Endocrine Abstracts

Diabetes Mellitus (DM) and Impaired Glucose Tolerance (IGT) in patients with cystic fibrosis(CF) signifies a six fold rise in mortality and is associated with declining pulmonary function. The pathophysiology is multifactorial but largely due to Insulinopenia which is due to global islet cell fibrosis and accompanied by loss of islet alpha cells. Insulin treatment improves weight, the bacterial milieu, and lung function but is associated with hypoglycaemia. These patients may be more at risk of hypoglycaemic unawareness as Glucagon secretion is also diminished. We sought to characterize the incidence, awareness and apparent symptoms of this patient group.

Patients attending the West of Scotland CF unit on Insulin treatment were invited to attend. The frequencies of mild hypoglycaemia experienced within this group were estimated retrospectively over the previous 6 months. The usual symptoms of hypoglycaemia and of awareness of hypoglycaemia were recorded using a well validated questionnaire (The Edinburgh Hypoglycaemia Scale) and principal component analysis with varimax rotation performed.

24 patients participated. Mean age was 30.69±9.08, mean duration of insulin treatment 7.33 years ±6.37 years. Overall HbA1c was 6.56±1.13%. While 5 patients (21%) of patients had had no hypoglycaemic events 13 had had between 1 and 4 episodes and 6 patients (25%) had 5 or more. The majority (75%) had hypoglycaemic awareness. The hypoglycaemia symptom score questionnaire revealed that the symptoms with the highest mean intensity were confusion, sweating, weakness, inability to concentrate, hunger and trembling, mostly autonomic.

In this group of Insulin treated patients with CF hypoglycaemic episodes are common, awareness is impaired and autonomic symptoms described more frequently.