NEW YORK (Reuters Health) – Depending on the particular regimen, insulin analogs can help 35% to 64% of patients with type 2 diabetes achieve the recommended hemoglobin A1C target of < 7%, researchers found in a meta-analysis of 16 relevant randomized controlled trials. Basically, the analysis found that basal insulin analogs get fewer patients to target A1C than prandial or biphasic insulin analogs, but they are associated with less hypoglycemia and weight gain, compared with biphasic insulin. “The best achievement rate is obtained with a basal-bolus regimen compared with biphasic insulin, without further risk of hypoglycemia or weight gain,” report Dr. Dario Giugliano, from Second University of Naples in Italy and colleagues report in the January 7 online issue of Diabetes Care. So which regimen is best? “Of course, this question is paramount, but the answer is, it depends,” Dr. Giugliano noted in an e-mail to Reuters Health. “There seems to be no ‘a priori’ insulin regimen that fits all diabetic patients. Physicians must look tor the best insulin regimen for that particular patient, in that particular stage of the disease, with the lowest risk of hypoglycemia,” the clinician advised. Insulin analogs are increasingly being used in people with type 2 diabetes who fail to reach target A1C through diet, exercise and oral drugs (metformin). Dr. Giugliano and colleagues identified 16 randomized controlled trials in which comparisons were made between different insulin analog regimens in a total of 7,759 patients with type 2 diabetes. Most trials were multinational and industry-sponsored. All were open-label in design and lasted between 3 and 36 months. As a group, the patients had a mean age of 58.2 years and a median A1C level of 8.6%. The researchers report that the likelihood of achieving the A1C goal of < 7% was greater with both biphasic and prandial insulin (odds ratios 1.88 and 2.07, respectively), compared with basal insulin. For biphasic insulin, this was associated with greater hypoglycemia (mean difference of 0.34 events per patient per 30 days) and weight gain. The authors emphasize, however, that the overall median incidence of hypoglycemia across all the comparisons was generally low, at 0.4 events per patient per 30 days, and weight gain was limited to 1 kg and 1.94 kg, for biphasic and prandial insulin, respectively. No difference in weight gain was found between biphasic versus prandial insulin or biphasic versus basal-bolus insulin. Compared with biphasic insulin, the basal-bolus regimen was associated with a greater likelihood of reaching the A1C goal (odds ratio, 1.75), with no greater hypoglycemia or weight gain. In absolute terms, the researchers say the basal-bolus regimen was best for reaching the A1C goal, with 63.5% of patients on this regimen achieving hemoglobin A1C < 7%. The analysis has limitations, the authors note, including a high degree of heterogeneity for some comparisons. Still, in most cases, they say the results were “qualitatively similar” across studies, in terms of the direction of the results, and sensitivity analysis eliminated heterogeneity in most cases. There was no evidence of publication bias. They also note that most of the studies analyzed had a short follow-up, so firm conclusions cannot be drawn about the long-term comparative effectiveness of the various regimens. “More studies are needed to understand better the effect of insulin analogs on long-term diabetes complications,” they add. Reference:
Efficacy of Insulin Analogs in Achieving the Hemoglobin A1C Target of <7% in Type 2 Diabetes

Diabetes Care, Published online January 7, 2011.