Loss of glycemic control in patients with type 2 diabetes mellitus who were receiving initial metformin, sulfonylurea, or thiazolidinedione monotherapy.
OBJECTIVE
To examine glycosylated hemoglobin (A1C) values longitudinally in patients who newly started metformin, sulfonylurea, or thiazolidinedione monotherapy; in a subset of patients whose A1C values were 7% or greater before starting therapy (baseline) and who achieved A1C goal (A1C < 7%) during therapy, rates of secondary failure (i.e., A1C value returned to > or = 7% during therapy) were compared for each drug.


METHODS
Four-year retrospective analysis.


METHODS
Administrative database from a large health care plan.


METHODS
Patients who filled at least one prescription for metformin (5453 patients), sulfonylurea (2373), and thiazolidinedione (1590) therapy, respectively, between January 1, 2001, and March 31, 2004, were enrolled.


RESULTS
Patients' demographic and clinical characteristics, baseline A1C values, changes in A1C values (last available result during follow-up minus baseline value), and A1C values before and after the addition of an antidiabetic drug other than the index drug (therapy intensification) were documented. Mean age was 50.7 years; 5027 (53.4%) were men. Mean baseline A1C value was 8.4%, and about 70% of patients had an AIC value of 7% or greater before starting therapy. Mean follow-up was 1.9 years, and mean decrease in A1C values was 1.47% (to 6.91%). The probabilities of attaining A1C goals were similar for patients receiving metformin, sulfonylurea, or thiazolidinedione therapy. The rate of therapy intensification among patients taking metformin (24.7%) was lower than that of patients taking a sulfonylurea (30.1%, p<0.001) but similar to that of those taking a thiazolidinedione (24.6%). Secondary failure occurred in 36.3% of patients; mean time from the start of therapy to its failure was about 1.51 years. Patients receiving a sulfonylurea were 1.25 (95% confidence interval [CI] 1.05-1.50) times more likely than patients receiving metformin to experience secondary failure, whereas failure rates were similar for thiazolidinediones and metformin (odds ratio 0.78, 95% CI 0.62-0.99).


CONCLUSIONS
In the subset of patients assessed for secondary failure, although treatment initially reduced A1C values, more than one third experienced failure. Real-world studies of A1C goal attainment must follow patients on a long-term basis to assess the maintenance of glycemic control over time.
Riedel
Aylin A
AA
Department of Health Economics and Outcomes, i3 Innovus, an Ingenix Company, Eden Prairie, Minnesota, USA.
Heien
Herbert
H
Wogen
Jenifer
J
Plauschinat
Craig A
CA
D000284:Administration, Oral; D000328:Adult; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008137:Longitudinal Studies; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D012189:Retrospective Studies; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*; D045162:Thiazolidinediones / Q000627:therapeutic use*; D017211:Treatment Failure
D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D008687:Metformin; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones