Objective: This study was undertaken to assess glycaemic control as well as changes in glycaemic control over time in patients with type 2 diabetes mellitus (T2DM) who added a sulphonylurea (SU) or thiazolidinedione (TZD) to their metformin monotherapy in typical treatment settings within seven European countries.
Methods: An observational, cross-sectional multicentre study with retrospective medical chart review was conducted in Finland, France, Germany, Norway, Poland, Spain and UK. T2DM patients who added a SU or a TZD to metformin monotherapy between January 2001 and January 2006 (i.e. index date) and who had > or = 1 haemoglobin A1C (HbA1C) measurement within 12 months before the visit date, which occurred from June 2006 to February 2007, were included in the study. Demographic and clinical data were collected from medical records. The main study outcome measure was the proportion of patients with adequate glycaemic control (defined according to the International Diabetes Federation as HbA1C < 6.5%) using the most recent HbA1C measurement before the visit date. In addition, patients were grouped based upon the interval from the index date to the most recent HbA1C measurement to evaluate goal attainment and treatment changes over time.
Findings: In this European cohort of 2023 T2DM patients on metformin and either an SU or a TZD (mean age = 60.4 years), 25.5% of patients had adequate glycaemic control. The average HbA1C level was 7.2% after a mean of 2.6 years of treatment with combination oral antihyperglycaemic agent (AHA) therapy. Among the patients (n = 227) with most recent HbA1C measurement within 1 year after first adding an SU or a TZD, 27% had adequate glycaemic control (HbA1C < 6.5%), with a mean (s.d.) HbA1C of 7.1% (1.0); 1.3% of these patients were using some type of insulin therapy. Among the patients (n = 176) with most recent HbA1C measurement occurring > or = 5 years after adding an SU or a TZD, 20% had adequate glycaemic control, with a mean (s.d.) HbA1C of 7.4% (1.17), and 29.6% of these patients were using insulin. Overall, patients with (vs. without) adequate glycaemic control had significantly (p < 0.05) lower HbA1C levels (7.6 vs. 8.2%) at the time of adding an SU or a TZD to ongoing metformin monotherapy, were less likely to report a history of macrovascular complications (20 vs. 26%) and were more often engaged in physical activity three to five times a week (29 vs. 23%).
Conclusions: Approximately one quarter of European out-patients with T2DM had adequate glycaemic control after a mean of 2.6 years following initiation of combination AHA therapy. Overall glycaemic control modestly declined over time, even though more patients were being treated with insulin. These findings highlight the progressive nature of the disease and need for more effective disease management/therapeutic alternatives.