Research suggests that reducing insulin resistance may slow or stop the progression to full-blown type 2 diabetes in people at high risk for developing the disease. People with chronic insulin resistance develop type 2 diabetes when they do not produce enough insulin to match metabolic requirements.
The findings were presented at the 61st Scientific Sessions of the American Diabetes Association in Philadelphia, Pennsylvania.
Thomas A. Buchanan, MD, and colleagues presented data from the Troglitazone in Prevention of Diabetes (TRIPOD) study. The trial looked at whether treatment with the insulin sensitizer troglitazone (400mg/day) could slow the progression to type 2 diabetes in a group of women with a recent history of gestational diabetes.
After a median of 30 months, the incidence of type 2 diabetes was significantly lower in troglitazone-treated patients compared with those who received a placebo (5.4% vs 12.3%).
After examining the data further, researchers also found that about one-third of the patients in the troglitazone group did not show an increase in insulin sensitivity with treatment, and these patients developed type 2 diabetes at the same rate as that of the placebo-treated group. In contrast, of the patients who experienced the largest decrease in insulin levels with the drug, none developed type 2 diabetes.
Patients in the troglitazone group who exhibited an increase in insulin sensitivity were further evaluated to determine if this protective effect persisted after the treatment ended. Of patients who completed the study and did not develop diabetes, 27 of 55 were reevaluated 8 months after stopping troglitazone.
Based on the risk factors and initial metabolic characteristics of the women in the treatment group, the investigators had predicted that 10 patients would exhibit type 2 diabetes after stopping the drug. However, at 8 months only 1 patient developed type 2 diabetes, despite the fact that insulin sensitivity returned to pre-study levels. Additional follow-up of these patients is ongoing.
The first nationwide type 2 diabetes prevention study, the Diabetes Prevention Program (DPP), was launched in 1996 and met its recruitment goals in June 1999. The trial, sponsored by the National Institutes of Health, randomized 3819 patients with impaired glucose tolerance to either an intense regimen of diet and exercise, metformin, or placebo to determine whether diabetes is delayed or prevented in the intervention groups. Each participant will be observed for at least 3 years and up to 6 years.
Article By: Ann Contijoch, PhD