Hitting targets reduced deaths and heart problems – but not by much

by Michael O’Leary
Early, intensive treatment of type-2 diabetes that targets multiple health factors such as high blood pressure and cholesterol reduced the number of people who had heart attacks and died but the difference was not large enough to be convincing, researchers say.

The ADDITION study is a collaboration of doctors in the United Kingdom, the Netherlands and Denmark. It started with screening for type-2 diabetes followed by a treatment phase comparing the results of usual treatment for the disease to that of rigorously treating patients in order to achieve strict targets for blood sugar, blood pressure and cholesterol levels. (Link to published site)

Five-year follow-up results were presented by Dr. Simon Griffin, of Cambridge University, England, at the annual scientific sessions of the American Diabetes Association and simultaneously published online June 25 in the Lancet (2011 June 25 ).

The study design was a bit unusual in that it didn’t compare patients treated with routine care versus patients treated with the more aggressive approach. Instead they compared the outcomes of patients randomly assigned to family practice doctors. In 157 practices with eligible patients treatment followed the current guidelines for managing type-2 diabetes. In 161 family practices the doctors underwent a special education program that emphasized aggressively managing patients’ treatments in order to achieve strict targets. Altogether there were 1,285 patients in the routine care group who completed the five years of follow-up compared to 1,574 patients in the intensive treatment group.

The intensive treatment involved adding medications such as aspirin or ACE inhibitors for high blood pressure, and statins for cholesterol, together with advice about diet and exercise until patients met targets of less than 7 percent for HbA2, blood pressure less than 135/85 mm Hg and LDL cholesterol of less than 5.0 mmol/L. It should be noted that the aggressive intervention did not prescribe a program of diet and exercise, it only advised patients to follow such a program.

The primary result they measured was the total or composite number of heart-related events, including deaths from heart disease, non-fatal heart attacks, non-fatal stroke, procedures to open narrowed arteries, and non-traumatic amputation that occurred within five years of starting the study.

Of the 196 patients in both groups that died, 60 patients (30.6 percent) died of cardiovascular causes. When they compared the total deaths of each group they found that the intensive treatment group had about a 9 percent lower risk of death from all causes compared to the routine care group. The composite of heart-related events occurred in 8.5 percent of the routine care group, compared to 7.2 percent of the intensive care group.

When they looked at the target levels of blood sugar, high blood pressure and cholesterol, they found both groups achieved average values below the targets, but there was greater improvement in the intensive care group. Unfortunately, the difference was not enough to be considered statistically significant.

In an editorial comment about the trial appearing in Internal Medicine News, Dr. Naveed Sattar of the British Heart Foundation, noted that the small difference between the two groups might be due a case of the guidelines for routine care catching up with the research. The guidelines changed during the study resulting in primary care doctors treating type-2 diabetes more intensively.

“Unforeseen changes to national guidelines during the trial meant that by the end of ADDITION-Europe, the treatment groups were similar in terms of allocated treatments such as statins and had similar prevalence of glycemia and cardiovascular risk factors. As a result, achieving the target of a 30 percent reduction in cardiovascular events with intensive therapy became unlikely.”