ADA: Intensive Therapy Yields Negligible Benefits in Type 2 Diabetes

In patients diagnosed with type 2 diabetes through screening in general practice, intensive multifactorial treatment improved cardiovascular risk factors, compared with usual care, new findings suggest, but those improvements were very small.…

There was only a trend toward a reduction in mortality and cardiovascular events (including heart attack, stroke, and amputation) in intensively treated patients. The differences between usual and intensive care were not statistically significant, reported principal investigator Simon J. Griffin, DM, from the Medical Research Council Epidemiology Unit, Institute of Metabolic Science, in Cambridge, United Kingdom. 

Findings from the ADDITION-Europe study were reported at a press briefing held to coincide with the American Diabetes Association (ADA) 71st Scientific Sessions; they were published online simultaneously in The Lancet. 

According to the researchers, many “patients already have evidence of diabetic complications and potentially modifiable cardiovascular risk factors at the time of diagnosis,” and screening is considered to be an efficient use of resources in diabetes. 

The objective of this study was to evaluate whether early intensive multifactorial treatment might improve outcomes, compared with usual care, if initiated soon after detection, by screening and before clinical diagnosis. 

The study consisted of 3055 patients (mean age, 60 years) found to have type 2 diabetes on screening; 1377 received usual care and 1678 received intensive treatment. Intensive treatment consisted of usual care plus additional target- and guideline-driven management of hyperglycemia, blood pressure, and cholesterol levels by medical treatment, and the promotion of healthy lifestyles, based on the stepwise regimen used in the Steno-2 and other trials. 

The study was conducted in Denmark, the Netherlands, and the United Kingdom. The same approach was used at all centers, although family physicians and patients made the final decisions about prescriptions and choice of individual treatments. 

Patients were followed for a mean of 5.3 years. Intensive treatment was associated with slightly, but significantly, increased prescription of treatments and improvements in cardiovascular risk factors (blood pressure and levels of cholesterol and glycosylated hemoglobin [HbA_1c]). 

The relative reduction in the incidence of first cardiovascular event was lower with usual care than with intensive care, indicating only a nonsignificant trend toward a reduction. Likewise, the incidence of all-cause mortality was lower with usual care, but the difference was not significant. 

“Although there is no evidence of harm associated with screening and intensive therapy, the extent to which the complications of diabetes can be reduced by earlier detection and treatment remains unclear,” Dr. Griffin and colleagues note. “Differences were greatest for myocardial infarction and smallest for stroke,” they add. 

During the first 2 to 3 years of follow-up, “the event rate was almost the same between the 2 groups, and then the differences started to magnify,” said Torsten Lauritzen, MD, from the Department of General Practice, School of Public Health, Aarhus University, in Denmark, during the press briefing. “We are going to follow the patients for another 5 years. Hopefully we will see an increasing difference between the 2 groups.”  

“One thing that strikes me about this study is how well the routine care group were treated,” said Sue Kirkman, MD, senior vice president of the ADA, in Alexandria, Virginia, during the press conference. “The fact that you didn’t see a significant difference might be because the routine care patients had excellent care, which would have minimized the difference between the 2 groups,” she said. 

In a related comment, David Preiss, MRCP, and Naveed Sattar, MD, from the British Heart Foundation and the Glasgow Cardiovascular Research Centre at the University of Glasgow, United Kingdom, noted that the lipid-lowering and antihypertensive therapies now used in the standard care of patients with type 2 diabetes might have diminished the apparent benefit of intensive therapy observed in ADDITION-Europe. 

“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 (i.e., HbA_1c) and, if so, to what extent this development might further reduce cardiovascular and mortality risks in patients with diabetes,” Drs. Preiss and Sattar note.

American Diabetes Association (ADA) 71st Scientific Sessions: Presented June 24, 2011.