The management of diabetes mellitus involves patient education and dietary modifications, both of which play a key role in determining the success of therapy. Other therapeutic measures include oral hypoglycaemic agents and insulin. In type II diabetic patients not responding to diet alone the second-generation sulphonylureas are preferred. Biguanides are indicated in the very obese type II diabetic, provided there are no contraindications. Where insulin therapy is indicated (e.g. type 1 diabetes mellitus), the trend is to use a human preparation because it evokes a very weak antibody response. Optimal diabetes control, as gauged by home blood glucose monitoring and glycosylated haemoglobin levels or, in the case of type II diabetics, fasting blood glucose levels, prevents the acute symptoms of diabetes mellitus as well as coma and in addition appears to minimise the risk of vascular complications.