EARLY METABOLIC IMPRINTING AND LIFESTYLE RISK FACTORS

AS DETERMINANTS OF CHILDHOOD OBESITY

C. Scerri

University of Malta Medical School, Msida (Malta)

INTRODUCTIONINTRODUCTION

LIFESTYLELIFESTYLE• ExerciseExercise

• Nutrition - childhoodNutrition - childhood

• Social statusSocial status

• The developed world is currently seeing an increase in childhood obesity rates.

• The reason for this changing epidemiology is multifactorial.

PERINATALPERINATAL

• GeneticGenetic

• Intra uterine Intra uterine nutritionnutrition

• Infant feedingInfant feeding

METHODOLOGYMETHODOLOGYEpidemiological investigationEpidemiological investigation

• The study was carried out among two study populations – Children aged 5-years of age [n = 236], and – Children aged 9-years of age [n=195].

• The children underwent standard anthropomorphic

measurements that were statistically correlated to the social status of the family, family history of metabolic syndrome, the child’s birth weight, breast feeding, physical activity habits and nutritional factors.

• The chi square test and student test were utilized as appropriate.

METHODOLOGY METHODOLOGY

• Height and weight of the participants were measured

• Body Mass Index (BMI) was subsequently calculated – BMI cut off values for overweight 5 year- old boys and girls

was considered to be 17.42 and 17.15 kg/m2 respectively 1.– For the 9 year olds the figures were 19.10 and 19.07 kg/m2

respectively 1.

• Waist circumference was measured from the study population – The chosen cut off 75th percentile waist circumference

measurements for 5-year-old boys and girls was 56.5 cm for both genders; while that for the 9-year-olds the figure was 67.0 and 65.7 cm respectively 2.

1. Cole TJ, Bellizzi MC, Flegal KM, Dietz WH. Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ 2000; 320(7244): 1240 -1243.2. Fernández JR, Redden DT, Pietrobelli A, Allison DB. Waist circumference percentiles in nationally representative samples of African-American, European-American, and Mexican-American children and adolescents. J Pediatr 2004; 145(4): 439 - 444.

RESULTSRESULTSPrevalencePrevalence

• The prevalence of childhood overweight-obesity in Maltese 5-year-old children as based on cut-off points defined in the literature was 28.8% for boys and 32.7% for girls.

• These proportions increased markedly with increasing age, so that 48.9% of Maltese 9-year-old males and 45.1% of girls were found to be overweight-obese.

RESULTSRESULTSEarly Metabolic Risk Factors – Intrauterine nutritionEarly Metabolic Risk Factors – Intrauterine nutrition

0

1

2

3

4

5

RE

LA

TIV

E R

ISK

RA

TIO

at 5yrs age at 9yrs age

<2500g

2500-3999g

>4000g

p=0.44

p<0.0001

p=0.03 p<0.0001

Relative Risk for overweight/obesity to lean by birth weight in children aged 5 and 9 years

• At 5 years of age statistically significant risk of obesity in high birth weight infants; no such risk in low birth weight infants [?catch-up period?]

• At 9 years of age statistically significant risk of obesity in low and high birth weight infants [U-shaped risk].

• The rate of bottle-feeding in the overweight-obese 5-year old group of children showed a statistically significant higher rate when compared to the lean 5-year-old children [p=0.04]. No such statistically significant relationship could be seen in the 9-year olds.

RESULTSRESULTSEarly Metabolic Risk Factors – Early infant feedingEarly Metabolic Risk Factors – Early infant feeding

0

10

20

30

40

50

60

% C

hild

ren

bo

ttle

fed

in in

fan

cy

at 5yrs age at 9yrs age

Lean

Obese

P = 0.81

P = 0.04

RESULTSRESULTSLifestyle Risk factors – Socio-economicLifestyle Risk factors – Socio-economic

• There did not appear to be any statistically There did not appear to be any statistically significant relationships between socio-significant relationships between socio-economic parameters and the tendency economic parameters and the tendency towards childhood obesity in both age groups.towards childhood obesity in both age groups.

Lifestyle Risk Factors – Physical activityLifestyle Risk Factors – Physical activity

• Though all parameters relating to physical Though all parameters relating to physical activity proved to have no statistical significance; activity proved to have no statistical significance; it appeared that the overweight-obese it appeared that the overweight-obese individuals at both age groups reported less individuals at both age groups reported less mean active physical activity time than their mean active physical activity time than their leaner counterparts.leaner counterparts.

• There was a marked statistical significant less There was a marked statistical significant less sleeping time in the overweight-obese nine year sleeping time in the overweight-obese nine year old group when compared to their lean old group when compared to their lean counterparts [counterparts [p=0.008p=0.008].].

RESULTSRESULTSLifestyle Risk Factors - DietLifestyle Risk Factors - Diet

• Although no statistical differences were noted between Although no statistical differences were noted between diet and obesity risk in the 5-year-old children, certain diet and obesity risk in the 5-year-old children, certain trends could be observed.trends could be observed.

• Less fresh fruit, vegetables, cheese, yoghurt, sweets, Less fresh fruit, vegetables, cheese, yoghurt, sweets, biscuits, and fast foods were consumed by the biscuits, and fast foods were consumed by the overweight-obese 5-year-old children.overweight-obese 5-year-old children.

• More fruit juice, soft drinks, diet drinks, milk whole fat, More fruit juice, soft drinks, diet drinks, milk whole fat, milk low fat, meat, fish and chips by this same group.milk low fat, meat, fish and chips by this same group.

RESULTSRESULTSLifestyle Risk Factors - DietLifestyle Risk Factors - Diet

• In contrast statistically significant In contrast statistically significant differences in dietary patterns were differences in dietary patterns were observed between the lean and observed between the lean and overweight-obese 9-year-olds.overweight-obese 9-year-olds.

• The overweight-obese group was The overweight-obese group was reported to consume a statistically lower reported to consume a statistically lower proportion of fruit juice [proportion of fruit juice [p=0.03p=0.03]],, flavouredflavoured milk [milk [p=0.03p=0.03]],, and a higher proportion of and a higher proportion of low fat milk [low fat milk [p=0.004p=0.004]]..

CONCLUSIONSCONCLUSIONS• Childhood obesity and the consequences of a life-long exposure to Childhood obesity and the consequences of a life-long exposure to

the obese state has become a major concern.the obese state has become a major concern.

• The present study suggests that the prevalence of overweight-The present study suggests that the prevalence of overweight-obesity in nine-year-old Maltese children has now reached an obesity in nine-year-old Maltese children has now reached an alarming rate of 45.1-48.9% depending on gender. alarming rate of 45.1-48.9% depending on gender.

• Early metabolic imprinting appears to play a significant role in Early metabolic imprinting appears to play a significant role in determining risk of developing obesitydetermining risk of developing obesity– Inter-relationship to intrauterine nutrition with higher eventual obesity Inter-relationship to intrauterine nutrition with higher eventual obesity

rates for low and high birth weight infantsrates for low and high birth weight infants

– Inter-relationship to early infant feeding with higher eventual obesity Inter-relationship to early infant feeding with higher eventual obesity rates for bottle-fed infantsrates for bottle-fed infants

The Thrifty Phenotype HypothesisThe Thrifty Phenotype HypothesisThe hypothesis postulates that poor nutrition in foetal and early infant life is detrimental to the development and functioning of β-cells and insulin-sensitive tissues, resulting in the emergence of insulin resistance in later life 3.

3. Miller J, Rosenbloom A, Silverstein J. Childhood obesity. J Clin Endocrinol Metab 2004; 89(9): 4211-4218.

CONCLUSIONSCONCLUSIONS

• The rapid increase in the prevalence of childhood obesity cannot be attributed to changes in the genetic makeup because the gene pool has not changed in the past decade4.

• Therefore the main concern must be to identify the changes in activity and diet that occurred simultaneously with changes in prevalence4.

– No socio-economic interrelationship found.– The study has shown a very poor association between physical activity

and nutrition patterns to the development of childhood obesity.– In both overweight-obese age groups there was a tendency noted on the

efforts to consume less ‘energy dense foods’ and it appears that there are definite efforts being made by the parents to control sweets and energy dense food to control weight.

• It is likely however that children by the age of 9 years have already attained their predisposition towards developing obesity and later features of the metabolic syndrome.

4. Burnait W, Cole T.J, LissaI.N, eds., Child and Adolescent Obesity; Causes and Consequences, Prevention and Management, Cambridge University Press, Cambridge 2006.

RECOMMENDATIONSRECOMMENDATIONS

• Measures to control for childhood obesity will be needed to be taken Measures to control for childhood obesity will be needed to be taken both ‘downstream’ in the school, home and neighbourhood both ‘downstream’ in the school, home and neighbourhood environment, and ‘upstream’ in terms for food supplies, commercial environment, and ‘upstream’ in terms for food supplies, commercial marketing and the promotion of healthier lifestyle marketing and the promotion of healthier lifestyle 5.5.

• The effective prevention and management, of childhood obesity The effective prevention and management, of childhood obesity must be a family focused approach best managed by the Family must be a family focused approach best managed by the Family Doctor.Doctor.– All obese children should have a full history and physical examination All obese children should have a full history and physical examination

performed.performed.

– Calculation and plotting of the BMI once a year in all children and Calculation and plotting of the BMI once a year in all children and adolescents. adolescents.

– Identification of risk factors of childhood obesity is paramount. Identification of risk factors of childhood obesity is paramount.

– Flagging on medical records of children who are at high risk of Flagging on medical records of children who are at high risk of becoming obese.becoming obese.

5. Jotangia D., Moody A., Stomatakis E., et al. (2005). Obestiy among children under 11. Health Survey for England: child obesity data, National Centre for Social Research.

RECOMMENDATIONSRECOMMENDATIONSHealth Living Advice To The FamilyHealth Living Advice To The Family

• Parents should not fetch and carry for their children.Parents should not fetch and carry for their children.• Think of activity as fun.Think of activity as fun.• A maximum of two hours of television or computer use A maximum of two hours of television or computer use

per day.per day.• Family car should be avoided.Family car should be avoided.• Using low fat dairy products.Using low fat dairy products.• Increasing amount of fruit and vegetables.Increasing amount of fruit and vegetables.• Making time to eat breakfast.Making time to eat breakfast.• Eating meals together as a family.Eating meals together as a family.• Drinking water with meals.Drinking water with meals.