Consumption of whole grains, fruit and vegetables is not associated with indices of renal function in the population-based longitudinal Doetinchem study

Diet Quality Components and Gut Microbiota of Patients on Peritoneal Dialysis

OBJECTIVES

To evaluate the associations between the quality of the diet and its components and microbial diversity and composition in peritoneal dialysis (PD) patients.

DESIGN AND METHODS

This cross-sectional study included PD patients for at least 3 months, aged 18-75 years and clinically stable. The Diet Quality Index (DQI), validated for the Brazilian population, is based on the energy density of 11 components ("sugar and sweets;" "beef, pork, and processed meat;" "refined grains and breads;" "animal fat;" "poultry, fish, and eggs;" "whole cereals, tubers, and roots;" "fruits"; "nonstarch vegetables;" "legumes and nuts;" "milk and dairy products;" and "vegetable oil"). A proportional score-based on the adequacy of the intake to Brazilian dietary guidelines-is calculated, and a final score ranged from 0 (worse) to 100 (better) is obtained. Fecal samples were collected at home, in a sterile material, kept refrigerated, and delivered to the clinic within 12 hours; α-diversity indices (Observed operational taxonomic units, Chao-1, Shannon's, Gini-Simpson's, Pielou eveness, and Faith phylogenetics) and microbial profile were determined by 16S ribosomal DNA with polymerase chain reaction-amplification and sequenced on an Illumina MiSeq platform.

RESULTS

Forty-three participants were included (53.5% men, 52.4 ± 14.1 years, body mass index: 25.9 ± 4.1 kg/m2, 30.2% had diabetes mellitus). DQI score was 50.5 (41.9-54.9). The lowest energy density was for the components "animal fat" and "whole cereals and breads, tubers, and roots," and the highest were for "refined grains and bread" and "beef, pork, and processed meat." Diversity indices and Enterorhabdus genus were directly associated with the energy density of the components "whole cereals and breads, tubers, and roots" and inversely with "refined grains and bread," after adjustments for age and diabetes.

CONCLUSIONS

Even low, the intake of whole cereals, tubers, and roots has the potential to positively influence the microbiota profile in PD patients.

Association between Whole Grain Intake and Chronic Kidney Disease

BACKGROUND

The relationship between whole grain intake and chronic kidney disease (CKD) remains uncertain.

OBJECTIVE

This study aimed to evaluate the association between whole grain intake and risk of CKD in Chinese adults.

METHODS

The present cross-sectional study used data from the China Health and Nutrition Survey conducted in 2009. Whole grain intake was measured using 3 consecutive 24-h dietary recalls and a household food inventory. A multivariable logistic regression model was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for risk of CKD. In addition, a restricted cubic spline was used to investigate the dose‒response relationship between whole grain and risk of CKD.

RESULTS

A total of 6747 participants were included, 728 of whom had CKD. Compared with those in the lowest whole grain intake group, those in the higher grain intake group had an inverse association with risk of CKD (Q2: adjusted OR 0.70, 95% CI: 0.54, 0.89; Q3: adjusted OR 0.54, 95% CI: 0.42, 0.69; and Q4: adjusted OR 0.29, 95% CI: 0.21, 0.41). The association between whole grain intake and CKD seems to be stronger for individuals who were male (P for interaction = 0.008) or smokers (P for interaction = 0.013). In addition, the restricted cubic spline suggested an obvious L-shaped correlation.

CONCLUSIONS

Increased whole grain intake was associated with a decreased risk of CKD in Chinese adults.

Association of fresh vegetable and salt-preserved vegetable consumptions with estimated glomerular filtration rate

OBJECTIVE

This study aimed to investigate the relationship between the consumption of fresh and salt-preserved vegetables and the estimated glomerular filtration rate (eGFR), which requires further research.

METHODS

For this purpose, the data of those subjects who participated in the 2011-2012 and 2014 surveys of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and had biomarker data were selected. Fresh and salt-preserved vegetable consumptions were assessed at each wave. eGFR was assessed using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on plasma creatinine. Furthermore, a linear mixed model was used to evaluate associations between fresh/salt-preserved vegetables and eGFR.

