Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05154500 |
| Other study ID # |
BB/S014039/1 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
August 29, 2018 |
| Est. completion date |
March 31, 2022 |
Study information
| Verified date |
January 2023 |
| Source |
Instituto de Investigacion Nutricional, Peru |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Two of the most common nutritional deficiencies are anemia and zinc deficiency. One strategy
for combating nutritional deficiencies is biofortification. The primary objective of the
proposed research is to determine in humans the bioavailability of iron and zinc from
biofortified potatoes as compared to a non-fortified local variety. The secondary objective
is to use the data obtained from the human studies to model the potential impact of the
introduction of biofortified potatoes to the alleviation of iron and zinc deficiencies in the
Andean Highlands and low and middle-income countries elsewhere.
Iron bioavailability studies: The investigators will compare bioavailability of iron from a
non-fortified potato variety with a biofortified potato that has significantly higher iron
content though the use of a randomized cross-over intervention study. Female volunteers will
consume both biofortified potato extrinsically labelled with 58FeSO4 and a nonfortified
potato labelled with 57FeSO4. Thirty women with marginal iron status (plasma ferritin < 25
ng/ml) will be selected from an initial screening of 180 women. Every woman will receive 2
different types of test meals in a series of 20 servings for 10 days each. Blood samples will
be collected during screening and on days 1, 15, 26 and 40 and the amount of 58Fe and 57Fe
incorporated into hemoglobin and serum ferritin quantified.
Zinc bioavailability study: The investigators will compare bioavailability of zinc from a
non-fortified potato variety with that of a biofortified potato that has significantly higher
zinc content (p<0.001) with a crossover study. Forty volunteers will be randomly assigned to
receive first either the biofortified or the non-fortified potato and receive the second meal
30 days later. Zinc absorption from two meals will be measured using the double stable
isotope technique. Every volunteer will be given an i.v. infusion of 70zinc and two test
meals of 250 g cooked potato labelled extrinsically with 67zinc separated by 3-4 hr. A spot
urine sample will be collected 96 hours after each set of test meal and the ratio of the two
isotopes measured to calculate absorption of zinc from the test meal.
Modelling and Impact assessment: Data on bioavailability will be used in a Disability
Adjusted Life Year model to assess the potential impact of biofortified potatoes to alleviate
iron and zinc deficiencies in the Andean Highlands and low and middle-income countries
elsewhere.
Description:
Type of Study and population Double blind randomized trial of naturally biofortified potatoes
to be carried out in Huancavelica, Perú. It will be recruited about 100 women and 80 men aged
18-45 years living in the city of Huancavelica.
ETHICS Applications was submitted and approved by Research Ethics Committee (REC) of the
University of East Anglia Faculty of Medicine and Health (FMH) in Norwich (UK) and a REC of
the Instituto de Investigacion Nutricional (IIN) in Peru.
Every participant will be fully informed of all the procedures and will be given the
opportunity to ask questions and receive any further details participants require.
The procedures (blood samples, urine samples, anthropometry, dietary recall) will be
explained to the individuals who agree to take part in the initial screening, and
participants will be invited to sign the first consent form.
SPECIFIC METHODS FOR IRON STUDY (Phase 1) Sample size The study requires an enrollment of a
total of 30 women to allow for 33% who do not adhere to the protocol, to reach a final sample
size of 20 women. The investigators estimate that the investigators may need to screen about
100 women.
Nutritional Status As part of the screening all the potential candidates will be weighed and
measured using standardized equipment.
Measurement of physical activity All the participants will be asked to use an actigraph (a
tri-axial accelerometer) which measures physical activity (movement) in three dimensions.
Blood sample An appropriately trained member of the study team will collect a venous blood
sample (approximately 6ml in a test tube with heparin) to measure ferritin, hemoglobin, and
CRP (screening and 3 more times: baseline, 16 and 40 days after first day of potato intake).
Urine sample Participants will be asked to provide a urine sample (30ml) to carry out a
pregnancy test using a test strip.
Sociodemographic and Food security survey The investigators will include a socioeconomic
survey and the ELCSA food security questionnaire both will be applied to all enrolled
participants.
Study Procedures According to the results of the screening and revision of the criteria for
inclusion and exclusion and following information and verification that participants
understand the iron study consent form, subjects will be invited to participate. Consented
participants will be randomly assigned to consume one or other of the two types of potato
(biofortified-A or not-B). The first potato variety will be given during the first 2 weeks
(day 1-12) and the second sequence between days 15-26, (in both cases excluding weekend days
Saturday and Sunday). The potatoes will be cooked in water and offered mashed.
Blood samples will be taken on 5 occasions, 1) at screening to verify compliance with the
exclusion and inclusion criteria; then on day 1 before participants eat the first type of
potato, day 15 before eating the second type of potato, day 26 after eating all both potato
types and on day 40 two weeks after eating all the potato.
Consumption of the potato Each participant will be served 500 g of potato divided into two
portions of 250 g each. each participant will take, depending on their allocation, 0.3 mg of
57FeSO4 (Peruanita potato) or 0.3 mg of 58FeSO4 (biofortified potato), diluted in 50 ml of
distilled water, which should be drunk while participants are eating the potato - halfway
through the meal. In addition, each participant will receive 200 ml of distilled water to
drink. The isotopes will be provided by ETH (Swiss Federal Institute of Technology in
Zurich). In addition, the isotopes that the investigators will use are stable isotopes, that
is participants exist naturally in the environment and as such do not pose any risk.
Collection of biological samples for the measurement of iron using stable isotopes Blood
samples will be collected throughout the intervention period as previously described and will
be sent to ETH, Zurich, following standard operating procedures. Participants will be
informed and will provide consent for the transfer and use of their samples outside Peru' for
the purpose of this research study. Samples will be anonymized and will not be transported
with personal identifiable data.
In terms of processing, samples will be mixed with NO3 and H2O2 and digested in a microwave,
followed by separation of the iron from the blood matrix by way of exchange-anion
chromatography and a solvent (diluent) or extraction from the solvent using distilled.
The isotopes will be analyzed using a plasma coupled inductive multicollector mass
spectrometer (Neptune; Thermo Finnigan). The amount of the labelled iron isotopes 57Fe and
58Fe will be measured 14 days after consumption of both types of potato has been completed.
The calculation (of absorption) will be done considering the subjects estimated blood volume
based on weight, height, and the subject's measured hemoglobin concentration (considering the
average of the initial and final blood sample). The calculation is based on the principle of
isotopic dilution considering as the factor for the iron isotope marker rather than the
monoisotopic marker8. For the calculation of the fraction absorbed the investigators will
assume 80% incorporation of the absorbed iron.
SPECIFIC METHODS FOR ZINC STUDY (Phase 2) Sample size The study requires a samples size of 40
women. This allows for a 40% loss to reach a final total of 24 women.
Procedures According to the results of screening, and after checking that participants comply
with all the inclusion criteria and none of the exclusion criteria participants will be
invited to participate in the zinc part of the study. For this participant will be given the
second consent form to read and those who accept and sign the form will be invited to
participate in the study.
The people who accept will be randomly allocated to eat one or other of the types of potato
(biofortified-A or no-B). All the participants will be given both types of potato but in
different order, in this way each participant will be their own control. The first variety of
potato will be given on day 1, after acceptance of participating in the study, and after
accepting and signing the consent form for this part: (consumption protocol and second
variety will be eaten 29 days after (the order of potato varieties will be randomly
assigned).
The investigators will take blood samples on three occasions: enrolment and days 1 and 29
(the days when participants eat the potato) after fasting for 8 hours (food) and 6 hours
(liquids).
Study Measurements Anthropometry As part of the screening all the potential candidates will
be weighed and measured using standardized equipment. According to their weight and BMI the
investigators will decide whether participants are eligible.
Consented participants will be asked to provide a venous blood sample (approximately 10ml in
a test tube with heparin). Plasma and packed red cells will be obtained from the blood
samples and stored at <18oC.
Urine sample Consented participants will provide a urine sample (30ml) as part of the
screening phase to carry out a pregnancy test. On days 1, 3, 4, 5, 6, 7, 29, 32, 33, 34, 35
and 36 the investigators will collect urine samples to analyze zinc content. On each day the
investigators need 100ml of urine, collected in the morning (between 7-12 o'clock in the
morning).
