Glycaemic levels triggering intensification of therapy in type 2 diabetes in the community: the Fremantle Diabetes Study

Objective: To assess the effectiveness of the management of type 2 diabetes in an urban Australian setting. Design and setting: The Fremantle Diabetes Study (FDS), a community-based longitudinal observational study. Patients: 531 FDS participants with type 2 diabetes, with mean age, 62.4 years (95% Cl, 40.9-79.3 years), 54% male, median diabetes duration 3.0 years (interquartile range [IQR], 0.7-7.0 years), with valid data from the baseline FDS assessment and five subsequent annual reviews between 1993 and 2001. Main outcome measures: Glycated haemoglobin (HbA(1c)) levels at annual review visits before and after change in blood glucose-lowering therapy Results: Over 2893 patient-years of follow-up, 97 patients (18%) progressed from dietary management to therapy with oral hypoglycaemic agents (OHA), and 45 (9%') progressed from OHA to insulin therapy, after a median duration of diabetes of 4.0 years (IQR, 2.9-5.5 years) and 8.1 years (IQR, 5.5-13.0 years), respectively. Median HbA(1c) concentrations (IQR) at the review before OHA or insulin were started were 7.7% (6.9%-8.8%) and 9.4% (8.0%-10.7%), respectively. At the next annual review, HbA(1c) levels in the two groups had fallen to 7.4% (6.5%-8.1%) and 7.9% (7.2%-9.5%), respectively (P <= 0.001). Intensification of therapy was associated with beneficial changes in serum lipid profiles, but not with an increase in frequency of hypoglycaemia. Conclusions: Most Australian patients with type 2 diabetes may be spending most of the duration of their disease with suboptimal glycaemic control (HbA(1c) > 7.0%), despite the availability of a range of effective therapies, including insulin.