Oral Presentation Australian & New Zealand Obesity Society 2014 Annual Scientific Meeting

One-year longitudinal obesity trends of rural Australian adolescents: preliminary results from the ARCHER study (#81)

Hoi Lun (Helen) Cheng 1 , Georgina Luscombe 2 , Karen Paxton 3 , Catherine Hawke 2 , Katharine Steinbeck 4
  1. Academic Department of Adolescent Medicine, The Children's Hospital at Westmead, Westmead
  2. School of Rural Health, The University of Sydney, Orange
  3. School of Rural Health, The University of Sydney, Dubbo
  4. Academic Department of Adolescent Medicine, The University of Sydney, Sydney

Background: Puberty is critical life-stage where significant physical and behavioural changes occur and long-term health pathways are established. Overweight and obesity during adolescence is common and often persists, potentially affecting health trajectories into adulthood. Despite the dynamic changes occurring at this life-stage, there are limited longitudinal studies that examine weight and health trends across puberty. ARCHER (Adolescent Rural Cohort Hormones, Health, Education, Environments and Relationships) is an ongoing longitudinal study of rural-dwelling young adolescents exploring the influence of puberty hormone change on health and wellbeing over three years.

Methods: At baseline and annually, adolescents and one parent/guardian complete questionnaires that collect demographic, behavioural, social, psychological and mental health information. Adolescent anthropometry and body composition are also measured, with a fasting blood sample collected. Adolescents provide three-monthly urine samples for measurement of puberty hormones. Data: mean±SD.

Results: A total of 342 adolescents (55% male; 11% Indigenous) were recruited across western New South Wales, with 313 available for anthropometry at the year one time-point. Baseline age, BMI z-score and waist circumference were 11.8±1.0y (male: 11.8±1.0y; female: 11.7±1.0y), 0.55±1.21 (male: 0.51±1.20; female: 0.60±1.23) and 66.3±11.0cm (male: 65.9±11.5cm; female: 66.7±10.3cm) respectively. Over one year, mean change in BMI z-score was -0.02±0.36 (male: -0.03±0.36; female: 0.00±0.35) with overweight/obesity prevalence increasing from 32% (17% male) to 34% (18% male). Of those starting at healthy weight, 7% (3% male) became overweight at year one, and one boy showed a shift from overweight to obesity. Conversely, 16% (11% male) of adolescents who were overweight/obese at baseline had shifted into a lower z-score category. There was no significant change in BMI z-scores (p=0.45) or z-score categories (p=0.77) across the two time points.

Conclusion: Whilst overweight and obesity did not change significantly across the first year of the ARCHER study, it was a prevalent issue in this group. Ongoing collection and analysis of data from this cohort may uncover potential predictors of weight change and health trajectories across adolescence.