ADDITION - geen voordeel van intensieve zorg DM type 2

Results from the ADDITION study (presented during the EASD Congress in Stockholm, Sweden) show no advantage of intensive versus routine care for the prevention of cardiovascular (CV) events in Type 2 diabetes.

The Anglo-Danish-Dutch Study in General Practice of Intensive Treatment and Complication Prevention in Type 2 Diabetic Patients Identified by Screening (ADDITION) was carried out in the UK, The Netherlands, and Denmark.The study assessed the impact of intensive versus routine care on the primary composite CV outcome of CV death, myocardial infarction (MI), stroke, revascularization, and non-traumatic amputation.

A total of 12,219 suitable patients, aged 40-69 years, underwent an oral glucose tolerance test and 3057 were subsequently diagnosed with Type 2 diabetes. Of these, 1379 patients were included in the routine care arm and 1678 patients in the intensive care arm. The mean follow-up time was 5.3 years.

Routine care followed the national guidelines of the country of residence, and changed accordingly over time. In the routine care arm, target levels for systolic blood pressure (SBP), total cholesterol, and glycated hemoglobin (HbA1c) at baseline (ie, in 2001) were below 140-155 mmHg, 5.0-6.0 mmol/l (193-232 mg/dl) and 6.5-7.0%, respectively.The intensive care arm aimed for corresponding targets below 120 mmHg, 3.5 mmol/l (135 mg/dl), and 6.5%.

Simon Griffin (University of Cambridge, UK), who presented the results at the European Association for the Study of Diabetes 46th Annual Meeting in Stockholm, Sweden, reported that 8.5% of patients in the routine arm versus 7.2% of patients in the intensive care arm experienced the primary endpoint. Although the intensive care group had a 17% reduced relative risk (RR) for experiencing the composite primary endpoint, this was not statistically significant.

The RRs for CV death, nonfatal MI, and revascularization were 12%, 30% and 21% lower in the intensive care arm versus the routine care arm, respectively. But again, these between-group differences were not statistically significant. Nonfatal stroke and all-cause mortality did not differ between the two groups.

Griffin commented that significant improvements in routine care for Type 2 diabetes over the last 10 years could be one explanation for the nonsignificant improvement in primary outcome in the intensive compared with the routine treatment arm.

Regarding previous concerns over possible increased mortality risk in intensively treated patients, Griffin said it was important to point out that "multifactorial intensive treatment, including maintaining an HbA1c at or below 6.5%, was not associated with an increase in risk for mortality" in this study.

"Indeed, the event rates and mortality rates in both groups were lower than expected, and cardiovascular risk factors improved in both groups over the 5 years," he added.