Associations of Total Protein or Animal Protein Intake and Animal Protein Sources with Risk of Kidney Stones: A Systematic Review and Dose-Response Meta-Analysis

Healthy dietary patterns, biological aging, and kidney stones: evidence from NHANES 2007-2018

Background

This study aims to investigate the comprehensive association between healthy dietary patterns, biological aging, and kidney stones in a large population-based cohort.

Methods

We analyzed data from 6 cycles of NHANES surveys from 2007 to 2018 and included a total of 26,755 participants. The association was examined using logistic regression, restricted cubic splines, and a mediation model. Machine learning with Shapley Additive Explanations (SHAP) was used to determine the relative importance of dietary factors. Sensitivity analysis was conducted to validate the stability of the results.

Results

A higher healthy dietary score was significantly associated with a reduced risk of kidney stone prevalence, as indicated by the Alternative Healthy Eating Index (AHEI) (OR = 0.76, 95% CI 0.69-0.84), the Dietary Approaches to Stop Hypertension Index (DASHI) (OR = 0.67, 95% CI 0.58-0.77), the Healthy Eating Index 2020 (HEI-2020) (OR = 0.80, 95% CI 0.72-0.89), and the Mediterranean Diet Index (MEDI) (OR = 0.81, 95% CI 0.73-0.89). Conversely, higher aging indicators were associated with an increased risk of kidney stones, including the following: Klemera-Doubal Method Age (KDMAge) (OR = 2.40, 95% CI 1.70-3.37) and Phenotypic Age (PhenoAge) (OR = 2.36, 95% CI 1.75-3.19). Mediation analyses suggested that aging indicators significantly mediated the relationship between healthy dietary patterns and kidney stones. Machine learning with SHAP revealed the relative importance of dietary patterns and specific dietary components in this association. The sensitivity analysis was largely consistent with the primary analyses.

Conclusion

These findings provide valuable insights into the complex interplay between dietary patterns, biological aging, and the risk of kidney stone. Promoting healthy dietary patterns may be an effective strategy for kidney stone prevention, potentially through the modulation of biological aging processes.

Higher dietary insulin index is directly associated with the odd of kidney stones

Kidney stones or Nephrolithiasis are the most common health condition associated with the urinary system. Dietary factors stand as important factors in the occurrence and development of kidney stones. This study aimed to examine the potential link between dietary insulin index (DII) and dietary insulin load (DIL) with prevalence of kidney stones. This cross-sectional study was conducted among adults aged 30 to 75 years in the Shahedieh district of Yazd, Iran, over the period of 2015-2016. DII and DIL were calculated using a validated semi-quantitative food-frequency questionnaire and mathematical formula. Diagnosis of kidney stones is made on the basis of information obtained from self-reported questionnaire (Yes/ No). To explore the association between DII and DIL with the odds of kidney stones, logistic regression was employed in crude and adjusted models. A total of 4,829 participants were included in this study. Individuals in the last quartile of DIL had 214% higher odds of kidney stones in the crude model (OR: 2.14, 95% CI: 1.62-2.83; P-trend < 0.001); this association was remained significant after adjustments for confounding variables (OR: 1.44, 95% CI: 1.04-1.97; P-trend: 0.019). There was a direct significant relationship between DII and odds of kidney stones among third and forth quartiles of DII (OR: 1.52, 95% CI: 1.16-1.98, P-trend = 0.002); but this association disappeared for adjusted models. Higher DII and DIL were associated with an increased odd of renal stones. Large longitudinal study is required to clarify these associations.

Impact of diet on renal stone formation

Background and Objectives

The incidence of kidney stones is increasing globally, with a preponderance in adults compared with that in adolescents and children. Dietary habits have been identified as significant contributing factors to kidney stone formation. This literature review aimed to explore the existing evidence on the impact of diet on renal stone formation.

Methods and Study Design

We conducted a comprehensive literature review and included 81 studies published between 1999 and 2023, limiting the search to articles published in English. The extracted data were analyzed to identify common themes, trends, and patterns related to the impact of diet on renal stone formation. We investigated the influence of dietary habits on the risk of nephrolithiasis.

