Continuous blood glucose monitoring: detection and prevention of hypoglycaemia

For patients with diabetes the best defence against the consequences of eit her hypoglycaemia or hyperglycaemia is to be able to recognise it and treat it promptly. In normal activity patients have problems in their diabetes m anagement despite adequate knowledge and therapies. Glucose sensors have be en developed that can be inserted subcutaneously in order to continuously m onitor glucose concentrations over several days. Studies have been conducte d with continuous glucose monitoring of patients with diabetes that reveal previously unrecognised periods of hypoglycaemia, ranging from a few minute s to several hours. Continuous monitoring during the nocturnal period can r eveal hypoglycaemic and hyperglycaemic episodes and the insulin usage can s ubsequently be adjusted to decrease the incidence, which may lead to reduct ion in the risk of long-term complications. Preliminary studies have alread y shown that better management can be obtained, with reductions in HbA(1c) levels, when 24-h profiles of glucose concentrations are obtained. Our ongo ing study of patients with type 1 diabetes assessing continuous glucose mon itoring have shown that glucose concentrations are only within a target ran ge of 4-10mmol/l for about 35 per cent of the time. Such measurements are l eading to better individualisation of diabetes management. While the presen t generation of glucose monitors only provide retrospective profiles, newer sensors are being developed that can detect real-time changes. These may f orm the basis of an alert to hypoglycaemic levels or ultimately be connecte d directly to continuous insulin infusion, particularly with rapid-acting i nsulin analogues, to maintain glucose within normal physiological limits.