Intensive insulin treatment prolonged life in diabetic patients after a heart attack by more than 2 years, according to researchers from the Karolinska Institute in Stockholm, Sweden.
The Diabetes Mellitus Insulin Glucose Infusion in Acute Myocardial Infarction (DIGAMI 1) trial began in 1990 and involved 620 patients.
As part of the trial, heart attack patients received either intensive insulin treatment or standard glucose-lowering treatment. The patients who were administered standard treatment only rarely received insulin, whereas those receiving the intensive treatment had an insulin-glucose infusion for at least 24 hours, followed by an injection of insulin four times a day for at least 3 months.
The researchers behind DIGAMI 1 - the results of which are published in The Lancet Diabetes & Endocrinology - were interested in seeing if the difference in treatment affected patients' mortality in the long term.
Many of the participants in the study died over the course of the 20-year follow-up. But the researchers found that patients who received the intensified insulin treatment lived for an average of 2-3 years longer than patients who had the standard treatment - an improvement in survival of almost 50%.
The study observes that patients who were less than 70 years old, and who had no previous history of heart problems or experience of insulin therapy when the trial started, seemed to benefit the most from the intensive insulin treatment. In these patients, survival was prolonged from 6.9 years after their heart attack to 9.4 years.
Despite the increased benefits to these "low cardiovascular risk" patients, however, the intensified insulin treatment did not improve the outcomes of patients at high cardiovascular risk who had no previous experience of insulin therapy. High cardiovascular risk patients were defined as having previously had a heart attack and being older than 70.
Advances in other treatments 'have improved outcomes for heart complications'
Since DIGAMI 1 began in 1990, there have been many advances in treatment options available for people with type 2 diabetes who have heart problems. These advances include the frequent use of statins to lower cholesterol and angiotensin-converting enzyme (ACE) inhibitors to control blood pressure.
If DIGAMI 1 had begun today, the life-extending benefit of the intensive insulin treatment would seem less, because other treatments have already improved outcomes for diabetic patients with cardiovascular complications.
The authors point out, therefore, that if DIGAMI 1 had begun today, the life-extending benefit of the intensive insulin treatment would seem less, because these other treatments have already improved outcomes for diabetes patients with cardiovascular complications.
In a linked comment, Denise Bonds, of the National Institutes of Health, Bethesda, MD, writes that the new study:
"[...] provides an important reminder of how quickly medicine is advancing, something that is often forgotten in the busy day-to-day practice of medicine. In 20 years, we have gone from few glucose-lowering therapies to over half a dozen oral therapy drugs, plus insulin, plus effective treatments to reduce the risk of elevated lipids and blood pressure. Now, the challenge is choosing the best treatment option for our patients."
Recently, Medical News Today reported on research from the Centers for Disease Control and Prevention (CDC) that showed the five major complications related to diabetes - heart attack, stroke, kidney failure, lower-limb amputation and deaths from high blood sugar - have declined in the US over the last 20 years.
Despite this decline in diabetes-related complications, the same period has seen a rise in diabetes prevalence from 6.5 million adult Americans in 1990 to more than 20 million in 2000.