Glycaemic profile characteristics and frequency of impaired awareness of hypoglycaemia in subjects with T1D and repeated hypoglycaemic events.

The aim of our study was to evaluate the frequency of hypoglycaemia unawareness and the continuous glucose profile in a group of subjects with Type 1 diabetes (T1D) with repeated non-severe/severe hypoglycaemia. Twenty patients (aged 35.2 +/- 7.6 years, duration of disease 16.4 +/- 6.4 years) were included. Hypoglycaemia awareness was evaluated using questionnaires and after an acute-induced hypoglycaemia. Glucose profile was studied using 72-h continuous glucose monitoring (CGM). All subjects were classified as having hypoglycaemia unawareness by questionnaires. Four patients displayed a "normal" signs/symptoms response to hypoglycaemia. The CGM revealed 18% of the measurements <70 mg/dl and this percentage was correlated with questionnaire score (r = 0.55, P < 0.035) and with the increase in the percentage of signs/symptoms during the induced hypoglycaemia (r = -0.57, P < 0.015). In patients exhibiting an "abnormal" response during hypoglycaemia, CGM values <70 mg/dl was higher (22.6 +/- 8.4%) than in those with a "normal" response (10.2 +/- 9.0%; P < 0.028). Summarising, in subjects with T1D and repeated hypoglycaemia the frequency of impaired awareness is substantially common. Its presence is related to a high proportion of ambulatory glycaemic profile below the desirable range.