Early diabetes diagnosis linked to higher risk of death

While type 2 diabetes (T2D) was once considered a disease largely confined to older people, the global epidemic of obesity and overweight has seen diagnoses rocket in young adults, adolescents and even appear in young children. New research published in Diabetologia shows that the earlier a person is diagnosed with T2D, the higher their risk of death from heart disease and stroke, but, unusually, the lower their risk of death from cancer.

In almost all countries of the world, diabetes rates are increasing substantially in younger adults, aged 20-45 years. Rates are also continuing to increase in adults over 45 years old, however not as sharply as in younger adults. The increase in the younger adults means there is a steadily growing pool of diabetes patients who are exposed to diabetes for a longer period in their lives.

The study by Professor Dianna Magliano and Professor Jonathan Shaw (Baker Heart and Diabetes Institute, Melbourne, Australia) and colleagues analysed the data of 743,709 Australians with T2D who were registered on Australia's National Diabetes Services Scheme (NDSS) over a 15-year period between 1997 and 2011. All-cause mortality and mortality due to cardiovascular disease (CVD), cancer and all other causes were identified.

The average (median) age at T2D diagnosis was 59 years, and a total of 115,363 deaths occurred during the study period. The authors say: "An earlier diagnosis of type 2 diabetes — and thus a longer duration of disease — was associated with a higher risk of all-cause mortality, primarily driven by cardiovascular disease (CVD) mortality."

The data showed that for two people of the same age, the one with a 10-year earlier diagnosis (equivalent to 10 years' longer duration of diabetes) had a 20% to 30% increased risk of all-cause mortality and about a 60% increased risk of CVD mortality.

The authors say: "Evidence is accumulating to suggest that earlier onset of type 2 diabetes is associated with an increased risk of complications and comorbidities compared with later onset, and that the development and progression of complications might be more aggressive in those with earlier onset."