RESTORATION OF HYPOGLYCEMIA AWARENESS IN PATIENTS WITH LONG-DURATION INSULIN-DEPENDENT DIABETES

Hypoglycaemia without warning is a dangerous complication of insulin-d ependent diabetes mellitus and it limits the use of intensified insuli n therapy to reduce chronic diabetic complications. To investigate the possibility of restoring awareness; symptomatic, cognitive, and hormo nal responses to controlled hypoglycaemia were studied in insulin-depe ndent diabetic patients with long disease duration (6 with good glycae mic control and 6 with poor control) before and after hypoglycaemia av oidance. At the start of the study, all had loss of hypoglycaemia awar eness. Responses to the initial challenge were small (pooled area unde r curve [AUC] adrenaline 5.75 [SE 0.07] nmol/L per 260 min, pooled AUC symptom score 80 [1.3]) and only started when plasma glucose was sign ificantly lower than the 2.8 (0.1) mmol/L at which cognitive function deteriorated. After 4.1 (1.1) months' scrupulous hypoglycaemia avoidan ce, hormone and symptom responses to the challenge were increased (AUC adrenaline 15.9 [0.1] nmol/L per 260 min, p = 0.01; AUC symptom score 275 [7], p < 0.001), starting at plasma glucose concentrations signif icantly higher than that causing cognitive dysfunction. Glycosylated h aemoglobin did not deteriorate significantly. We conclude that the nor mal hierarchy of subjective awareness before cognitive dysfunction dur ing hypoglycaemia can be restored by avoiding hypoglycaemia. This is i ndependent of disease duration or initial metabolic control.