In subjects with type 2 diabetes inadequately controlled with oral antidiabetic agents (OADs), insulin therapy is usually started to improve glycaemic control after failure of diet, exercise and OADs.1 Although there is no standard way to introduce insulin treatment, premixed formulations are a popular option. They offer an altative to basal-bolus therapy and provide basal and prandial coverage with a single injection. Indeed, Koivisto et al2 in 1999 reported that 39% of patients with type 2 diabetes worldwide used premixed insulin as part of their therapeutic regimen. The modem premixed insulins, such as biphasic insulin aspart 30 (BIAsp 30) are most frequently prescribed twice-daily (BID) in clinical Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China (Yang WY)