Dietary Habits and Risk of Kidney Function Decline in an Urban Population

Age and estimated glomerular filtration rate in Chinese older adults: a cohort study from 2014 to 2020

Objectives

This study aimed to fill the data gap of the course of renal function decline in old age and explore changes in renal function across different health states with increasing age.

Methods

This observational, retrospective, single-center cohort study included 5,112 Chinese older adults (3,321 men and 1,791 women, range 60-104 years). The individual rate of estimated glomerular filtration rate (eGFR) decline was analyzed using linear mixed-effects model to account for repeated measures over the years.

Results

The median age was 66 years, median BMI was 24.56 kg/m2, and median eGFR was 89.86 mL/min.1.73 m2. For every 1-year increase in age, women's eGFR decreased by 1.06 mL/min/1.73 m2 and men's by 0.91 mL/min/1.73 m2. We observed greater age-related eGFR decline in men and women with high systolic blood pressure (SBP). Men with high triglyceride (TG), high low-density lipoprotein cholesterol (LDL-C), and low high-density lipoprotein cholesterol (HDL-C), had greater age-related eGFR decline. In women, different BMI groups showed significant differences in age-related eGFR decline, with the highest decline in those with obesity. Additionally, participants with normal baseline eGFR had a faster age-related decline than those with low baseline eGFR.

Conclusion

The eGFR declined linearly with age in Chinese older adults, with women exhibiting a slightly faster decline than men. Both men and women should be cautious of SBP. Older adults with normal baseline renal function experienced a faster eGFR decline. Men with high TG, LDL-C, and low HDL-C levels, as well as obese women, should be vigilant in monitoring renal function.

The Fruit and Veggies for Kidney Health Study: A Prospective Randomized Trial

Rationale & Objective

Providing fruits and vegetables (F&Vs) to health care system patients with elevated urine albumin-creatinine ratio (ACR) reduced ACR, slowed chronic kidney disease (CKD) progression and reduced cardiovascular disease (CVD) risk factors in previous studies. This study evaluated a community-based strategy in lower-income populations to identify African Americans with elevated ACR before health care system involvement and sustain them in a 6-month F&V protocol with (F&V + Cook) and without (F&V Only) cooking instructions, with the hypothesis that adjuvant cooking instructions with F&Vs would further reduce ACR.

Study Design

Prospective, randomized, parallel 2-arm design.

Setting & Participants

African American adults with ACR >10 mg/g creatinine randomized to 1 of 2 study arms.

Interventions

Two cups/day of F&Vs with or without cooking instructions in participants followed 6 months.

Outcomes

Participants sustaining the F&V protocol and between-group indicators of CVD risk, kidney injury, and dietary intake at 6 weeks and 6 months.

Results

A total of 142 African American adults (mean age, 57.0 years; ACR, 27.4 mg/g; body mass index, 34.4; 24.9% CKD 1; 24.8% CKD 2; 50.4% CKD 3; 55% female) randomized to F&V Only (n=72) or F&V + Cook (n=70), and 71% were retained at 6 months. Participants received 90% of available F&V pick-ups over 6 weeks and 69% over 6 months. In the adjusted model, 6-month ACR was 31% lower for F&V + Cook than F&V Only (P = 0.02). Net 6-week F&V intake significantly increased and biometric variables improved for participants combined into a single group.

Limitations

Small sample size, low-baseline ACR, and potential nonresponse bias for 24-hour dietary recall measure.

Conclusions

These data support the feasibility of identifying community-dwelling African Americans with ACR indicating elevated CVD and CKD risk and sustaining a F&V protocol shown to improve kidney outcomes and CVD risk factors and provides preliminary evidence that cooking instructions adjuvant to F&Vs are needed to lower ACR.

Funding

National Institute on Diabetes, Digestive, and Kidney Diseases grant "Reducing chronic kidney disease burden in an underserved population" (R21DK113440).

Trial Registration

NCT03832166.

Plain-Language Summary

African Americans, particularly those in low-income communities, have increased rates of chronic kidney disease (CKD) with worsening outcomes over time. Giving fruits and vegetables to individuals with CKD identified in health care systems was previously shown to reduce kidney damage, measured by urine protein albumin, and slow kidney function decline. We recruited African Americans in low-income communities with increased urine albumin levels. They received fruits and vegetables for 6 months, and we tested whether added cooking instructions further reduced urine albumin levels. Most participants continued to receive fruits and vegetables throughout the 6 months. Those given cooking instructions had lower urine albumin levels after 6 months, indicating decreased kidney damage. Providing cooking instructions with fruits and vegetables appears to lessen kidney damage more than just fruits and vegetables alone.

