Dietary patterns and chronic kidney disease risk: a systematic review and updated meta-analysis of observational studies

Ultra-processed food consumption and the risk of incident chronic kidney disease: a systematic review and meta-analysis of cohort studies

BACKGROUND

Recent individual studies have indicated that ultra-processed food (UPF) consumption may be associated with the incidence of chronic kidney disease (CKD). We conducted a systematic review and meta-analysis based on those longitudinal studies evaluating the relationship between UPF consumption and the risk of incident CKD, and synthesizing the results.

METHOD

PubMed, Embase, The Cochrane Library, Web of Science, and Scopus were searched from inception through 22 March 2023. Any longitudinal studies evaluating the relationship between UPF consumption and the risk of incident CKD were included. Two researchers independently conducted the literature screening and data extraction. RR and its 95% CI were regarded as the effect size. The Newcastle-Ottawa Scale (NOS) was applied to assess the quality of the studies included, and the effect of UPF consumption on the risk of incident CKD was analyzed with STATA version 15.1. This study's protocol was registered in PROSPERO (CRD42023411951).

RESULTS

Four cohort studies with a total of 219,132 participants were included after screening. The results of the meta-analysis suggested that the highest UPF intake was associated with an increased risk of incident CKD (RR = 1.25; 95% CI: 1.18-1.33).

CONCLUSIONS

High-dose UPF intake was associated with an increased risk of incident CKD. However, the underlying mechanisms remain unknown. Thus, more standardized clinical studies and further exploration of the mechanisms are needed in the future.

Association between blood pressure and new onset of chronic kidney disease in non-diabetic Japanese adults: A population-based longitudinal study from 1998 to 2023

BACKGROUND AND AIMS

Hypertension is a risk factor for developing chronic kidney disease (CKD). Studies of adult participants in the USA reported that hypertension increased the risk of developing CKD even in the non-diabetic population. However, studies in non-diabetic populations are limited and additional studies in other races are required. This study aimed to examine the relationship between hypertension and the development of CKD in non-diabetic Asian adults.

METHODS AND RESULTS

In this longitudinal study, non-diabetic Japanese adults who took annual checkups from 1998 to 2023 were included. CKD was defined as <60 mL/min/1.73 m2, and hypertension was classified into four levels according to the guidelines of the American College of Cardiology/American Heart Association. The Weibull accelerated failure time model was selected because the proportional hazards assumption was violated. Of the 7363 (men: 40.3%) people in the final cohort, 2498 (men: 40.1%) developed CKD after a mean follow-up of 7.99 years. Elevated blood pressure (BP) and hypertension stage 2 had a 9% (95% confidence interval [CI]: 1%-16%) and 11% (95% CI: 5%-17%) shorter survival time to CKD onset, respectively, than normal BP. Hypertension stage 1 also had a shorter survival to CKD onset by point estimate, but all 95% CIs crossed 1 in all models.

CONCLUSIONS

In a relatively healthy Asian population without diabetes, controlling BP to an appropriate range reduces the risk of developing CKD.

Dietary inflammatory index and lower glomerular filtration rate in Mexican adults

We hypothesized that higher scores on the dietary inflammatory index (DII) would be associated with a lower glomerular filtration rate (GFR). This cross-sectional study included 2098 participants from Mexican Teachers Cohort Study, the Health Workers Cohort Study, and the Comitán Study belonging to the RenMex consortium. Energy-adjusted DII scores were estimated using a semi-quantitative food frequency questionnaire (FFQ). eGFR was estimated by the CKD Epidemiology Collaboration equation. Quantile regression models and ordered regression models were estimated to assess the associations of interest. Median age of study participants was 47 years, median eGFR was 102.9 mL/min/1.73m2, and the median energy-adjusted DII was 0.89 (range, -2.25, +4.86). The median eGFR was lower in participants in the highest percentile of DII compared to those in the lowest percentile (103.8 vs 101.4). We found that continuous and categorical energy-adjusted DII scores were associated with lower eGFR, especially at the lower percentiles. In adjusted ordered logistic regression, we found that the highest DII category was associated with 1.80 times the odds of belonging to the mildly decreased eGFR category or moderately decreased eGFR category compared lowest DII category (OR: 1.80, 95%CI 1.35, 2.40). A high DII score was associated with a lower eGFR among the Mexican population. Additional studies are crucial to validate these findings and explore potential strategies to reduce the consumption of pro-inflammatory foods as a preventive approach for chronic kidney disease (CKD).

