Background. Childhood obesity is considered to have reached epidemic levels in developed countries. A number of studies have reported remarkably strong, replicable associations with obesity indices for the FTO gene.

We investigated the prospect of breastfeeding protection from obesity markers on a genotype dependent way for the FTO rs9939609 and rs11075989 polymorphisms in the GENDAI cohort - 1138 children attending fifth and sixth grade living in the Attica region of Greece (53% girls; mean age: 11.2+/-0.7 years) recruited from randomly selected elementary schools.

For both SNPs, children homozygotes for the risk allele presented higher values of BMI, waist, waist to hip ratio, skinfolds (triceps and subscapular) body fatness and TNF-a levels. Multivariate analysis showed that, after controlling for age, sex, physical activity, Tanner stage and energy intake, the impact of both SNPs on body composition variables and on TNF-a levels remained statistically important. We looked then on breastfeeding variable and we found that the prevalence of any breastfeeding was 80.6% with the majority of breast feeders reporting duration of 2-4 months. Including breastfeeding as a covariant in the model we revealed that breastfeeding was inversely associated with waist to hip ratio (beta+/-SE: -0.075+/-0.016, p=0.0004). Additionally to that a strong interaction was observed with both SNPs for waist to hip ratio and for body fatness.

We want to use a sample of the ALSPAC cohort to replicate our findingds in the GENDAI cohort. For this purpose we are requesting data on children for which there is available information on breastfeading (see below) and genotypes for SNP rs9939609.

In the GENDAI study data on the method of infant feeding were obtained from self-completion questionnaires sent to each mother. Information on breastfeeding duration was available as a categorical variable, and for this study we had information on the exclusivity of breastfeeding and of breastfeeding and formula on the same time. A positive answer was recorded if the duration of breastfeeding exceeded one month.

We would like to request

Breastfeading Mother Questionnaire Birth to 6 months

Sex Child

Body weight Child Clinic at the age of 10-12 years

Height Child '' ''

Waist circumference Child '' ''

Waist to hip ratio Child '' ''

TNF-a (pg/ml) Child '' ''

skinfolds

triceps Child '' ''

subscapular Child '' ''

body fatness Child '' ''

Genotype rs9939609 Child