Ignite Creation Date:
2024-05-06 @ 3:46 PM
Last Modification Date:
2024-10-26 @ 1:56 PM
Study NCT ID:
NCT04740541
Status:
RECRUITING
Last Update Posted:
2024-02-23
First Post:
2021-02-01
Brief Title:
Threonine Requirement in Adult Males With Crohns Disease Using IAAO
Sponsor:
The Hospital for Sick Children
Organization:
The Hospital for Sick Children
Study Overview
Official Title:
Determination of Threonine Requirement in Adult Males With Crohns Disease Using the Indicator Amino Acid Oxidation IAAO Methodology
Status:
RECRUITING
Status Verified Date:
2024-02
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
The goal of the current study is to measure the requirement for threonine in patients with CD using the IAAO method and compare the requirement to previously determined threonine requirement estimated in young adults using the IAAO technique It is hypothesize that the requirement for threonine in patients with CD will be higher than the threonine requirement previously determined in young adults using the IAAO method Up to 10 clinically stable patients with CD will be recruited from the IBD Clinic at Mt Sinai Hospital Toronto and subsequently followed up at the Clinical Research Center CRC The Hospital for Sick Children SickKids Toronto Canada Before the study begins the participants will be required to visit the CRC Room 5500 Hill Wing The Hospital for Sick Children for a pre-study assessment of their height weight fat mass fat free mass resting metabolic rate and medical history These assessments will take about 3 hours to complete They will need to have been fasted for 10 hours prior to the pre-study assessment The pre-study assessment is needed to calculate their dietary requirements for the study and to assess health status After signing the consent form the subjects will complete the screening procedures height weight fasting blood sample and medical history questionnaire BIA Skinfold and calorimetry
Each study will consist of a 2-day adaptation period to a prescribed diet in accordance with the energy requirement of the subject and 1-study day The diet will provide an adequate amount of protein of 1 g proteinkgd The 2-day adaptation period is to allow the body to adapt to an adequate amount of protein as it has been shown that protein kinetics is altered without it
Dietary intakes during this time will be provided in the form of lactose-free milk shakes Scandishake with added carbohydrate SolCarb and protein beneprotein to meet the subjects requirement
Following the 2 days of adaptation is the study day where threonine intake will be randomly assigned and phenylalanine Phe kinetics will be measured with the use of isotopically labelled Phe On this day VCO2 will be measured by calorimetry immediately after the 5th meal for a period of 20 minutes
On the study day 3rd day of each 3-day period the diet will be provided as 8 hourly isocaloric isonitrogenous meals made up of a flavored liquid formula and protein free cookies developed for use in amino acid kinetic studies Each meal will represent 112th of the subjects total daily requirements The nitrogen protein content of the diet will be provided in the form of a crystalline amino acid mixture based on the amino acid composition of egg protein
A daily multivitamin supplement will be provided during the study period
No other food or beverages will be consumed on the adaptation days except water 1 cup clear tea or 1 cup clear coffee
During the 8-hr study day no other food or drink will be consumed except water
Urine and breath samples will be collected at baseline and at isotopic steady state
Breath samples will be collected simultaneously with urine samples
Five baseline breath samples will be collected 60 45 30 15 min and just before the tracer protocol begins
Three baseline urine samples will be collected 60 30 min and just before the tracer protocol begins
Four plateau breath samples will be collected every 15 minutes 25 h after the tracer protocol begins
Three plateau breath samples will be collected every 30 minutes 25 h after the tracer protocol begin
Breath samples will be collected with subjects breathing into an Exetainers plastic tube and samples will be stored in pre-evacuated glass tubes at room temperature until analysis
Urine samples will be collected in Eppendorf tubes and stored at - 20 º C until analyzed for 1-13C phenylalanine enrichment
The rate of CO2 production VCO2 will be measured on each testing day using a ventilated hood indirect calorimeter at meal 5 to quantify 13CO2 excretion in breath
Subjects can choose to withdraw from the study at any time and for any reason based on hisher individual judgment In particular if a subject is unable to tolerate the diet whether it is regards to taste loose stools or constipated stools heshe has the right to withdraw at any time during the study
Each study will consist of a 2-day adaptation period to a prescribed diet in accordance with the energy requirement of the subject and 1-study day The diet will provide an adequate amount of protein of 1 g proteinkgd The 2-day adaptation period is to allow the body to adapt to an adequate amount of protein as it has been shown that protein kinetics is altered without it
