Clinical trial NCT02996513: Assessing Model Parameters for Applying the Retinol Isotope Dilution (RID) Method
Official title: Assessing Model Parameters for Applying the Retinol Isotope Dilution (RID) Method in Preschool Nigerian Children Living in an Area With a High Malaria Burden
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vitamin A Deficiency
Malaria
Inflammation
Keywords: Vitamin A status
Retinol Isotope Dilution
Nigeria
Preschool children
Malaria
Inflammation
Lead sponsor: Wageningen University
Sponsor class: OTHER
Collaborators: name: University of Ibadan
name: Newcastle University
name: University of California, Davis
name: Penn State University
name: HarvestPlus
First posted: 2016-12-19
Enrollment: 60
Sex: ALL
Minimum age (years): 36
Maximum age (years): 59
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief summary: For assessing body retinol pools in preschool children, it is recommended that a blood sample is taken 14-21 days after isotope dosing. During this period, dietary intake of vitamin A should be controlled. Shortening of this period as has been validated for adults would reduce the burden for the children as well as improve research efficiency. The aim is to validate a 4-day protocol for assessing body retinol pools in preschool children by modelling data derived by retinol isotope dilution (RID) method. Venous blood samples will be collected of 60 children 4 days after dosing of 0.4 mg 13C-labeled retinyl acetate. A second venous blood sample will be collected at 6, 8, 12 hrs; and 1, 2, 4, 7, 11, 16, 22 and 28 days after dosing in subgroups of 6 children, randomly divided over the 10 additional time points. Body retinol pools will be modelled, and the time point at which a parsimonious model applies (presumably at day 4) will be assessed.

Detailed description: For assessing body retinol pools in preschool children, it is recommended that a blood sample is taken 14-21 days after isotope dosing. During this period, dietary intake of vitamin A should be controlled. Shortening of this period as has been validated for adults would reduce the burden for the children as well as improve research efficiency. The aim is to validate a 4-day protocol for assessing body retinol pools in preschool children by modelling data derived by retinol isotope dilution (RID) method. A secondary aim is to compare body retinol pools between children with and without inflammation and to assess the effect of asymptomatic malaria on model parameters. Preschool children (n=60), 36-59 months of age, residing in Telemu, Osun State, Nigeria will be recruited for the study. The study design is an observational pre/post study, for which body retinol pools will be measured using the RID method. Venous blood samples will be collected of all children 4 days after dosing of 0.4 mg 13C-labeled retinyl acetate. A second venous blood sample will be collected at 6, 8, 12 hrs; and 1, 2, 4, 7, 11, 16, 22 and 28 days after dosing in subgroups of 6 children, randomly divided over the 10 additional time points. Children presenting with asymptomatic malaria will be treated, and a convenience subsample (n=10) will undergo a second assessment of body retinol pools determined with a venous blood collection on day 4 post-dosing only. Body retinol pools will be modelled, and the time point at which a parsimonious model applies (presumably at day 4) will be assessed. Presence of asymptomatic malaria and markers of inflammation will be assessed in all children at all time points. Body retinol pools and model parameters between subgroups of children with and without asymptomatic malaria and/or inflammation will be compared. Pre/post comparisons of body retinol pool estimates will be done for the follow up subsample.

Eligibility criteria: Inclusion Criteria:

* Apparently healthy
* Between 36 and 59 months of age
* Living in the community of Telemu, Osun State, Nigeria, or its neighbouring communities

Exclusion Criteria:

* Active or recent disease with a potential effect on study outcome
* Hb concentration \<70 g/dL
* Mental state that is incompatible with participation in the study
* Recent exposure to 13C-retinol stable isotopes
* Unwillingness to participate by verbal or physical expression

Primary outcomes:
measure: Vitamin A status
timeFrame: 28 days
Secondary outcomes:
measure: Prevalence of malaria (plasmodium falciparum)
timeFrame: 28 days
measure: Prevalence of inflammation
timeFrame: 28 days
measure: Serum retinol
timeFrame: 28 days
measure: Blood haemoglobin concentration
timeFrame: 28 days
measure: Ferritin concentration
timeFrame: 28 days
measure: Soluble transferrin receptor concentration
timeFrame: 28 days
measure: Retinol binding protein
timeFrame: 28 days
Other outcomes:
measure: Body weight
timeFrame: Baseline
measure: Dietary intake of energy, protein, fat, carbohydrates, vitamins and minerals
timeFrame: Baseline
measure: Body length
timeFrame: Baseline
Locations:
city: Ibadan
country: Nigeria
facility: University of Ibadan
state: Oyo State
Study officials:
affiliation: Wageningen University
name: Alida Melse-Boonstra, PhD
role: PRINCIPAL_INVESTIGATOR
References: