Association of Plant Protein Intake With Risk of Incident CKD: A UK Biobank Study

Association between the inflammatory potential of diet and chronic renal failure: A cohort study of 163 433 UK Biobank participants

OBJECTIVES

There is some preclinical evidence suggesting a pro-inflammatory diet reduces kidney function. In the present study, we aimed to investigate the association of inflammatory potential of diet with the risk of chronic renal failure (CRF).

METHODS

Cox regression models were used to examine the association between the energy-adjusted dietary inflammation index (E-DII) quartiles and CRF adjusting varying degrees of confounders. Restricted cubic spline regression was additionally adopted to determine the association of the continuous E-DII and CRF risk. A series of sensitivity and subgroup analyses were also conducted.

RESULTS

A total of 163,433 participants entered the primary analysis. During a mean follow-up period of 12.65 years, incident CRF occurred in 5, 333 participants (3.26%). The E-DII scores was stratified into four quartile groups. In a fully adjusted multivariable model, the adjusted hazard ratio for the second, third, and highest quartiles of E-DII intake was 1.12 (95% confidence interval [CI]: 1.04-1.21), 1.21 (95% CI: 1.12-1.31), and 1.23 (95% CI: 1.14-1.33), respectively, compared with the lowest quartile. Trend test indicated a statistically significant increasing trend with increasing E-DII quartiles (P < 0.0001). Similarly, restricted cubic spline regression displayed a positive association of continuous E-DII with CRF, wherein higher scores were linked to an elevated risk of CRF. Results of sensitivity analyses demonstrated consistent findings.

CONCLUSIONS

Diet with higher proinflammatory potential was linked to an increased risk of CRF. Implementing measures to limit the intake of pro-inflammatory foods or promoting the adoption of an anti-inflammatory dietary pattern could potentially reduce the occurrence of CRF.

Global, regional, and National Burden of chronic kidney disease attributable to dietary risks from 1990 to 2021

Background

Dietary risks are increasingly reported as a cause of chronic kidney disease (CKD). However, the trends in the burden of CKD attributable to dietary risks have yet to be fully elucidated.

Methods

This study extracted two major indicators related to CKD caused by dietary risks from the Global Burden of Disease (GBD) database for the years 1990 to 2021, including deaths and disability-adjusted life years (DALYs). It used estimated annual percentage change (EAPC) and percentage change to assess the trends in the burden of CKD caused by dietary risks. The relationship between Socio-demographic Index (SDI) and disease burden was also further analyzed. Additionally, we utilized the contemporary age-period-cohort model from NORDPRED to project future burden of CKD attributable to dietary risks.

Results

In 2021, globally, the number of deaths due to CKD caused by dietary risks was 317,010, and the number of DALYs was 7,971,281, approximately 2-3 times that of 1990, and it was expected to continue to rise before 2040. The global death rates and DALY rates of CKD related to dietary risks had increased, with EAPCs of 0.63 (95% CI: 0.57 to 0.69) and 0.39 (95% CI: 0.35 to 0.42), respectively. From a gender perspective, men were more likely to suffer from CKD due to dietary risks. From an age pattern perspective, in 2021, the number of deaths due to CKD caused by dietary risks peaked among men aged 70-74 and women aged 85-89. Additionally, the highest number of DALYs due to CKD caused by dietary risks was observed among men and women aged 65-69. In terms of socioeconomic factors, from 1990 to 2021, as the SDI increased, the age-standardized death rates and DALY rates due to CKD caused by dietary risks generally decreased. Among the seven dietary habits related to dietary risks, low vegetable intake, low fruit intake, and high sodium intake had the greatest impact.

Conclusion

In summary, over the past 32 years, the burden of CKD attributable to dietary risks has rapidly increased globally, and it is expected to continue rising until 2040. Therefore, interdisciplinary actions involving education, policy, and healthcare should be taken to mitigate this growing trend.

Adherence to a Healthful Plant-Based Diet and Risk of Chronic Kidney Disease Among Individuals with Diabetes

OBJECTIVE

Chronic kidney disease (CKD) is highly prevalent among people with diabetes. While identifying modifiable risk factors to prevent a decline in kidney function among those living with diabetes is pivotal, there is limited evidence on dietary risk factors for CKD. In this study, we examined the associations between healthy and less healthy plant-based diets (PBDs) and the risk of CKD among those with diabetes, and to identify potential underlying mechanisms.