Dietary intakes during this time will be provided in the form of lactose-free milk shakes Scandishake with added carbohydrate SolCarb and protein beneprotein to meet the subjects requirement
Following the 2 days of adaptation is the study day where threonine intake will be randomly assigned and phenylalanine Phe kinetics will be measured with the use of isotopically labelled Phe On this day VCO2 will be measured by calorimetry immediately after the 5th meal for a period of 20 minutes
On the study day 3rd day of each 3-day period the diet will be provided as 8 hourly isocaloric isonitrogenous meals made up of a flavored liquid formula and protein free cookies developed for use in amino acid kinetic studies Each meal will represent 112th of the subjects total daily requirements The nitrogen protein content of the diet will be provided in the form of a crystalline amino acid mixture based on the amino acid composition of egg protein
A daily multivitamin supplement will be provided during the study period
No other food or beverages will be consumed on the adaptation days except water 1 cup clear tea or 1 cup clear coffee
During the 8-hr study day no other food or drink will be consumed except water
Urine and breath samples will be collected at baseline and at isotopic steady state
Breath samples will be collected simultaneously with urine samples
Five baseline breath samples will be collected 60 45 30 15 min and just before the tracer protocol begins
Three baseline urine samples will be collected 60 30 min and just before the tracer protocol begins
Four plateau breath samples will be collected every 15 minutes 25 h after the tracer protocol begins
Three plateau breath samples will be collected every 30 minutes 25 h after the tracer protocol begin
Breath samples will be collected with subjects breathing into an Exetainers plastic tube and samples will be stored in pre-evacuated glass tubes at room temperature until analysis
Urine samples will be collected in Eppendorf tubes and stored at - 20 º C until analyzed for 1-13C phenylalanine enrichment
The rate of CO2 production VCO2 will be measured on each testing day using a ventilated hood indirect calorimeter at meal 5 to quantify 13CO2 excretion in breath
Subjects can choose to withdraw from the study at any time and for any reason based on hisher individual judgment In particular if a subject is unable to tolerate the diet whether it is regards to taste loose stools or constipated stools heshe has the right to withdraw at any time during the study
Detailed Description:
BACKGROUND The current Dietary Reference Intake DRI recommendations for essential amino acid requirements are based on recommendations for young healthy adults and have not been directly determined in patients with Crohns disease Protein and amino acids are key components of our diet Having defined the requirement of the essential amino acid Threonine in healthy adults using the IAAO the investigators are now in an ideal position to define the needs in vulnerable populations such as patients with chronic inflammatory conditions such as Crohns disease CD
Studies in animals suggest an increase in the threonine requirement in Crohns and colitis models If this is also true in humans knowledge of the threonine requirement in patients with IBD could provide valuable information for improvement in medical nutritional management of this patient population Improved medical nutrition therapy could likely shorten recovery time andor increase the period of remission in patients with IBD
Method
Indicator Amino Acid Oxidation
Hypothesis
It is hypothesized that the requirement for threonine in patients with CD will be higher than the threonine requirement previously determined in young adults using the IAAO method 19 mgkgd
Objectives
1 To determine the requirement for threonine in patients with CD using the IAAO technique by measuring the oxidation of L-1-13 C phenylalanine to 13 CO 2 F 13 CO 2 in response to graded intakes of leucine
2 To compare on the basis of body weight and fat-free mass the requirement derived from this study to the requirement of threonine determined previously in young adults by the IAAO method
Subjects
Up to 10 clinically stable patients with CD will be recruited from the IBD Clinic at Mt Sinai Hospital Toronto who will be identified by Dr Mark Silverberg for this study and subsequently followed up at the Clinical Research Center CRC The Hospital for Sick Children SickKids Toronto Canada Before the study begins the participants will be required to visit the CRC Room 5500 Hill Wing The Hospital for Sick Children for a pre-study assessment of their height weight fat mass fat free mass resting metabolic rate and medical history These assessments will take about 3 hours to complete They will need to have been fasted for 10 hours prior to the pre-study assessment We need the pre-study assessment to calculate their dietary requirements for the study and to assess health status
