Progression to renal replacement therapy or renal-related death (RRT/RRD) is greater in people with young-onset type 2 diabetes than those with type 1 diabetes, Australian research shows.

However a linkage study of data from the RPAH Diabetes Centre, the Australian National Death Index and the Australia and New Zealand Dialysis and Transplant Registry, found survival on renal replacement therapy was poor in both patient groups.

The study found 4.5% of 1,248 patients with type 1 diabetes progressed to RRT/RRD compared to 6.4% of 1,534 patients with type 2 diabetes diagnosed at between 15 and 35 years of age.

The study, published in the Journal of Diabetes and its Complications, found individuals with young-onset type 2 diabetes had a two-fold greater hazard of developing the composite renal endpoint of RRT/RRD than those with type 1 diabetes.

The difference remained after adjustment for gender, ethnicity and duration of diabetes but was no longer significant after adjustment for BMI.

The study noted that similar numbers of males and females progressed to RRT in the type 1 diabetes group but more males (72%) than females in the type 2 diabetes group.

Haemodialysis was the most common modality of RRT in both type 1 and type 2 diabetes and commenced at a median age of 49.2 and 52.1 years respectively.

There was no significant difference in survival on dialysis between the groups (p=0.83) and the cumulative incidence of mortality was 40% after 6 years of dialysis.

Similarly there was no significant difference in the rates of renal transplant in each diabetes group (0.9% v 0.8%) or mortality post-transplant.

“In this Australian cohort, those with young-onset type 2 diabetes (YT2DM) had a greater rate of progression to end stage kidney disease (ESKD) than those with type 1 diabetes (YT1DM),” the study authors said.

“Nonetheless, once ESKD was reached, survival on RRT was similarly poor in both groups; the cumulative incidence of mortality was 40% at 6 years irrespective of diabetes type.”

The investigators, led by Dr Timothy Middleton from the RPAH, noted that an association between obesity and CKD has been appreciated for many years.

“However, the presence of obesity during adolescence is particularly concerning. Given the high prevalence of obesity in YT2DM, an increasing demand for RRT can be anticipated over coming decades,” they said.

They noted there has already been a significant  increase in renal transplants in patients with young-onset diabetes.

The study investigators said proactive risk factor management in young adults with diabetes was necessary, although the most appropriate management strategies remained unclear.

“Favourable renal findings observed in cardiovascular outcome trials for SGLT2 inhibitors suggest an emerging role for this class of medications as reno-protective agents.”

“However, applicability of these findings in YT2DM is uncertain; few young adults participated in the relevant trials and current treatment guidelines for youth rely heavily upon data extrapolated from older adult populations.”

Similarly, while RAAS blockade has been shown to be reno-protective in adults, the evidence was lacking in young people, they said.