apart from Look AHEAD. The addition of a VLCD to a WMP was not cost-effective compared with a WMP alone. RYGB was cost-effective compared with no surgery and WMPs, but the model did not replicate long-term cost savings found in previous studies. Qualitative data suggested that participants could be attracted to take part in WMPs through endorsement by their health-care provider or through perceiving innovative activities, with WMPs being delivered to groups. Features improving long-term weight loss included having group support, additional behavioural support, a physical activity programme to attend, a prescribed calorie diet or a calorie deficit.

LIMITATIONS

Reviewed studies often lacked generalisability to UK settings in terms of participants and resources for implementation, and usually lacked long-term follow-up (particularly for complications for surgery), leading to unrealistic weight regain assumptions. The views of potential and actual users of services were rarely reported to contribute to service design. This study may have failed to identify unpublished UK evaluations. Dual, blinded numerical data extraction was not undertaken.

CONCLUSIONS

Roux-en-Y gastric bypass was costly to deliver, but it was the most cost-effective intervention. Adding a VLCD to a WMP was not cost-effective compared with a WMP alone. Most WMPs were cost-effective compared with current population obesity trends.

FUTURE WORK

Improved reporting of WMPs is needed to allow replication, translation and further research. Qualitative research is needed with adults who are potential users of, or who fail to engage with or drop out from, WMPs. RCTs and economic evaluations in UK settings (e.g. Tier 3, commercial programmes or primary care) should evaluate VLCDs with long-term follow-up (≥ 5 years). Decision models should incorporate relevant costs, disease states and evidence-based weight regain assumptions.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016040190.

FUNDING

The National Institute for Health Research Health Technology Assessment programme. The Health Services Research Unit and Health Economics Research Unit are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.

How much excess weight loss can reduce the risk of hypertension?

Background

A 25% relative reduction in the prevalence of hypertension is a global target. This meta-analysis estimated the effect of excess weight loss on hypertension.

Methods

We searched PubMed, Web of Science and Scopus until January 2016. We included prospective cohort studies addressing the association between overweight/obesity and hypertension. We expressed the strength of association using risk ratio and the excess risk using attributable risk fraction with 95% CI based on the random-effects model.

Results

We found 7617 references and included 10 studies with 173 828 participants. Compared with normal weight, the risk ratio of hypertension was 1.52 (1.37, 1.67; 9 studies, I2 = 82.4%) for overweight and 2.17 (1.84, 2.50; 9 studies, I2 = 88.9%) for obesity. The excess risk of hypertension attributable to overweight was 32% (24%, 40%; 8 studies, I2 = 85.5%) and that attributable to obesity was 47% (40%, 54%; 8 studies, I2 = 88.2%). That means, excess weight loss may reduce the risk of hypertension by between 24% and 40% in people who are overweight and by between 40% and 54% in people who are obese.

Conclusions

Excess weight loss is a vital strategy for controlling hypertension and is sufficient for achieving the global target, particularly if it is accompanied with other preventive measures.

Systolic Blood Pressure Control Among Individuals With Type 2 Diabetes: A Comparative Effectiveness Analysis of Three Interventions

BACKGROUND

The relative effectiveness of 3 approaches to blood pressure control-(i) an intensive lifestyle intervention (ILI) focused on weight loss, (ii) frequent goal-based monitoring of blood pressure with pharmacological management, and (iii) education and support-has not been established among overweight and obese adults with type 2 diabetes who are appropriate for each intervention.

METHODS

Participants from the Action for Health in Diabetes (Look AHEAD) and the Action to Control Cardiovascular Risk in Diabetes (ACCORD) cohorts who met criteria for both clinical trials were identified. The proportions of these individuals with systolic blood pressure (SBP) <140 mm Hg from annual standardized assessments over time were compared with generalized estimating equations.

RESULTS

Across 4 years among 480 Look AHEAD and 1,129 ACCORD participants with baseline SBPs between 130 and 159 mm Hg, ILI (OR = 1.46; 95% CI = [1.18-1.81]) and frequent goal-based monitoring with pharmacotherapy (OR = 1.51; 95% CI = [1.16-1.97]) yielded higher rates of blood pressure control compared to education and support. The intensive behavioral-based intervention may have been more effective among individuals with body mass index >30 kg/m2, while frequent goal-based monitoring with medication management may be more effective among individuals with lower body mass index (interaction P = 0.047).

CONCLUSIONS

Among overweight and obese adults with type 2 diabetes, both ILI and frequent goal-based monitoring with pharmacological management can be successful strategies for blood pressure control.

CLINICAL TRIALS REGISTRY

clinicaltrials.gov identifiers NCT00017953 (Look AHEAD) and NCT00000620 (ACCORD).

Participation in a Structured Weight Loss Program and All-Cause Mortality and Cardiovascular Morbidity in Obese Patients With Chronic Kidney Disease

OBJECTIVE

To determine if participation in a weight loss program impacted upon a composite end point of all-cause mortality and cardiovascular morbidity in obese patients with chronic kidney disease (CKD).

DESIGN

Retrospective cohort study.

SUBJECTS

All patients with a body mass index (BMI) >30 kg/m(2) or >28 kg/m(2) with at least 1 comorbidity (hypertension, diabetes, or dyslipidemia) referred to an established weight management program (WMP) from 2005 to 2009 at a metropolitan tertiary teaching hospital were eligible for inclusion in the study cohort.

INTERVENTION

Twelve-month structured weight loss program.

