Effect of Dialysis-specific Therapeutic Diet on Biochemical Parameters in Dialysis Patients

Effects of Dialysis-specific Therapeutic Diet in Dialysis Patients

In patients with kidney failure, disturbances in bone turnover, mineral metabolism, vascular calcification, uremia, inflammation, immunity, nutrition, and gut microbial metabolites are frequent. Unhealthy diet causes altered mineral metabolism, elevated uremic toxin level, immune dysregulation, inflammation, protein-energy wasting and dysbiosis. The investigators hypothesize that therapeutic diet intervention reverses these uremic complications and thereby reduces cardiovascular risk in patients with kidney failure. In this study, the investigators crafted 4-week dialysis-specific therapeutic diet to illustrate the clinical implications of therapeutic diet for dialysis patients.

Study Overview

• Status: Not yet recruiting
• Conditions: End-Stage Kidney Disease
• Intervention / Treatment: Other: Dialysis-specific therapeutic diet

Detailed Description

In patients with kidney failure, disturbance in bone turnover and mineral metabolism, and nutritional deficiency is prevalent, leading to vascular calcification, uremia, inflammation, immune dysregulation, and gut microbial dysbiosis, and these abnormalities are associated with increased risk of fracture, extraskeletal or vascular calcification and cardiovascular mortality. It is well known that an unhealthy diet plays an important role in bone-mineral metabolism, uremia, inflammation, protein-energy wasting, and dysbiosis, and therefore nutritional therapy may help to manage these uremic complications to reduce cardiovascular risk in patients with kidney failure. Importantly, serum biomarkers regarding the above-mentioned abnormalities are acutely and closely related to food intake. To our knowledge, no study to date has examined the multifactorial effects of nutritional intervention on bone turnover, mineral metabolism, vascular calcification, uremia, inflammation, immunity, nutrition, and gut microbial metabolites in dialysis patients.

To examine the beneficial effects of nutritional intervention on clinical outcomes, the investigators crafted the dialysis-specific therapeutic diet which was characterized by adequate calorie and protein amounts, natural food ingredients with a low phosphorus-to-protein ratio, higher portions of plant-based food, and high fiber content. In the previous studies, the investigators found that the therapeutic diet rapidly reversed mineral abnormalities within the 1-week intervention period. Among these changes, reduction in serum phosphate level achieved in 2 days, modifications of intact parathyroid hormone (PTH) and calcium levels in 5 days, and reductions in intact and C-terminal fibroblast growth factor-23 (FGF23) levels in 7 days of therapeutic diet intervention. Although the therapeutic diet tended to change uremic toxin level, neither inflammatory nor nutritional markers changed which may be explained by short duration of intervention. It is of interest to know whether the therapeutic diet has a favorable effect on bone turnover, vascular calcification, and gut microbial dysbiosis. In this continuity planning, the investigators are therefore going to analyze the 4-week diet-induced changes in biomarkers regarding bone turnover, vascular calcification, and gut microbial metabolites in addition to the previously assessed mineral metabolism, uremia, inflammation, immunity, and nutrition in dialysis patients.

This project aims to explore the multiple diverse effects of dialysis-specific healthy diet on the changes of bone turnover, mineral metabolism, vascular calcification, uremia, inflammation, immunity, nutrition, and gut microbial metabolites in dialysis patients. In contrast to the previous approaches, bone biomarkers for both of bone formation and bone resorption, vascular calcification biomarkers, and gut microbial metabolites will be comprehensively examined. Revealing a complex correlation between the nutritional factors and bone turnover, mineral metabolism, vascular calcification, uremia, inflammation, immunity, nutrition, and gut microbial dysbiosis, this project may shed light on understanding of diet-mediated bone-mineral and uremic homeostasis and uncover strategies of nutritional therapy. A better knowledge of diet-induced pathway on human body homeostasis may lead to new strategies for preventing fracture, vascular calcification or cardiovascular disease risk.

