Dataset Information

Dietary acid load and chronic kidney disease in elderly adults: Protein and potassium intake.

ABSTRACT:

Background

Dietary net endogenous acid production (NEAP), which represents total dietary load of nonvolatile acid, may affect kidney function. Estimated NEAP (eNEAP) is calculated indirectly by the ratio of protein and potassium intake. A few studies are available assessing the association between eNEAP and chronic kidney disease (CKD), and its relation to dietary protein and potassium intake in the elderly.

Methods

A total 1,369 community-dwelling elderly Koreans in the Kangbuk Samsung Cohort Study (KSCS) were evaluated using a food frequency questionnaire (FFQ) and comprehensive health examination. We evaluated the association between eNEAP and the CKD. We also examined their relation to protein and potassium intake.

Results

eNEAP was correlated with potassium intake (r = -0.410, P < 0.001), but was not correlated with protein intake (r = -0.004, P = 0.879). In a full multivariate adjustment for sociodemographic factors, dietary factors, and comorbidities, the participants with higher eNEAP quartiles (Q2, Q3, Q4) had higher odds of CKD compared to the lowest eNEAP quartile (Q1); OR (95% CI) were 1.47 (0.78-2.72), 1.66 (0.85-3.23), and 2.30 (1.16-4.60) respectively (P for trend = 0.019). The odds of CKD decreased for participants with higher potassium intake quartiles (Q2, Q3, Q4) compared to the lowest potassium intake quartile (Q1); OR (95% CI) were 0.52 (0.28-0.95), 0.50 (0.26-0.96), and 0.50 (0.21-0.99) respectively (P for trend = 0.050). Protein intake was not associated with CKD. The association between eNEAP and CKD was similar in subgroup analysis.

Conclusion

Dietary acid load was associated with CKD. Among the nutrients related to dietary acid load, potassium intake was negatively associated with CKD, but protein intake was not associated with CKD in elderly adults.

SUBMITTER: Ko BJ

PROVIDER: S-EPMC5617182 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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Publications

Dietary acid load and chronic kidney disease in elderly adults: Protein and potassium intake.

Ko Byung-Joon BJ Chang Yoosoo Y Ryu Seungho S Kim Eun Mi EM Lee Mi Yeon MY Hyun Young Youl YY Lee Kyu-Beck KB

PloS one 20170927 9

<h4>Background</h4>Dietary net endogenous acid production (NEAP), which represents total dietary load of nonvolatile acid, may affect kidney function. Estimated NEAP (eNEAP) is calculated indirectly by the ratio of protein and potassium intake. A few studies are available assessing the association between eNEAP and chronic kidney disease (CKD), and its relation to dietary protein and potassium intake in the elderly.<h4>Methods</h4>A total 1,369 community-dwelling elderly Koreans in the Kangbuk S ...[more]

PMID: 28953915

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Project description:Background and objectivesProtein and potassium intake and the resulting diet-dependent net acid load may affect kidney stone formation. It is not known whether protein type or net acid load is associated with risk of kidney stones.Design, setting, participants, & measurementsWe prospectively examined intakes of protein (dairy, nondairy animal, and vegetable), potassium, and animal protein-to-potassium ratio (an estimate of net acid load) and risk of incident kidney stones in the Health Professionals Follow-Up Study (n=42,919), the Nurses' Health Study I (n=60,128), and the Nurses' Health Study II (n=90,629). Multivariable models were adjusted for age, body mass index, diet, and other factors. We also analyzed cross-sectional associations with 24-hour urine (n=6129).ResultsDuring 3,108,264 person-years of follow-up, there were 6308 incident kidney stones. Dairy protein was associated with lower risk in the Nurses' Health Study II (hazard ratio for highest versus lowest quintile, 0.84; 95% confidence interval, 0.73 to 0.96; P value for trend <0.01). The hazard ratios for nondairy animal protein were 1.15 (95% confidence interval, 0.97 to 1.36; P value for trend =0.04) in the Health Professionals Follow-Up Study and 1.20 (95% confidence interval, 0.99 to 1.46; P value for trend =0.06) in the Nurses' Health Study I. Potassium intake was associated with lower risk in all three cohorts (hazard ratios from 0.44 [95% confidence interval, 0.36 to 0.53] to 0.67 [95% confidence interval, 0.57 to 0.78]; P values for trend <0.001). Animal protein-to-potassium ratio was associated with higher risk (P value for trend =0.004), even after adjustment for animal protein and potassium. Higher dietary potassium was associated with higher urine citrate, pH, and volume (P values for trend <0.002).ConclusionsKidney stone risk may vary by protein type. Diets high in potassium or with a relative abundance of potassium compared with animal protein could represent a means of stone prevention.

