Population level outcomes of advancements in diabetes care

© 2021 Katerina Vivian KiburgThe development of diabetes-related complications is a major healthcare problem. The overall aim of this thesis is to document trends in the incidence of diabetes-related complications, focusing on those related to cardiovascular and renal disease. Diabetes care has improved significantly over past decades, resulting in improved glycaemic control and an increase in the number of patients achieving various metabolic goals. Indeed, the application of multifactorial, target driven interventions has been shown to reduce the development and progression of diabetes related complications in the clinical trial setting. Furthermore, novel glucose lowering medications have recently been shown to reduce the development of cardiovascular and renal complications in recent clinical trials. It is possible that these recent improvements in diabetes management have contributed to reductions in complications in the general diabetes population. In this thesis I examined changes in rates of diabetes related complications in people with and without diabetes over time in Victoria, Australia. The research described in this thesis is mainly centred on an analysis of trends in hospital admissions in Victoria, Australia for various diabetes related complications. This thesis shows that there was a significant decline in the cardiovascular outcomes of, incident AMI, stroke and heart failure presentations for patients with type 1 diabetes, type 2 diabetes and without diabetes between 2004 and 2016. The greatest rate of decline was observed in patients with type 2 diabetes, followed by patients with type 1 diabetes. My research also demonstrates that there was a significant decline in end stage renal disease presentations (separate to those for dialysis and transplantation) for patients with type 1 diabetes, type 2 diabetes or no diabetes. However, rates of admissions for diabetic nephropathy and specifically for dialysis and transplantation remained stable. This lack of translation of a reduction in ESRD presentations to reduced rates of dialysis and transplantation may be due to changes in clinical practices, such as greater access and eligibility for renal replacement programs. The continuing large number of patients with diabetic nephropathy represent an opportunity for the better implementation of best practice guidelines aimed at slowing the development and progression of diabetic kidney disease. In addition, I was able to show that overall rates of lower extremity amputations (LEA) declined for patients with type 2 diabetes, compared to those with type 1 diabetes who did not experience such a decline. Concerningly, a significant rise was seen in all types of LEA for younger patients with type 1 diabetes, whereas pleasingly, older patients with type 2 diabetes saw a decline in rates of LEA. While there is a large amount known on the numbers of people that experience cardiovascular events, less is known about the intravascular burden of coronary artery disease in people with and without diabetes. I was able to show a significant increase over time in the burden of coronary artery disease for patients with type 2 diabetes, compared to those without diabetes in whom no change was observed. A key finding was that following adjustment for the use of traditional cardiovascular protective medications such as statins, renin-angiotensin system inhibitors and anti-platelet drugs, there was no significant difference in the extent of intra-coronary artery disease between patients with and without type 2 diabetes. The implication of this finding is that the aggressive use of traditional preventative therapies can greatly help to reduce the excess burden of disease within the coronary arteries of patients with type 2 diabetes. The improvement in rates of traditional diabetes related complications has led to a corresponding increase of non-traditional complications, including malignancies. In the last results chapter of this thesis, I was able to show that for patients with type 2 diabetes and malignancies there was a significantly increased risk of emergency department presentations, inpatient admissions and all-cause mortality compared to patients with malignancies but without diabetes. This thesis adds to a growing body of evidence of the negative impact of diabetes, on patient outcomes and the importance of risk factor modification and multifactorial interventions. It highlights that although improvements in hospital admission rates for many diabetes related complications are occurring, the overall burden of complications still remains a major public health problem. Unfortunately, my work also shines a light on the changing face of diabetes complications and the potential problems associated with the emergence of non-traditional complications, such as malignancies