Efficacy and tolerability of self-titrated biphasic insulin aspart 70/30 in patients aged >65 years with type 2 diabetes: an exploratory post hoc subanalysis of the INITIATEplus trial.

Author(s): Oyer DS, Shepherd MD, Coulter FC, Bhargava A, Deluzio AJ, Chu PL, Trippe BS

Affiliation(s): Associates in Internal Medicine, Chicago, Illinois 60611, USA. d-oyer@northwestern.edu

Publication date & source: 2011-07, Clin Ther., 33(7):874-83. Epub 2011 Jul 8.

BACKGROUND: The Initiation of Insulin to reach A1C Target (INITIATEplus) trial studied the effect of self-titrating biphasic insulin aspart 70/30 (BiAsp 30) twice daily during 24 weeks in insulin-naive patients with type 2 diabetes who were poorly controlled by oral medication, and originally randomized according to frequency of dietary counseling interventions. OBJECTIVE: The purpose of this study was to compare the efficacy and tolerability of biphasic insulin aspart 70/30 (BIAsp 30, NovoLog Mix 70/30) in INITIATEplus patients </=65 versus >65 years old, irrespective of dietary counseling frequency, and to test the hypothesis that self-titrating BIAsp 30 in patients >65 years old could be well-tolerated and effective in this age group. METHODS: An exploratory post hoc subanalysis, using standard statistical methods, was performed on patients stratified according to age. Data collected from 3492 patients in the intent-to-treat population who were </=65 years old and 716 patients who were >65 years old compared glycosylated hemoglobin (HbA(1c)) and plasma glucose changes from baseline. Hypoglycemia rates and adverse event (AE) incidence were compared for the tolerability population of 4007 patients </=65 years old and 805 patients >65 years old. RESULTS: Baseline-adjusted HbA(1c) changes for patients </=65 versus >65 years old were -2.38% versus -2.73% (P < 0.0001), with final HbA(1c) achieving 7.55% and 7.06%, respectively. Thirty-nine percent of patients </=65 years old achieved HbA(1c) </=7% compared with 51% of patients >65 years old. Baseline-adjusted fasting plasma glucose decreases were greater for the >65 year old population (85.2 vs 91.2 mg/dL; P = 0.004; </=65 vs >65 years old, respectively). Minor hypoglycemia was reported in 9.7% and 7.7% of patients </=65 versus >65 years old, respectively (0.52 vs 0.41 episodes per patient per year [ppy]; P = 0.01). Major hypoglycemia occurred in 1.5% and 3.1% of patients (0.05 vs 0.14 episodes ppy, </=65 vs >65 years old, respectively; P < 0.0001). Nocturnal major hypoglycemia was reported for 0.4% and 0.6% of patients (P = 0.0028), whereas nocturnal minor hypoglycemia was reported for 3.8% and 2.6% (P = 0.007) of patients </=65 and >65 years old, respectively. AEs were reported for 24% and 28% of patients </=65 and >65 years old, respectively, serious AEs were reported for 4% and 9% of patients, respectively, and AE-related withdrawals were reported for 1.3% and 2% of patients, respectively. CONCLUSIONS: Self-titrated biphasic insulin aspart 70/30 was found to be well-tolerated and effective in type 2 diabetes patients >65 years old, as well as in patients </=65 years old. HbA(1c) and fasting plasma glucose decreases were significantly (P < 0.05) higher for patients >65 years old versus patients </=65 years old. Tolerability was indicated by major and minor hypoglycemia rates at or below <0.5 episodes ppy in both age groups. Overall rates of AE and serious AEs were higher among patients > 65 years; withdrawals related to AEs were 2% compared with 1.3% in the younger age group. Copyright (c) 2011 Elsevier HS Journals, Inc. All rights reserved.