Project description:ObjectiveBlood biomarkers of dietary intake are more objective than self-reported dietary intake. Metabolites associated with dietary acid load were previously identified in 2 chronic kidney disease (CKD) populations. We aimed to extend these findings to a general population, replicating their association with dietary acid load, and investigating whether the individual biomarkers were prospectively associated with incident CKD.MethodsAmong 15,792 participants in the Atherosclerosis Risk in Communities cohort followed up from 1987 to 1989 (baseline) to 2019, we evaluated 3,844 black and white men and women with dietary and metabolomic data in cross-sectional and prospective analyses. We hypothesized that a higher dietary acid load (using equations for potential renal acid load and net endogenous acid production) was associated with lower serum levels of 12 previously identified metabolites: indolepropionylglycine, indolepropionate, N-methylproline, N-δ-acetylornithine, threonate, oxalate, chiro-inositol, methyl glucopyranoside, stachydrine, catechol sulfate, hippurate, and tartronate. In addition, we hypothesized that lower serum levels of these 12 metabolites were associated with higher risk of incident CKD.ResultsEleven out of 12 metabolites were significantly inversely associated with dietary acid load, after adjusting for demographics, socioeconomic status, health behaviors, health status, and estimated glomerular filtration rate: indolepropionylglycine, indolepropionate, N-methylproline, threonate, oxalate, chiro-inositol, catechol sulfate, hippurate, methyl glucopyranoside (α + β), stachydrine, and tartronate. N-methylproline was inversely associated with incident CKD (hazard ratio: 0.95, 95% confidence interval: 0.91, 0.99, P = .01). The metabolomic biomarkers of dietary acid load significantly improved prediction of elevated dietary acid load estimated using dietary data, beyond covariates (difference in C statistics: 0.021-0.077, P ≤ 1.08 × 10-3).ConclusionInverse associations between candidate biomarkers of dietary acid load were replicated in a general population. N-methylproline, representative of citrus fruit consumption, is a promising marker of dietary acid load and could represent an important pathway between dietary acid load and CKD.

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Project description:The prevalence of chronic kidney disease (CKD) is increasing and dietary interventions may be a strategy to reduce this burden. In the general population, higher potassium intake is considered protective for cardiovascular health. Due to the risk of hyperkalemia in CKD, limiting potassium intake is often recommended. However, given that poor cardiovascular function can cause kidney damage, following a low-potassium diet may be deleterious for patients with CKD. The aim of this systematic review was to summarize the evidence on dietary potassium intake and CKD progression. Multiple databases were searched on 7 June 2019 and data were managed with Covidence. No intervention trials met the inclusion criteria. Eleven observational studies met the inclusion criteria (10 post hoc analyses, 1 retrospective cohort), representing 49,573 stage 1-5 predialysis patients with CKD from 41 different countries. Of the 11 studies, 6 studies reported exclusively on early CKD (stage 1-2), 4 studies separately reported analyses on both early and late (stage 3-5) CKD, and 2 studies reported exclusively on late CKD. A total of 9 studies reported risk of disease progression in early CKD; in 4 studies high potassium intake was associated with lower risk, while in 2 studies the low intake showed a higher progression of risk, and 3 studies reported no relation. In late CKD, results are mixed: 2 studies suggested benefit of higher potassium intake and 1 suggested benefit of lower potassium intake, whereas 3 studies were neutral. These results should be interpreted with caution, as considerations preventing firm conclusions include 1) the overall low range of dietary potassium intake, with all studies reporting an average intake below the 2004 Kidney Disease Outcomes Quality Initiatives guidelines, and 2) the method used to assess potassium intake in most studies (i.e., urine) in late stages of CKD. Ideally, well-controlled intervention studies are needed to understand how dietary potassium intake is linked to CKD progression.