Results

Although the role of fluid intake in relation to stone formation is clear, existing evidence on how different types of beverages (coffee, tea, fruit juices, and soft drinks) affect kidney stone formation is conflicting. Other factors such as protein, sodium chloride, calcium, oxalate, fat, and carbohydrate intake have also been discussed as contributors to nephrolithiasis. Thus, diet should be appropriately modified to reduce the risk of stone formation in susceptible individuals. A history of nephrolithiasis has been found to increase the risk of both chronic kidney disease and end-stage renal disease. The review acknowledges the limitations inherent in conducting a literature review, including the potential for publication bias and the reliance on available published studies.

Conclusions

These findings highlight the importance of understanding and preventing nephrolithiasis.

Causal associations between 45 dietary intake habits and urolithiasis: insights from genetic studies

Background

Different dietary habits can have varying effects on human health and metabolism, and these can be intervened and regulated. Kidney stones, as a disease caused by multiple factors, are largely attributed to diet and metabolism, but the potential causal relationship with dietary intake habits remains unclear. Therefore, this study aims to link the predicted dietary intake based on 45 genetic factors with urolithiasis and explore the potential causal relationship.

Methods

We extracted complete genome-wide association studies (GWASs) data on 45 dietary intake traits from the UK Biobank study. Data on kidney stones were obtained from the FinnGen database. In both univariable and multivariable Mendelian randomization analyses, we used inverse variance weighted (IVW) as the primary method to calculate P values, odds ratios (ORs), and 95% confidence intervals (CIs). We examined result heterogeneity using Cochran's Q test. We also carefully investigated potential sources of horizontal pleiotropy using the Mendelian randomization (MR)-PRESSO and MR-Egger methods, and conducted linkage disequilibrium score regression (LDSC) analysis on the corrected P values.

Results

Through univariable analysis, we identified 11 dietary habits that potentially causally associate with kidney stones among the 45 examined traits, including 9 protective factors and 2 risk factors. Based on the corrected results with false discovery rate (FDR) and sensitivity analysis, we found one relatively robust evidence. We controlled for common stone risk factors, such as body mass index and smoking, as confounders in multivariable analysis, and no significant results were observed after controlling for these confounders. Based on the LDSC analysis, most of the evidence supports significant genetic correlations with urolithiasis among the 11 traits with potential causal associations.

Conclusions

This study confirms the impact of certain dietary factors on the development of kidney stones. Our findings contribute to providing evidence for dietary adjustments in daily life or dietary guidance specifically targeting kidney stone patients.

A review of dairy food intake for improving health among black adults in the US

The adult life stage encompasses a range of new experiences, opportunities, and responsibilities that impact health and well-being. During this life stage, health disparities continue to increase for Black Americans, with Black adults having a disproportionate burden of obesity, chronic diseases, comorbidities, and worse treatment outcomes compared to their White peers. While many of the underlying factors for these disparities can be linked to longstanding sociopolitical factors such as systemic racism, food insecurity, and poor access to healthcare, there are also several modifiable risk factors that are known to significantly impact health outcomes, such as improving diet quality, increasing physical activity, and not smoking. Of all the modifiable risk factors known to impact health, improving dietary habits is the factor most consistently associated with better outcomes for body weight and chronic disease. Of the major food groups recommended by the 2020-2025 Dietary Guidelines for Americans (DGA) for achieving healthier dietary patterns, dairy foods have a nutrient profile which matches most closely to what Black Americans are inadequately consuming (e.g., vitamin A, vitamin D, calcium, magnesium). However, Black adults tend to consume less than half the recommended daily servings of dairy foods, in part, due to issues with lactose intolerance, making higher intake of dairy foods an ideal target for improving diet quality and health in this population. This review examines the current body of evidence exploring the links between dairy intake, obesity, cardiometabolic disease risk, chronic kidney disease, and the most common types of cancer, with a special focus on health and disparities among Black adults. Overall, the evidence from most systematic reviews and/or meta-analyses published in the last decade on dairy intake and health outcomes has been conducted on White populations and largely excluded research on Black populations. The findings from this extensive body of research indicate that when teamed with an energy-restricted diet, meeting or exceeding the DGA recommended 3 daily servings of dairy foods is associated with better body weight and composition outcomes and lower rates of most common chronic diseases than lower intake (<2 servings per day). In addition to the number of daily servings consumed, the specific types (e.g., milk, yogurt, cheese) and subtypes (e.g., low-fat, fermented, fortified) consumed have also been shown to play major roles in how these foods impact health. For example, higher intake of fermented dairy foods (e.g., yogurt) and vitamin D fortified dairy products appear to have the most protective effects for reducing chronic disease risk. Along with lactose-free milk and cheese, yogurt is also generally low in lactose, making it an excellent option for individuals with lactose intolerance, who are trying to meet the DGA recommendations for dairy food intake.

