Combination of oral antidiabetic agents with basal insulin versus premixed insulin alone in randomized elderly patients with type 2 diabetes mellitus

Abstract

Objectives: To compare initiation of insulin therapy by adding once-daily insulin glargine to oral antidiabetic agents (OADs) with switching patients to premixed 30% regular, 70% human neutral protamine hagedorn insulin (70/30) without OADs.

Design: A 24-week, multicenter, open, randomized (1:1), parallel study.

Setting: Three hundred sixty-four poorly controlled patients with type 2 diabetes mellitus were treated with once-daily morning insulin glargine with continued OADs (glimepiride+metformin) (glargine+OAD) or twice-daily 70/30 alone. Insulin dosage in each group was titrated to target fasting blood glucose (FBG) of 100 mg/dL or less (<or=5.6 mmol/L) using a weekly titration algorithm.

Participants: This planned subgroup analysis of the original study was based on 130 insulin-naive patients aged 65 and older with FBG of 120 mg/dL or greater (>or=6.7 mmol/L) and hemoglobin (Hb)A(1c) levels between 7.5% and 10.5% on OADs (glargine+OAD, n=67; 70/30, n=63).

Measurements: HbA(1c), FBG, hypoglycemia, insulin dose, and adverse events were recorded.

Results: HbA(1c) decreased from baseline to endpoint for both glargine+OAD (from 8.8% to 7.0%) and 70/30 (from 8.9% to 7.4%); adjusted mean HbA(1c) decrease for glargine+OAD and 70/30 was -1.9% and -1.4%, respectively (P=.003). More patients reached HbA(1c) of 7.0% or less without confirmed nocturnal hypoglycemia with glargine+OAD (n=37, 55.2%) than with 70/30 (n=19, 30.2%) (P=.006). FBG decreased significantly more with glargine+OAD (-57 mg/dL (-3.2 mmol/L)) than with 70/30 (-40 mg/dL (-2.2 mmol/L)) (P=.002). Patients treated with glargine+OAD experienced fewer episodes of any hypoglycemia (3.68/patient-year) than did those treated with 70/30 (9.09/patient-year) (P=.008).

Conclusion: In elderly patients, addition of once-daily morning glargine+OAD is a simple regimen to initiate insulin therapy, restoring glycemic control more effectively and with less hypoglycemia than twice-daily 70/30 alone.