The Association between Dietary Habits and Rapid Postoperative Recovery of Rotator Cuff Repair

Some nutritional factors have been suggested to improve postoperative outcomes in rotator cuff (RC) repair, but dietary effects on the recovery speed after the surgery remain undefined. To investigate the potential roles of dietary habits in this context, we analyzed the 12-month follow-up data of 55 patients with RC repair and found that these patients could be categorized into a rapid recovery group (n = 35) and slow recovery group (n = 20) according to their postoperative recovery patterns. Group-based logistic analysis revealed that habitual intakes of meat (OR = 1.84, 95%CI, 1.22-2.76, p = 0.003), fruits (OR = 2.33, 95%CI, 1.26-5.67, p = 0.01), and wheat-flour foods (OR = 1.62, 95%CI, 1.2-2.25, p = 0.002) were significantly associated with rapid recovery. Moreover, among all intakes of wheat-flour foods, intakes of steamed and boiled flour products were also associated with rapid recovery. Further mediation analysis showed that eosinophilic granulocytes (EOs) significantly mediated the association between rapid RC recovery and the habitual intakes of meat (mediation proportion = 17.5%, P-mediation < 0.0001), fruits (17.9%, p < 0.0001), and wheat-flour foods (11.4%, p < 0.0001). Thus, our study suggests that certain dietary habits play beneficial roles in the context of postoperative recovery for RC repair.

Diet Quality and Kidney Outcomes in Adolescent and Adult American Indians: the Strong Heart Family Study

BACKGROUND

The burden of kidney disease is exceedingly high among American Indians (AIs). We sought to examine the relationship of diet quality, a modifiable risk factor, and kidney outcomes in AI adolescents and adults, hypothesizing that healthier diets are associated with lower odds of incident albuminuria and eGFR decline.

METHODS

This is an analysis from the Strong Heart Family Study, a longitudinal study of cardiovascular disease and its risk factors among AIs from Arizona, North and South Dakota, and Oklahoma (n = 1720, mean age 39 + / - 16 years, 16% adolescents at baseline). Participants completed two exams (baseline: 2001-2003; follow-up: 2007-2009). The primary exposure was diet quality, expressed as the Alternative Healthy Eating Index 2010 (AHEI), on a 110-point scale (assessed using a 119-item Block food frequency questionnaire). The primary outcomes were as follows: 1) incident albuminuria (albumin to creatinine ratio 30 mg/g or greater); and 2) eGFR decline of 30% or greater. Generalized estimating equations were used to examine the association of AHEI (in quartiles) with outcomes.

RESULTS

Ten percent of participants (6% of adolescents) had incident albuminuria and 2% of participants (2% of adolescents) had eGFR decline. For those with normal fasting glucose levels, the odds ratio (OR) for incident albuminuria comparing extreme quartiles of diet quality (least healthy [reference] versus healthiest quartiles) was 0.48 (95% CI 0.28, 0.81) after adjustment for demographics and comorbidities.

CONCLUSIONS

For American Indians with normal fasting glucose, higher diet quality decreases the odds of developing albuminuria. These findings inform future efforts to prevent CKD in American Indian adolescents and young adults.

The association of dietary patterns with incident chronic kidney disease and kidney function decline among middle-aged Korean adults: a cohort study

OBJECTIVES

This study assessed the association of dietary patterns with the incidence of chronic kidney disease (CKD) and kidney function decline among Korean adults.

METHODS

Data were collected from the records of 20,147 men and 39,857 women who participated in the Health Examinees study. Principal component analysis was used to identify 3 dietary patterns (prudent, flour-based food and meat, and white rice-based), and CKD risk was defined using the Epidemiology Collaboration equation for estimated glomerular filtration rate: (eGFR) <60 mL/min/1.73 m2. A kidney function decline was defined as a >25% decrease in eGFR from baseline.

RESULTS

During the 4.2-year follow-up, 978 participants developed CKD and 971 had a 25% decline in kidney function. After adjusting for potential impact variables, compared with the lowest quartile of the prudent dietary pattern, participants in the highest quartile had a 37% lower risk of kidney function decline among men (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.47 to 0.85); while higher adherence to the flour-based food and meat dietary pattern was associated with an increased risk of CKD in both men (HR, 1.63; 95% CI, 1.22 to 2.19) and women (HR, 1.47; 95% CI, 1.05 to 2.05) as well as a decline in kidney function in both men (HR, 1.49; 95% CI, 1.07 to 2.07) and women (HR, 1.77; 95% CI, 1.33 to 2.35).

CONCLUSIONS

Although a higher adherence to the prudent dietary pattern was inversely associated with the risk of kidney function decline in men, there was no association with CKD risk. In addition, a higher adherence to the flour-based food and meat dietary pattern increased the risk of CKD and kidney function decline. Further clinical trials are needed to confirm these associations.

Health Literacy, Numeracy, and Dietary Approaches to Stop Hypertension Accordance Among Hypertensive Adults

BACKGROUND

Health literacy (HL) and health numeracy (HN), the ability to interpret and act on quantitative health information, are important for hypertension self-management such as limiting sodium intake. We examined associations of HL, HN, and Dietary Approaches to Stop Hypertension (DASH) diet accordance.

PARTICIPANTS

Among 1,073 hypertensive adults enrolled in a Baltimore, Maryland-based cohort study, we performed a cross-sectional analysis. Rapid Estimate of Adult Literacy in Medicine (REALM) measured HL and Test of Functional Health Literacy in Adults (TOFHLA) numeracy score measured HN.

METHOD

DASH accordance was based on nine key nutrients. Linear regression models estimated associations of HL and HN with DASH total and sodium score, inclusive of dietary supplement data.

RESULTS

In our sample, 39% of participants were male, 66% were Black, 40.2% lived in poverty, and 29.5% reported food insecurity. Fully, 32.5% had limited HL and 14.5% had limited HN. Mean DASH score overall was 2 (range = 0-7.5); only 6.9% were DASH accordant (score ≥4.5). In age and sex adjusted models, higher REALM was associated with a higher DASH score in the overall sample; the relationship of HN with DASH was statistically significant among White but not Black participants. Educational attainment appeared to explain both findings. There were no significant associations between HL or HN and DASH sodium scores.

CONCLUSION

Differences in educational attainment explained the relation of higher HL and greater accordance to the DASH diet in a population of hypertensive adults. Understanding these factors is vital to reducing disparities in hypertension and its sequelae.

Challenges of Emerging Wearable Sensors for Remote Monitoring toward Telemedicine Healthcare

Digitized telemedicine tools with the Internet of Things (IoT) started advancing into our daily lives and have been incorporated with commercial wearable gadgets for noninvasive remote health monitoring. The newly established tools have been steered toward a new era of decentralized healthcare. The advancement of a telemedicine wearable monitoring system has attracted enormous interest in the multimodal big data acquisition of real-time physiological and biochemical information via noninvasive methods for any health-related industries. The expectation of telemedicine wearable creation has been focused on early diagnosis of multiple diseases and minimizing the cost of high-tech and invasive treatments. However, only limited progress has been directed toward the development of telemedicine wearable sensors. This Perspective addresses the advancement of these wearable sensors that encounter multiple challenges on the forefront and technological gaps hampering the realization of health monitoring at molecular levels related to smart materials mostly limited to single use, issues of selectivity to analytes, low sensitivity to targets, miniaturization, and lack of artificial intelligence to perform multiple tasks and secure big data transfer. Sensor stability with minimized signal drift, on-body sensor reusability, and long-term continuous health monitoring provides key analytical challenges. This Perspective also focuses on, promotes, and highlights wearable sensors with a distinct capability to interconnect with telemedicine healthcare for physical sensing and multiplex sensing at deeper levels. Moreover, it points out some critical challenges in different material aspects and promotes what it will take to advance the current state-of-art wearable sensors for telemedicine healthcare. Ultimately, this Perspective is to draw attention to some potential blind spots of wearable technology development and to inspire further development of this integrated technology in mitigating multimorbidity in aging societies through health monitoring at molecular levels to identify signs of diseases.

Self-Perceived Barriers and Facilitators to Dietary Approaches to Stop Hypertension Diet Adherence Among Black Americans With Chronic Kidney Disease: A Qualitative Study

OBJECTIVE

The Dietary Approaches to Stop Hypertension (DASH) eating plan improves hypertension in Black individuals and is associated with favorable chronic kidney disease (CKD) outcomes. Yet, adherence to DASH is low among US adults in general, particularly among Black Americans. We assessed perceptions about DASH, its cultural compatibility, and barriers and facilitators to DASH adherence in Black adults with CKD.

DESIGN AND METHODS

We conducted focus groups and semistructured individual interviews involving 22 Black men and women with CKD Stages 3-4 from outpatient clinics at a US academic medical center. Transcripts of audio-recorded interviews were analyzed using thematic analysis.

RESULTS

Among participants (2 focus groups [N = 8 and 5] and 9 individual interviews), 13 (59%) had CKD Stage 3, 13 (59%) were female, the median age was 61 years, and 19 (90%) had hypertension. After receiving information about DASH, participants perceived it as culturally compatible based on 3 emergent themes: (1) Black individuals already eat DASH-recommended foods ("Blacks eat pretty much like this"), (2) traditional recipes (e.g., southern or soul food) can be modified into healthy versions ("you can come up with decent substitutes to make it just as good"), and ( 3) diet is not uniform among Black individuals ("I can't say that I eat traditional"). Perceived barriers to DASH adherence included unfamiliarity with serving sizes, poor cooking skills, unsupportive household members, and high cost of healthy food. Eleven (52%) reported after paying monthly bills that they "rarely" or "never" had leftover money to purchase healthy food. Perceived facilitators included having local access to healthy food, living alone or with supportive household members, and having willpower and internal/external motivation for change.

CONCLUSIONS

Black adults with CKD viewed DASH as a healthy, culturally compatible diet. Recognizing that diet in Black adults is not uniform, interventions should emphasize person-centered, rather than stereotypically culture-centered, approaches to DASH adherence.

Primary Medical Care Integrated with Healthy Eating and Healthy Moving is Essential to Reduce Chronic Kidney Disease Progression

Increasing adverse outcomes in patients with chronic kidney disease reflect growth of patients with early-stage chronic kidney disease and their increasing per population rates of these outcomes. Progression of chronic kidney disease, more than current level of kidney function, is the primary driver of adverse chronic kidney disease-related outcomes. Racial/ethnic minorities progress faster to end-stage kidney disease with greater risk for adverse outcomes. Diabetes and hypertension cause two-thirds of end-stage kidney disease, for which primary medical care integrated with healthy eating and increased physical activity (healthy moving) slows chronic kidney disease progression. Patients with early-stage chronic kidney disease are appropriately managed by primary care practices but most lack infrastructure to facilitate this integration that reduces adverse chronic kidney disease-related outcomes. Individuals of low socioeconomic status are at greater chronic kidney disease risk, and flexible regulatory options in Medicaid can fund infrastructure to facilitate healthy eating and healthy moving integration with primary medical care. This integration promises to reduce chronic kidney disease-related adverse outcomes, disproportionately in racial/ethnic minorities, and thereby reduce chronic kidney disease-related health disparities.

Dose-response relationship between dietary inflammatory index and diabetic kidney disease in US adults

OBJECTIVE

The impact of the dietary potential inflammatory effect on diabetic kidney disease (DKD) has not been adequately investigated. The present study aimed to explore the association between dietary inflammatory index (DII) and DKD in US adults.

DESIGN

This is a cross-sectional study.

SETTING

Data from the National Health and Nutrition Examination Survey (2007-2016) were used. DII was calculated from 24-h dietary recall interviews. DKD was defined as diabetes with albuminuria, impaired glomerular filtration rate or both. Logistic regression and restricted cubic spline models were adopted to evaluate the associations.

PARTICIPANTS

Data from the National Health and Nutrition Examination Survey (2007-2016) were used, which can provide the information of participants.

RESULTS

Four thousand two-hundred and sixty-four participants were included in this study. The adjusted OR of DKD was 1·04 (95 % CI 0·81, 1·36) for quartile 2, 1·24 (95 % CI 0·97, 1·59) for quartile 3 and 1·64 (95 % CI 1·24, 2·17) for quartile 4, respectively, compared with the quartile 1 of DII. A linear dose-response pattern was observed between DII and DKD (Pnonlinearity = 0·73). In the stratified analyses, the OR for quartile 4 of DII were significant among adults with higher educational level (OR 1·83, 95 % CI 1·26, 2·66) and overweight or obese participants (OR 1·67, 95 % CI 1·23, 2·28), but not among the corresponding another subgroup. The interaction effects between DII and stratified factors on DKD were not statistically significant (all P values for interactions were >0·05).

CONCLUSIONS

Our findings suggest that a pro-inflammatory diet, shown by a higher DII score, is associated with increased odd of DKD.

Lifestyle and chronic kidney disease: A machine learning modeling study

Background

Individual lifestyle varies in the real world, and the comparative efficacy of lifestyles to preserve renal function remains indeterminate. We aimed to systematically compare the effects of lifestyles on chronic kidney disease (CKD) incidence, and establish a lifestyle scoring system for CKD risk identification.

Methods

Using the data of the UK Biobank cohort, we included 470,778 participants who were free of CKD at the baseline. We harnessed the light gradient boosting machine algorithm to rank the importance of 37 lifestyle factors (such as dietary patterns, physical activity (PA), sleep, psychological health, smoking, and alcohol) on the risk of CKD. The lifestyle score was calculated by a combination of machine learning and the Cox proportional-hazards model. A CKD event was defined as an estimated glomerular filtration rate <60 ml/min/1.73 m², mortality and hospitalization due to chronic renal failure, and self-reported chronic renal failure, initiated renal replacement therapy.

Results

During a median of the 11-year follow-up, 13,555 participants developed the CKD event. Bread, walking time, moderate activity, and vigorous activity ranked as the top four risk factors of CKD. A healthy lifestyle mainly consisted of whole grain bread, walking, moderate physical activity, oat cereal, and muesli, which have scored 12, 12, 10, 7, and 7, respectively. An unhealthy lifestyle mainly included white bread, tea >4 cups/day, biscuit cereal, low drink temperature, and processed meat, which have scored −12, −9, −7, −4, and −3, respectively. In restricted cubic spline regression analysis, a higher lifestyle score was associated with a lower risk of CKD event (p for linear relation < 0.001). Compared to participants with the lifestyle score < 0, participants scoring 0–20, 20–40, 40–60, and >60 exhibited 25, 42, 55, and 70% lower risk of CKD event, respectively. The C-statistic of the age-adjusted lifestyle score for predicting CKD events was 0.710 (0.703–0.718).

Conclusion

A lifestyle scoring system for CKD prevention was established. Based on the system, individuals could flexibly choose healthy lifestyles and avoid unhealthy lifestyles to prevent CKD.

Prospective associations between a priori dietary patterns adherence and kidney function in an elderly Mediterranean population at high cardiovascular risk

Purpose

To assess the association between three different a priori dietary patterns adherence (17-item energy reduced-Mediterranean Diet (MedDiet), Trichopoulou-MedDiet and Dietary Approach to Stop Hypertension (DASH)), as well as the Protein Diet Score and kidney function decline after one year of follow-up in elderly individuals with overweight/obesity and metabolic syndrome (MetS).

