Risk factors for frequent and severe hypoglycemia in type 1 diabetes

OBJECTIVE - To determine the risk of frequent and severe hypoglycemia and t he associated demographic and clinical risk factors. RESEARCH DESIGN AND METHODS - Demographic and diabetes self-management fact ors were measured in 415 subjects followed prospectively for 4-6.5 years of type I diabetes duration as participants in a population -based incident c ohort. Blood samples were collected up to three times yearly to test glycos ylated hemoglobin (GHb) levels. Reports of frequent (2-4 times/week) and se vere (lost consciousness) hypoglycemia as well as other diabetes self-manag ement data were collected by questionnaires. RESULTS - Frequent hypoglycemia was common (33 and 35% of participants repo rted this on the 4- and 6.5-year questionnaires, respectively), whereas sev ere hypoglycemia occurred much less often. Better glycemic control (odds ra tio [OR] 1.3 per 2% decrease in GHb, 95% Cl 1.1-1.5) and more frequent self -monitored blood glucose (1.5 per blood glucose check, 1.3-1.7) were indepe ndently related to frequent hypoglycemia. The association of frequent hypog lycemia 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 man agement and blood glucose monitoring independently predicted frequent but n ot severe hypoglycemia. This information may be useful for updating patient s such that minor changes in diabetes management might decrease the daily b urden of this condition while maintaining intensive insulin therapy.