title: Risk factors for frequent and severe hypoglycemia in type 1 diabetes.
abstract: OBJECTIVE
  To determine the risk of frequent and severe hypoglycemia and the associated demographic and clinical risk factors.
  
  
  METHODS
  Demographic and diabetes self-management factors were measured in 415 subjects followed prospectively for 4-6.5 years of type 1 diabetes duration as participants in a population-based incident cohort. Blood samples were collected up to three times yearly to test glycosylated hemoglobin (GHb) levels. Reports of frequent (2-4 times/week) and severe (lost consciousness) hypoglycemia as well as other diabetes self-management data were collected by questionnaires.
  
  
  RESULTS
  Frequent hypoglycemia was common (33 and 35% of participants reported this on the 4- and 6.5-year questionnaires, respectively), whereas severe hypoglycemia occurred much less often. Better glycemic control (odds ratio [OR] 1.3 per 2% decrease in GHb, 95% CI 1.1-1.5) and more frequent self-monitored blood glucose (1.5 per blood glucose check, 1.3-1.7) were independently related to frequent hypoglycemia. The association of frequent hypoglycemia with intensive insulin therapy increased with age. Better glycemic control (1.5 per 2% decrease in GHb, 1.2-2.0) and older age were related to severe hypoglycemic reactions. No sociodemographic factors other than age increased the risk of hypoglycemia.
  
  
  CONCLUSIONS
  Frequent hypoglycemia was common in a population representing the full range of glycemic control in the community. Intensive insulin management and blood glucose monitoring independently predicted frequent but not severe hypoglycemia. This information may be useful for updating patients such that minor changes in diabetes management might decrease the daily burden of this condition while maintaining intensive insulin therapy.
authors.affiliation: Department of Preventive Medicine, University of Wisconsin Medical School, Madison, Wisconsin 53705, USA. ciallen@facstaff.wisc.edu
authors.forename: C
authors.initials: C
authors.lastname: Allen
authors.forename: T
authors.initials: T
authors.lastname: LeCaire
authors.forename: M
authors.initials: M
authors.lastname: Palta
authors.forename: K
authors.initials: K
authors.lastname: Daniels
authors.forename: M
authors.initials: M
authors.lastname: Meredith
authors.forename: D J
authors.initials: DJ
authors.lastname: D'Alessio
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003710:Demography; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004522:Educational Status; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000453:epidemiology*; D007223:Infant; D007348:Insurance, Health / Q000706:statistics & numerical data; D008297:Male; D009790:Occupations; D016017:Odds Ratio; D012307:Risk Factors; D012648:Self Care; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014922:Wisconsin