the correlation of estimated dietary protein with estimates based on nitrogen excretion was 0.56...
TRANSCRIPT
The correlation of estimated dietary protein with estimates based
on nitrogen excretion was 0.56 (winter) and 0. 48 (summer).
Sodium intake (mg/day)
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7000
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0
So
diu
m e
xcre
ted
in
uri
ne
(m
g/l)
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7000
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0
Winter
Summer
MethodsData was collected over 1 week periods in winter (January-March)
and summer (June- September), 2000.
A 24 hr recall covered the first day of participation (D1) and
subjects were instructed to record on the other days (checked
at visits on days 3, 4, 6 and 8.
24hr urine collections, monitored for completeness by the
administration of 3 tablets of 80mg of PABA, were made on D1
and D7. Only apparently complete collections were used in
these analyses (n = 107 in winter and 93 in summer).
Blood was collected on the morning of D8.
Individuals with a ratio of estimated energy consumption (by
7DDD) to estimated BMR (EI/BMR) less than 1.35 were
classified as energy under-reporters (Goldberg cut-point).
The open ended estimated 7DDD contained written instructions to
record portion sizes, pages to record foods eaten during
seven day time period (before breakfast, breakfast,
midmorning, lunch, early evening ) for each of seven days. An
album was provided including color photographs of different
foods and dishes , each set of photographs depicted 3
different portion sizes of a common food item to aid
estimation of portion weight.
The dietary database system was developed by the National
Institute of Hygiene (Sofia) and based In Microsoft Access. It
incorporated information on 904 simple or constituent foods
(taken here to include drinks). 397 composite foods defined by
standard (national) recipes. Food information was adjusted in
the light of responses regarding methods of food preparation.
During data entry a further 2013 composite foods were defined
based on local recipes (1089 in winter and a further 924 in
summer).
To analyse intakes of foods and of nutrients, the system
decomposes composite foods back to their constituent foods.
The record for each food in the database incorporates
estimates of losses during preparation and cooking and the
proportion waste.
The associations between the biomarkers and the reported intakes were assessed separately for each of the intake-biomarker pairs. The accepted level of significance was set at p =0.05. All statistical analyses were performed using SPSS 11.0
ResultsThe mean EI/BMR ratio was 1.43 ± 0.40 in winter and 1.27 ± 0.39 in summer and was higher for males. 48 % of subjects in winter and 63 % in summer were classified as energy under-reporters using estimated EI: estimated BMR < 1.35.
361361 VValidation of a 7 day diet diary using urinary and blood alidation of a 7 day diet diary using urinary and blood biomarkers: biomarkers: VVarna arna DDiet and iet and SStroke troke SStudytudy
Krassimira Stoeva1, Klara Dokova1, John Powles2, Veselka Duleva3, Stefka Petrova3, Nevijana Feschieva1, Shirley Runswick4, Maria O'Connell5, Elliot Berry6, Sheila Bingham4
(1) Dept of Social Medicine, Medical University, Varna, Bulgaria, (2) Dept of Public Health and Primary Care, University of Cambridge (3) National Centre for Hygiene, Medical Ecology and Nutrition, Sofia (4) MRC Dunn Human Nutrition Unit, Cambridge (5) MRC Human Nutrition Research, Cambridge (6) Department of Medicine, Hadassah Hebrew University Hospital, Jerusalem
Funding source
RURAL AREA
URBAN AREA
The village of Grozdevo is some 60 km to the south-west of Varna. Population about - 2600 people.
Primorski district is is
one of the biggest living
areas in Varna including
approximately 28% of the
urban population (about
86 000 inhabitants)
SubjectsSubjects eligible for participation are in the age
group 45 to 74 years, devided in 3 age- and sex-specific strata, residents of the study areas - Urban (District Primorski) and Rural (Grozdevo village).
188 (97 urban and 91 rural) subjects volunteered to participate in the validation study from them 160 (78 urban and 82 rural) continued their participation in the summer cycle of the study.
Fieldwork
Study schedule
Urine collections
Blood collections
Energy under-recording
The 7-day diet diary
An interviewer explaining to a study volunteer how to use the dietary album.
Energy under-recording
Statistical analysis
Nutrient database
BMI (kg/m2)
70605040302010
EI:
BM
R
4,0
3,5
3,0
2,5
2,0
1,5
1,0
,5
0,0
Summer
Winter
Under-reporting was
associated with BMI
(80% had BMI’s > 25).
7 day diet diary in comparison with biomarkers
Protein Intake (g/day)
20016012080400
Pro
tein
fro
m U
rin
ary
Nitro
ge
n (
g/l)
200
160
120
80
40
0
Winter
Summer
y winter = 50.7 + 0.4 x r = 0.56
y summer = 52.6 + 0.3 x r = 0.48
Correlations between estimated Na and K consumption and urinary excretion lay in the range 0.42 (Na, winter) to 0.31 (K, summer).
For Vitamin C, correlations were lower (as expected) when intakes were high (winter, r = 0.43; summer, r = 0.16).
y winter = 3385.9 + 0.7x r = 0.42y summer = 3270 + 0.7x r = 0.44
Dietary vs. Urinary nitrogen
Dietary vs. Urinary Sodium and Potassium
Potassium intake (mg/day)
7000600050004000300020001000
Po
tassiu
m e
xcre
ted
in
uri
ne
(m
g/l)
7000
6000
5000
4000
3000
2000
1000
0
Winter
Summer
Vitamin C intake (mg/day)
7006005004003002001000
Pla
sm
a A
sco
rbic
Acid
(m
mo
l/l)
120
100
80
60
40
20
0
Winter
Summer
y winter = 33.1 + 0.2x r = 0.43y summer = 64.4 + 0.02 r = 0.16
Conclusions
Use of a 7DDD proved feasible (though challenging and laborious)
in urban and rural areas in a country classified by the World Bank
as ‘moderately indebted lower middle income’.
Assuming a true group mean Physical Activity Level (energy
expenditure/BMR) ≥ 1.55, energy under-reporting was ≥ 8% in
winter and ≥ 18% in summer.
The 7 DDD appeared able to classify individuals by their intakes of
protein, sodium, potassium and vitamin C to a comparable extent
to its performance in western populations. Validity in Bulgaria may
be aided by the much smaller variety of foods consumed.
The results for dietary constituents of special interest for future
studies of stroke – sodium, potassium and vitamin C (as a
biomarker for fruits and vegetables) – were satisfactory.
y winter = 33.1 + 0.2x r = 0.43
y summer = 64.4 + 0.02 r = 0.31
Introduction
Dietary correlates of high vascular risk in
Bulgaria remain largely uninvestigated.
Epidemiological study of dietary exposures
requires a dietary assessment instrument with
known levels of validity for the exposures of
interest in the population of interest.
Aim
To assess the validity of estimates of dietary
intakes from a 7-day diet diary (7DDD) by
comparing them with:
estimated energy requirements;
urinary nitrogen (for estimating protein
intake), sodium and potassium excretion;
plasma vitamin C concentration.
% under-reporting energy
48%63%
Winter Summer
Web address: http://www.phpc.cam.ac.uk/varna/stroke/index.html