Analysis of Dietary Patterns Associated with Kidney Stone Disease Based on Data-Driven Approaches: A Case-Control Study in Shanghai

The main objective of this study was to analyze dietary patterns using data-driven approaches and to explore preventive or risk dietary factors for kidney stone disease (KSD). A case-control matching study was conducted in adults (n = 6396) from a suburb of Shanghai. A food frequency questionnaire was used to assess the consumption of various types of food, and B-ultrasound was used to identify kidney stones. Principal component analysis and regression were used to generate dietary patterns and further explore the relationship between dietary patterns and KSD. LASSO regression and post-selection inference were used to identify food groups most associated with KSD. Among males, the "balanced but no-sugary-beverages pattern" (OR = 0.78, p < 0.05) and the "nuts and pickles pattern" (OR = 0.84, p < 0.05) were protective dietary patterns. Among females, "high vegetables and low-sugary-beverages pattern" (OR = 0.83, p < 0.05) and "high-crustaceans and low-vegetables pattern" (OR = 0.79, p < 0.05) were protective dietary patterns, while the "comprehensive pattern with a preference for meat" (OR = 1.06, p < 0.05) and "sugary beverages pattern" (OR = 1.16, p < 0.05) were risk dietary patterns. We further inferred that sugary beverages (p < 0.05) were risk factors and pickles (p < 0.05) and crustaceans (p < 0.05) were protective factors.

Popular Diets and Kidney Stones

Popular diets often influence dietary patterns, which have different implications for kidney stone risk. Despite the wide variety of popular diets, some general principles can be gleaned from investigating their potential impact on nephrolithiasis. Plant-based diets, including Dietary Approaches to Stop Hypertension, Mediterranean, flexitarian, and vegetarian diets, may protect against nephrolithiasis when they consist largely of unprocessed plant foods, while carbohydrate-restricted diets (including high-protein diets and the ketogenic diet) may raise kidney stone risk. Patients should be advised to consume a diet rich in whole plants, particularly fruits and vegetables, and minimize their consumption of animal proteins. Accompanying fruits and vegetables that are higher in oxalate content with more water and some dairy intake may also be useful. (We address the oxalate content of fruits and vegetables further below). Calcium consumption is an important component of decreasing the risk of kidney stones, as higher dietary calcium from dairy or nondairy sources is independently associated with lower kidney stone risk. Patients should also be advised to be conscious of fat intake, as fat in the intestinal lumen may complex with calcium and therefore increase urinary oxalate excretion. Finally, patients should avoid consumption of processed foods, which often contain added fructose and high sodium content, two factors that increase kidney stone risk.

Effective deep learning classification for kidney stone using axial computed tomography (CT) images

INTRODUCTION

Stone formation in the kidneys is a common disease, and the high rate of recurrence and morbidity of the disease worries all patients with kidney stones. There are many imaging options for diagnosing and managing kidney stone disease, and CT imaging is the preferred method.

