PHILADELPHIA — Adding more than one dose of prandial insulin may not be beneficial for patients who are unable to achieve adequate glycemic control with insulin glargine, according to data presented here at the American Diabetes Association’s 72nd Scientific Sessions.
Researchers have hypothesized that stepwise additions of prandial insulin to basal insulin in patients with type 2 diabetes can lower HbA1c to 7%. However, previous studies have suggested that adding one prandial dose may be just as effective, Matthew C. Riddle, MD, endocrinology and diabetes specialist at Oregon Health and Science University, said during a presentation.
Riddle and colleagues studied subgroups of patients in an arm of the All to Target trial, including 191 participants in their analysis. These participants had an average age of 55 years; average BMI of 32.7; an average HbA1c of 9.4%; were using two to three oral medications; and had been diagnosed with type 2 diabetes for a mean of 9.5 years.
“The idea was to identify which subpopulation and what characteristics lead to the requirement for three injections of insulin,” Riddle said.
Of all patients, 150 completed 60 weeks of the study. The treatment included titrated insulin glargine (Lantus, Sanofi-Aventis) as an addition to oral medication, followed by one prandial dose of insulin glulisine (Apidra, Sanofi-Aventis) if HbA1c levels failed to improve by 12 weeks. If HbA1c was greater than 7% at weeks 24, 36 or 48, researchers intensified treatment up to three doses of insulin glulisine daily.
After 60 weeks or at the last on-treatment observation, 38% of patients were taking insulin glargine alone. Twenty-four percent ended with one, 21% with two and 18% with three doses of additional insulin glulisine. There were no significant differences in age, sex, duration of type 2 diabetes, BMI or oral medication use between these groups at baseline.
However, mean baseline HbA1c differed among groups (P<.01), with patients who ended with insulin glargine alone having the lowest HbA1c (9%) vs. those requiring three additional doses of insulin glulisine (10.4%). Mean HbA1c was also higher in this group at endpoint (6.8% vs. 8.3%; P<.001). Weight gain was similar among the groups, but insulin dose was higher in for patients requiring multiple doses (P<.01).
Those ending with insulin glargine alone or insulin glargine plus one additional dose of prandial insulin comprised 62% of all patients and they achieved average HbA1c levels of 6.8% and 6.9%, respectively, at endpoint. In contrast, those requiring two or more additional doses of insulin glulisine generally failed to achieve HbA1c of 7% or lower.
“We conclude from this that many type 2 diabetic patients with high HbA1c on oral agent therapy alone can restore HbA1c to below 7% with basal insulin alone or with a single injection of prandial insulin. But those who do not attain the target with a single prandial injection pose a therapeutic problem which is not routinely solved by progressing to full basal therapy. We postulate that the high baseline HbA1c is the most obvious predictor for poor outcome and we speculate that both physiologic and behavioral factors may contribute to difficulties of this group,” Riddle said. – by Samantha Costa
For more information:
Riddle MC. Abstract#14-OR. Presented at: the American Diabetes Association’s 72nd Scientific Sessions in Philadelphia, June 8-12.
Disclosure: Dr. Riddle reports receiving consultancy fees and research support from Sanofi-Aventis, Amylin Pharmaceuticals, Eli Lilly and Company; research support from GlaxoSmithKline; and is on the speakers’ bureau for Sanofi-Aventis. Dr. Gao reports employment with BDM Consulting Inc., which receives funding from Sanofi-Aventis. Dr. Vlajnic reports employment with Sanofi-Aventis.