After signing the consent form the subjects will complete the screening procedures height weight fasting blood sample and medical history questionnaire BIA Skinfold and calorimetry
The voluntaries will receive financial compensation for the costs incurred while participating in the study
All procedures in the study will be approved by the Research Ethics Board at SickKids
Experimental Design
The experimental design will be based on the minimally invasive IAAO model for collecting breath and urine instead of blood during the study day A maximum total of 50 IAAO studies will be carried out to determine the requirement for threonine in patients with CD Up to 10 male patients with CD will be recruited Each subject will be studied for at least 2 intake levels and up to at a maximum of 5 different intake levels of threonine Each level of intake will be randomly assigned to subjects
At the pre-study assessment the subjects resting energy expenditure REE will be measured by continuous open-circuit indirect calorimetry and body composition will be measured by skinfold thickness and bioelectrical impedance analysis BIA Subjects will also be weighed at the pre-study assessment and at the start of each IAAO study day to ensure accurate prescription of diets and isotopes and to confirm weight maintenance throughout the study
Each study will consist of a 2-day adaptation period to a prescribed diet in accordance with the energy requirement of the subject and 1-study day The diet will provide an adequate amount of protein of 1 g proteinkg-1d-1 The 2-day adaptation period is to allow the body to adapt to an adequate amount of protein as it has been shown that protein kinetics is altered without it Following the 2 days of adaptation is the study day where threonine intake will be randomly assigned and phenylalanine Phe kinetics will be measured with the use of L-1-13CPhe On this day VCO2 will be measured by calorimetry immediately after the 5th meal for a period of 20 minutes
Dietary Intake and Experimental Diet
3-day protocol
On days 1 and 2 the subject will consume an adaptation diet and on the 3rd day participate in an 8-hour testing period Each 3-day protocol will be separated by at least one week wash-out period
Dietary intakes during the 2-day adaptation period before the day 3 IAAO study will be provided in the form of lactose-free milk shakes Scandishake with added carbohydrate SolCarb and protein beneprotein to meet the subjects requirement The protein will be provided from the scandishake as milk protein casein and whey and providing 1gkg-1day-1 protein intake Total calories will be provided as resting energy expenditure REE measure by indirect calorimetry and multiplied by 17 On the adaptation days the diet will be provided as four isonitrogenous isocaloric meals spread evenly throughout the day
On the study day 3rd day of each 3-day period the diet will be provided as 8 hourly isocaloric isonitrogenous meals made up of a flavored liquid formula and protein free cookies developed for use in amino acid kinetic studies Each meal will represent 112th of the subjects total daily requirements The nitrogen protein content of the diet will be provided in the form of a crystalline amino acid mixture based on the amino acid composition of egg protein The energy intake on the study day will be provided as REE x 15
Tyrosine will be provided in excess at 40 mgkgday
Phenylalanine will be provided at a constant intake of 20mgkgd
Threonine will be provided at graded intakes ranging from 3-45 mgkgd and alanine levels will be adjusted to balance the changing levels of leucine and ensure formulas are isonitrogenous
A daily multivitamin supplement will be provided during the study period
No other food or beverages will be consumed on the adaptation days except water 1 cup clear tea or 1cup clear coffee
During the 8-hr study day no other food or drink will be consumed except water
Study Day
The study day diet will be divided into 8 isonitrogenous isocaloric meals each representing one-twelfth of the total subjects daily requirements
On the morning of each study day the subject will consume 4 of the hourly meals at home and then visit the research laboratory The subject will then start to consume the remaining 4 out of the 8 isocaloric meals at hourly intervals
Up to 5 dietary threonine intake levels will be tested in random order as mentioned under experimental design
1-13C phenylalanine will be given as the tracer in the 5th meal and continue to be administered with the remaining meals
Body-composition measurements
Body composition will be determined by bioelectrical impedance analysis BIA and multiple skin fold-thickness measurements at the beginning of study during the pre-study assessment Four Skinfold thicknesses triceps biceps subscapular and suprailiac will be measured to obtain estimates of fat mass BIA will be performed by using a fixed-frequency analyzer 50 kHz BIA model 101A RJL Systems Equations described previously will be used to calculate FFM
Isotope Infusion Protocol
1-13C phenylalanine will be used as the isotope Oral priming dose of 066 mgkg will be administered with the fifth meal and an hourly oral dose of 12 mgkgd will begin simultaneously and continue for 3 hrs with meals 6 7 and 8 A total of 4 isotopic doses are given to ensure background 13CO2 in breath reaches equilibration
At the same time which the priming dose of L-13Cphe is administered an oral priming dose of 0176 mgkg of bicarbonate NaH13CO3 will also be given
The amount of phenylalanine given as the isotope on the study day will be subtracted from dietary phenylalanine to maintain the total dietary intake at 20 mg Phe kgd
Tyrosine intake will be maintained at 40 mgkg-1d-1 to ensure an excess of tyrosine
Breath and urine samples are collected periodically before and after the tracers are consumed
Sample Collection
Urine and breath samples will be collected at baseline and at isotopic steady state
Breath samples will be collected simultaneously with urine samples
Five baseline breath samples will be collected 60 45 30 15 min and just before the tracer protocol begins
Three baseline urine samples will be collected 60 30 min and just before the tracer protocol begins
Four plateau breath samples will be collected every 15 minutes 25 h after the tracer protocol begins
Three plateau breath samples will be collected every 30 minutes 25 h after the tracer protocol begin
Breath samples will be collected with subjects breathing into an Exetainers plastic tube and samples will be stored in pre-evacuated glass tubes at room temperature until analysis
Urine samples will be collected in Eppendorf tubes and stored at - 20 º C until analyzed for 1-13C phenylalanine enrichment
The rate of CO2 production VCO2 will be measured on each testing day using a ventilated hood indirect calorimeter at meal 5 to quantify 13CO2 excretion in breath
Sample Analysis
Breath expired 13 CO2 enrichment will be measured by continuous flow isotope ratio mass spectrometer IRMS
Urinary 1-13C phenylalanine enrichment will be analyzed by gas chromatography tandem mass spectrometry LC-MS-MS
Estimation of Isotopic Kinetics Whole-body phenylalanine flux will be calculated as previously described according to the stochastic model of Matthews et al Isotopic steady state in the tracer enrichment at baseline and plateau will be represented as the unchanging values of L-1-13Cphenylalanine in urine and 13CO2 in breath
Phenylalanine flux umolkgh will be calculated from the dilution of orally administered 13C-phenylalanine into the metabolic pool at steady state by using enrichment of 13C- phenylalanine in urine The rate of appearance of 13CO2 in breath F13CO2 umolkgh after the oxidation of ingested 13C-phenylalanine will be calculated according to the model of Matthews et al by using a factor of 082 to account for carbon dioxide retained in the bodys bicarbonate pool The rate of phenylalanine oxidation umolkgh will be calculated from F13CO2 and urinary 13C-phenylalanine enrichment
Statistical Analysis
A paired t test will be used to test for differences in FFM and percentage of body fat differences in the two body-composition methods of BIA and skinfold ANOVA will be used to test for differences among the various estimates of body composition fat and FFM and correlation analysis will be performed to test for associations
Threonine intakes will be completely randomized within subjects with the amount of threonine intake serving as the main treatment effect The effect of threonine on phenylalanine flux oxidation and F13CO2 will be tested by using a mixed linear model with subject as a random variable PROC MIXED by using SAS Differences between individual fluxes will be compared by ANOVA with post hoc analysis using the Bonferroni multiple-comparisons test
Threonine requirement will be determined by applying a biphasic linear regression crossover analysis to determine the breakpoint EAR and subsequently calculate the 95 CI The mean threonine requirement will be estimated by applying a nonlinear mixed-effects model PROC NLMIXED SAS Institute to the oxidation and F13CO2 data Observations within subjects will be regarded as statistically depended
Studies in animals suggest an increase in the threonine requirement in Crohns and colitis models If this is also true in humans knowledge of the threonine requirement in patients with IBD could provide valuable information for improvement in medical nutritional management of this patient population Improved medical nutrition therapy could likely shorten recovery time andor increase the period of remission in patients with IBD
Method
Indicator Amino Acid Oxidation
Hypothesis
It is hypothesized that the requirement for threonine in patients with CD will be higher than the threonine requirement previously determined in young adults using the IAAO method 19 mgkgd
Objectives
1 To determine the requirement for threonine in patients with CD using the IAAO technique by measuring the oxidation of L-1-13 C phenylalanine to 13 CO 2 F 13 CO 2 in response to graded intakes of leucine
