Prevalence of Diabetes Mellitus and Risk Factors in South Western Sydney: Where Are We Now?

Objective: There is a substantial and growing burden from diabetes globally. South Western Sydney (SWS), New South Wales, with its ethnic and socioeconomic (SE) diversity, is a rapidly growing district with a population profile suggesting a high prevalence of diabetes. This monograph provides an overview of baseline diabetes epidemiology across South Western Sydney local government areas (SWSLGA). Methods: The prevalence of diabetes mellitus (DM) among SWS residents in March 2018 was investigated using population data from the Australian National Census, diabetes data from the National Diabetes Services Scheme (NDSS), and supplemented information for diabetes related factors from NSW Adult Health survey 2017. Prevalence of diabetes by type, gender, age group and socioeconomic (SE) factor in addition to the diabetes-related complications for each SWS local government area (LGA) was estimated. Results: The prevalence of diabetes in SWS was 6.7% (64,389/960,552) affecting males (6.7%, 31,936) and females (6.7%, 32,448) equally. The rates in 4/7 LGA's were higher than the national rates and ranged from 6.5% in Bankstown (23,851) to 7.6% in Fairfield (16,389). The majority (87.2%, 55,936) had Type 2 diabetes (T2DM). Type 1 diabetes (T1DM), gestational diabetes (GDM), and other diabetes types made up 7.8%, 4.3% and 0.7% of the NDSS registrants, respectively. The T2DM proportions were higher than National proportions for T2DM in Fairfield (90.1% vs 87.2%) and for GDM in 6/7 LGAs (range 12.2% - 24.2% vs 12.7%). Camden, Wollondilly and Wingecarribee had higher than National proportions (9.3%) with T1DM. The diabetes risk factors of obesity (20.3 to 24.1%), in both men and women, overweight or obesity in females (44.6 to 52.1%) increased from 2011 - 16. Between 2011-16 adequate physical activity and consumption of vegetable increased 4.5% (from 47.7 to 52.2%) and 1.5% (3.9 to 5.4%) respectively, but adequate fruit consumption declined 0.8% (49.4 to 48.6%). Although the hospitalisation rate due to diabetes as a primary indication has remained stable over time across the district, it was disproportionately high in people with T1DM (affecting 8% of the diabetes population but accountable for 31% of hospitalisations with diabetes as a primary cause). The rates of potentially preventable hospitalisation for conditions related to diabetes increased linearly between 2013-16 (156 to 248 per 100,000 people) across SWSLHD. The rate of hospitalisation in Bankstown was double the NSW rate in 2015-16 (309 vs 149 per 100,000 people). The rate of diabetes-related lower knee amputations were higher in SWSLGAs compared to the National rates (164 versus 146 amputations per 100,000 people). In 2016, 5 about 11% of all diabetes attributable deaths in NSW involved residents from SWS. Conclusion: The prevalence of diabetes in four of 7 SWS LGAs was higher than State and National rates affecting one in 8 persons and increasing with age. Fairfield, Campbelltown, Liverpool and Bankstown districts were most affected, with higher T2DM prevalence, while Liverpool, Camden and Campbelltown had about 1.5 times higher rates of GDM compared to the National rate. These findings, together with the increasing rates of diabetes, obesity and overweight and the high rate of complications including hospitalisation, amputations, mortality and pregnancy complications, underscore the urgent need for a district diabetes plan. This would require close working between primary and secondary care, and evidence based strategies to reduce the incidence of diabetes.