title: Prevalence and prediction of unrecognised diabetes mellitus and impaired glucose tolerance following acute stroke.
abstract: BACKGROUND
  diabetes mellitus not only increases the risk of ischaemic stroke two- to four-fold but also adversely inXuences prognosis. The prevalence of recognised diabetes mellitus in acute stroke patients is between 8 and 20%, but between 6 and 42% of patients may have undiagnosed diabetes mellitus before presentation. Post-stroke hyperglycaemia is frequent and of limited diagnostic value and the oral glucose tolerance test assumes that the patient is clinically stable and eating normally. There is a need for a simple and reliable method to predict new diabetes mellitus in acute stroke patients.
  
  
  OBJECTIVE
  to determine the prevalence of unrecognised diabetes mellitus and impaired glucose tolerance on hospital admission and 12 weeks later in acute stroke patients with post-stroke hyperglycaemia > or = 6.1 mmol/l. To measure the accuracy of hyperglycaemia and elevated glycosylated haemoglobin concentration in predicting the presence of unrecognised diabetes mellitus at 12 weeks.
  
  
  METHODS
  acute (<24 hours) stroke patients (cerebral infarction and primary intracerebral haemorrhage) with admission hyperglycaemia between 6.0 and 17 mmol/l and without a previous history of insulin-treated diabetes mellitus who were randomised into the Glucose Insulin in Stroke Trial between October 1997 and May 1999 were studied. The Glucose Insulin in Stroke Trial is a randomised controlled trial investigating the benefits of maintaining euglycaemia in acute stroke patients with mild to moderate hyperglycaemia. At 12 weeks, survivors underwent a 75 g oral glucose tolerance test. The positive predictive value and negative predictive value of admission plasma glucose > or = 6.1 mmol/l and elevated glycosylated haemoglobin concentration in predicting the presence of diabetes mellitus were used to estimate the prevalence of unrecognised diabetes mellitus in a consecutive series of 582 acute stroke admissions.
  
  
  RESULTS
  582 consecutive acute stroke patients were assessed for eligibility for the Glucose Insulin Stroke Trial, of whom 83 (14%) had recognised diabetes mellitus. One hundred and forty-two patients were randomised and 62 underwent a 3-month oral glucose tolerance test, of whom 26 (42%) had normal glucose tolerance, 23 (37%) had impaired glucose tolerance and 13 (21%) had diabetes mellitus. Admission plasma glucose > or = 6.1 mmol/l and glycosylated haemoglobin > or = 6.2% predicted the presence of previously unrecognised diabetes mellitus at 12 weeks with a positive predictive value of 80% and negative predictive value of 96%. The estimated prevalence of unrecognised diabetes mellitus in the total series of acute stroke admissions was 16-24%.
  
  
  CONCLUSIONS
  one-third of all acute stroke patients may have diabetes mellitus. For patients presenting with post-stroke hyperglycaemia, impaired glucose tolerance or diabetes mellitus is present in two-thirds of survivors at 12 weeks. Admission plasma glucose > or = 6.1 mmol/l combined with glycosylated haemoglobin > or = 6.2% are good predictors of the presence of diabetes mellitus following stroke.
authors.affiliation: Newcastle University Department of Medicine for the Elderly, F Floor, Sunderland Royal Hospital, Kayll Road, Sunderland SR4 7TP, UK. chris.gray@chs.northy.nhs.uk
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Gray
authors.forename: Jon F
authors.initials: JF
authors.lastname: Scott
authors.forename: Joyce M
authors.initials: JM
authors.lastname: French
authors.forename: K G M M
authors.initials: KG
authors.lastname: Alberti
authors.forename: Janice E
authors.initials: JE
authors.lastname: O'Connell
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D018149:Glucose Intolerance / Q000150:complications* / Q000453:epidemiology; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D020521:Stroke / Q000150:complications*
chemical_list: D006442:Glycated Hemoglobin