Comparison of effects of insulin aspart three times a day versus insulin detemir once a day on oxidative stress in patients with type 2 diabetes.

The main purpose of this study was to investigate whether treatment with long-acting insulin once a day or short-acting insulin three times before each meal daily has a stronger antioxidative effect in patients with type 2 diabetes. These patients had not been treated previously with insulin and were hospitalized for initiation of glycemic control by insulin injection. The patients (n=43) were assigned consecutively and alternately to a group treated with insulin aspart injection three times daily just before each meal and a group treated with insulin detemir injection once daily before bedtime. The results showed that insulin aspart three times a day produced a greater improvement in plasma glucose, and particularly in mean postprandial plasma glucose, compared with insulin detemir once a day (p = 0.0006 for comparison of changes between the two insulin treatments). The amount of insulin needed to approach the target levels of plasma glucose was larger in the insulin aspart group (26.0 ± 10.7 U/day vs. 13.7 ± 4.9 U/day; p < 0.0001). However, only insulin detemir significantly decreased oxidative stress evaluated based on the level of urinary 8-iso-prostaglandin F2α (p = 0.0079), although the mechanisms are not fully evident.