2 To compare on the basis of body weight and fat-free mass the requirement derived from this study to the requirement of threonine determined previously in young adults by the IAAO method
Subjects
Up to 10 clinically stable patients with CD will be recruited from the IBD Clinic at Mt Sinai Hospital Toronto who will be identified by Dr Mark Silverberg for this study and subsequently followed up at the Clinical Research Center CRC The Hospital for Sick Children SickKids Toronto Canada Before the study begins the participants will be required to visit the CRC Room 5500 Hill Wing The Hospital for Sick Children for a pre-study assessment of their height weight fat mass fat free mass resting metabolic rate and medical history These assessments will take about 3 hours to complete They will need to have been fasted for 10 hours prior to the pre-study assessment We need the pre-study assessment to calculate their dietary requirements for the study and to assess health status
After signing the consent form the subjects will complete the screening procedures height weight fasting blood sample and medical history questionnaire BIA Skinfold and calorimetry
The voluntaries will receive financial compensation for the costs incurred while participating in the study
All procedures in the study will be approved by the Research Ethics Board at SickKids
Experimental Design
The experimental design will be based on the minimally invasive IAAO model for collecting breath and urine instead of blood during the study day A maximum total of 50 IAAO studies will be carried out to determine the requirement for threonine in patients with CD Up to 10 male patients with CD will be recruited Each subject will be studied for at least 2 intake levels and up to at a maximum of 5 different intake levels of threonine Each level of intake will be randomly assigned to subjects
At the pre-study assessment the subjects resting energy expenditure REE will be measured by continuous open-circuit indirect calorimetry and body composition will be measured by skinfold thickness and bioelectrical impedance analysis BIA Subjects will also be weighed at the pre-study assessment and at the start of each IAAO study day to ensure accurate prescription of diets and isotopes and to confirm weight maintenance throughout the study
Each study will consist of a 2-day adaptation period to a prescribed diet in accordance with the energy requirement of the subject and 1-study day The diet will provide an adequate amount of protein of 1 g proteinkg-1d-1 The 2-day adaptation period is to allow the body to adapt to an adequate amount of protein as it has been shown that protein kinetics is altered without it Following the 2 days of adaptation is the study day where threonine intake will be randomly assigned and phenylalanine Phe kinetics will be measured with the use of L-1-13CPhe On this day VCO2 will be measured by calorimetry immediately after the 5th meal for a period of 20 minutes
Dietary Intake and Experimental Diet
3-day protocol
On days 1 and 2 the subject will consume an adaptation diet and on the 3rd day participate in an 8-hour testing period Each 3-day protocol will be separated by at least one week wash-out period
Dietary intakes during the 2-day adaptation period before the day 3 IAAO study will be provided in the form of lactose-free milk shakes Scandishake with added carbohydrate SolCarb and protein beneprotein to meet the subjects requirement The protein will be provided from the scandishake as milk protein casein and whey and providing 1gkg-1day-1 protein intake Total calories will be provided as resting energy expenditure REE measure by indirect calorimetry and multiplied by 17 On the adaptation days the diet will be provided as four isonitrogenous isocaloric meals spread evenly throughout the day
On the study day 3rd day of each 3-day period the diet will be provided as 8 hourly isocaloric isonitrogenous meals made up of a flavored liquid formula and protein free cookies developed for use in amino acid kinetic studies Each meal will represent 112th of the subjects total daily requirements The nitrogen protein content of the diet will be provided in the form of a crystalline amino acid mixture based on the amino acid composition of egg protein The energy intake on the study day will be provided as REE x 15
Tyrosine will be provided in excess at 40 mgkgday
Phenylalanine will be provided at a constant intake of 20mgkgd
Threonine will be provided at graded intakes ranging from 3-45 mgkgd and alanine levels will be adjusted to balance the changing levels of leucine and ensure formulas are isonitrogenous
A daily multivitamin supplement will be provided during the study period
No other food or beverages will be consumed on the adaptation days except water 1 cup clear tea or 1cup clear coffee
During the 8-hr study day no other food or drink will be consumed except water
Study Day
The study day diet will be divided into 8 isonitrogenous isocaloric meals each representing one-twelfth of the total subjects daily requirements
On the morning of each study day the subject will consume 4 of the hourly meals at home and then visit the research laboratory The subject will then start to consume the remaining 4 out of the 8 isocaloric meals at hourly intervals
Up to 5 dietary threonine intake levels will be tested in random order as mentioned under experimental design
1-13C phenylalanine will be given as the tracer in the 5th meal and continue to be administered with the remaining meals
Body-composition measurements
Body composition will be determined by bioelectrical impedance analysis BIA and multiple skin fold-thickness measurements at the beginning of study during the pre-study assessment Four Skinfold thicknesses triceps biceps subscapular and suprailiac will be measured to obtain estimates of fat mass BIA will be performed by using a fixed-frequency analyzer 50 kHz BIA model 101A RJL Systems Equations described previously will be used to calculate FFM
Isotope Infusion Protocol
1-13C phenylalanine will be used as the isotope Oral priming dose of 066 mgkg will be administered with the fifth meal and an hourly oral dose of 12 mgkgd will begin simultaneously and continue for 3 hrs with meals 6 7 and 8 A total of 4 isotopic doses are given to ensure background 13CO2 in breath reaches equilibration
At the same time which the priming dose of L-13Cphe is administered an oral priming dose of 0176 mgkg of bicarbonate NaH13CO3 will also be given
The amount of phenylalanine given as the isotope on the study day will be subtracted from dietary phenylalanine to maintain the total dietary intake at 20 mg Phe kgd
Tyrosine intake will be maintained at 40 mgkg-1d-1 to ensure an excess of tyrosine
Breath and urine samples are collected periodically before and after the tracers are consumed
Sample Collection
Urine and breath samples will be collected at baseline and at isotopic steady state
Breath samples will be collected simultaneously with urine samples
Five baseline breath samples will be collected 60 45 30 15 min and just before the tracer protocol begins
Three baseline urine samples will be collected 60 30 min and just before the tracer protocol begins
Four plateau breath samples will be collected every 15 minutes 25 h after the tracer protocol begins
Three plateau breath samples will be collected every 30 minutes 25 h after the tracer protocol begin
Breath samples will be collected with subjects breathing into an Exetainers plastic tube and samples will be stored in pre-evacuated glass tubes at room temperature until analysis
Urine samples will be collected in Eppendorf tubes and stored at - 20 º C until analyzed for 1-13C phenylalanine enrichment
The rate of CO2 production VCO2 will be measured on each testing day using a ventilated hood indirect calorimeter at meal 5 to quantify 13CO2 excretion in breath
Sample Analysis
Breath expired 13 CO2 enrichment will be measured by continuous flow isotope ratio mass spectrometer IRMS
Urinary 1-13C phenylalanine enrichment will be analyzed by gas chromatography tandem mass spectrometry LC-MS-MS
Estimation of Isotopic Kinetics Whole-body phenylalanine flux will be calculated as previously described according to the stochastic model of Matthews et al Isotopic steady state in the tracer enrichment at baseline and plateau will be represented as the unchanging values of L-1-13Cphenylalanine in urine and 13CO2 in breath
Phenylalanine flux umolkgh will be calculated from the dilution of orally administered 13C-phenylalanine into the metabolic pool at steady state by using enrichment of 13C- phenylalanine in urine The rate of appearance of 13CO2 in breath F13CO2 umolkgh after the oxidation of ingested 13C-phenylalanine will be calculated according to the model of Matthews et al by using a factor of 082 to account for carbon dioxide retained in the bodys bicarbonate pool The rate of phenylalanine oxidation umolkgh will be calculated from F13CO2 and urinary 13C-phenylalanine enrichment
Statistical Analysis
A paired t test will be used to test for differences in FFM and percentage of body fat differences in the two body-composition methods of BIA and skinfold ANOVA will be used to test for differences among the various estimates of body composition fat and FFM and correlation analysis will be performed to test for associations
Threonine intakes will be completely randomized within subjects with the amount of threonine intake serving as the main treatment effect The effect of threonine on phenylalanine flux oxidation and F13CO2 will be tested by using a mixed linear model with subject as a random variable PROC MIXED by using SAS Differences between individual fluxes will be compared by ANOVA with post hoc analysis using the Bonferroni multiple-comparisons test
Threonine requirement will be determined by applying a biphasic linear regression crossover analysis to determine the breakpoint EAR and subsequently calculate the 95 CI The mean threonine requirement will be estimated by applying a nonlinear mixed-effects model PROC NLMIXED SAS Institute to the oxidation and F13CO2 data Observations within subjects will be regarded as statistically depended
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None