RESULTS

The results indicated that the median baseline and follow-up eGFRs were 72.47 mL/min/1.73 m² and 70.26 mL/min/1.73 m², respectively. After applying adjusted linear mixed model analysis to the data, the results revealed that compared to almost daily intake, occasional consumption of fresh vegetables was associated with a lower eGFR (β=-2.23, 95% CI: -4.23, -0.23). Moreover, rare or no consumption of salt-preserved vegetables was associated with a higher eGFR (β = 1.87, 95% CI: 0.12, 3.63) compared to individuals who consumed salt-preserved vegetables daily.

CONCLUSION

Fresh vegetable consumption was direct, whereas intake of salt-preserved vegetables was inversely associated with eGFR among the oldest subjects, supporting the potential benefits of diet-rich fresh vegetables for improving eGFR.

Dietary quality indices and recurrent chronic kidney disease in Taiwanese post-renal transplant recipients

Background

This study investigated the association between dietary quality indices and recurrent chronic kidney disease (rCKD) in Taiwanese post-renal transplant recipients (RTRs).

Methods

This prospective study recruited RTRs aged >18 years with a functioning allograft and without any acute rejection in the past 3 months from September 2016 to June 2018. Dietary quality indices included the Alternative Healthy Eating Index (AHEI) and AHEI-2010, and the Taiwanese version of the AHEI (AHEI-Taiwan) was calculated using 3-day dietary records, and calculated scores were divided into quartiles. Laboratory data were collected from medical records. rCKD was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m². Logistic regression analysis was performed to analyze the associations.

Results

This study included 102 RTRs. The RTRs with higher AHEI, AHEI-Taiwan, and AHEI-2010 scores were older and had higher eGFRs and lower odds of rCKD. As compared with the lowest quartile, patients with the highest quartiles of the AHEI [odds ratio (OR), 0.10; 95% confidence interval (95% CI): 0.02, 0.49; p-trend = 0.004), AHEI-2010 (OR, 0.17; 95% CI: 0.04, 0.72; p-trend = 0.016], and AHEI-Taiwan (OR, 0.13; 95% CI: 0.03-0.59; p-trend = 0.008) had lower odds of rCKD, respectively. As compared with the lowest quartile, patients who consumed the highest quartiles of red and processed meat had 11.43 times higher odds of rCKD (OR, 11.43; 95% CI: 2.30-56.85; p for trend <0.01).

Conclusion

Higher dietary quality indices are associated with lower odds of rCKD in Taiwanese RTRs. Particularly, a positive association between a higher intake of red meat and processed meat and higher odds of rCKD remained exists after transplantation in Taiwanese RTRs. Further dietary guidelines and individualized dietary education were necessary for RTRs to prevent graft function deterioration.

Fibre Intake in Chronic Kidney Disease: What Fibre Should We Recommend?

Chronic kidney disease (CKD) is a major global health problem that challenges all patients' healthcare needs. Fibre consumption benefits kidney patients by acting preventively on associated risk factors, improving intestinal microbiota composition or reducing metabolic acidosis and inflammation. In this review, we focus on increasing fibre consumption and the quality of fibre to recommend, in addition to increasing the consumption of foods that naturally have it in their design, that can resort to fortified foods or fibre supplements. The Western nutritional practice, which is low in fibre and rich in animal proteins, saturated fats, sodium, and sugar, increases the risk of mortality in these patients. On the contrary, patterns with higher consumption of fibre and vegetable proteins, such as the Mediterranean, vegetarian, or Plant dominant low protein diet (PLADO), seem to have a preventive effect on the associated risk factors and influence CKD progression. Until now, the use of fibre supplements has not achieved an evident impact on clinical results. Fibre-rich foods contain other nutrients that reduce cardiovascular risk. Promoting diets richer in vegetables and guaranteeing adequate energy and protein intake is a challenge for the multidisciplinary teams involved in the standard of care for CKD.