METHODS

We conducted a prospective analysis among 7,747 UK Biobank participants with prevalent diabetes. Multivariable Cox proportional hazard regression models were used to examine the associations between healthful and unhealthful PBDs and the risk of CKD. Causal mediation analyses were further employed to explore the underlying mechanisms of the observed associations.

RESULTS

Among 7,747 study participants with diabetes, 1,030 developed incident CKD over 10.2 years of follow-up. Higher adherence to a healthy PBD was associated with a 24% lower CKD risk (HRQ4 versus Q1: 0.76 [95%CI: 0.63-0.92], ptrend = 0.002), while higher adherence to an unhealthy PBD was associated with a 35% higher risk (HRQ4 versus Q1: 1.35 [95%CI: 1.11-1.65], ptrend = 0.006). The observed associations were predominantly mediated by markers of body fatness (proportion mediated: 11-25%) and kidney function (23-89%).

CONCLUSIONS

In this prospective cohort study of middle-aged adults with diabetes, adherence to a healthy PBD was associated with lower CKD risk, whereas adherence to an unhealthy PBD was associated with a higher CKD risk. Associations were primarily mediated by markers of lower body fatness and improved kidney function.

Diet quality patterns and chronic kidney disease incidence: a UK Biobank cohort study

BACKGROUND

Only a few studies have investigated the role of diet on the risk of chronic kidney disease (CKD) in European populations and have mainly focused on the Mediterranean diet. This is the first study to evaluate the association between various diet quality indices and CKD incidence in British adults.

OBJECTIVE

To study the relationship between a set of 6 different diet quality indices and CKD incidence among British adults.

METHODS

A prospective cohort with 106,870 participants from the UK Biobank, followed from 2009 to 2012 through 2021. Food consumption was obtained from ≥2 24-h dietary assessments. Dietary patterns were assessed using previously established indices: Alternate Mediterranean Index (aMED), Alternative Healthy Eating Index 2010, dietary approaches to stop hypertension (DASH), healthful plant-based diet index (hPDI), unhealthful plant-based diet index (uPDI), and dietary inflammatory index (DII). Incident CKD was obtained from clinical records, death registries, and self-reports. Analyses were performed with Cox regression models and adjusted for the main confounders.

RESULTS

After a median follow-up of 9.27 y, 2934 cases of CKD were ascertained. Hazard ratios (95% confidence interval) of CKD for the highest compared with lowest tertile of adherence to each diet score were 0.84 (0.76, 0.93) for aMED, 0.94 (0.85, 1.03) for alternative healthy eating index 2010, 0.77 (0.70, 0.85) for DASH, 0.79 (0.72, 0.87) for hPDI, 1.27 (1.16, 1.40) for uPDI, and 1.20 (1.18, 1.33) for DII. The results were robust in sensitivity analyses.

CONCLUSIONS

In British adults, higher adherence to the aMED, DASH, and hPDI patterns was associated with lower risk of CKD, whereas greater adherence to the uPDI and DII patterns was associated with greater risk.

Integrating the new pharmacological standard of care with traditional nutritional interventions in non-dialysis CKD

Chronic kidney disease (CKD) is widely recognized as a leading and growing contributor to global morbidity and mortality worldwide. Nutritional therapy is the basic treatment for metabolic control, and may contribute to nephroprotection; however, the absence of solid evidence on slowing CKD progression together with poor adherence to dietary prescription limit de facto its efficacy and prevent its more widespread use. Sodium-glucose transport protein 2 inhibitors (SGLT2is) are now considered the new standard of care in CKD; in addition, novel potassium binders, glucagon-like peptide-1 receptor antagonists (GLP1-RAs) and nonsteroidal mineralocorticoid receptor antagonists (nsMRAs) show either direct (SGLT2i, GLP1-RA, nsMRA) or indirect (potassium binders that enable the optimal use of renin-angiotensin-aldosterone system inhibitors) nephroprotective effects. These drugs could potentially lead to a more permissive diet, thereby allowing the patient to reap the benefits of this approach. In particular, SGLT2is, and to a lesser extent also GLP1-RAs and nsMRAs in patients with diabetic kidney disease, can counterbalance hyperfiltration as well as the higher protein intake often recorded in obese patients; on the other hand, potassium binders can facilitate following plant-based diets, which are considered healthy because of the high content of essential micronutrients such as antioxidant vitamins, minerals, alkalies, and fibers. In this review paper, we discuss the current pharmacological paradigm shift that places a new, broader standard of care in light of its interaction with nutritional therapy in order to optimize the global approach to patients with CKD not on dialysis.

Nutritional assessment and medical dietary therapy for management of obesity in patients with non-dialysis chronic kidney disease: a practical guide for endocrinologist, nutritionists and nephrologists. A consensus statement from the Italian society of endocrinology (SIE), working group of the club nutrition-hormones and metabolism; the Italian society of nutraceuticals (SINut), club ketodiets and nutraceuticals "KetoNut-SINut"; and the Italian society of nephrology (SIN)

PURPOSE

Chronic kidney disease (CKD) is a serious health concern with an estimated prevalence of about 13.4% worldwide. It is cause and consequence of various comorbidities, including cardiovascular diseases. In parallel, common pathological conditions closely related to ageing and unhealthy dietary habits increase the risk of CKD development and progression, including type 2 diabetes and obesity. Among these, obesity is either independent risk factor for new onset kidney disease or accelerates the rate of decline of kidney function by multiple mechanisms. Therefore, the role of diets aimed at attaining weight loss in patients with obesity is clearly essential to prevent CKD as to slow disease progression. Various dietary approaches have been licensed for the medical dietary therapy in CKD, including low-protein diet and Mediterranean diet. Interestingly, emerging evidence also support the use of low-carbohydrate/ketogenic diet (LCD/KD) in these patients. More specifically, LCD/KDs may efficiently promote weight loss, improve metabolic parameters, and reduce inflammation and oxidative stress, resulting in a dietary strategy that act globally in managing collateral conditions that are directly and indirectly related to the kidney function.

CONCLUSION

This consensus statement from the Italian Society of Endocrinology (SIE), working group of the Club Nutrition - Hormones and Metabolism; the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut"; and the Italian Society of Nephrology (SIN) is intended to be a guide for Endocrinologist, Nutritionists and Nephrologist who deal with the management of patients with obesity with non-dialysis CKD providing a practical guidance on assessing nutritional status and prescribing the optimal diet in order to best manage obesity to prevent CKD and its progression to dialysis.

Plant-based diets for kidney disease prevention and treatment

PURPOSE OF REVIEW

Plant-based diets are associated with a lower risk of hypertension, diabetes, cardiovascular disease, and mortality. Using the most recent evidence, we critically appraised the role of plant-based diets in primary and secondary prevention of chronic kidney disease (CKD) with a focus on key nutritional factors (dietary acid load, phosphorus, potassium, sodium, and fiber).

RECENT FINDINGS

In healthy individuals, observational studies found that greater intake of plant protein and higher adherence to plant-based diets (overall, healthful, and provegetarian) was associated with a lower risk of CKD. In those with CKD, plant-based diets were associated with a lower risk of mortality, improved kidney function, and favorable metabolic profiles (fibroblast growth factor-23, uremic toxins, insulin sensitivity, inflammatory biomarkers). Only few studies reported nutrient content of plant-based diets. These studies found that plant-based diets had lower dietary acid load, lower or no significant difference in phosphorus and sodium, and higher potassium and fiber. One study reported that vegetarian diets were associated with severe vitamin D deficiency compared to nonvegetarian diets.

SUMMARY

Plant-based diets provide several benefits for prevention and management of CKD, with little risk for individuals with CKD. Incorporation of vitamin D rich foods in plant-based diets may be helpful.

Plant-based diet in hyperkalemic chronic kidney disease patients receiving sodium zirconium cyclosilicate: a feasibility clinical trial

BACKGROUND

Plant-based diets (PBD) may induce hyperkalemia in chronic kidney disease (CKD) patients.

OBJECTIVES

We explored the safety and feasibility of PBD in hyperkalemic CKD patients receiving the potassium binder sodium zirconium cyclosilicate (SZC).

METHODS

In the current 6-wk trial, 26 hyperkalemic patients with CKD stage 4-5 not on dialysis received a low-protein low-potassium diet plus SZC for 3 wk and then a PBD with high potassium content delivered as a weekly food basket while continuing SZC for subsequent 3 wk. Plasma potassium was monitored weekly and SZC was titrated to achieve normokalemia. The 24-h urine excretion of potassium and sodium, 24-h food records, dietary quality, nutritional status, Bristol stool scale, Quality of life (QoL), and renal treatment satisfaction were assessed at baseline (week 0), week 3, and week 6.

