ESPE Abstracts

Background: Emerging evidence suggests FTO polymorphisms are associated with obesity-related comorbidities including type 2 diabetes (T2DM), hypertension and polycystic ovarian syndrome (PCOS). However association of FTO with other comorbidities such as obstructive sleep apnoea (OSA) in paediatric populations is less clear.

Objective and hypotheses: To investigate the prevalence of obesity-related comorbidities according to FTO genotype in an obese paediatric cohort.

Method: Data were collected from patients attending the weight management service at The Royal Children’s Hospital (Melbourne). Comorbidities assessed were; impaired glucose tolerance/T2DM, hypertension, hyperlipidaemia, non-alcoholic fatty liver disease, OSA, PCOS, mental health and eating disorders, orthopaedic and neurological disorders. A binary comorbidity score was assigned (range: 1–9), to assess additive risk. Genotype (FTO rs9939609 SNP alleles; Sequenom MassARRAY MALDI-TOF MS), activity levels (Actical accelerometry) and dietary consumption(Australian Food Frequency Questionnaire), were measured and collected. Data were statistically analysed using χ², one-way ANOVA and logistic regression as appropriate.

Results: Amongst the 197 patients genotyped (age; 10.8 (±3.5) years, BMI-Z score; 2.44 (±0.44), male/female ratio; 91/106), 45 were risk allele homozygous (AA), 100 heterozygous (AT), and 52 non-risk allele homozygous (TT). There were no significant differences in anthropometric, biochemical or physical activity measures. Dietary survey analysis revealed minor differences between FTO genotype groups (vitamin A; P=0.01, retinol; P=0.02). Using recessive modelling, patients with AA genotype were twice as likely to have OSA than those with AT or TT genotypes, after adjusting for total percentage body fat (OR 2.21 (CI: 1.01–4.89), P=0.04) but not BMI-Z. No further effects of FTO genotype on other obesity comorbidities were observed.

Conclusion: Recessive genotype FTO risk allele was associated with increased presentation of clinical paediatric OSA, independent of body fat percentage. FTO genotype may independently or synergistically magnify the burden of obesity-related comorbidities.