Methods

We prospectively analyzed 5675 participants (55–75 years) from the PREDIMED-Plus study. At baseline and at one year, we evaluated the creatinine-based estimated glomerular filtration rate (eGFR) and food-frequency questionnaires-derived dietary scores. Associations between four categories (decrease/maintenance and tertiles of increase) of each dietary pattern and changes in eGFR (ml/min/1.73m²) or ≥ 10% eGFR decline were assessed by fitting multivariable linear or logistic regression models, as appropriate.

Results

Participants in the highest tertile of increase in 17-item erMedDiet Score showed higher upward changes in eGFR (β: 1.87 ml/min/1.73m²; 95% CI: 1.00–2.73) and had lower odds of ≥ 10% eGFR decline (OR: 0.62; 95% CI: 0.47–0.82) compared to individuals in the decrease/maintenance category, while Trichopoulou-MedDiet and DASH Scores were not associated with any renal outcomes. Those in the highest tertile of increase in Protein Diet Score had greater downward changes in eGFR (β: − 0.87 ml/min/1.73m²; 95% CI: − 1.73 to − 0.01) and 32% higher odds of eGFR decline (OR: 1.32; 95% CI: 1.00–1.75).

Conclusions

Among elderly individuals with overweight/obesity and MetS, only higher upward change in the 17-item erMedDiet score adherence was associated with better kidney function after one year. However, increasing Protein Diet Score appeared to have an adverse impact on kidney health. Trial Registration Number: ISRCTN89898870 (Data of registration: 2014).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-022-02838-7.

Lab-on-Eyeglasses to Monitor Kidneys and Strengthen Vulnerable Populations in Pandemics: Machine Learning in Predicting Serum Creatinine Using Tear Creatinine

The serum creatinine level is commonly recognized as a measure of glomerular filtration rate (GFR) and is defined as an indicator of overall renal health. A typical procedure in determining kidney performance is venipuncture to obtain serum creatinine in the blood, which requires a skilled technician to perform on a laboratory basis and multiple clinical steps to acquire a meaningful result. Recently, wearable sensors have undergone immense development, especially for noninvasive health monitoring without a need for a blood sample. This article addresses a fiber-based sensing device selective for tear creatinine, which was fabricated using a copper-containing benzenedicarboxylate (BDC) metal-organic framework (MOF) bound with graphene oxide-Cu(II) and hybridized with Cu₂O nanoparticles (NPs). Density functional theory (DFT) was employed to study the binding energies of creatinine toward the ternary hybrid materials that irreversibly occurred at pendant copper ions attached with the BDC segments. Electrochemical impedance spectroscopy (EIS) was utilized to probe the unique charge-transfer resistances of the derived sensing materials. The single-use modified sensor achieved 95.1% selectivity efficiency toward the determination of tear creatinine contents from 1.6 to 2400 μM of 10 repeated measurements in the presence of interfering species of dopamine, urea, and uric acid. The machine learning with the supervised training estimated 83.3% algorithm accuracy to distinguish among low, moderate, and high normal serum creatinine by evaluating tear creatinine. With only one step of collecting tears, this lab-on-eyeglasses with disposable hybrid textile electrodes selective for tear creatinine may be greatly beneficial for point-of-care (POC) kidney monitoring for vulnerable populations remotely, especially during pandemics.

Dietary patterns and chronic kidney disease outcomes: A systematic review

Chronic kidney disease (CKD) is a serious public health problem and its prevalence is growing in many countries, often related to issues resulting from the lifestyle in growing economies and the population's life expectancy. Nutritional therapy is a beneficial but still neglected strategy for preventing CKD and delaying disease progression. The aim of this study was to assess the association of dietary patterns with CKD development and progression. Observational studies conducted in adult humans and the correlation between the adopted dietary pattern and prevalent and incident cases of CKD were assessed. A significant association was observed between unhealthy dietary patterns and an increased risk of developing or worsening CKD, as well as an adverse effect. Whereas healthy eating patterns characterized by the consumption of fruit, vegetables and dietary fibre showed nephroprotective outcomes.

Nutrition in Chronic Kidney Disease-The Role of Proteins and Specific Diets

Chronic kidney disease (CKD) is a global public health burden, needing comprehensive management for preventing and delaying the progression to advanced CKD. The role of nutritional therapy as a strategy to slow CKD progression and uremia has been recommended for more than a century. Although a consistent body of evidence suggest a benefit of protein restriction therapy, patients' adherence and compliance have to be considered when prescribing nutritional therapy in advanced CKD patients. Therefore, these prescriptions need to be individualized since some patients may prefer to enjoy their food without restriction, despite knowing the potential importance of dietary therapy in reducing uremic manifestations, maintaining protein-energy status.

Healthful dietary patterns and risk of end-stage kidney disease: the Singapore Chinese Health Study

BACKGROUND

Although adherence to healthful dietary patterns has been associated with a lower risk of kidney function decline in Western populations, evidence in Asian populations remains scanty.

OBJECTIVES

We examined predefined dietary patterns, namely, the Alternate Healthy Eating Index-2010 (AHEI-2010), the Dietary Approaches to Stop Hypertension (DASH), and the alternate Mediterranean diet (aMED), in relation to risk of end-stage kidney disease (ESKD).