It is to conduct a randomized controlled trial with cross-over design at a dialysis unit of tertiary teaching hospital in Northern Taiwan. Subjects with aged older than 20 years, end-stage kidney disease (ESKD) undergoing maintenance dialysis for more than three months, having adequate dialysis and good dietary compliance will be included. Participants will be randomly assigned into two groups: group A and group B. Those in group A will receive study diet for 4 weeks, followed by 16-week washout period and then receive 4-week usual diet. The opposite order of diets will be prescribed in group B. The study meals are prepared in the hospital cafeteria. Dietary compositions of the study diets were analyzed before the start of the study. The study outcome measures are difference in change-from-baseline values of abnormal mineral metabolism, altered bone turnover, vascular calcification, uremic toxin production, immune dysregulation, nutrition, inflammation and gut microbial metabolites between the therapeutic diet and the usual diet.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Wan-Chuan Tsai, M.D., Ph.D.; Phone Number: +886277281780; Email: mkks618@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Subjects with aged older than 20 years
• End-stage kidney disease (ESKD) undergoing maintenance dialysis for more than three months
• Must have adequate dialysis
• Good dietary compliance

Exclusion Criteria:

• Serum albumin level less than 2.5 g/dL
• Hospitalization within the past 4 weeks
• Prebiotics, probiotics, symbiotics or antibiotics use within the past 4 weeks
• History of psychiatric disorders
• Having mental retardation
• Those who dislike of the study meals
• Soft diet requirement
• Vegetarian

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Study diet; 4-week therapeutic diet intervention as experimental group	Other: Dialysis-specific therapeutic diet; A healthy diet for dialysis patients
No Intervention: Usual diet; 4-week usual diet as control group, no dietary intervention in this group, participants consumed their habitual diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentrations of intact fibroblast growth factor 23 (pg/mL)	Difference in change-from-baseline intact fibroblast growth factor 23 (pg/mL) between therapeutic diet and usual diet	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentrations of C-terminal fibroblast growth factor 23 (RU/mL)	Difference in change-from-baseline C-terminal fibroblast growth factor 23 (RU/mL) between therapeutic diet and usual diet	4 weeks
Concentrations of phosphate (mg/dL)	Difference in change-from-baseline phosphate (mg/dL) between therapeutic diet and usual diet	4 weeks
Concentrations of calcium (mg/dL)	Difference in change-from-baseline calcium (mg/dL) between therapeutic diet and usual diet	4 weeks
Concentrations of intact parathyroid hormone (pg/mL)	Difference in change-from-baseline intact parathyroid hormone (pg/mL) between therapeutic diet and usual diet	4 weeks
Concentrations of bone-specific alkaline phosphatase (μg/L)	Difference in change-from-baseline bone-specific alkaline phosphatase (μg/L) between therapeutic diet and usual diet	4 weeks
Concentrations of procollagen-type 1 N-terminal-propeptide (P1NP) (ng/mL)	Difference in change-from-baseline procollagen-type 1 N-terminal-propeptide (P1NP) (ng/mL) between therapeutic diet and usual diet	4 weeks
Concentrations of tartrate resistance acid phosphatase-5b (TRACP-5b) (mIU/ml)	Difference in change-from-baseline tartrate resistance acid phosphatase-5b (TRACP-5b) (mIU/ml) between therapeutic diet and usual diet	4 weeks
Concentrations of alkaline phosphatase (ALP) (IU/L)	Difference in change-from-baseline alkaline phosphatase (ALP) (IU/L) between therapeutic diet and usual diet	4 weeks
Concentrations of free indoxyl sulfate (mg/L)	Difference in change-from-baseline free indoxyl sulfate (mg/L) between therapeutic diet and usual diet	4 weeks
Concentrations of free p-cresol sulfate (mg/L)	Difference in change-from-baseline free p-cresol sulfate (mg/L) between therapeutic diet and usual diet	4 weeks
Concentrations of pre-albumin (g/dL)	Difference in change-from-baseline pre-albumin (g/dL) between therapeutic diet and usual diet	4 weeks
Concentrations of albumin (g/dL)	Difference in change-from-baseline albumin (g/dL) between therapeutic diet and usual diet	4 weeks
Concentrations of C-reactive protein (mg/dL)	Difference in change-from-baseline C-reactive protein (mg/dL) between therapeutic diet and usual diet	4 weeks
Absolute number (per μl blood) of CD4+ (cluster of differentiation 4) T cells	Difference in change-from-baseline absolute number (per μl blood) of CD4+ (cluster of differentiation 4) T cells between therapeutic diet and usual diet	4 weeks
Absolute number (per μl blood) of CD8+ (cluster of differentiation 8) T cells	Difference in change-from-baseline absolute number (per μl blood) of CD8+ (cluster of differentiation 8) T cells between therapeutic diet and usual diet	4 weeks
Absolute number (per μl blood) of monocytes	Difference in change-from-baseline absolute number (per μl blood) of monocytes between therapeutic diet and usual diet	4 weeks
Concentrations of fetuin-A (μg/ml)	Difference in change-from-baseline fetuin-A (μg/ml) between therapeutic diet and usual diet	4 weeks
Concentrations of trimethylamine-N-oxide (TMAO) (μM)	Difference in change-from-baseline trimethylamine-N-oxide (TMAO) (μM) between therapeutic diet and usual diet	4 weeks

