the correlation of estimated dietary protein with estimates based on nitrogen excretion was 0.56...

The correlation of estimated dietary protein with estimates based

on nitrogen excretion was 0.56 (winter) and 0. 48 (summer).

Sodium intake (mg/day)

8000

7000

6000

5000

4000

3000

2000

1000

0

So

diu

m e

xcre

ted

in

uri

ne

(m

g/l)

10000

9000

8000

7000

6000

5000

4000

3000

2000

1000

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