Consumption of the potato The subjects will be given a total of 1000 g of potato in two 500 g
portions. The first portion will be given while participants are fasted, (at least 8 hours
for food and 6 hours for drink) and in two separate servings (each one 250 g). When
participants have eaten the first 250 g serving, the subject will receive 0.25 mg of 67Zn
diluted in 50 ml of bottled water and then participants will receive the second serving of
potato. Two hours later, participants will receive an intravenous infusion of 70Zn (200 ug)
diluted in 50 ml of bottled water. After a further 2 hours participants will receive the
second two servings of potato, and, as before, after the first serving participants will
receive 0.25 mg of 67Zn diluted in 50 ml of bottled water. During this period and for 3 hours
after the second portion of potato the subject will not consume any food or liquid, except
for water which participants will be provided with. Each subject will receive 200 ml of water
with each meal and 200 ml of water between meals. Currently, using isotopes is the best
method for measuring the absorption of zinc. In addition, the isotopes that will be used are
stable isotopes, that is participants exist naturally in the environment and pose no risk. No
food or drink can be consumed for at least 3 hours after eating the final portion of potato.
Blood samples for measurement of zinc The investigators will take a total of three blood
samples in total. Absorption using stable isotopes (Day 29) The blood samples that have been
collected will be sent to ETH, Zurich. ETH will undertake the analysis of CRP for Zinc. The
CRP will be measured using an ELISA kit. The plasma zinc concentration will be measured by
induction plasma coupled mass spectrometry.
Urine samples for measurement of zinc using stable isotopes Samples of urine will be
concentrated using freeze drying and then mineralized by digestion in a microwave oven
(MLS-Turbowave; MLS GmbH) using a mixture of HNO3 and zinc isolated from the master matrix by
ion exchange chromatography. The investigators will use ultrapure acids for the preparation
of the samples.
Determination of zinc absorption Blood and zinc isotopic composition will be analyzed in
duplicate at the ETH Human Nutrition Laboratory. Urine samples will be mineralized by
microwave digestion (MLS-ETHOS plus; MLS GmbH) using a mixture of HNO3 and H2O2 and zinc
isolated from the sample matrix by ion-exchange chromatography (Wegmuller et al 2014). All
acids used for the preparation of samples will be ultrapure. 70Zn:66Zn and 67Zn:66Zn isotopic
ratios will be measured to determine 70Zn and 67Zn enrichment in the urine samples by using a
high-resolution double-focusing magnetic sector field multi-collector inductively coupled
plasma mass spectrometer (Finnigan Neptune; Thermo Electron).12 Fractional absorption of the
67Zn dose from the test meals will be calculated by using the oral to i.v. tracers ratio
method applied to spot urine samples, according to principles described by Friel et al.
7-day food record Using the method of registering all foods eaten over a 7-day period the
investigators can obtain information on all foods eaten in a week (including Saturday and
Sunday). To achieve this, the investigators will ask the subjects to make a record of all
foods consumed, details of food preparation, and all drinks (including water) that
participants have eaten or drunk. Participants should note the meal at which the food and
drink were consumed, and the time taken to eat it (breakfast, lunch, supper and between meals
(snacks) and the amount eaten at each time of the day. To do this the investigators will give
the subjects a tablet in which to register the consumption/meals and as well take a photo of
all the food eaten.
METHODS SPECIFIC FOR IMPACT ASSESSMENT The data on dietary intake, serum ferritin and iron
bioavailability will be used for two modelling approaches. Firstly, the investigators will
apply the Disability Adjusted Life Year (DALY) method, which is an appropriate method to
estimate nutritional and health impacts of biofortified crops. This will build upon models
that have been developed jointly by CIP and IIN that has made assumptions concerning iron and
zinc bioavailability from potatoes. Secondly, the investigators will use data on habitual
iron intake, serum ferritin concentrations and calculated physiological requirements for iron
to adapt a model estimate dietary iron bioavailability in Europe, the Andean highland region
and, more generally, to low- and middle-income countries.