Chronic Kidney Disease Diets for Kidney Failure Prevention: Insights from the IL-11 Paradigm

Nearly every fifth adult in the United States and many older adults worldwide are affected by chronic kidney disease (CKD), which can progress to kidney failure requiring invasive kidney replacement therapy. In this review, we briefly examine the pathophysiology of CKD and discuss emerging mechanisms involving the physiological resolution of kidney injury by transforming growth factor beta 1 (TGFβ1) and interleukin-11 (IL-11), as well as the pathological consequences of IL-11 overproduction, which misguides repair processes, ultimately culminating in CKD. Taking these mechanisms into account, we offer an overview of the efficacy of plant-dominant dietary patterns in preventing and managing CKD, while also addressing their limitations in terms of restoring kidney function or preventing kidney failure. In conclusion, this paper outlines novel regeneration strategies aimed at developing a reno-regenerative diet to inhibit IL-11 and promote repair mechanisms in kidneys affected by CKD.

Dietary acid load in health and disease

Maintaining an appropriate acid-base equilibrium is crucial for human health. A primary influencer of this equilibrium is diet, as foods are metabolized into non-volatile acids or bases. Dietary acid load (DAL) is a measure of the acid load derived from diet, taking into account both the potential renal acid load (PRAL) from food components like protein, potassium, phosphorus, calcium, and magnesium, and the organic acids from foods, which are metabolized to bicarbonate and thus have an alkalinizing effect. Current Western diets are characterized by a high DAL, due to large amounts of animal protein and processed foods. A chronic low-grade metabolic acidosis can occur following a Western diet and is associated with increased morbidity and mortality. Nutritional advice focusing on DAL, rather than macronutrients, is gaining rapid attention as it provides a more holistic approach to managing health. However, current evidence for the role of DAL is mainly associative, and underlying mechanisms are poorly understood. This review focusses on the role of DAL in multiple conditions such as obesity, cardiovascular health, impaired kidney function, and cancer.

Ultra-processed food consumption and chronic kidney disease risk: a systematic review and dose-response meta-analysis

Background

High intake of ultra-processed food (UPF) has been associated with increased risk of chronic kidney disease(CKD), but the results remain inconsistent. We therefore performed this systematic review and dose–response meta-analysis of observational studies that shed light on the association between UPF consumption and the risk of CKD.

Methods

A systematic literature search of PubMed, Embase, Web of Science, Scopus and China National Knowledge Infrastructure (CNKI) databases was carried out to find the eligible articles published up to October 31, 2023. Random-effects or fixed-effects models were used to pool the relative risks(RRs) and their 95% confidence intervals (CIs).The potential sources of heterogeneity across studies were examined using the Cochran’s Q test and I-square(I2). Publication bias was examined using the visual inspection of asymmetry in funnel plots and quantified by Begg’s and Egger’s tests.

Results

Eight studies (six cohort and two cross-sectional studies) exploring the association between UPF consumption and risk of CKD, were included in the final analysis. The pooled analyses revealed that high consumption of UPF was associated with an increased risk of CKD (RR = 1.25; 95%CI: 1.09–1.42, p &lt; 0.0001). Moreover, a 10% increase of UPF consumption was associated with a 7% higher risk of CKD (RR = 1.07; 95%CI: 1.04–1.10, p &lt; 0.001). Dose–response analysis of all included studies showed a linear association between UPF consumption and the risk of CKD (RR = 1.02; 95%CI:0.99–1.05, Pdose–response = 0.178, Pnonlinearity = 0.843).

Conclusion

Our findings indicate that high consumption of UPF is significantly associated with an increased risk of CKD. Future research with prospective design is required to confirm this positive association.

Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023478483, PROSPERO identifier CRD42023478483.

Long-term exposure to high perceived temperature and risk of mortality among patients with chronic kidney disease

Health risks due to climate change are emerging, particularly from high-temperature exposure. The perceived temperature is an equivalent temperature based on the complete heat budget model of the human body. Therefore, we aimed to analyze the effect of perceived temperature on overall mortality among patients with chronic kidney disease. In total, 32,870 patients with chronic kidney disease in Seoul participated in this retrospective study (2001-2018) at three medical centers. The perceived temperature during the summer season was calculated using meteorological factors, including the air temperature near the automated weather station, dew point temperature, wind velocity, and total cloud amount. We assessed the association between perceived temperature using Kriging spatial interpolation and mortality in patients with CKD in the time-varying Cox proportional hazards model that was adjusted for sex, age, body mass index, hypertension, diabetes mellitus, estimated glomerular filtration rate, smoking, alcohol consumption, and educational level. During the 6.14 ± 3.96 years of follow-up, 3863 deaths were recorded. In multivariable analysis, the average level of perceived temperature and maximum level of perceived temperature demonstrated an increased risk of overall mortality among patients with chronic kidney disease. The concordance index for mortality of perceived temperature was higher than temperature, discomfort index, and heat index. When stratified by age, diabetes mellitus, and estimated glomerular filtration rate, patients with chronic kidney disease with young age (age <65 years) showed higher hazard ratio for mortality (interaction P = 0.049). Moreover, the risk of death in the winter and spring seasons was more significant compared to that of the summer and autumn seasons. Therefore, long-term exposure to high perceived temperature during summer increases the risk of mortality among patients with chronic kidney disease.

Sociodemographic patterning of dietary profiles among Inuit youth and adults in Nunavik, Canada: a cross-sectional study

OBJECTIVES

Country (traditional) foods are integral to Inuit culture, but market food consumption is increasing. The Qanuilirpitaa? 2017 Nunavik Health Survey (Q2017) reported similar country food consumption frequency compared to that in 2004; however, examining food items individually does not account for diet patterns, food accessibility, and correlations between food items. Our objective was to identify underlying dietary profiles and compare them across sex, age, ecological region, and food insecurity markers, given the links among diet, health, and sociocultural determinants.

METHODS

Food frequency and sociodemographic data were derived from the Q2017 survey (N = 1176). Latent profile analysis identified dietary profiles using variables for the relative frequencies of country and market food consumption first, followed by an analysis with those for country food variables only. Multinomial logistic regression examined the associations among dietary profiles, sociodemographic factors, and food insecurity markers (to disassociate between food preferences and food access).

RESULTS

Four overall dietary profiles and four country food dietary profiles were identified characterized by the relative frequency of country and market food in the diet. The patterns were stable across several sensitivity analyses and in line with our Inuit partners' local knowledge. For the overall profiles, women and adults aged 30-49 years were more likely to have a market food-dominant profile, whereas men and individuals aged 16-29 and 50+ years more often consumed a country food-dominant profile. In the country food profiles, Inuit aged 16-29 years were more likely to have a moderate country food profile whereas Inuit aged 50+ were more likely to have a high country food-consumption profile. A low country and market food-consumption profile was linked to higher prevalence of food insecurity markers.

CONCLUSION

We were able to identify distinct dietary profiles with strong social patterning. The profiles elucidated in this study are aligned with the impact of colonial influence on diet and subsequent country food promotion programs for Inuit youth. These profiles will be used for further study of nutritional status, contaminant exposure, and health to provide context for future public health programs.

COVID-19 and Nutrition: Focus on Chronic Kidney Disease

Some chronic diseases, including chronic kidney disease (CKD), may be associated with poor outcomes, including a high rate of hospitalization and death after COVID-19 infection. In addition to the vaccination program, diet intervention is essential for boosting immunity and preventing complications. A healthy diet containing bioactive compounds may help mitigate inflammatory responses and oxidative stress caused by COVID-19. In this review, we discuss dietary interventions for mitigating COVID-19 complications, including in persons with CKD, which can worsen COVID-19 symptoms and its clinical outcomes, while diet may help patients with CKD to resist the ravages of COVID-19 by improving the immune system, modulating gut dysbiosis, mitigating COVID-19 complications, and reducing hospitalization and mortality. The concept of food as medicine, also known as culinary medicine, for patients with CKD can be extrapolated to COVID-19 infection because healthy foods and nutraceuticals have the potential to exert an important antiviral, anti-inflammatory, and antioxidant role.

A population-based longitudinal study on glycated hemoglobin levels and new-onset chronic kidney disease among non-diabetic Japanese adults

Chronic kidney disease (CKD) is a major global public health problem. Recent studies reported that diabetes and prediabetes are risk factors for developing CKD; however, the exact glycated hemoglobin (HbA1c) cut-off value for prediabetes remains controversial. In this study, we aimed to examine the relationship between HbA1c levels and subsequent CKD development in greater detail than previous studies. Longitudinal data of annual checkups of 7176 Japanese non-diabetic people (male: 40.4%) from 1998 to 2022 was analyzed. HbA1c values were categorized into < 5.0%, 5.0-5.4%, 5.5-5.9%, and 6.0-6.4%. CKD was defined as an estimated glomerular filtration rate < 60 ml/min/1.73 m2. The descriptive statistics at study entry showed that higher HbA1c values were associated with male, older, overweight or obese, hypertensive, or dyslipidemic people. During a mean follow-up of 7.75 person-years, 2374 participants (male: 40.0%) developed CKD. The Weibull accelerated failure time model was selected because the proportional hazards assumption was violated. The adjusted time ratios of developing CKD for HbA1c levels of 5.5-5.9% and 6.0-6.4% compared with 5.0-5.4% were 0.97 (95% confidence interval: 0.92-1.03) and 1.01 (95% confidence interval: 0.90-1.13), respectively. There was no association between HbA1c in the prediabetic range and subsequent CKD development.

Assessment of the impact of glyphosate and 2,4-D herbicides on the kidney injury and transcriptome changes in obese mice fed a Western diet

The development of chronic kidney disease has been associated with comorbidities resulting from the consumption of Westernized dietary (WD) patterns, including obesity and other metabolic dysfunctions. Kidneys also have a crucial role in the metabolism and excretion of xenobiotics, including herbicides. There is limited knowledge regarding the simultaneous exposure to WD and glyphosate (glypho) and 2,4-D, the most used herbicides globally. Thus, this study examined whether exposure to glypho and/or 2,4-D, either individually or in mixed, could impact the early effects of WD intake on kidney histology and gene expression in a rodent model. Male C57BL6J mice were fed a WD containing 20% lard, 0.2% cholesterol, 20% sucrose, and high sugar solution with 23.1 and 18.9 g/L of D-fructose and D-glucose for six months. During this period, the mice also received glypho (0.05 or 5 mg/kg/day), 2,4-D (0.02 or 2 mg/kg/day), or a mixture of both (0.05 +0.02, 5 +2 mg/kg/day) via intragastric administration five times per week. The doses were within or below the established regulatory limits. While single or mixed exposures did not alter WD-induced obesity, tubular lipid vacuolation, or increased serum creatinine levels; the exposure to higher doses of the mixture (5 +2) reduced the mesangial matrix area and tubular cell proliferation, while increasing the density of F4/80 macrophages in the renal interstitium. In terms of transcriptomic analysis, the herbicide mixture altered the expression of 415 genes in the kidney, which were found to be associated with immune response processes, particularly those related to phagocyte activity. While discrete, findings indicate that herbicide mixtures, rather than single exposures, might induce minor deleterious effects on the kidneys of obese mice under WD intake.

Association between ultra-processed food intake and risk of colorectal cancer: a systematic review and meta-analysis

Background

Although some epidemiological studies have shown a positive relationship between high intake of ultra-processed food (UPF) and risk of colorectal cancer (CRC), the results remain inconsistent. Therefore, we conducted this systematic review and meta-analysis to clarify the association between UPF intake and CRC risk.

Methods

PubMed/MEDLINE, Web of Science, EMBASE, China National Knowledge Infrastructure (CNKI) and Wan fang databases were used to search the relevant studies published up to February 2023. The summary relative risks (RRs) with the corresponding 95% confidence intervals (CIs) were estimated by comparing the highest category vs. the lowest category of UPF intake, using the random-effects models (DerSimonian-Laird method). Heterogeneity between studies was explored using the Cochran's Q test and I-square (I²). Publication bias was assessed by examining the funnel plots, and quantified by Begg's or Egger's tests.

Results

A total of seven articles (three cohort and four case-control studies), involving 18,673 CRC cases and 462,292 participants, were included in our study. Combining nine effect sizes from seven articles, an increased risk of CRC was shown in the highest compared with the lowest category of UPF intake (RR = 1.26; 95%CI:1.14-1.38, p < 0.0001). Subgroup analyses showed a positive association between UPF intake and CRC risk in case-control studies (RR = 1.41; 95%CI: 1.22-1.63, p < 0.0001). When we conducted analyses separately by study area, there was a significant association between UPF intake and CRC risk in developed countries (RR = 1.20; 95%CI: 1.11-1.30, p < 0.0001).

Conclusion

Our results show that high UPF intake is significantly associated with a higher risk of CRC, in the absence, however, of a dose-response association. Further studies in particular of large prospective cohort studies are necessary to confirm these results.

Protective effects of peanut skin extract on high-fat and high-fructose diet-induced kidney injury in rats

Chronic kidney disease (CKD) is becoming a major public health problem worldwide. This study aimed to explore whether peanut skin extract (PSE) has protective effects against high-fat and high-fructose (HF) diet-induced kidney injury. Rats were fed HF diet in the whole experiment, while rats in PSE-treated groups were supplemented with PSE. Finally, PSE reduced kidney tissue weight, perinephric fat weight, and levels of serum ammonia, creatinine, and urea nitrogen, along with decreases of renal IL-1β and TNF-α level. Histological examination indicated that PSE alleviated renal tubular dilatation, and degeneration and partial exfoliation of renal tubular epithelial cells. In addition, PSE decreased serum and urinary uric acid level, together with reductions of XOD production and XOD activity both in serum and liver, and down-regulated expressions of renal NLRP3 and ERS proteins. Thus, PSE may be a potential functional food for protecting against renal injury in high energy intake.

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.

Adherence to the Dietary Approaches to Stop Hypertension diet reduces the risk of breast cancer: A systematic review and meta-analysis

Background

Despite increasing evidence for the association of adherence to the Dietary approaches to stop hypertension (DASH) diet with breast cancer risk, the results remain inconclusive. The purpose of the current systematic review was to summarize the evidence from previous observational studies and explore the potential association between DASH diet and breast cancer risk using meta-analysis.

Methods

A comprehensive literature search was conducted using the databases of PubMed, Web of Science, CNKI and Wanfang Data to identify the relevant publications from inception up to July 2022. The pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated for the highest versus the lowest categories of DASH score in relation to breast cancer risk, using a random-effects model. The Cochran's Q test and I-squared (I ²) statistic were used to detect the sources of heterogeneity among the included studies.