METHODS

We included 56,985 Chinese adults (aged 45-74 y) in the Singapore Chinese Health Study who were free of cancer, stroke, coronary artery disease, and ESKD at recruitment (1993-1998). Dietary pattern scores were calculated based on a validated 165-item FFQ. AHEI-2010 and aMED scores were modified by excluding the alcohol intake component because daily drinking has been associated with a higher risk of ESKD in our study population. We identified 1026 ESKD cases over a median follow-up of 17.5 y via linkage with the nationwide Singapore Renal Registry. Multivariable Cox regression models were used to compute HRs and their 95% CIs.

RESULTS

Higher scores of all 3 dietary patterns were associated with lower ESKD risk in a dose-dependent manner. Compared with the lowest quintiles, the multivariable-adjusted HRs (95% CIs) of ESKD were 0.75 (0.61, 0.92) for the highest quintile of AHEI-2010, 0.67 (0.54, 0.84) for DASH, and 0.73 (0.59, 0.91) for aMED (all P-trend ≤ 0.004). These inverse associations were stronger with increasing BMI (in kg/m2), and the HRs for the diet-ESKD association were lowest in the obese (BMI ≥ 27.5), followed by the overweight (BMI = 25 to <27.5) participants, compared with those in lower BMI categories; the P-interaction values between BMI and diet scores were 0.03 for AHEI-2010, 0.004 for aMED, and 0.06 for DASH.

CONCLUSIONS

Adherence to healthful dietary patterns was associated with a lower ESKD risk in an Asian population, especially in overweight or obese individuals.

Association of Diet Quality Indices with Longitudinal Changes in Kidney Function in U.S. Hispanics/Latinos: Findings from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Background

Recent studies suggest an association between diet quality and incident CKD. However, Hispanics/Latinos were under-represented in these studies. We examined the relationship of diet quality with change in kidney function in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

Methods

Individuals who participated in HCHS/SOL visits 1 (2008-2011) and 2 (2014-2017) were analyzed (n=9921). We used Alternate Healthy Eating Index 2010 (AHEI-2010), Dietary Approaches to Stop Hypertension (DASH), and Mediterranean Diet (MeDS) scores as measures of dietary quality. Scores were calculated from two 24-hour dietary recalls administered at visit 1 and categorized into quartiles of each dietary score (higher quartiles correspond to a healthier diet). Kidney function was assessed at both visits using eGFR and urine albumin-creatinine ratio (UACR). Annualized change was computed as the difference in eGFR or UACR between visits divided by follow-up time in years. Weighted linear-regression models were used to examine the association between quartiles of each dietary quality index and annualized change in eGFR and UACR, adjusted for potential confounders.

Results

At visit 1, the mean (SD) age of participants was 41 (0.28) years, and 56% were female. The baseline mean eGFR was 107.1 ml/min per 1.73 m², and baseline median UACR was 6.1 mg/g. On average, eGFR declined by 0.65 ml/min per 1.73 m² per year, and UACR increased by 0.79 mg/g per year over a 6-year period. Lower AHEI-2010 quartiles were associated with eGFR decline in a dose-response manner (P trend=0.02). Higher AHEI-2010 quartiles showed a trend toward lower annualized change in UACR, but the result did not reach significance. Neither MeDS nor DASH scores were associated with eGFR decline or change in UACR.

Conclusions

Unhealthy diet, assessed at baseline by AHEI-2010, was associated with kidney-function decline over 6 years. Improving the quality of foods and nutrients according to the AHEI-2010 may help maintain kidney function in the Hispanic/Latino community.

Association between dietary patterns and renal function in a cross-sectional study using baseline data from the ELSA-Brasil cohort

Previous analyses of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) identified four main dietary patterns (DP). The aim of this study was to explore the association between the previously defined DP and renal function (RF). A cross-sectional study using the ELSA-Brasil baseline data was carried out. DP (“traditional”, “fruits and vegetables”, “bakery”, and “low sugar/low fat), metabolic syndrome (MS) using the Joint Interim Statement criteria, microalbuminuria (MA), and glomerular filtration rate (eGFR) through the CKD-EPI equation were evaluated. Abnormal RF was defined as eGFR<60 mL·min^-1·(1.73 m²)^-1 and MA≥3.0 mg/dL. Factors associated with RF were determined and mediation analysis was performed to investigate the association between DP, MS, and RF. A total of 15,105 participants were recruited, with a mean age of 52±9 years; 8,134 participants (54%) were females. The mediation analysis identified indirect associations between “bakery” and “fruits and vegetables”, and both were associated with decreased eGFR and albuminuria in both genders, compared with “traditional” and “low sugar/low fat” patterns in the general population. There was a direct association of the “bakery” pattern with MA in men (OR: 1.17, 95%CI: 1.92-1.48). The “fruits and vegetables” pattern also showed a direct association with reduced eGFR in women (OR: 1.65, 95%CI: 1.28-2.12), although there was no significance after adjustment. The “fruits and vegetables” and “bakery” DPs were associated with renal dysfunction. The only independent, direct association was between “bakery” DP and MA in men, raising concerns about DP and renal damage in men.

