Dr S Saxena 1 Dr G Ambler 2 Prof. TJ Cole 3 Prof A. Majeed 1 1 Imperial College London, 2 UCLH Trust, 3 Institute of Child Health.

Dr S Saxena1 Dr G Ambler2

Prof. TJ Cole3 Prof A. Majeed1

1Imperial College London, 2UCLH Trust, 3Institute of Child Health

England and Scotland have one of the fastest growing obesity rates in the world….more than doubled between 1980 and the early nineties...(2001 figures) show 21% of men and 23.5% of women over 16 years have a Body Mass Index of 30 or more in England.

Background

• Obesity epidemic world wide

• US rising faster in African-Americans

• British South Asians & Afro-Caribbean adults at risk of cardiac disease

• British South Asian children have worse biochemical risk profiles for cardiac disease

Interrelationships

Diabetes

Cardiovascular disease

Black Caribbean

S. Asian ethnicity

Obesity

Aims

To compare the percentage of obese or overweight children within different ethnic and socio-economic groups

Health Survey for England1999

• Annual cross sectional survey

• Focus on ethnic minority groups

• Random sampling of private households

• Interview & nurse visit for measurements

Sampling

Ethnic boostn=3891

Ethnic groupsn=4857

General Populationn=6552

“Core”general

pop n=2061

Chinese n=342

Ethnicgroupsn=354

postcode sectors

household

screening

Systematic samplingRandom sampling

Ethnic group categories in HSE99

‘Chinese’

‘Bangladeshi’

‘Pakistani’

‘Indian’

‘Afro-Caribbean’

‘General population’

ETHNIC GROUPS COMPARED

‘Irish’

height 2weight /BMI =(kg) (m)(kg/m2)

Body Mass Index

Measure

*US reference population # UK growth reference charts (1991)

Defining obesity in children

Adults overweight: BMI 25 kg/m2

obese: BMI 30 kg/m2*

• In children, BMI rapidly changes with age• In US,85th and 95th centile for OW and OB*• UK growth reference charts adopt this#

IOTF standard 2000

Overweight Obesity

% Response rates

Gen Pop Ethnic boost

Household 76 71

Interview 97 92-96

Nurse visit 89 86

Results : Socio-economic status of ethnic groups

Social Ethnicity

class

G.PopAC Ind Pak Bang Chin Irish

I+II 34 22 28 18 9 37 39

IIIn 13 22 10 6 7 16 15

IIIm 31 22 30 40 35 31 29

IV+V 20 28 28 23 33 10 16

Results : Socio-economic status of ethnic groups

Social Ethnicity

class

G.PopAC Ind Pak Bang Chin Irish

I+II 34 22 28 18 9 37 39

IIIn 13 22 10 6 7 16 15

IIIm 31 22 30 40 35 31 29

IV+V 20 28 28 23 33 10 16

Risk of being overweight in girls by social class

0

0.4

0.8

1.2

1.6

I & II IIIn IIIm IV&V

Ad

just

ed o

dd

s ra

tios

Social class

Risk of being overweight in boys by social class

0

0.4

0.8

1.2

1.6

I & II IIIn IIIm IV&V

Ad

just

ed o

dd

s ra

tio

Social class

Risk overweight in boys by ethnic group

0

0.5

1

1.5

2

2.5

3

Genpopn

Afro-Carib

Indian Pakistani Bangla Chinese Irish

Ethnic group

Ad

just

ed

od

ds

rat

io

Risk overweight in girls by ethnic group

Ethnic group

0

0.5

1

1.5

2

2.5

Genpopn

Afro-Carib

Indian Pakistani Bangla Chinese Irish

Ad

just

ed

od

ds

rat

io

Risk of obesity in boys by ethnic group

0

0.5

1

1.5

2

2.5

3

Genpopn

Afro-Carib

Indian Pakistani Bangla Chinese Irish

Ethnic group

Ad

just

ed

od

ds

rat

io

Risk of obesity in girls by ethnic group

00.5

11.5

22.5

33.5

4

4.55

Genpopn

Afro-Carib

Indian Pakistani Bangla Chinese Irish

Ethnic group

Ad

just

ed

od

ds

rat

io

Strengths of study

Power: Large

Representative:Population based study

Measure: Objective (BMI)

Ethnic group comparisons: limitations

• Different heights for same BMI

• Different fat composition for same BMI

• Ethnic group reported by parent

• Data cross sectional

Conclusions

• Ethnicity strong determinant of obesity in children

• British Afro-Caribbean & Pakistani girls at increased risk of obesity

• Indian and Pakistani boys more likely to be overweight

• Social class differences do not contribute to obesity in children

Possible explanations

Biologicalgenetic

susceptibility

Behaviouraldiet

exercise patterns

Factors related to ethnic group

ENERG Y REG ULATIO N

Body fat stores

Future studies

• Longitudinal studies for cumulative risk

• Develop standards for child obesity

• Include ethnicity in assessing cardiac risk