Modifiable Lifestyle Factors for Primary Prevention of CKD: A Systematic Review and Meta-Analysis

BACKGROUND

Despite increasing incidence of CKD, no evidence-based lifestyle recommendations for CKD primary prevention apparently exist.

METHODS

To evaluate the consistency of evidence associating modifiable lifestyle factors and CKD incidence, we searched MEDLINE, Embase, CINAHL, and references from eligible studies from database inception through June 2019. We included cohort studies of adults without CKD at baseline that reported lifestyle exposures (diet, physical activity, alcohol consumption, and tobacco smoking). The primary outcome was incident CKD (eGFR<60 ml/min per 1.73 m²). Secondary outcomes included other CKD surrogate measures (RRT, GFR decline, and albuminuria).

RESULTS

We identified 104 studies of 2,755,719 participants with generally a low risk of bias. Higher dietary potassium intake associated with significantly decreased odds of CKD (odds ratio [OR], 0.78; 95% confidence interval [95% CI], 0.65 to 0.94), as did higher vegetable intake (OR, 0.79; 95% CI, 0.70 to 0.90); higher salt intake associated with significantly increased odds of CKD (OR, 1.21; 95% CI, 1.06 to 1.38). Being physically active versus sedentary associated with lower odds of CKD (OR, 0.82; 95% CI, 0.69 to 0.98). Current and former smokers had significantly increased odds of CKD compared with never smokers (OR, 1.18; 95% CI, 1.10 to 1.27). Compared with no consumption, moderate consumption of alcohol associated with reduced risk of CKD (relative risk, 0.86; 95% CI, 0.79 to 0.93). These associations were consistent, but evidence was predominantly of low to very low certainty. Results for secondary outcomes were consistent with the primary finding.

CONCLUSIONS

These findings identify modifiable lifestyle factors that consistently predict the incidence of CKD in the community and may inform both public health recommendations and clinical practice.

Source and Composition in Amino Acid of Dietary Proteins in the Primary Prevention and Treatment of CKD

Nutrition is a cornerstone in the management of chronic kidney disease (CKD). To limit urea generation and accumulation, a global reduction in protein intake is routinely proposed. However, recent evidence has accumulated on the benefits of plant-based diets and plant-derived proteins without a clear understanding of underlying mechanisms. Particularly the roles of some amino acids (AAs) appear to be either deleterious or beneficial on the progression of CKD and its complications. This review outlines recent data on the role of a low protein intake, the plant nature of proteins, and some specific AAs actions on kidney function and metabolic disorders. We will focus on renal hemodynamics, intestinal microbiota, and the production of uremic toxins. Overall, these mechanistic effects are still poorly understood but deserve special attention to understand why low-protein diets provide clinical benefits and to find potential new therapeutic targets in CKD.

Plant-based diets to manage the risks and complications of chronic kidney disease

Traditional dietary recommendations for patients with chronic kidney disease (CKD) focus on the quantity of nutrients consumed. Without appropriate dietary counselling, these restrictions can result in a low intake of fruits and vegetables and a lack of diversity in the diet. Plant nutrients and plant-based diets could have beneficial effects in patients with CKD: increased fibre intake shifts the gut microbiota towards reduced production of uraemic toxins; plant fats, particularly olive oil, have anti-atherogenic effects; plant anions might mitigate metabolic acidosis and slow CKD progression; and as plant phosphorus has a lower bioavailability than animal phosphorus, plant-based diets might enable better control of hyperphosphataemia. Current evidence suggests that promoting the adoption of plant-based diets has few risks but potential benefits for the primary prevention of CKD, as well as for delaying progression in patients with CKD G3-5. These diets might also help to manage and prevent some of the symptoms and metabolic complications of CKD. We suggest that restriction of plant foods as a strategy to prevent hyperkalaemia or undernutrition should be individualized to avoid depriving patients with CKD of these potential beneficial effects of plant-based diets. However, research is needed to address knowledge gaps, particularly regarding the relevance and extent of diet-induced hyperkalaemia in patients undergoing dialysis.