Adherence to healthy dietary pattern and risk of kidney disease: a systematic review and meta-analysis of observational studies

Epidemiological studies show that adherence to healthy dietary patterns may be associated with a lower risk of decline in kidney function. However, existing evidence has not been quantitatively gathered. Pertinent observational studies investigating the association of adherence to a healthy dietary pattern, either priori-defined dietary pattern/indices or data-driven dietary patterns, with risk of kidney disease in the general population were identified by searching Medline and Scopus databases to May 28, 2018. A random-effects meta-analysis was applied. The analysis included eight prospective cohorts (5734 cases among 569,688 participants) and five cross-sectional studies (1955 cases among 16,614 participants). Higher adherence to a healthy dietary pattern (either priori-defined or data-driven dietary patterns) was associated with a 28% lower risk of kidney disease in the analysis of prospective cohort studies (RR = 0.72, 95 % CI = 0.58, 0.86; I² = %71, n = 8). A subgroup analysis based on definition of healthy dietary pattern resulted in significant inverse association only in the subgroup of Dietary Approaches to Stop Hypertension dietary pattern (RR: 0.74, 95 % CI: 0.54, 0.93; I² = 73%, n = 5). A dose-response analysis indicated a monotonic inverse association between adherence to the Dietary Approaches to Stop Hypertension dietary pattern with risk of kidney disease. A 32% lower risk was observed in the analysis of cross-sectional studies (OR: 0.68, 95 %CI: 0.53, 0.83, I² = 0%, n = 5). The findings suggest that higher adherence to a healthy dietary pattern is associated with a lower risk of kidney disease.

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.

Geriatric nutrition risk index is associated with renal progression, cardiovascular events and all-cause mortality in chronic kidney disease

BACKGROUND

Malnutrition is common and associated with poor outcomes in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Recently, the geriatric nutritional risk index (GNRI) was reported as a novel tool for evaluating nutritional status. However, the association between GNRI and renal outcome, cardiovascular (CVD) events, and mortality in patients with CKD remains unclear.

METHODS

A prospective cohort study with adult patients with CKD stages 1-4 was conducted at 39 centers around China starting in 2011. Patients were divided into quartiles (Q1, Q2, Q3, and Q4) according to their GNRI category.

RESULTS

A total of 2791 CKD patients within a median follow-up of 4.38 years were included. A low GNRI quartile was independently associated with progression to ESRD, CVD events, and overall mortality. Compared to that in the Q1 group (the reference group), belonging to a higher GNRI quartile significantly reduced the risk of progression to ESRD in the crude and multivariate-adjusted models. Moreover, a significant inverse association was found between those in the high GNRI quartiles and overall mortality among patients with CKD (HR 0.25; 95% CI 0.15-0.43; p = 0.0007, Q4 vs. Q1) after multivariate adjustment. In addition, there was also a significant association between GNRI and CVD events (HR 0.57; 95% CI 0.39-0.84; p = 0.005, Q4 vs. Q1). Moreover, after adjusting for other confounders, only the Q3 group remained significantly fewer CVD events (HR 0.44; 95% CI 0.19-0.98; p = 0.04).

CONCLUSIONS

These findings suggest that GNRI might be a useful prognostic tool for patients with CKD.

Adherence to the dietary approaches to stop hypertension-style diet is inversely associated with chronic kidney disease: a systematic review and meta-analysis of prospective cohort studies

No conclusive information is available about the association between the Dietary Approaches to Stop Hypertension (DASH)-style diet and chronic kidney disease (CKD). Hence, we aimed to summarize the findings of prospective cohort studies on the relationship between adherence to the DASH-style diet and risk of CKD. A systematic search was done using relevant keywords in the online databases for relevant publications up through July 2018. In total, we included 6 studies in the current systematic review and meta-analysis, with a total sample size of 568 156 individuals and 9249 cases of CKD. Combining 6 effect sizes from 6 studies revealed a significant inverse association between adherence to the DASH diet and risk of CKD (Combined effect size: 0.72, 95% CI: 0.61-0.85, P < .001). In addition, adherence to a DASH-style diet was inversely associated with a risk of rapid decline in estimated glomerular filtration rate (eGFR) (Combined effect size: 0.74, 95% CI: 0.54-0.99, P = .04) and microalbuminuria (Combined effect size: 0.61, 95% CI: 0.43-0.88, P = .009), but not with low eGFR. Adherence to the DASH-style diet, as a healthy dietary pattern, might be beneficial for the prevention of CKD.

Healthy Dietary Patterns and Incidence of CKD: A Meta-Analysis of Cohort Studies

BACKGROUND AND OBJECTIVES

Whether a healthy dietary pattern may prevent the incidence of developing CKD is unknown. This study evaluated the associations between dietary patterns and the incidence of CKD in adults and children.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This systematic review and meta-analysis identified potential studies through a systematic search of MEDLINE, Embase and references from eligible studies from database inception to February 2019. Eligible studies were prospective and retrospective cohort studies including adults and children without CKD, where the primary exposure was dietary patterns. To be eligible, studies had to report on the primary outcome, incidence of CKD (eGFR<60 ml/min per 1.73 m²). Two authors independently extracted data, assessed risk of bias and evidence certainty using the Newcastle-Ottawa scale and GRADE.

