Metformin/Rosiglitazone Tied to Early Decrease in Diabetes
But subsequent deterioration in insulin resistance and β-cell function similar to placebo
FRIDAY, July 8 (HealthDay News) -- Low-dose metformin/rosiglitazone therapy is associated with an initial delay in development of type 2 diabetes in individuals with impaired glucose tolerance, but it did not affect the worsening insulin resistance and β-cell dysfunction that occurs over time, according to a study published in the July issue of Diabetes Care.
Ravi Retnakaran, M.D., from Mount Sinai Hospital in Toronto, and colleagues evaluated the temporal changes in glycemic control, insulin sensitivity, and β-cell function in 207 participants from the Canadian Normoglycemia Outcome Evaluation trial. Participants from the rosiglitazone/metformin and placebo groups underwent annual oral glucose tolerance testing. The insulin sensitivity and β-cell function were assessed by the Matsuda index and the insulin secretion-sensitivity index-2, respectively.
The researchers found that glycemic parameters and insulin sensitivity showed improvement in patients in the rosiglitazone/metformin group in year one, but they subsequently deteriorated, similar to the placebo group. Generalized estimating equation analysis further indicated that both insulin sensitivity and β-cell function decreased significantly over time and showed no significant time-by-treatment interaction.
"These data suggest that low-dose rosiglitazone/metformin therapy had an early effect that decreased the subsequent development of diabetes during the trial but did not modify the natural history of worsening insulin resistance and β-cell dysfunction over time," the authors write.
Two authors disclosed financial ties to GlaxoSmithKline, which provided the study medication and funded the trial.