kashin-beck disease: evaluation of mineral intake in young tibetan children from endemic areas...

KASHIN-BECK DISEASE: EVALUATION OF MINERAL INTAKE IN YOUNG TIBETAN CHILDREN FROM ENDEMIC AREAS

GEORGES LOGNAY, FRANÇOISE MATHIEU

MICHAËL DERMIENCE

ANNÉE ACADÉMIQUE 2009-2010

I. Introduction

1. Objectives

2. Tibet Autonomous Region, P.R. China

3. Kashin-Beck disease

4. Trace elements and their roles in relation

to bone metabolism

Table of contents

II. Material and methods

1. Choice of families and sampling

2. Nutritional survey

3. Mineral elements analyses

4. Validation of methods

5. Evaluation of daily intakes

Table of contents

III. Results and discussion



3. Analyses of foods mineral contents


IV. Conclusion and perspectives

Table of contents

I. Introduction

Main objective: to measure the mineral content of most consumed Tibetan

foods

Secondary objectives: to compare the measured food contents with food reference

tables

to develop a food sample procedure matching field conditions

to establish and validate an analytical method of measurement

to estimate mineral daily intakes by the means of a nutritional program: Kidmenu®

1. Objectives

Located in the South-Western border area of Popular Republic of China

About 1,228,400 km², and over 2.62 millions peoples

Physionomy is diversified (mountains, deserts, grasslands and forests)

Many rivers have their sources in Tibetan Plateau (Yangtze, Yellow River, Brahmaputra, Ganges, etc)

Farming and animal husbandry are the major agricultural activities but productivity is very low


According to Haubruge and al.(2000), Malaisse and al.(2008) populations share out 4 macro-ecosytems: ◦ The urban zone

◦ The suburban zone which is mechanized and has communication media

◦ The agricultural zone with subsistence farming

◦ The pastoral zone over 4500 m with nomads and yaks

The Kashin-Beck disease is only encountered in the agricultural group.

Diet is a major difference between this group and the others.


Kashin-Beck disease is an endemic and chronic osteochondropathy

This disease is characterized by short stature and skeletal deformities especially in long bones and joints

Symptoms appear during childhood (3-5 years) and become progressively worse

Clinical and radiological diagnosis exist, distinguishing several stages


Although many studies have already been conducted and many others are still underway, its ethiology remains unknown

A multifactorial hypothesis has been proposed:selenium deficiency

high concentration of organic matters in drinking water

mycotoxin in cereals


Calcium

Phosphorus

Magnesium

Iron

Zinc

Copper

Manganese

Selenium

4. Mineral elements and their roles in relation to bone metabolism

Nickel

Molybdenum

Arsenic

Strontium

Fluorine

Cadmium

Daily reference intakes (DRIs), West Suitor et al., 2006 :

4. Trace elements and their roles in relation to bone metabolism

Life Stage Group P (mg/d) Ca (mg/d) Mg (mg/d) Fe (mg/d)

RDA/AI* UL RDA/AI* UL RDA/AI* UL RDA/AI* UL

1-3 years 460 3000 500* 2 500 80 65 7 40

4-8 years 500 3000 800* 2 500 130 110 10 40

Zn (mg/d) Cu (µg/d) Mn (mg/d) Se (µg/d)

RDA/AI* UL RDA/AI* UL RDA/AI* UL RDA/AI* UL

1-3 years 3 7 340 1 000 1.2* 2 20 90

4-8 years 5 12 440 3 000 1.5* 3 30 150

Ni (mg/d) As (µg/d) Mo (µg/d)

RDA/AI* UL RDA/AI* UL RDA/AI* UL

1-3 years ND 0.2 ND ND 17 300

4-8 years ND 0.3 ND ND 22 600

II. Material and methods

10 families from two distinct areas:

Living in endemic areas

Including a 3 to 5 year-old child

This child having a KBD brother or sister


A sampling campaign split up into two periods

Most eaten foods collected in each family:


Barley flour Wheat flourRice

PotatoBlack teaYak butter

Two foods collected in Lhasa:

Chinese cabbageInstant noodles

24-Hour food recall of the 3-5 years old child


Mineralization: microwave-assisted wet process

Mineral measurements:

Flame Atomic Absorption Spectrometry (FAAS)

Electrothermal Atomic Absorption Spectrometry (ETAAS)

Hydride generation

Cold vapour generation

Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)

Molecular Absorption (UV-Vis)

3. Mineral elements analyses

Certified reference materials (CRM):

◦ Trueness

◦ Fidelity

Repeatability study:

◦ CRM

◦ Sample

4. Validation of the method

Nutritional survey

Food contents

P. De Voghel’study, 2008

Kidmenu®

Daily intakes: Ca, P, Mg, Fe, Zn, Cu & Mn

Comparison with DRIs table


III. Results and discussion

Food sampling

Dry matters and comparison with reference tables (USDA, Souci):

± equals to references, slightly different for barley flour


Extremely monotonous cereal-based diet

Poor diversity of dishes

Most common beverages:

Butter tea

Chang

Consumption of :

Meat is low

Fruits and dairy products is rare


Limit of quantification:


Outliers set aside via the Grubb’s test

All determination coefficient (R²) of calibration curves > 0.998

Method successfully validated (except for Se, Sr and As)

Repeatability: RSD < 10%

Food mineral contents expressed in mg/100g FM

Compared to reference tables (USDA, Souci):

Iron content is markedly high

Selenium is clearly deficient

Black tea is rich in elements

Brewed black tea is drunk so much diluted that

mineral contents is finally really low


Creation of anamnesis, edition of children’s menus and coding of food contents in Kidmenu®

Some restrictions:

◦ Omission of some foods (milk, yak meat, chang, fruits, etc.)

◦ Standardization of dish (cooking pot)

◦ Relative density approximation


Mineral intakes compared to daily reference intakes:

We confirm a marked deficiency in Ca


1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

80

90

100

Calcium_January

min.av.max.

child number

% o

f RDA

1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

80

90

100

Calcium_May

min.av.max.

child number

% o

f RDA



Ca/P ratio rarely exceeds 0.1





Fe and Cu are in excess and sometimes reach upper

limits





Fe and Cu are in excess and sometimes reach upper limits

Zn is around 100 % of RDA but absorbability is

probably weak






Zn is around 100 % of RDA but absorbability is probably

weak

Selenium approximation suggests a deficiency






Zn is around 100 % of RDA but absorbability is probably weak

Selenium approximation suggests a deficiency

Manganese often exceeds till two or three times upper

limits!


IV. Conclusion and perspectives

Original nutritional study in the Kashin-Beck ethiology context

Main objective and secondary objectives were reached

This work presents limits:

• Omission of some foods

• Representativeness ?• Extrapolation to every endemic areas ?

• Bioavailability of minerals is a critical point

• Bioavailability largely influences DRIs

• DRIs are established for a standard population with a quite balanced diet

Tibetans may not be compared to a standard population and their diet is not balanced at all

Antinutritional factors could be measured (phytate,...)

Bioavailability could be evaluated by experimentations (e.g. rats fed with a Tibetan diet)

A larger study over a longer term covering both endemic and non-endemic regions is required for definite conclusions to be reached

AcknowledgementsPr. Georges Lognay

Ph.D. Françoise Mathieu William Claus and the KBD fund asbl-vzw

Pr. Jean-Paul Barthélémy Ir. Philippe MaesenPr. Philippe Goyens

Ms. Martine Robert and M.D. Shancy RoozeThe members of the BEAGx and especially Laurent Lessire

The Tibet Center for Disease Control and Prevention The KBD fund team in T.A.R.

The members of the analytical chemistry unitPh.D. Jean-Michel Romnee

The Tibetan familiesMy family and my friends

Thanks for your attention

kashin-beck disease: evaluation of mineral intake in young tibetan children from endemic areas...

Documents

low slide

kidmenu slide

introduction slide

discussion slide

rare slide

sister slide

barley flour slide

crm sample slide