Adults with type 2 diabetes have a 15% greater risk for death from any cause compared to the general population, which is a historically low level, according to a nationwide study involving more than 400,000 persons with type 2 diabetes in Sweden and more than 2 million matched controls. The risk of death varied considerably among patient subgroups, with a notably increased risk of death among patients younger than 55 years of age with type 2 diabetes, researchers reported in a recent issue of the New England Journal of Medicine.
The study included 435,369 patients with type 2 diabetes enrolled in the Swedish National Diabetes Register. Each was matched to 5 randomly selected controls (n=2,117,483) who were matched by age, sex, and country. The mean follow-up was 4.6 for the diabetes group and 4.8 years for the control group.
Overall, the death rate was higher among people with diabetes than among controls (17.7% versus 14.5%; adjusted hazard ratio [aHR], 1.15). The researchers suggested that the relatively low mortality rate in the diabetes group may be related to the more common use of statins and blood-pressure medications among patients with diabetes. Improvements in glycemic control over time were also noted.
Cardiovascular disease and diabetes-related conditions were major contributors to the excess risk of death among people with diabetes, whereas cancer had a relatively small effect. The rate of cardiovascular death was 7.9% in the diabetes group versus 6.1% among the control group (aHR, 1.14).
The excess risk of death from any cause and cardiovascular death among patients with diabetes was associated with worse glycemic control, severe renal complications, impaired renal function, and younger age.
Impact of Younger Age on Mortality Risk
Among patients with diabetes age 75 years or older, the overall risk of death approached that found in the general population (aHR, 1.03). However, the excess risk increased continuously among younger age groups (Table).
Interestingly, patients 65 to 74 years of age with normoalbuminuria and a glycated hemoglobin level of 6.9% or less had a risk that was lower than that among controls. The risk was also lower among patients 75 years of age or older with a glycated hemoglobin level of 7.8% or less than among controls, but the risk was substantially higher among patients younger than 55 years of age than among controls, despite a glycated hemoglobin level in the target range and normoalbuminuria.
Tancredi M, Rosengren A, Svensson AM, et al. Excess mortality among persons with type 2 diabetes. N Engl J Med. 2015;373(18):1720-1732.