Dietary Patterns Based on Estimated Glomerular Filtration Rate and Kidney Function Decline in the General Population: The Lifelines Cohort Study

No specific dietary patterns have been established that are linked with loss of kidney function. We aimed to identify an estimated glomerular filtration rate-based dietary pattern (eGFR-DP) and to evaluate its association with eGFR decline and chronic kidney disease (CKD) incidence in the general population. We included 78,335 participants from the Lifelines cohort in the Northern Netherlands. All participants had an eGFR >60 mL/min/1.73 m² at baseline and completed a second visit five years later. The eGFR-DP was constructed at baseline using a 110-item food frequency questionnaire by reduced rank regression, stratified by sex. Logistic regression was performed to evaluated the association between the eGFR-DP score and either a ≥20% eGFR decline or incident CKD. Among women, eGFR-DP were characterized by high consumption of egg, cheese, and legumes and low consumption of sweets, white meat, and commercially prepared dishes. In men, eGFR-DP were characterized by high consumption of cheese, bread, milk, fruits, vegetables, and beer and low consumption of white and red meat. A higher eGFR-DP score was associated with a lower risk of a ≥20% eGFR decline (OR 4th vs. 1st quartile, women: 0.79 [95% CI: 0.73-0.87]; men: 0.67 [0.59-0.76]). The association between the eGFR-DP score and CKD incidence was lost upon adjustment for baseline eGFR. Our results provide support for dietary interventions to prevent kidney function decline in the general population.

Diet and Kidney Function: a Literature Review

PURPOSE OF REVIEW

The burden of chronic kidney disease (CKD) is increasing worldwide. For CKD prevention, it is important to gain insight in commonly consumed foods and beverages in relation to kidney function.

RECENT FINDINGS

We included 21 papers of prospective cohort studies with 3-24 years of follow-up. We focused on meat, fish, dairy, vegetables, fruit, coffee, tea, soft drinks, and dietary patterns. There was convincing evidence that a healthy dietary pattern may lower CKD risk. Plant-based foods, coffee, and dairy may be beneficial. Unhealthy diets and their components, such as red (processed) meat and sugar-sweetened beverages, may promote kidney function loss. For other foods and beverages, associations with CKD were neutral and/or the number of studies was too limited to draw conclusions. Healthy dietary patterns are associated with a lower risk of CKD. More research is needed into the effects of specific food groups and beverages on kidney function.

Dietary patterns and risk of incident chronic kidney disease: the Atherosclerosis Risk in Communities study

BACKGROUND

Adherence to healthy dietary patterns, measured by the Healthy Eating Index (HEI), Alternative Healthy Eating Index (AHEI), and alternate Mediterranean diet (aMed) scores, is associated with a reduced risk of cardiovascular disease. The association between these scores and chronic kidney disease (CKD) is undetermined.

OBJECTIVE

We aimed to estimate the association between the HEI, AHEI, and aMed scores and risk of incident CKD.

METHODS

We conducted a prospective analysis in 12,155 participants aged 45-64 y from the Atherosclerosis Risk in Communities (ARIC) Study. We calculated HEI-2015, AHEI-2010, and aMed scores for each participant and categorized them into quintiles of each dietary score. Incident CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 accompanied by ≥25% decline in estimated glomerular filtration rate, a kidney disease-related hospitalization or death, or end-stage renal disease. We used cause-specific hazard models to estimate risk of CKD from the quintile of the dietary score through to 31 December 2017.

RESULTS

There were 3980 cases of incident CKD over a median follow-up of 24 y. Participants who had higher adherence to the HEI-2015, AHEI-2010, and aMed scores were more likely to be female, have higher educational attainment, higher income level, be nonsmokers, more physically active, and diabetic compared with participants who scored lower. All 3 dietary scores were associated with lower CKD risk (P-trend < 0.001). Participants who were in the highest quintile of HEI-2015 score had a 17% lower risk of CKD (HR: 0.83; 95% CI: 0.74, 0.92) compared with participants in the lowest quintile. Those in quintile 5 of AHEI-2010 and aMed scores, respectively, had a 20% and 13% lower risk of CKD compared with those in quintile 1.

CONCLUSION

Higher adherence to healthy dietary patterns during middle age was associated with lower risk of CKD.

A Diet Rich in Vegetables and Fruit and Incident CKD: A Community-Based Prospective Cohort Study

RATIONALE & OBJECTIVE

A diet rich in vegetables and fruit can lower blood pressure and may reduce cardiovascular risk. However, the association between this dietary pattern and incident chronic kidney disease in the general population is unknown.

STUDY DESIGN

A community-based prospective cohort study.

SETTING & PARTICIPANTS

9,229 study participants with normal kidney function from the Korean Genome and Epidemiology Study database.

PREDICTORS

Daily consumption of nonfermented and fermented vegetables and fruit classified into tertiles based on a validated semiquantitative food-frequency questionnaire.

OUTCOMES

Incident occurrence of estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m², incident proteinuria (≥1+ by dipstick test), and repeated measures of estimated net endogenous acid production.

ANALYTICAL APPROACH

Multivariable cause-specific hazards model to assess the association of vegetable and fruit intake with incident chronic kidney disease.

RESULTS

During a mean follow-up of 8.2 years, 1,741 (21.9/1,000 person-years [PY]) participants developed eGFRs < 60mL/min/1.73m². Incident eGFR < 60mL/min/1.73m² occurred less frequently with higher intake of nonfermented vegetables, occurring at rates of 22.8/1,000 PY, 22.7/1,000 PY, and 20.1/1,000 PY for the lowest, middle, and highest tertiles, respectively; P for trend < 0.001. The incidence of proteinuria was also lower in the middle and highest tertiles. In a multivariable cause-specific hazards model, the highest tertile of nonfermented vegetable intake was associated with 14% lower risk for incident eGFR < 60mL/min/1.73m² than the lowest tertile. The highest tertile was also associated with 32% lower risk for proteinuria than the lowest tertile. There were no associations of fermented vegetable and fruit intake with incidence of eGFR < 60mL/min/1.73m². However, the highest tertiles of both fermented vegetable and fruit intake were associated with 14% and 45% lower risks for incident proteinuria compared with the lowest tertiles (both P < 0.001). During follow-up, estimated net endogenous acid production increased in the lowest tertile of intake of nonfermented or fermented vegetables and fruit, whereas it decreased in the highest tertile.

LIMITATIONS

Self-reported dietary intake, single ethnicity population.

CONCLUSIONS

A diet rich in vegetables and fruit may reduce the risk for kidney disease.

A higher ratio of refined grain to whole grain is associated with a greater likelihood of chronic kidney disease: a population-based study

A growing number of studies suggest that diet and renal function are related. However, little is known about the link between both whole grain (WG) and refined grain (RG) consumption and kidney function parameters. Thus, we investigated the association of WG and RG with urinary albumin to creatinine ratio (ACR) and prevalent chronic kidney disease (CKD). Data from participants of the National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2010 were collected. Estimated glomerular filtration rate (eGFR) was calculated by the CKD Epidemiology Collaboration equation. Survey design and sample weights were taken into consideration for statistical analyses. Finally, we included 16 325 participants from NHANES, 6·9 % of whom had prevalent CKD. In models adjusted for age, sex, race, fasting blood glucose, blood pressure, adiposity, hypertension and diabetes status, mean eGFR significantly increased across increasing quartiles of WG (Q1: 88·2 v. Q4: 95·4 ml/min per 1·73 m2, P&lt;0·001), whereas it significantly decreased across increasing quartiles of RG (Q1: 97·2 v. Q4: 88·4 ml/min per 1·73 m2, P&lt;0·001). Furthermore, serum uric acid levels and ACR significantly decreased across quartiles of WG (both P&lt;0·001). In multivariable-adjusted logistic regression models, the likelihood of prevalent CKD was 21 % lower in the highest WG quartile compared with the lowest one. In conclusion, our results shed light on the beneficial impact of WG on kidney function and CKD, whereas RG is adversely associated with eGFR.