Prevalence and Risk Factors of Type 2 Diabetes in Older Vietnam-Born Australians

Duong Thuy Tran, Louisa R. Jorm, Maree Johnson, Hilary Bambrick, Sanja Lujic

Vietnamese immigrants in Australia represent the second largest Vietnamese community in developed countries, following the United States. However, limited information is available about prevalence of type 2 diabetes (T2D) and the relative roles of socio-demographic characteristics, lifestyle factors, and Vietnamese ethnicity per se in this population. This study investigated the prevalence of T2D and its risk factors in older Vietnam-born Australians, in comparison to native-born Australians. The study used baseline questionnaire data from 787 Vietnam- and 196,866 Australia-born individuals (≥45 years), who participated in the 45 and Up Study, which is Australia's largest population-based cohort study. Country of birth specific prevalence of T2D and its risk factors were age-standardised to the 2006 Australian population (≥45 years). Multivariable logistic regression models were built for each group to assess the relationship between T2D and socio-demographic characteristics, family history of diabetes, lifestyle factors and health status. Compared to Australia-born counterparts, Vietnam-born individuals had significantly (p < 0.001) higher age-standardised prevalence of T2D (14.7 vs 7.4 %) and significantly (p < 0.001) lower levels of vegetable consumption (≥5 serves/day, 19.4 vs 33.5 %), physical activity (≥5 sessions/week, 68.7 vs 78.5 %) and overweight and obesity (body mass index ≥25 kg/m(2), 21.5 vs 62.7 %). The increased risk of T2D associated with a family history of diabetes for Vietnam-born people [adjusted odds ratio (OR) 7.14, 95 % CI 4.15-12.28] was almost double that for Australia-born people (OR 3.77, 95 % CI 3.63-3.90). The patterns of association between T2D and other factors were similar between the two groups. The findings suggest a genetic predisposition to T2D in people of Vietnamese ethnicity. Reducing lifestyle risk factors for diabetes and better management of diabetes are priorities for Vietnam-born populations.