MAIN OUTCOME MEASURES

Combined outcome of all-cause mortality, myocardial infarction, stroke, and hospitalization for congestive heart failure; kidney transplantation waitlisting.

RESULTS

A total of 169 obese patients with CKD commenced the WMP and 169 did not-becoming the observational control group (CON). There were no significant differences between groups for age, BMI, sex, ethnicity, smoking, hypertension, or kidney function at baseline, although CON included more patients with diabetes than WMP (49% vs. 38%, P = .03). Kaplan-Meier survival analysis with log-rank test differed between groups for the combined outcome (P = .03). Cox regression analysis with adjustment for age, sex, ethnicity, hypertension, diabetes, kidney function, baseline BMI, and smoking status, indicated that patients in WMP had a significantly longer event-free period for the combined outcome, than those in CON (adjusted hazard ratio 0.53; 95% confidence interval [CI] 0.29-0.97; P = .04). Participation in the WMP did not increase the likelihood of kidney transplantation waitlisting (odds ratio [OR] 1.06; 95% CI 0.39-2.87; P = .9). Lower baseline BMI and greater weight loss over 12 months were the only factors related to kidney transplantation waitlisting (adjusted R(2) = 0.426).

CONCLUSIONS

Participation in a structured weight loss program may be associated with improved outcomes in obese patients with CKD.

Current issues in the management and monitoring of hypertension in chronic kidney disease

PURPOSE OF REVIEW

This review highlights recent developments in the management and monitoring of hypertension in adults with chronic kidney disease (CKD), not on dialysis.

RECENT FINDINGS

Ambulatory blood pressure (BP) monitoring and self-measured BP monitoring can classify abnormal BP patterns better than clinic BP readings. Self-measured BP monitoring lowers BP and allows tailoring of antihypertensive treatment. Dosing of antihypertensive medication at night improves nocturnal hypertension. Recent guidelines recommend a BP target less than 140/90 mmHg for patients with CKD without proteinuria and less than 130/80 mmHg for those with proteinuria. Lower salt intake is associated with a greater effect of renin-angiotensin-aldosterone system blockage in CKD. Lifestyle modification resulting in weight loss reduces BP in individuals with CKD. Of overweight or obese CKD patients, 8% report taking weight loss medication, which is a potential safety concern. Weight loss from intensive lifestyle modification in individuals with diabetes prevents CKD.

SUMMARY

Although we have effective tools to monitor and lower BP, we still need clinical outcome studies to inform BP targets for specific age groups, types of CKD disease, and comorbidities. How to treat obesity to improve hypertension and other comorbidities in patients with CKD remains another important area of research.

Effects of weight loss on renal function in obese CKD patients: a systematic review

Obesity is an independent risk factor for the development and progression of chronic kidney disease (CKD). We conducted a systematic review to assess the benefits of intentional weight loss in obese subjects with altered glomerular filtration rate (GFR), proteinuria or albuminuria. MEDLINE, EMBASE and CENTRAL databases were searched for articles reporting longitudinal data on the effect of weight loss on renal parameters in obese patients with altered kidney function. Thirty-one (2013 subjects) were included. In the 13 studies where weight loss was achieved by bariatric surgery, body mass index (BMI) significantly decreased in all studies; GFR decreased in six studies on hyperfiltration patients and increased in one study on patients with CKD Stage 3-4. Albuminuria decreased in six studies and proteinuria decreased in five studies. In six studies, weight loss was achieved by antiobesity agents: BMI decreased in all studies; GFR decreased in four studies and albuminuria in three. Eleven studies analysed the effects of diet, alone or in combination with lifestyle modifications. A significant decrease in BMI was reported in all studies; GFR increased in two studies, remained stable in four studies and decreased in two studies on hyperfiltration patients. Albuminuria decreased in six studies and remained stable in one study. Proteinuria decreased in five studies. In obese patients with altered renal function, weight loss, particularly if achieved by surgical interventions, improves proteinuria, albuminuria and normalizes GFR. Larger, long-term studies are needed to analyse the durability of this improvement and the effects on renal outcomes, such as CKD progression and the development of ESKD.

Inflammatory factors and exercise in chronic kidney disease

Patients with chronic kidney disease frequently present with chronic elevations in markers of inflammation, a condition that appears to be exacerbated by disease progression and onset of haemodialysis. Systemic inflammation is interlinked with malnutrition and muscle protein wasting and is implicated in a number of morbidities including cardiovascular disease: the most common cause of mortality in this population. Research in the general population and other chronic disease cohorts suggests that an increase in habitual activity levels over a prolonged period may help redress basal increases in systemic inflammation. Furthermore, those populations with the highest baseline levels of systemic inflammation appear to have the greatest improvements from training. On the whole, the activity levels of the chronic kidney disease population reflect a sedentary lifestyle, indicating the potential for increasing physical activity and observing health benefits. This review explores the current literature investigating exercise and inflammatory factors in the chronic kidney disease population and then attempts to explain the contradictory findings and suggests where future research is required.

Optimal nutrition for predialysis chronic kidney disease

Diet potentially plays a major role in the progression and complications of predialysis CKD. Moderate protein consumption along with a diet low in sodium might slow kidney disease progression. Increasing vegetable protein intake might decrease serum phosphorus, uremic toxins, and kidney damage. Because obesity might be an important factor in the increasing prevalence of CKD, dietary strategies targeting obesity might also benefit CKD progression. In those with more advanced CKD, dietary calcium and phosphorus restriction could minimize vascular calcification. Dietary fiber and vitamin D supplementation might also be important to decrease inflammation in CKD.