Trial Outcomes & Findings for Kidney Transplant Low-AGE Diet Study (NCT NCT05104242)

Last Updated: 2024-12-06

Results Overview

Tissue accumulation of advanced glycation end-products was assessed by measuring skin autofluorescence (SAF) using a validated Autofluorescence Reader. SAF is calculated as the ratio between emission and excitation and is expressed as arbitrary units (AU). Three measurements were conducted and the average value of these was used for statistical analysis. SAF reference value for the age group of 50-60 years is 2.1±0.4 AU

Recruitment status

COMPLETED

Study phase

Target enrollment

38 participants

Primary outcome timeframe

6 months

Results posted on

2024-12-06

Participant Flow

A total of 48 kidney transplant recipients from the Department of Renal Medicine, Royal Derby Hospital were assessed for eligibility from February to April 2022.

Of the 48 kidney transplant recipients assessed for eligibility, 10 did not meet the inclusion criteria: 9 had skin autofluorescence levels below the general population mean value for age and 1 was classified as being malnourished according to the Subjective Global Assessment).

Participant milestones

Participant milestones
Measure	Standard Diet - Control Group The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.
Overall Study STARTED	19	19
Overall Study COMPLETED	17	13
Overall Study NOT COMPLETED	2	6

Reasons for withdrawal

Reasons for withdrawal
Measure	Standard Diet - Control Group The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.
Overall Study Withdrawal by Subject	1	5
Overall Study Control group: Acute kidney injury requiring dialysis Intervention group: transplant rejection	1	1

Baseline Characteristics

Kidney Transplant Low-AGE Diet Study

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Standard Diet - Control Group n=19 Participants The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group n=19 Participants The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.	Total n=38 Participants Total of all reporting groups
Age, Continuous	55 years STANDARD_DEVIATION 12 • n=99 Participants	56 years STANDARD_DEVIATION 10 • n=107 Participants	56 years STANDARD_DEVIATION 11 • n=206 Participants
Sex: Female, Male Female	7 Participants n=99 Participants	4 Participants n=107 Participants	11 Participants n=206 Participants
Sex: Female, Male Male	12 Participants n=99 Participants	15 Participants n=107 Participants	27 Participants n=206 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=99 Participants	0 Participants n=107 Participants	0 Participants n=206 Participants
Race (NIH/OMB) Asian	3 Participants n=99 Participants	1 Participants n=107 Participants	4 Participants n=206 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=99 Participants	0 Participants n=107 Participants	0 Participants n=206 Participants
Race (NIH/OMB) Black or African American	0 Participants n=99 Participants	1 Participants n=107 Participants	1 Participants n=206 Participants
Race (NIH/OMB) White	16 Participants n=99 Participants	16 Participants n=107 Participants	32 Participants n=206 Participants
Race (NIH/OMB) More than one race	0 Participants n=99 Participants	1 Participants n=107 Participants	1 Participants n=206 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=99 Participants	0 Participants n=107 Participants	0 Participants n=206 Participants
Region of Enrollment United Kingdom	19 participants n=99 Participants	19 participants n=107 Participants	38 participants n=206 Participants
Skin autofluorescence	2.9 Arbitrary units STANDARD_DEVIATION 0.6 • n=99 Participants	3.0 Arbitrary units STANDARD_DEVIATION 0.8 • n=107 Participants	2.9 Arbitrary units STANDARD_DEVIATION 0.7 • n=206 Participants
Dietary AGE intake	17201 Kilounits/day n=99 Participants	20225 Kilounits/day n=107 Participants	18558 Kilounits/day n=206 Participants

PRIMARY outcome

Timeframe: 6 months

Outcome measures

Outcome measures
Measure	Standard Diet - Control Group n=17 Participants The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group n=13 Participants The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.
Skin Autofluorescence (SAF) Levels at 6 Months	2.8 Arbitrary units Standard Deviation 0.6	2.8 Arbitrary units Standard Deviation 0.5

SECONDARY outcome

Timeframe: 6 months

Adherence to the low AGE diet (achieving dietary AGE intake \<8000 kilounits \[kU\]/day) and the standard diet for persons with a kidney transplant was evaluated by means of a 3-day food diary (2 weekdays and 1 weekend day) every month (i.e., assessed from 1-6 months but only adherence at 6 months was reported).

Outcome measures

Outcome measures
Measure	Standard Diet - Control Group n=17 Participants The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group n=13 Participants The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.
Participant Adherence to Diets	17 Participants	9 Participants

SECONDARY outcome

Timeframe: 0, 3 and 6 months

SAF was measured at baseline, 3 and 6 months. The rate of change of SAF among these 3 time points (i.e., SAF trend) was then calculated by fitting a regression line using the SLOPE function in Microsoft Excel 2016, where the y-axis represented SAF values and the x-axis represented time points.

Outcome measures

Outcome measures
Measure	Standard Diet - Control Group n=17 Participants The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group n=13 Participants The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.
Skin Autofluorescence (SAF) Trend.	-0.22 Arbitrary units/year Standard Deviation 0.75	-0.45 Arbitrary units/year Standard Deviation 1.19

SECONDARY outcome

Timeframe: 6 months

A validated food frequency questionnaire was used to quantify the content of AGEs in foods.

Outcome measures

Outcome measures
Measure	Standard Diet - Control Group n=17 Participants The control group was advised to follow their usual diet but aiming to achieve an energy intake of 25-35 kcal/kg/day, and a protein intake of 0.75 g/kg/day for females and 0.84 g/kg/day for males	Low AGE Diet - Intervention Group n=13 Participants The intervention group was advised to follow a low-AGE diet which consisted in using high-water content cooking methods (e.g., stewing, steaming, boiling, poaching), instead of dry-heat methods (e.g., frying, grilling, roasting). In addition, the intervention group was provided with detailed written advice and counselling on how to choose foods low in AGEs and the amount and frequency of consumption allowed per day/week/month (e.g., choose a low-fat spread instead of butter - use 2 tsp 3-4/week). The goal was to reduce dietary AGE intake to \<8000 kilounits (kU)/day.
Dietary AGE Intake at 6 Months	20447 Kilounits/day Interval 14093.0 to 25044.0	5515 Kilounits/day Interval 4206.0 to 8631.0

Adverse Events

Standard Diet - Control Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Low AGE Diet - Intervention Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Catherine Johnson

University Hospitals of Derby & Burton NHS Foundation Trust, Royal Derby Hospital

Phone: 01332 789354

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place