β-cell function preservation after 3.5 years of intensive diabetes therapy.
OBJECTIVE
To assess β-cell function preservation after 3.5 years of intensive therapy with insulin plus metformin (INS group) versus triple oral therapy (TOT group) with metformin, glyburide, and pioglitazone.


METHODS
This was a randomized trial of 58 patients with treatment-naïve newly diagnosed type 2 diabetes. All patients were treated with insulin and metformin for a 3-month lead-in period followed by random assignment to the INS or TOT group. β-Cell function was assessed using a mixed-meal challenge test at randomization and 6, 12, 18, 30, and 42 months. Analyses were intention to treat and performed with repeated-measures models.


RESULTS
Completion rates at 3.5 years were 83% in the insulin group and 72% in the TOT group, with good compliance in both groups (87 ± 20% in the INS group vs. 90 ± 15% in the TOT group). β-Cell function was preserved at 3.5 years after diagnosis, with no significant change from baseline or difference between the two groups as measured by area under the curve (AUC) of C-peptide (P = 0.14) or the ratio of C-peptide to glucose AUC (P = 0.7). Excellent glycemic control was maintained in both groups (end-of-study HbA(1c) 6.35 ± 0.84% in the INS group vs. 6.59 ± 1.94% in the TOT group). Weight increased in both groups over time (from 102.2 ± 24.9 kg to 106.2 ± 31.7 kg in the INS group and from 100.9 ± 23.0 kg to 110.5 ± 31.8 kg in the TOT group), with no significant difference between groups (P = 0.35). Hypoglycemic events decreased significantly over time (P = 0.01) but did not differ between groups (P = 0.83).


CONCLUSIONS
β-Cell function can be preserved for at least 3.5 years with early and intensive therapy for type 2 diabetes with either insulin plus metformin or triple oral therapy after an initial 3-month insulin-based treatment period.
Department of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Lindsay B
LB
Harrison
Beverley
B
Adams-Huet
Philip
P
Raskin
Ildiko
I
Lingvay
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005905:Glyburide / Q000008:administration & dosage; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D050417:Insulin-Secreting Cells / Q000502:physiology*; D008297:Male; D008687:Metformin / Q000008:administration & dosage*; D008875:Middle Aged; D010349:Patient Compliance; D000077205:Pioglitazone; D045162:Thiazolidinediones / Q000008:administration & dosage
D001786:Blood Glucose; D005905:Glyburide; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; D000077205:Pioglitazone; D045162:Thiazolidinediones