Effect of Protein Intake During Hemodialysis on Blood Pressure and Arterial Stiffness Indices

Study Overview
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Brief Summary
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Open label, randomized, cross-over clinical study comparing the acute effect of high versus low protein meals during dialysis on intradialytic blood pressure, 24-hour ambulatory blood pressure and arterial stiffness indices on maintenance hemodialysis patients.

Detailed Description
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A series of demographic, anthropometric and clinical data will be collected prior to enrollment. The intervention will last 3 consecutive weeks. Eligible subjects will be randomised to one group (high or low protein meals during dialysis) for one week (3 dialysis sessions). Second week will be a wash out period (patients will not consume meals during dialysis) and during the third week randomised subjects will cross over to the other study group. Every meal will provide 1/3 of daily recommended energy and protein intake (35 kcal/kg body weight/day, 0.7 gr protein/kg body weight/day for low protein meals and 1.5 gr protein/kg body weight/day for high protein meals). All the meals will be prepared in the hospital's kitchen and will be personalized to each patient's preferences. The meal will be given one hour after the start of the session and should be consumed completely during dialysis. Patients will be evaluated for the following parameters during their midweek dialysis session: Intradialytic blood pressure 24-hour ambulatory blood pressure Arterial stiffness indices (Central Aortic blood pressure, Pulse Wave Velocity, Augmentation Index) Hemodialysis adequacy Nutritional status Intradialytic blood pressure, 24-hour ambulatory blood pressure and arterial stiffness indices will be evaluated with the use of the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany). Urea reduction ratio (URR) and Kt/V (standard and equilibrated) will be used as measures for dialysis adequacy. Possible changes in patients nutritional status will be assessed using the Malnutrition-Inflammation Score (MIS).

Official Title
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Acute Effect of Protein Intake During Dialysis on Intradialytic Blood Pressure, 24-hour Ambulatory Blood Pressure and Arterial Stiffness Indices in Maintenance Hemodialysis Patients.

Conditions
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End Stage Renal Disease, Hypotension During Dialysis, Protein Malnutrition, Arterial Sclerosis

Intervention / Treatment
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* Other: High-protein meals
* Other: Low- protein meals
* Other: No meals


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients to have provided informed written consent Patients undergoing maintenance hemodialysis for at least 3 months prior to enrollment Ability to self-ingest food during the dialysis session Exclusion Criteria: History of malignancy or any other clinical condition associated with very poor prognosis Hospitalization for acute myocardial infarction, unstable angina or acute ischemic stroke within the 3 previous months Patients receiving parenteral nutrition Body mass index (BMI) of >40 kg/m2 Bilateral functioning or non-functioning arteriovenous fistula (AVF) and/or arteriovenous graft (AVG) used as dialysis access Patients with major amputations (eg lower limbs) Women during pregnancy or lactation Patients with unsuccessful 24-hour ambulatory recording of blood pressure with Mobil-O-Graph device, in accordance with the current European Society of Hypertension Guidelines.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Open label, randomized, cross-over clinical study.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-protein meals<br>Patients with End Stage Renal disease on maintenance hemodialysis will consume high protein meals during their dialysis sessions for one week. | Other: High-protein meals<br>* Patients on maintenance hemodialysis will consume high protein meals during dialysis for one week (3 dialysis sessions)<br>|
| Experimental: Low-protein meals<br>Patients with End Stage Renal disease on maintenance hemodialysis will consume low protein meals during their dialysis sessions for one week | Other: Low- protein meals<br>* Patients on maintenance hemodialysis will consume low protein meals during dialysis for one week (3 dialysis sessions)<br>|
| Experimental: No meals<br>Patients with End Stage Renal disease on maintenance hemodialysis will not consume meals during their dialysis sessions for one week | Other: No meals<br>* Patients on maintenance hemodialysis will not consume meals during dialysis for one week (3 dialysis sessions)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of meal versus no meal consumption during hemodialysis on intradialytic blood pressure | Meal consumption is expected to lower intradialytic blood pressure and increase hypotensive events during hemodialysis. Intradialytic blood pressure will be evaluated with the use of the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany) during the midweek dialysis session. | 3 weeks | 
| Effect of high versus low protein meal consumption during dialysis on intradialytic blood pressure | High protein meals are expected to affect less intradialytic blood pressure than low protein meals. Intradialytic blood pressure will be evaluated with the use of the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany) during the midweek dialysis session. | 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of high versus low protein meal consumption during dialysis on 24-hour ambulatory blood pressure | 24-hour blood pressure will be evaluated with the use of the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany). Measurement of 24-hour ambulatory blood pressure will start at the beginning of the midweek dialysis session for each group (high versus low protein meals during dialysis). | 3 weeks | 
| Effect of high versus low protein meal consumption during dialysis on Pulse Wave Velocity | Pulse Wave Velocity will be measured for each group (high versus low protein meals) during the midweek dialysis session using the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany). | 3 weeks | 
| Effect of high versus low protein meal consumption during dialysis on Augmentation Index | Augmentation Index will be measured for each group (high versus low protein meals) during the midweek dialysis session using the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany). | 3 weeks | 
| Effect of high versus low protein meals during dialysis on hemodialysis adequacy. | Hemodialysis adequacy will be calculated for each patient group (high versus low protein meals) using the Urea reduction ratio (URR) and Kt/V (standard and equilibrated) for the midweek dialysis session. | 3 weeks | 
| Effect of high versus low protein meals during dialysis on patients nutritional status | Nutritional status will be calculated for each group (high versus low protein meals) using the Malnutrition-Inflammation Score (MIS). The Malnutrition-Inflamation score (MIS) is composed of 10 components which include: dry weight change over the last 3-6 months, current dietary intake, gastrointestinal symptoms, functional capacity (nutritionally related functional impairment), co-morbidity (including number of years on dialysis), decreased fat stores or loss of subcutaneous fat on physical examination (below eyes, triceps, biceps, chest), signs of muscle wasting (temple, clavicle, scapula, ribs, quadriceps, knee, interosseous), body mass index calculation, serum albumin levels, and serum total iron binding capacity. Each component of the MIS has 4 levels of severity, from 0 (normal) to 3 (severely abnormal). The sum of all 10 MIS components can range from 0 (normal) to 30 (severely malnourished); higher score reflects a more severe degree of malnutrition and inflammation. | 3 weeks |