Unawareness of hypoglycaemia in insulin-treated diabetic patients: prevalence and relationship to autonomic neuropathy.
Three-hundred and two insulin-treated diabetic patients were questioned about hypoglycaemia using a structured questionnaire interview. Two-hundred and twenty-six patients (75%) had normal symptomatic awareness, 48 (16%) had partial awareness, 21 (7%) had absent awareness of hypoglycaemia, and 7 (2%) denied ever experiencing hypoglycaemia. Patients with complete loss of awareness of hypoglycaemia had diabetes of longer duration; none had a HbA1 concentration within the non-diabetic range. Loss of awareness of hypoglycaemia was associated with an increased incidence of severe hypoglycaemia, 19 (91%) of the patients with absent awareness, and 33 (69%) with partial awareness of hypoglycaemia experiencing severe hypoglycaemia over 1 year compared with only 41 (18%) of patients with normal awareness of hypoglycaemia (p less than 0.001). Cardiovascular autonomic function tests were performed in 226 (75% of the whole group). Of the patients who had diabetes for more than 15 years, 54% (n = 39) with normal awareness of hypoglycaemia, compared with 59% (n = 10) with absent awareness of hypoglycaemia, had evidence of cardiovascular autonomic impairment (NS). Seven (41%) of the 17 patients with absent awareness of hypoglycaemia and diabetes of greater than 15 years duration had no evidence of autonomic dysfunction. Loss of hypoglycaemia awareness is a common problem in patients with insulin-treated diabetes of long duration, is associated with an increased incidence of severe hypoglycaemia, but is not invariably associated with abnormal cardiovascular autonomic function tests.
Hepburn
D A
DA
Diabetic Department, Royal Infirmary, Edinburgh, Scotland.
Patrick
A W
AW
Eadington
D W
DW
Ewing
D J
DJ
Frier
B M
BM
D000293:Adolescent; D000328:Adult; D000368:Aged; D001364:Awareness / Q000502:physiology*; D003430:Cross-Sectional Studies; D003929:Diabetic Neuropathies / Q000503:physiopathology / Q000523:psychology*; D006334:Heart Function Tests; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000503:physiopathology / Q000523:psychology*; D007328:Insulin / Q000009:adverse effects*; D008875:Middle Aged; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
D007328:Insulin