RESULTS

Mean plasma potassium decreased from 5.5 to 4.4 mEq/L within 48-72 h after baseline, then rose to 4.7-5.0 mEq/L throughout the remaining study period following dose adjustments of SZC that matched the increased potassium intake of PBD from week 3 to week 6. Over the study period, 24-h urinary potassium excretion decreased from week 0 to week 3 and increased from week 3 to week 6. During the study, 58% of patients had fasting plasma potassium between 3.5 and 5.0 mEq/L and there was no episode of plasma potassium >6.5 mEq/L or <3.0 mEq/L during the study. P-carbon dioxide increased from baseline until week 6 (21 ± 2 to 23 ± 2 mEq/L; P = 0.002; mean ± SD), whereas remaining laboratory values remained unchanged. Fiber intake, dietary quality, the domain physical functioning from QoL, and 1 question of renal treatment satisfaction improved, whereas stool type and frequency did not change after starting PBD.

CONCLUSIONS

PBD in hyperkalemia-prone CKD patients receiving SZC improved dietary quality and increased the intake of healthy foods, whereas plasma potassium concentration remained stable within normal values for most patients.

TRIAL REGISTRATION NUMBER

This trial was registered at the https://clinicaltrials.gov/study/NCT04207203 as NCT04207203.

Associations between frailty, genetic predisposition, and chronic kidney disease risk in middle-aged and older adults: A prospective cohort study

OBJECTIVES

Cross-sectional evidence has shown that frailty is highly prevalent in patients with chronic kidney disease (CKD). However, there is limited evidence of the longitudinal associations between frailty, genetic predisposition to CKD, and the risk of CKD in the general population. Therefore, this study aimed to examine such associations among participants in the UK Biobank.

STUDY DESIGN

This is a prospective cohort study included 370,965 middle-aged and older adults from the UK Biobank. Physical frailty was assessed using a modified version of the Fried phenotype classification. A weighted genetic risk score was built using 263 variants associated with estimated glomerular filtration rate.

MAIN OUTCOME MEASURES

Incident CKD was identified from hospital inpatient records.

RESULTS

Over a median follow-up of 12.3 years, we documented a total of 11,121 incident CKD cases. Time-dependent Cox proportional hazards regression models indicated that individuals with frailty (hazard ratio [HR]: 1.94, 95 % confidence interval [CI]: 1.81-2.08) and pre-frailty (HR: 1.27, 95 % CI: 1.22-1.33) had an increased risk of developing CKD, compared with non-frail individuals. No significant interaction between frailty and genetic risk score was observed (P for interaction = 0.41). The highest risk was observed among the individuals with high genetic risk and frailty (HR: 2.31, 95 % CI: 2.00-2.68).

CONCLUSION

Our results demonstrated that frailty and pre-frailty were associated with increased risk of incident CKD in middle-age and older adults, regardless of genetic risk of CKD. Our study underscores the importance of frailty screening and intervention as a potential strategy to prevent CKD. Future clinical trials are needed to validate our findings.

Treatment of chronic kidney disease in older populations

As the world population ages, an expected increase in the prevalence of chronic kidney disease (CKD) among older individuals will pose a considerable challenge for health care systems in terms of resource allocation for disease management. Treatment strategies for older patients with CKD should ideally align with those applied to the general population, focusing on minimizing cardiovascular events and reducing the risk of progression to kidney failure. Emerging therapies, such as SGLT-2 inhibitors and GLP-1 receptor agonists, hold promise for the effective management of CKD in older individuals. In addition, non-pharmacological interventions such as nutritional and exercise therapies have a crucial role. These interventions enhance the effects of pharmacotherapy and, importantly, contribute to the maintenance of cognitive function and overall quality of life. Various factors beyond age and cognitive function must be taken into account when considering kidney replacement therapy for patients with kidney failure. Importantly, all treatment options, including dialysis, transplantation and conservative management approaches, should be tailored to the individual through patient-centred decision-making. The dynamic integration of digital technologies into medical practice has the potential to transform the management of CKD in the aging population.

Compliance with a Healthful Plant-Based Diet Is Associated with Kidney Function in Patients with Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic kidney disorder with multiple cyst formation that progresses to chronic kidney disease (CKD) and end-stage kidney disease. Plant-based diets have attracted considerable attention because they may prevent CKD development. This study investigated whether adherence to a plant-based diet is associated with kidney function in patients with ADPKD. The overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI) were calculated using dietary intake data. Among 106 ADPKD patients, 37 (34.91%) were classified as having advanced CKD (eGFR < 60 mL/min/1.73 m2). The overall PDI and hPDI were lower, but the uPDI was higher in patients with advanced CKD than in those with early CKD. The hPDI was negatively correlated with the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio. Moreover, the hPDI was inversely associated with advanced CKD [odds ratio (OR): 0.117 (95% confidence interval (CI): 0.039-0.351), p < 0.001], and the uPDI was positively associated with advanced CKD [OR: 8.450 (95% CI: 2.810-25.409), p < 0.001]. The findings of the current study demonstrate that greater adherence to a healthful plant-based diet is associated with improved kidney function in ADPKD patients.