Results

Overall, eleven studies, involving 23,254 breast cancer cases and 449,273 participants, were included in this systematic review and meta-analysis. Combining 16 effect sizes from 11 studies, a significant inverse association between adherence to the DASH diet and risk of breast cancer was observed (RR = 0.79; 95% CI: 0.70, 0.90, P < 0.0001). Stratified analysis showed a significant association between adherence to the DASH diet and risk of breast cancer in case-control studies (RR = 0.49; 95% CI: 0.27-0.89, P = 0.019), and a marginally significant association in prospective cohort studies (RR = 0.92; 95% CI: 0.86-0.98, P = 0.014), respectively. Besides, a more significant association between DASH score and reduced risk of breast cancer was observed in Asian countries (RR = 0.50; 95% CI: 0.31-0.81, P = 0.005) than in the United States (RR = 0.93; 95% CI: 0.89-0.99, P = 0.012). Similarly, when we conducted analyses separately by menopausal status, we found a significant inverse association between DASH diet and breast cancer risk in postmenopausal women (RR = 0.58; 95% CI: 0.39-0.87, P = 0.008).

Conclusion

The results of this systematic review and meta-analysis indicate a significant inverse association between adherence to the DASH diet and risk of breast cancer. Further large prospective studies and randomized controlled trials are required to confirm our findings.

Healthy dietary patterns, foods, and risk of glioma: A systematic review and meta-analysis of observational studies

Background

Accumulating epidemiological evidence has shown the favorable associations between healthy dietary patterns and risk of glioma, although the results remain inconclusive.

Objective

We therefore carried out a systematic review and meta-analysis to summarize the evidence from previous published studies, and to clarify the effects of healthy dietary patterns, typical healthy foods on glioma.

Methods

PubMed, Web of Science, CNKI, and Wan fang data were searched from inception up to September 2022 for eligible studies. Two authors independently performed the literature search, study selection, data extraction, and quality assessment. Heterogeneity across studies was estimated using the Cochran's Q test and I ² statistic. According to heterogeneity, the fixed-effects model or random-effects model was selected to obtain the relative risk (RR) of the merger. Subgroup analysis, sensitivity analysis and publication bias were also used for our analysis.

Results

Twenty-four articles that met the selection criteria, involving 7,278 glioma cases and 2,143,528 participants, were included in our analysis. There was a reduced risk of glioma in the highest compared with the lowest categories of healthy dietary patterns (RR = 0.58; 95% CI: 0.44-0.77; P < 0.0001). Moreover, compared with the lowest intakes, the highest intakes of vegetables (RR = 0.84; 95% CI: 0.73-0.96; P = 0.012) and fruits (RR = 0.85; 95% CI: 0.72-1.00; P = 0.045) significantly reduce the risk of glioma. However, the intakes of fresh fish, nuts, whole grains, and dairy products showed no statistically significant associations with the risk of glioma (P > 0.05).

Conclusion

Findings from this systematic review and meta-analysis indicate that higher intakes of healthy dietary patterns, vegetables, and fruits are significantly associated with the lower risk of glioma. Further studies, particularly with prospective design, are required to confirm our findings.

Health-related patterns and chronic kidney disease in the Brazilian population: National Health Survey, 2019

Objective

The aim of this study was to identify patterns related to health and their association with chronic kidney disease (CKD) in the Brazilian population.

Methods

We used data from the National Health Survey (PNS), 2019. Participants were interviewed and answered questions related to socioeconomic and demographic information (gender, age, education, race/color), health conditions (presence of hypertension, diabetes mellitus, hyperlipidemia, cardiovascular disease, overweight and CKD) and lifestyle (smoking, alcohol consumption, physical activity and food consumption). To identify patterns, we used exploratory factor analysis. We performed logistic regression models to describe the association of CKD with each pattern in crude models and adjusted for gender, age group, education level and race/color.

Results

A total of 90,846 individuals were evaluated. The prevalence of CKD was 1.49% (95% CI: 1.3-1.6). Three health-related patterns - metabolic factors, behavioral risk factors and behavioral protective factors - were identified by factor analysis. Metabolic factors were determined by the presence of hypertension, diabetes mellitus, hyperlipidemia and cardiovascular diseases. Behavioral risk factors were determined by smoking, alcohol consumption, regular consumption of soft drinks, sweets and artificial juices, and high salt consumption. The protective behavioral factors were established by the practice of physical activity and regular consumption of vegetables and fruits. Participants of the highest tertile for metabolic factors were more likely to have CKD in the adjusted model (OR = 3.61, 95% CI: 2.69-4.85), when compared to those of the lower tertile.

