Effect of screening for type 2 diabetes on risk of cardiovascular disease and mortality: a controlled trial among 139,075 individuals diagnosed with diabetes in Denmark between 2001 and 2009

Abstract

Aims/hypothesis There is continuing debate about the net benefits of population screening for type 2 diabetes. We compared the risk of cardiovascular disease (CVD) and mortality among incident cases of type 2 diabetes in a screened group with those in an unscreened group. Methods In this register-based non-randomised controlled trial, eligible individuals were all men and women aged 40-69 years without known diabetes, registered with a general practice in Denmark (n = 1,912,392). Conclusions/interpretation A single round of diabetes screening and cardiovascular risk assessment in middle-aged Danish adults in general practice was associated with a significant reduction in risk of all-cause mortality and CVD events in those diagnosed with diabetes.

Effect of population screening for type 2 diabetes and cardiovascular risk factors on mortality rate and cardiovascular events: a controlled trial among 1,912,392 Danish adults

“…The possibility also remains that screening for diabetes and CVD risk factors followed by multifactorial treatment may have effects on microvascular and other morbidity not evaluated in this study. Furthermore, in a separate paper comparing the mortality rate and cardiovascular outcomes in individuals with incident diabetes in the screened group with those from the unscreened group, we show significant benefits for those diagnosed with diabetes in the screening practices [34]. Thus, while screening for diabetes and CVD risk factors may not have an impact at the population level, it appears to have benefits for the small subgroup found to have undiagnosed prevalent diabetes.…”

Does the evidence support population-wide screening for type 2 diabetes? No

“…In the second paper [11], Simmons and colleagues compared the mortality and non-fatal CVD outcomes of those newly diagnosed with diabetes in the practices included in the ADDITION screening programme (including individuals identified through the screening programme as well as those identified through standard clinical procedures) with those who were diagnosed through usual processes in the rest of Denmark. The main finding is that people who were identified with diabetes in the screening practices had 21% and 16% lower mortality and CVD rates, respectively, compared with people diagnosed with diabetes in the rest of the country.…”

Should we screen for type 2 diabetes among asymptomatic individuals? Yes

“…The studies were both part of the ADDITION-Europe study, but this time from the Danish limb (ADDITION-Denmark). One of these studies shows no reduction in mortality rate in participants in the screening programme vs the general Danish population [7], while the other [8] [9] among those who were screened and had their diabetes diagnosed early. What are we to make of these discordant findings?…”

“…Simmons et al have now presented two additional controlled studies in this issue of Diabetologia, which investigated whether screening for type 2 diabetes, in asymptomatic individuals, is associated with a reduction in mortality [7,8]. The studies were both part of the ADDITION-Europe study, but this time from the Danish limb (ADDITION-Denmark).…”