In patients diagnosed through screening in general practice, intervention to promote early intensive management of patients with type 2 diabetes was associated with only a small, nonsignificant reduction in the incidence of cardiovascular events and death, based on the ADDITION-Europe study published June 25 in the Lancet.
In a pragmatic, cluster-randomized, parallel-group trial conducted in Denmark, the Netherlands and the U.K., 343 general practices were randomly assigned screening of registered patients without known diabetes followed by routine care of diabetes or screening followed by intensive treatment of multiple risk factors.
Simon J. Griffin, MD, of the University of Cambridge, England, and colleagues analyzed data from 3,055 patients with type 2 diabetes (1,377 in usual care arm, 1,678 in intensive treatment arm) with mean age 60 years.
The primary endpoint was first cardiovascular event, including cardiovascular mortality and morbidity, revascularization and non-traumatic amputation within five years. Patients and staff assessing outcomes were unaware of the practice’s study group assignment.
The incidence of first cardiovascular event was 7.2 percent in the intensive treatment group and 8.5 percent in the routine care group and of all-cause mortality was 6.2 percent and 6.7 percent, respectively. But these findings were not statistically significant.
“When compared with routine care, an intervention to promote target-driven, intensive management of patients with type 2 diabetes detected by screening was associated with small increases in the prescription of drugs and improvements in cardiovascular risk factors, but was not associated with significant reductions in the incidence of cardiovascular events or death over five years,” the authors wrote. “The extent to which the complications of diabetes can be reduced by earlier detection and treatment remains uncertain."
Griffin and colleagues also noted that the differences between study groups for all components of the primary endpoint favored the intensive treatment group. Differences were greatest for MI and smallest for stroke. Yet, they added: “we cannot rule out the possibility that these findings were due to chance. … The generalisability of our findings to other settings should be considered in light of the non-random recruitment of general practices.”
In an accompanying Lancet commentary, David Preiss, MD, and Naveed Sattar, PhD, MD, of the British Heart Foundation and Glasgow Cardiovascular Research Centre at the University of Glasgow, Scotland, wrote that recommendations produced in the last five to seven years for routine prescribing of statins to lower cholesterol and blood pressure-lowering drugs in usual care for diabetes has limited the potential of more intensive treatment to deliver additional differences in outcomes in this patient group.
“The key questions now are whether a sizeable reduction in the lead time between diabetes onset and clinical diagnosis can be achieved by implementation of simpler diagnostic criteria (ie, HbA1c) and, if so, to what extent this development might further reduce cardiovascular and mortality risks in patients with diabetes,” Preiss and Sattar concluded.