• Over 10 years, the average A1C value was 7.0 percent in the intensive-therapy group compared with 7.9 percent in the conventional-therapy group (11 percent reduction) (show figure 1).

• The risk for any diabetes-related end point (see abstract for definition of endpoints [2] ) was 12 percent lower in the intensive-therapy group (P = 0.029) and 10 percent lower for any diabetes-related death (P = 0.34) (show figure 2). It was estimated that 19.6 patients would have to be treated to prevent any single end point in one patient in 10 years.

• Most of the risk reduction in the intensive therapy group was due to a 25 percent risk reduction in microvascular disease (P = 0.001) (show figure 3); there was no reduction in macrovascular disease. (See "Macrovascular disease" below, section on UKPDS).

• The benefits of intensive therapy appeared to be independent of the type of treatment administered.

• Patients in the intensive therapy group had more hypoglycemic episodes and weight gain; weight gain was greater in those receiving insulin (4.0 kg) than in those receiving chlorpropamide (2.6 kg) or glibenclamide (1.7 kg).

The reduction in microvascular complications in patients receiving intensive therapy was of a smaller magnitude than in patients with type 1 diabetes in the DCCT [1] . In the DCCT, for example, the incidence of new retinopathy was 12 percent with intensive therapy versus 54 percent with conventional therapy. One possible explanation for this difference is that the difference in A1C values was smaller between the intensive and conventional therapy groups in the UKPDS (7.0 versus 7.9 percent) compared to the DCCT (7.2 versus 9.1 percent).