Improved survival among patients with complicated type 2 diabetes in Denmark: a prospective study (2002-2010)

CONTEXT: It is unclear to what extent recent advances in diabetes care have reduced the excess mortality in patients with complicated type 2 diabetes.

OBJECTIVE: The aim of this study was to estimate time trends in mortality among patients with complicated type 2 diabetes at the Steno Diabetes Center relative to the general Danish background population. DESIGN, SETTING, AND STUDY PARTICIPANTS: We performed a longitudinal follow-up study from 2002 to 2010 of 5844 patients with type 2 diabetes at the Steno Diabetes Center, Denmark. All-cause and cause-specific mortality was identified from the national death register.

MAIN OUTCOME MEASURES: Poisson regression was used to model mortality rates by sex, age, age of diabetes onset, and calendar time.

RESULTS: A total of 1341 deaths occurred (802 men and 539 women) during 32,913 person-years of follow-up. Total mortality rates in the diabetes population decreased by 5.5% (95% confidence interval 2.9%-8.0%) per year in men and by 3.3% (0.0%-6.4%) per year in women. Among men but not women, this decline was significantly steeper than the decline in mortality in the Danish background population (men, -3.0% [-5.6% to -0.4%]; women, -1.4 [-4.6% to 2.0%]). The decline in overall mortality was explained by a decline in cardiovascular mortality for both men and women.

CONCLUSION: Overall and cardiovascular mortality have decreased during the last decade among Danish patients with complicated type 2 diabetes, and for men, the decline in mortality was more pronounced than in the general population.