RESULTS

Eighteen prospective cohort studies involving 630,108 adults (no children) with a mean follow-up of 10.4±7.4 years were eligible for analysis. Included studies had an overall low risk of bias. The evidence certainty was moderate for CKD incidence and low for eGFR decline (percentage drop from baseline or reduced by at least 3 ml/min per 1.73 m² per year) and incident albuminuria. Healthy dietary patterns typically encouraged higher intakes of vegetables, fruit, legumes, nuts, whole grains, fish and low-fat dairy, and lower intakes of red and processed meats, sodium, and sugar-sweetened beverages. A healthy dietary pattern was associated with a lower incidence of CKD (odds ratio [OR] 0.70 (95% confidence interval [95% CI], 0.60 to 0.82); I²=51%; eight studies), and incidence of albuminuria (OR 0.77, [95% CI, 0.59 to 0.99]; I²=37%); four studies). There appeared to be no significant association between healthy dietary patterns and eGFR decline (OR 0.70 [95% CI, 0.49 to 1.01], I²=49%; four studies).

CONCLUSIONS

A healthy dietary pattern may prevent CKD and albuminuria.

DASH Diet and Blood Pressure Among Black Americans With and Without CKD: The Jackson Heart Study

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP) more effectively in blacks compared to other US racial subgroups. Considering chronic kidney disease (CKD) raises BP through complex mechanisms, DASH may affect BP differently among blacks with and without CKD. We compared the association of DASH accordance to BP and prevalent hypertension among blacks with and without CKD.

METHODS

Our study involved 3,135 black Americans enrolled in the Jackson Heart Study (2000-2004) with diet and office BP data. Using linear models adjusted for demographics, health behaviors, and clinical factors, we determined the association of a modified DASH score (excluding sodium intake, ranging from 0 to 8 with increasing DASH accordance) with BP. We performed tests for interaction between DASH score and CKD status.

RESULTS

Among participants (mean age: 55 years; hypertension: 60%; CKD: 19%), the median DASH score was similar among participants with and without CKD (1.0 [interquartile range (IQR): 0.5-2] and 1.0 [IQR: 0.5-1.5]). CKD status modified the association of the DASH score with systolic BP (SBP) and diastolic BP (DBP; P interactions were 0.06 and <0.01). Among participants without CKD, SBP and DBP were not associated with the DASH score (-0.4 [95% confidence interval: -1.0, 0.1] mm Hg and -0.1 [-0.4, 0.2] mm Hg per one unit higher DASH score). Among participants with CKD, one unit higher DASH score was associated with lower SBP by 1.6 (0.5, 2.6) mm Hg and lower DBP by 0.9 (0.3, 1.5) mm Hg.

CONCLUSIONS

Despite low DASH scores overall, better DASH accordance was associated with lower BP among Black Americans with CKD.

Dietary Patterns and Renal Health Outcomes in the General Population: A Review Focusing on Prospective Studies

Healthy dietary patterns may promote kidney health and prevent adverse renal outcomes. Although reviews have summarized the findings from studies on dietary patterns for chronic kidney disease (CKD) management, less is known about dietary patterns for maintaining kidney health prior to CKD development. The current review summarized the results from observational studies from March 2009 to March 2019 investigating associations between dietary patterns and renal outcomes in the general population. The main renal outcome assessed was CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m2). A total of twenty-six research articles met the inclusion criteria. Adherence to the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets were significantly associated with a decreased risk of CKD in the majority of the studies. Furthermore, a posteriori "unhealthy" dietary patterns were associated with an increased risk of CKD. In conclusion, the findings from this review suggest that adherence to DASH and Mediterranean dietary patterns may be useful in promoting kidney health and preventing CKD in the general population. More studies, in particular among minorities, are warranted to investigate the role of diet, a potentially modifiable factor, in promoting kidney health.

Chronic kidney disease

Chronic kidney disease (CKD) is defined by persistent urine abnormalities, structural abnormalities or impaired excretory renal function suggestive of a loss of functional nephrons. The majority of patients with CKD are at risk of accelerated cardiovascular disease and death. For those who progress to end-stage renal disease, the limited accessibility to renal replacement therapy is a problem in many parts of the world. Risk factors for the development and progression of CKD include low nephron number at birth, nephron loss due to increasing age and acute or chronic kidney injuries caused by toxic exposures or diseases (for example, obesity and type 2 diabetes mellitus). The management of patients with CKD is focused on early detection or prevention, treatment of the underlying cause (if possible) to curb progression and attention to secondary processes that contribute to ongoing nephron loss. Blood pressure control, inhibition of the renin-angiotensin system and disease-specific interventions are the cornerstones of therapy. CKD complications such as anaemia, metabolic acidosis and secondary hyperparathyroidism affect cardiovascular health and quality of life, and require diagnosis and treatment.