Effect of Biphasic Insulin Compared to Biphasic Insulin Combined With Insulin Aspart, With or Without Metformin in Type 2 Diabetes

Inclusion Criteria: * Type 2 diabetic subjects * Current treatment with Biphasic Human Insulin 30/70 twice daily alone or in combination with any oral hypoglycaemic agent for at least 3 months prior to entering the trial * HbA1c at least 12% * Willing and able to perform self blood glucose monitoring (SMBG) Exclusion Criteria: * History of drug or alcohol dependence * Receipt of any investigational drug within the last month prior to this trial * Anticipated change in dose of prescription medication, which may influence glucose regulation (Mono Amino Oxidase-inhibitors, non selective beta-adrenergic agents, anabolic steroids and systemic glucocorticoids) * Severe uncontrolled hypertension * Recurrent severe hypoglycemia as judged by investigator * Any disease or condition, which the Investigator feels, would interfere with the trial