Association between dietary protein intake and risk of chronic kidney disease: a systematic review and meta-analysis

Objective

There is suggestive data indicating a correlation among dietary protein intake and the progression of chronic kidney disease (CKD). Nonetheless, the exact associations between dietary protein intake and the incidence of CKD have remained uncertain. We performed the first meta-analysis to explore the correlation among total protein, plant protein, animal protein intake and CKD risk.

Methods

The study conformed the PRISMA statement guidelines. We comprehensively searched PubMed, Web of Science, and Embase until to December 2023. The retrieved studies underwent rigorous evaluation for eligibility, and relevant data were meticulously extracted. The Newcastle-Ottawa Scale (NOS) tool was applied to evaluate the risk of bias. Subsequently, relevant data were extracted and pooled to evaluate the relations among dietary protein intake and CKD incidence.

Results

Totally, 6,191 articles were identified, six studies were eligible. A total of 148,051 participants with 8,746 CKD cases were included. All studies had a low overall risk of bias. Higher total, plant and animal protein intake were all correlated with decreased CKD incidence, pooled risk ratios (RRs) and 95% confidence intervals (CIs) were as follows: (RR = 0.82, 95% CI = 0.71-0.94, p = 0.005; I2 = 38%, p = 0.17); (RR = 0.77, 95% CI = 0.61-0.97, p = 0.03; I2 = 77%, p = 0.001); (RR = 0.86, 95% CI = 0.76-0.97, p = 0.02; I2 = 0%, p = 0.59), respectively. For fish and seafood within animal protein: RR = 0.84, 95% CI = 0.74-0.94. Subgroup analysis showed that geographical region, sample size, follow-up time, not assessing protein by food frequency questionnaire, using %energy as the measurement index, not adjusting for several covariates may be the sources of heterogeneity for plant protein. A significant non-linear relation among plant protein and incident CKD was observed by dose-response analysis.

Conclusion

The data showed a lower CKD risk significantly associated higher-level dietary total, plant or animal protein (especially for fish and seafood) intake. Further prospective studies demonstrating the correlations of precise sources, intake and duration of dietary protein and incident CKD are warranted.

Sugar types, genetic predictors of the gut microbiome, and the risk of chronic kidney disease: a prospective cohort study

Background: Emerging studies suggest that focusing on the intake of specific types or sources of sugars may yield greater benefits in preventing chronic kidney disease (CKD). Objective: We aimed to investigate the associations between free and non-free sugar intakes and CKD risk as well as the potential sugar type-gut microbiome interactions. Methods: A total of 138 064 participants from the UK Biobank were included in this prospective study. The free and non-free sugar intakes were assessed using repeated web-based 24-hour dietary recalls. A cause-specific competing risk model was used to estimate hazard ratios (HRs) and the corresponding confidence intervals (CIs) of incident CKD, treating deaths before incident CKD as competing events. Results: During a median follow-up of 10.5 years, 2,923 participants (2.1%) developed CKD. The free sugar intake was positively associated with the risk of CKD (HRquartile 4 vs. quartile 1 = 1.32, 95% CI = 1.18, 1.47), with a nonlinear relationship (P for nonlinearity = 0.01, the risk increased rapidly after free sugars made up 10% of the total energy). The non-free sugar intake was inversely associated with CKD risk (HRquartile 4 vs. quartile 1 = 0.68, 95% CI = 0.60, 0.77), with an L-shaped nonlinear curve (p for nonlinearity = 0.01, the turning point was at 13.5% of the total energy). We found that the associations between free sugar and non-free sugar intakes and CKD risk were more pronounced in participants with high genetically predicted gut microbial abundance. Furthermore, a significant interaction was observed between the genetically predicted gut microbial abundance and non-free sugar intake (P for interaction = 0.04). Conclusion: A higher intake of free sugars was associated with an elevated risk of CKD, whereas a higher intake of non-free sugars was associated with a reduced risk of CKD. The impact of free sugar intake and non-free sugar intake may be modified by the gut microbial abundance.