INSULIN THERAPY IN TYPE-II DIABETES

When diet therapy is no longer effective in keeping the fasting plasma glucose level < 6 mmol l(-1), a basal insulin supplement from a long- acting insulin such as ultralente can be added instead of using a sulp honylurea or metformin. The dose of insulin required can be predicted from the level of the fasting plasma glucose and the degree of obesity , which provides an index of the accompanying insulin resistance. The risk of hypoglycaemia is minimal provided that the dose is adjusted ac cording to the fasting plasma glucose concentration and the patient ca n continue a normal life-style without restrictions concerning exercis e or the size of individual meals. If given in appropriate doses a bas al insulin supplement does not induce marked weight gain and insulin t herapy is equally appropriate in patients with insulin deficiency and insulin resistance. Maintaining near-normal glucose concentrations pro bably outweighs a putative risk of hyperinsulinaemia. In more severely affected patients, such as those with sulphonylurea failure, soluble insulin to cover meals in addition to a basal insulin supplement is ne eded. At this stage it is usual to stop tablet therapy and treat patie nts with either a basal and prandial insulin regimen or with twice dai ly soluble and isophane mixtures. Nevertheless, in elderly patients in whom regular meals cannot be guaranteed, continuing with sulphonylure a therapy and adding a basal insulin supplement can be a safe and effe ctive way of preventing hyperglycaemic symptoms.