Use this URL to cite or link to this record in EThOS:
Title: Exploring the relationship between impaired awareness of hypoglycaemia and autonomic neuropathy in type one diabetes mellitus
Author: Walkinshaw, Emma
ISNI:       0000 0004 7657 3163
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
Background: Severe hypoglycaemia is a much feared complication of type one diabetes mellitus (T1DM) and historically diabetic autonomic neuropathy (DAN) was described as the underlying mechanism. The aim of these studies was to clarify if there is a relationship between DAN and impaired awareness of hypoglycaemia (IAH), the role DAN has in preventing improvement in IAH and cardiac autonomic response to hypoglycaemia. Methods: Participants with T1DM and IAH (Gold score =4), and participants with T1DM and normal awareness of hypoglycaemia (Gold score <4) were recruited. They underwent cardiac autonomic function testing and were invited to undergo a stepped hyperinsulinaemic hypoglycaemic clamp study. The participants with IAH underwent a treatment programme aimed at improving awareness of hypoglycaemia. Results: The prevalence of DAN and IAH was associated with a longer duration of disease. Awareness of hypoglycaemia improved in all patient groups (mean improvement Gold score =1) independent of cardiac autonomic function status but younger participants and those with a shorter duration of disease showed greater improvements. During hypoglycaemic clamp studies baseline heart rate was higher and vagal tone lower, in participants with diabetes compared to participants without diabetes. During hypoglycaemia heart rate increased with vagal withdrawal in participants with T1DM and normal awareness of hypoglycaemia. Little change in heart rate or heart rate variability was seen in participants with IAH. Conclusions: The presence of cardiac autonomic neuropathy is not associated with IAH. Heart rate response to hypoglycaemia was time dependent and differed according to self reported awareness of hypoglycaemia. We suspect this is due to a failure of autonomic responses to hypoglycaemia associated with long duration of disease and reduced autonomic responses following repeated episodes of hypoglycaemia. Future work would be aimed at epidemiological studies to document an accurate prevalence of DAN and examining the possible associations with other complications of diabetes.
Supervisor: Heller, Simon Sponsor: Not available
Qualification Name: Thesis (M.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available