Incidence of type 2 diabetes in Aboriginal Australians: an 11-year prospective cohort study

Abstract

BackgroundDiabetes is an important contributor to the health inequity between Aboriginal and non-Aboriginal Australians. This study aims to estimate incidence rates of diabetes and to assess its associations with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) among Aboriginal participants in a remote community.MethodsSix hundred and eighty six (686) Aboriginal Australians aged 20 to 74 years free from diabetes at baseline were followed for a median of 11 years. During the follow-up period, new diabetes cases were identified through hospital records. Cox proportional hazards models were used to assess relationships of the incidence rates of diabetes with IFG, IGT and body mass index (BMI).ResultsOne hundred and twenty four (124) new diabetes cases were diagnosed during the follow up period. Incidence rates increased with increasing age, from 2.2 per 1000 person-years for those younger than 25 years to 39.9 per 1000 person-years for those 45-54 years. By age of 60 years, cumulative incidence rates were 49% for Aboriginal men and 70% for Aboriginal women. The rate ratio for developing diabetes in the presence of either IFG or IGT at baseline was 2.2 (95% CI: 1.5, 3.3), adjusting for age, sex and BMI. Rate ratios for developing diabetes were 2.2 (95% CI: 1.4, 3.5) for people who were overweight and 4.7 (95% CI: 3.0, 7.4) for people who were obese at baseline, with adjustment of age, sex and the presence of IFG/IGT.ConclusionsDiabetes incidence rates are high in Aboriginal people. The lifetime risk of developing diabetes among Aboriginal men is one in two, and among Aboriginal women is two in three. Baseline IFG, IGT and obesity are important predictors of diabetes.

Diabetes mellitus in the australian indigenous community

“…Indigenous presenting DM or not, tend to have a higher pre-valence of overweight/obesity than non-Indigenous. Wang, Hoy & Si [13] demonstrated that obesity is a relevant factor to increase the DM rates among aborigines. Furthermore, DM has a higher incidence in obese than in non-obese Australians ( Table 1) [4].…”

“…Isolation reduces the possibility of purchasing fresh fruit and vegetables, influencing negatively in the quality of the diet [23]. However, the BMI and DM rates have been increasing among Aborigines living in remote [13,23,24] and urban areas [25]. In addition, Aboriginal living in remote areas reported almost double the incidence of DM than those living in nonremote areas [4].…”

The independent associations of HbA1c, C-reactive protein and birth weight with cardiovascular disease, diabetes mellitus and chronic kidney disease in a remote Indigenous Australian community: a prospective cohort study

“…Australian communities have some of the highest prevalence of CVD, diabetes and renal disease in the world [2,24,25]. A recent government report detailed the increased rates and earlier onset of CVD, diabetes and CKD for Indigenous Australians [21].…”

“…The health screening examinations represent over 80% of the age-eligible population [2], which is largely attributable to the strong relationship between Prof Hoy's group and the participating Indigenous Australian community. There is an established, long-term relationship of trust, respect and honesty as well as ongoing communication and information sharing between researchers and the community, which is paramount in the collaboration's success [5].…”

“…This community identified high prevalence and incidence rates of chronic diseases, such as cardiovascular disease (CVD) [1], diabetes [2] and renal disease [3], and also a high rate of premature natural deaths [4]. The consequence of this partnership was the conduct of two community-wide health screens, in 1992-1999 and 2004-2006, to explore the associations of chronic disease risk factors and biomarkers which may provide opportunities to reduce the burden of the community's disadvantage.…”