Project description:BackgroundEvidence indicates that reducing dietary salt may reduce the incidence of heart disease and delay decline in kidney function in people with chronic kidney disease (CKD). This is an update of a review first published in 2015.ObjectivesTo evaluate the benefits and harms of altering dietary salt for adults with CKD.Search methodsWe searched the Cochrane Kidney and Transplant Register of Studies up to 6 October 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.Selection criteriaRandomised controlled trials comparing two or more levels of salt intake in adults with any stage of CKD.Data collection and analysisTwo authors independently assessed studies for eligibility, conducted risk of bias evaluation and evaluated confidence in the evidence using GRADE. Results were summarised using random effects models as risk ratios (RR) for dichotomous outcomes or mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI).Main resultsWe included 21 studies (1197 randomised participants), 12 in the earlier stages of CKD (779 randomised participants), seven in dialysis (363 randomised participants) and two in post-transplant (55 randomised participants). Selection bias was low in seven studies, high in one and unclear in 13. Performance and detection biases were low in four studies, high in two, and unclear in 15. Attrition and reporting biases were low in 10 studies, high in three and unclear in eight. Because duration of the included studies was too short (1 to 36 weeks) to test the effect of salt restriction on endpoints such as death, cardiovascular events or CKD progression, changes in salt intake on blood pressure and other secondary risk factors were examined. Reducing salt by mean -73.51 mmol/day (95% CI -92.76 to -54.27), equivalent to 4.2 g or 1690 mg sodium/day, reduced systolic/diastolic blood pressure by -6.91/-3.91 mm Hg (95% CI -8.82 to -4.99/-4.80 to -3.02; 19 studies, 1405 participants; high certainty evidence). Albuminuria was reduced by 36% (95% CI 26 to 44) in six studies, five of which were carried out in people in the earlier stages of CKD (MD -0.44, 95% CI -0.58 to -0.30; 501 participants; high certainty evidence). The evidence is very uncertain about the effect of lower salt intake on weight, as the weight change observed (-1.32 kg, 95% CI -1.94 to -0.70; 12 studies, 759 participants) may have been due to fluid volume, lean tissue, or body fat. Lower salt intake may reduce extracellular fluid volume in the earlier stages of CKD (-0.87 L, 95% CI -1.17 to -0.58; 3 studies; 187 participants; low certainty evidence). The evidence is very uncertain about the effect of lower salt intake on reduction in antihypertensive dose (RR 2.45, 95% CI 0.98 to 6.08; 8 studies; 754 participants). Lower salt intake may lead to symptomatic hypotension (RR 6.70, 95% CI 2.40 to 18.69; 6 studies; 678 participants; moderate certainty evidence). Data were sparse for other types of adverse events.Authors' conclusionsWe found high certainty evidence that salt reduction reduced blood pressure in people with CKD, and albuminuria in people with earlier stage CKD in the short-term. If such reductions could be maintained long-term, this effect may translate to clinically significant reductions in CKD progression and cardiovascular events. Research into the long-term effects of sodium-restricted diet for people with CKD is warranted.

Dataset Information

Dietary acid load and chronic kidney disease in elderly adults: Protein and potassium intake.

Background

Methods

Results

Conclusion

Publications

Dietary acid load and chronic kidney disease in elderly adults: Protein and potassium intake.

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