Conclusion

The pattern referring to metabolic factors was associated with a higher chance of presenting CKD.

Dietary protein score and carbohydrate quality index with the risk of chronic kidney disease: Findings from a prospective cohort study

BACKGROUND/AIM

This study aimed to examine the associations between dietary protein score and carbohydrate quality index (CQI) and the risk of chronic kidney disease (CKD) in Iranian adults.

METHODS

This population-based cohort study was performed within the Tehran Lipid and Glucose Study framework on 6,044 subjects aged ≥18 years old, who were followed up for a mean of 7.7 years. Dietary protein score and CQI were determined using a food frequency questionnaire. CKD was defined as an estimated glomerular filtration rate <60 ml/min/1.73 m2. A multivariate Cox proportional hazard regression model was used to estimate the risk of CKD across tertiles of protein score and CQI.

RESULTS

The mean (standard deviation) of age and body mass index of participants were 37.9 (12.8) years and 26.8 (4.7) kg/m2, respectively. During the 7.7 ± 2.7 years of follow-up, 1,216 cases (20.1%) of CKD were ascertained. In the final adjusted model, individuals in the highest tertile of protein score had decreased risk of CKD (HR: 0.85, 95% CI: 0.74-0.98, P trend = 0.033). Also, there is a significant association between total carbohydrate score (HR: 0.85, 95% CI: 0.73-0.99, P trend = 0.016), the ratio of whole grain/total grains (HR: 0.81, 95% CI: 0.70-0.94, P trend = 0.004), and glycemic index (HR: 1.30, 95% CI: 1.12-1.51, P trend < 0.001) and risk of CKD. However, no significant association was found between total protein intakes, plant-to-animal ratio, and solid carbohydrate/total carbohydrate with the risk of CKD.

CONCLUSION

Our results revealed a diet with a high protein score and high quality of carbohydrates, characterized by higher intakes of plant proteins, low glycaemic index (GI) carbohydrates, whole grain, fibers, and lower intakes of animal proteins, can be related to reduced CKD risk.

The Intake of Ultra-Processed Foods and Prevalence of Chronic Kidney Disease: The Health Examinees Study

Emerging evidence links several health outcomes to the consumption of ultra-processed food (UPF), but few studies have investigated the association between UPF intake and kidney function. This cross-sectional study investigated the prevalence of chronic kidney disease (CKD) in relation to UPF intake in Korea. Data were obtained from the 2004−2013 Health Examinees (HEXA) study. The intake of UPF was assessed using a 106-item food frequency questionnaire and evaluated using the NOVA classification. The prevalence of CKD was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/m2. Poisson regression models were used to compute the prevalence ratios (PR) of CKD according to quartiles of the proportion of UPF intake (% food weight). A total of 134,544 (66.4% women) with a mean age of 52.0 years and an eGFR of 92.7 mL/min/m2 were analysed. The median proportion of UPF in the diet was 5.6%. After adjusting for potential confounders, the highest quartile of UPF intake was associated with the highest prevalence of CKD (PR 1.16, 95% CI 1.07−1.25), and every IQR (6.6%) increase in the proportion of UPF in the diet was associated with a 6% higher prevalence of CKD (PR 1.06, 95% CI 1.03−1.09). Furthermore, the highest consumption of UPF was inversely associated with eGFR (Q4 vs. Q1: β −1.07, 95% CI −1.35, −0.79; per IQR increment: (β −0.45, 95% CI −0.58, −0.32). The intake of UPF was associated with a high prevalence of CKD and a reduced eGFR. Longitudinal studies in the Korean population are needed to corroborate existing findings in other populations.

