Time trends in mortality rates in type 1 diabetes from 2002 to 2011

Aims/hypothesis

The aim of this study was to estimate absolute and relative mortality rates in patients with type 1 diabetes at the Steno Diabetes Centre relative to the general Danish background population.

Methods

Patients with type 1 diabetes (n?=?4,821) were followed from 1 January 2002 until 1 January 2011, with death from any cause as the main outcome. Poisson regression was used to model mortality rates by age, diabetes duration and calendar time, according to sex.

Results

In the period 2002–2010, a total of 673 deaths (402 men, 271 women) occurred in the study population during 33,847 years of follow-up of type 1 diabetes. The predominant cause of death in patients with type 1 diabetes was cardiovascular disease. Mortality rates were highest among those with the lowest age at onset, particularly men. The mortality rate in the diabetic population decreased over that time period by 6.6% and 4.8% per year in men and women, respectively; this was substantially greater than the decrease in mortality rates in the background population. The decline in standard mortality rate was 4.3% per year in men and 2.6% per year in women. Patients who did not develop nephropathy had only slightly elevated mortality rates compared with the background population.

Conclusions/interpretation

Despite advances in care, mortality rates in the past decade continue to be greater in patients with type 1 diabetes than in those without diabetes; however, the mortality rate in patients decreased over the study period faster than that of the background population. Nephropathy seems to be the main driver of the excess mortality.