OBJECTIVES

Radiologists need to manually analyse large numbers of CT slices to diagnose kidney stones, and this process is laborious and time-consuming. This study used deep automated learning (DL) algorithms to analyse kidney stones. The primary purpose of this study is to classify kidney stones accurately from CT scans using deep learning algorithms.

METHODS

The Inception-V3 model was selected as a reference in this study. Pre-trained with other CNN architectures were applied to a recorded dataset of abdominal CT scans of patients with kidney stones labelled by a radiologist. The minibatch size has been modified to 7, and the initial learning rate was 0.0085.

RESULTS

The performance of the eight models has been analysed with 8209 CT images recorded at the hospital for the first time. The training and test phases were processed with limited authentic recorded CT images. The outcome result of the test shows that the Inception-V3 model has a test accuracy of 98.52 % using CT images in detecting kidney stones.

CONCLUSIONS

The observation is that the Inception-V3 model is successful in detecting kidney stones of small size. The performance of the Inception-V3 Model is at a high level and can be used for clinical applications. The research helps the radiologist identify kidney stones with less computational cost and disregards the need for many experts for such applications.

Stone diet and dietary change: understanding determinants for dietary change behaviour in patients following urinary stones

BACKGROUND

Dietary habit is one of the most important methods to prevent and treat urinary stones. However, only limited evidence of the experiences of dietary management among urinary stone patients in Malaysia is available. This study aimed to explore participants' current dietary practices after the diagnosis of urinary stones and to identify the factors that facilitate their dietary changes.

METHODS

A qualitative study with purposive sampling was conducted using face-to-face semistructured interviews. A total of 20 participants from a tertiary general hospital in Kuantan, Malaysia, were recruited in this study. Data were analysed using framework analysis.

RESULTS

Two themes emerged from the analysis. The first theme explained the changes in the dietary practice of the participants postdiagnosis. The second theme revealed that the participants' dietary changes were greatly influenced by personal factors and external support from professionals, family and peers.

CONCLUSIONS

Urinary stone patients highlighted the fear of complications, self-determination and knowledge of nutrition as the main drivers of their dietary change postdiagnosis. Emphasising proper nutritional care by assessing and evaluating dietary self-management among patients can facilitate effective self-care in stone prevention management.

The Association between Dietary Sugar Intake and Nephrolithiasis: Results from National Health and Nutrition Examination Survey 2007-2018

BACKGROUND

Dietary sugar intake is gradually considered a risk factor for many diseases. A sugary diet was positively associated with risk of nephrolithiasis, but the specific relationships remain undefined.

OBJECTIVES

To determine associations between risk of nephrolithiasis and dietary sugar intake.

METHODS

This cross-sectional study involved 21,590 participants based on the National Health and Nutrition Examination Survey from 2007 to 2018. Amounts of dietary sugar intake (g/d) were the main exposure, including total sugar intake, added sugar intake, and food sources. Associations were analyzed by logistic regression models and restricted cubic splines using complex weighted designs.

RESULTS

Weighted mean intake [standard error] of total sugar and added sugar were 111.2 [2.0] g/d and 73.7 [1.9] g/d in participants with nephrolithiasis, respectively. In the fully adjusted regression model, compared to those in quartile 1, the population in quartile 4 of total sugar intake showed a significant risk of nephrolithiasis [odds ratio (OR): 1.23; 95% confidence interval (CI): 1.00-1.51]; OR for added sugar intake was 1.56 (95% CI: 1.25-1.94). The risks of nephrolithiasis increased steadily when total sugar and added sugar intake exceeded ∼150 g/d and 63 g/d in restricted cubic spline analyses, respectively. The highest sugar intake from beverages was associated with an increased risk of nephrolithiasis (OR for total sugar: 1.36; 95% CI: 1.07-1.72; OR for added sugar: 1.37; 95% CI: 1.09-1.73). Added sugar intake from meat, egg, and oil was significantly associated with risk of nephrolithiasis (quartile 4, OR: 1.22; 95% CI: 1.02-1.47), whereas total sugar intake from dairy products was in reverse (quartile 4, OR: 0.67; 95% CI: 0.54-0.82).