Alcohol consumption and its association with chronic kidney disease: Evidence from a 12-year China health and Nutrition Survey

BACKGROUND AND AIMS

Alcohol consumption is a major threat to global health. The aim of the present study was to explore the association between alcohol consumption and chronic kidney disease (CKD) in a Chinese population.

METHODS AND RESULTS

A total of 4664 participants, aged ≥18 years, who participated in a baseline alcohol survey in 1997 and were followed up in 2009 of the China Health and Nutrition Survey (CHNS), were recruited in the current study. Data on alcohol consumption was obtained using standardized questionnaires, with CKD (defined as eGFR <60 mL/min/1.73 m²) as the outcome. The results showed that 37.3% of the participants had consumed alcohol at the baseline. Current drinkers were mainly men, with at least senior high school education, and a history of smoking. In the 2009 survey, 14.5% of the participants had CKD. Association analyses revealed that alcohol drinkers had a lower likelihood of CKD than non-drinkers (11.0% vs. 16.6%, aOR: 0.76, 95%CI: 0.58-1.00), after adjusting potential covariates. Restricted cubic splines revealed that the relationship between alcohol consumption and CKD prevalence was U-shaped. The probability of CKD significantly increased when alcohol consumption exceeded 18 standard drinks per week (aOR: 1.66, 95%CI: 1.00-2.76). Approximately one-fourth of participants changed their drinking patterns during the 12-year follow-up, and male drinkers with persistent drinking patterns had the lowest prevalence of CKD (aOR: 0.48, 95% CI: 0.31-0.73).

CONCLUSION

Alcohol consumption showed a U-shaped association with CKD. Moderate drinkers exhibited a lower disease prevalence compared with non-drinkers and heavy drinkers. Further studies should be conducted to explore the mechanisms underlying this protective effect. However, non-drinkers should not start drinking alcohol even with this protective effect.

Association between Use of Nutrition Labels and Risk of Chronic Kidney Disease: The Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2019

Nutrition labeling on food packages is increasingly found to promote healthier food choices associated with lower risk of chronic kidney disease (CKD). To examine associations between nutrition labels use and CKD risk, we conducted a nationally representative cross-sectional study of 32,080 adults from the 2008−2019 Korean National Health and Nutrition Examination Survey. Nutrition labels use was collected via self-reported questionnaires. Ascertainment and severity of CKD was determined by estimated glomerular filtration rate or proteinuria. In multivariable-adjusted (MV) logistic regression models, increasing awareness and use of nutrition labels was significantly associated with lower CKD risk (MV-adjusted OR “nutrition labels aware and use” group vs. “nutrition labels unaware” group [95% CIs]: 0.75 [0.59−0.95], Ptrend:0.03). This inverse association varied with CKD’s risk of progression, with 21% and 42% reduced risk observed for CKD subtypes with “moderate” and “high” risk of progression, respectively (all Ptrend ≤ 0.04). Furthermore, the nutrition labels use and CKD risk association significantly differed by age, with 35% reduced risk observed in the older group aged 49 years or older, but not in the younger group (Pinteraction < 0.001). Our results suggest increasing perception and use of nutrition labels may contribute to CKD prevention and its early asymptomatic progression, especially in older adults.

Dietary Lipids and Dyslipidemia in Chronic Kidney Disease

The progression of chronic kidney disease (CKD) leads to altered lipid metabolism. CKD patients exhibit high blood triglyceride (TG) levels, reduced concentrations and functionality of high-density lipoproteins (HDL), and elevated levels of atherogenic small, dense, low-density lipoproteins (sdLDL). Disorders of lipid metabolism and other metabolic disturbances place CKD patients at high risk for cardiovascular disease (CVD). Extensive evidence supports the cardioprotective effects of unsaturated fatty acids, including their beneficial effect on serum cholesterol and TG levels. Dietary lipids might therefore be especially important in the nutritional management of CKD. We review current dietary recommendations for fat intake by CKD patients and suggest potential nutritional interventions by emphasizing dietary lipids that might improve the blood lipid profile and reduce cardiovascular risk in CKD.