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.

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-naïve 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.