Six year weight change and type 2 diabetes among Australian Indigenous adults

Aims: To estimate weight change over 6 years among Indigenous Australian adults and the association with incident diabetes in north Queensland. Methods: Baseline anthropometric measurements, behavioural factors, and blood samples were collected from 1674 Indigenous adults during 1999-2000 in 19 rural communities in north Queensland. Follow-up of 487 participants occurred during 2004-2007. Weight change was compared by age, sex, socioeconomic status, ethnicity, and behavioural factors. The association between weight change and diabetes incidence stratified by baseline BMI was studied using Cox's Proportional Hazard Model. Results: Significantly more weight was gained among younger participants (absolute interval weight gain: 12.5. kg among 15-24 year olds, 5.1. kg in 25-34 year olds, 3.4. kg in 35-44 year olds, and 1.0. kg in those over 45 years), and by those whose BMI was normal at baseline. Women were more likely than men to have substantial weight gain (43.3 vs 25.1%). Weight change was not associated with diabetes incidence but baseline obesity tripled the risk of developing diabetes (HR: 3.1, 95% CI: 1.6-6.1). Conclusions: Indigenous Australian adults studied here showed very high levels of weight gain over a short period. Interventions aimed at maintaining healthy weight, particularly among young Indigenous people are needed.