CONCLUSIONS

Total and added sugar intake, sugar intake from beverages, and added sugar intake from meat, egg, and oil were associated with an increased risk of nephrolithiasis, whereas total sugar intake from dairy products was negatively associated.

Protein intake and risk of urolithiasis and kidney diseases: an umbrella review of systematic reviews for the evidence-based guideline of the German Nutrition Society

PURPOSE

Changes in dietary protein intake metabolically affect kidney functions. However, knowledge on potential adverse consequences of long-term higher protein intake (HPI) for kidney health is lacking. To summarise and evaluate the available evidence for a relation between HPI and kidney diseases, an umbrella review of systematic reviews (SR) was conducted.

METHODS

PubMed, Embase and Cochrane Database of SRs published until 12/2022 were searched for the respective SRs with and without meta-analyses (MA) of randomised controlled trials or cohort studies. For assessments of methodological quality and of outcome-specific certainty of evidence, a modified version of AMSTAR 2 and the NutriGrade scoring tool were used, respectively. The overall certainty of evidence was assessed according to predefined criteria.

RESULTS

Six SRs with MA and three SRs without MA on various kidney-related outcomes were identified. Outcomes were chronic kidney disease, kidney stones and kidney function-related parameters: albuminuria, glomerular filtration rate, serum urea, urinary pH and urinary calcium excretion. Overall certainty of evidence was graded as 'possible' for stone risk not to be associated with HPI and albuminuria not to be elevated through HPI (above recommendations (> 0.8 g/kg body weight/day)) and graded as 'probable' or 'possible' for most other kidney function-related parameters to be physiologically increased with HPI.

CONCLUSION

Changes of the assessed outcomes may have reflected mostly physiological (regulatory), but not pathometabolic responses to higher protein loads. For none of the outcomes, evidence was found that HPI does specifically trigger kidney stones or diseases. However, for potential recommendations long-term data, also over decades, are required.

Effects of Coenzyme Q10 Supplementation on Lipid Profiles in Adults: A Meta-analysis of Randomized Controlled Trials

CONTEXT

Previous meta-analyses have suggested that the effects of coenzyme Q10 (CoQ10) on lipid profiles remain debatable. Additionally, no meta-analysis has explored the optimal intake of CoQ10 for attenuating lipid profiles in adults.

OBJECTIVE

This study conducted a meta-analysis to determine the effects of CoQ10 on lipid profiles and assess their dose-response relationships in adults.

METHODS

Databases (Web of Science, PubMed/Medline, Embase, and the Cochrane Library) were systematically searched until August 10, 2022. The random effects model was used to calculate the mean differences (MDs) and 95% CI for changes in circulating lipid profiles. The novel single-stage restricted cubic spline regression model was applied to explore nonlinear dose-response relationships.

RESULTS

Fifty randomized controlled trials with a total of 2794 participants were included in the qualitative synthesis. The pooled analysis revealed that CoQ10 supplementation significantly reduced total cholesterol (TC) (MD -5.53 mg/dL; 95% CI -8.40, -2.66; I2 = 70%), low-density lipoprotein cholesterol (LDL-C) (MD -3.03 mg/dL; 95% CI -5.25, -0.81; I2 = 54%), and triglycerides (TGs) (MD -9.06 mg/dL; 95% CI -14.04, -4.08; I2 = 65%) and increased high-density lipoprotein cholesterol (HDL-C) (MD 0.83 mg/dL; 95% CI 0.01, 1.65; I2 = 82%). The dose-response analysis showed an inverse J-shaped nonlinear pattern between CoQ10 supplementation and TC in which 400-500 mg/day CoQ10 largely reduced TC (χ2 = 48.54, P < .01).

CONCLUSION

CoQ10 supplementation decreased the TC, LDL-C, and TG levels, and increased HDL-C levels in adults, and the dosage of 400 to 500 mg/day achieved the greatest effect on TC.