Hypoglycemia in Glyburide-Treated Gestational Diabetes Is It Dose-Dependent?

OBJECTIVE: To estimate whether there is a relationship between glyburide dose and the rate of hypoglycemic episodes in women with gestational diabetes mellitus (GDM). METHODS: We studied 674 women with GDM who were treated with glyburide and diagnosed from 2000 to 2009. Glucose data were downloaded from memory-based meters at each visit and analyzed to estimate the incidence of recorded episodes of hypoglycemia and the association with concurrent dose of glyburide therapy (2.5, 5, 10, 15, or 20 mg). Hypoglycemia was defined as a blood glucose of less than 50 mg/dL, further classified as "severe hypoglycemia" if the event required the assistance of another person for resuscitation, "symptomatic hypoglycemia" if it was associated with typical neurogenic symptoms, or "asymptomatic hypoglycemia" if the biochemical reading was less than 50 mg/dL with no symptoms or accompanied by mild symptoms that did not impair the patient's ability to function. RESULTS: Patients recorded a mean of 272 glucose values. Sixty-seven percent of the patients experienced no blood glucose values in the hypoglycemic range. 33% had 1-7% of their total blood glucose values within the hypoglycemic range. All recordings of hypoglycemic episodes were asymptomatic; no patient reported a severe or symptomatic hypoglycemic episode. A significant association was found between the incidence of asymptomatic hypoglycemia and mean blood glucose (P<.001). No association was found between glyburide dose and incidence of asymptomatic hypoglycemia. No association between glyburide dose or mean blood glucose value and the incidence of neonatal hypoglycemia was found. CONCLUSION: Incremental increases in glyburide dose are not associated with an increase in the incidence of hypoglycemic episodes. (Obstet Gynecol 2011;117:349-53) DOI: 10.1097/AOG.0b013e318207782a