Continuing Disparities in Cardiovascular Risk Factors and Complications Between Aboriginal and Anglo-Celt Australians With Type 2 Diabetes

Abstract

OBJECTIVE: To determine whether disparities in the nature and management of type 2 diabetes persist between Aboriginal and the majority Anglo-Celt patients in an urban Australian community. RESEARCH DESIGN AND METHODS: Baseline data from the observational Fremantle Diabetes Study collected from 1993 to 1996 (phase I) and from 2008 to 2011 (phase II) were analyzed. Patients characterized as Aboriginal or Anglo-Celt by self-report and supporting data underwent comprehensive assessment, including questionnaires, examination, and biochemical testing in a single laboratory. Generalized linear modeling with age/sex adjustment was used to examine differences in changes in variables in the two groups between phases I and II. RESULTS: The indigenous participants were younger at entry and at diabetes diagnosis than the Anglo-Celt participants in both phases. They were also less likely to be educated beyond primary level and were more likely to be smokers. HbA(1c) decreased in both groups over time (Aboriginal median 9.6% [interquartile range 7.8-10.7%] to 8.4% [6.6-10.6%] vs. Anglo-Celt median 7.1% [6.2-8.4%] to 6.7% [6.2-7.5%]), but the gap persisted (P = 0.65 for difference between phases I and II by ethnic group). Aboriginal patients were more likely to have microvascular disease in both phases. The prevalence of peripheral arterial disease (ankle-brachial index ≤0.90 or lower-extremity amputation) increased in Aboriginal but decreased in Anglo-Celt participants (15.8-29.7 vs. 30.7-21.5%; P = 0.055). CONCLUSIONS: Diabetes management has improved for Aboriginal and Anglo-Celt Australian patients, but disparities in cardiovascular risk factors and complications persist.