Collaborators and Investigators

• Sponsor: Far Eastern Memorial Hospital
• Investigators: Principal Investigator: Wan-Chuan Tsai, M.D., Ph.D., Far Eastern Memorial Hospital

Publications and helpful links

General Publications

• Tsai WC, Wu HY, Peng YS, Hsu SP, Chiu YL, Chen HY, Yang JY, Ko MJ, Pai MF, Tu YK, Hung KY, Chien KL. Effects of lower versus higher phosphate diets on fibroblast growth factor-23 levels in patients with chronic kidney disease: a systematic review and meta-analysis. Nephrol Dial Transplant. 2018 Nov 1;33(11):1977-1983. doi: 10.1093/ndt/gfy005.
• Tsai WC, Wu HY, Peng YS, Hsu SP, Chiu YL, Yang JY, Chen HY, Pai MF, Lin WY, Hung KY, Chu FY, Tsai SM, Chien KL. Short-Term Effects of Very-Low-Phosphate and Low-Phosphate Diets on Fibroblast Growth Factor 23 in Hemodialysis Patients: A Randomized Crossover Trial. Clin J Am Soc Nephrol. 2019 Oct 7;14(10):1475-1483. doi: 10.2215/CJN.04250419. Epub 2019 Sep 13.
• Tsai WC, Peng YS, Wu HY, Hsu SP, Chiu YL, Liu LC, Tsai SM, Chien KL. Accuracy of a Nutrient Database in Estimating the Dietary Phosphorus-to-Protein Ratio and Using a Boiling Method in Low-Phosphate Hospital Diets. Sci Rep. 2018 Oct 15;8(1):15246. doi: 10.1038/s41598-018-33657-8.
• Tsai WC, Wu HY, Chiu YL, Yang JY, Pai MF, Wu YR, Lin WY, Hung KY, Chien KL, Hsu SP, Peng YS. Acute effects of dietary phosphorus intake on markers of mineral metabolism in hemodialysis patients: post hoc analysis of a randomized crossover trial. Ren Fail. 2021 Dec;43(1):141-148. doi: 10.1080/0886022X.2020.1870138.
• Tsai WC, Hsu SP, Chiu YL, Wu HY, Luan CC, Yang JY, Pai MF, Lin CJ, Lin WY, Sun WH, Peng YS. Short-Term Effects of a Therapeutic Diet on Biochemical Parameters in Hemodialysis Patients: A Randomized Crossover Trial. J Ren Nutr. 2023 Nov;33(6):731-739. doi: 10.1053/j.jrn.2023.04.003. Epub 2023 Apr 27.

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2024
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): June 1, 2029

Study Registration Dates

• First Submitted: April 15, 2024
• First Submitted That Met QC Criteria: April 15, 2024
• First Posted (Actual): April 22, 2024

Study Record Updates

• Last Update Posted (Actual): April 23, 2024
• Last Update Submitted That Met QC Criteria: April 19, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Urologic Diseases; Disease Attributes; Renal Insufficiency; Renal Insufficiency, Chronic; Chronic Disease; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Kidney Failure, Chronic
• Other Study ID Numbers: FEMH-IRB-TSAI2024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual-level deidentified participant data will be made available by the corresponding author of the paper upon request by email. The data will be available for 3 years after formal publication.
• IPD Sharing Time Frame: The data will become available after completing the study for 1 year and for 3 years after formal publication.
• IPD Sharing Access Criteria: Data will be made available by the corresponding author of the paper upon request by email.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No