Insulin-meal interval and short-term glucose fluctuation in tightly controlled gestational diabetes mellitus.

OBJECTIVE: To study the effect of two insulin-meal intervals on short-term glucose fluctuations in tightly controlled gestational diabetes mellitus (GDM). METHODS: We performed a prospective and paired study in 11 Japanese GDM women requiring insulin for good glycemic control during the third trimester. The women were subjected to test two insulin-meal intervals: 15 min and 30 min. Both regimens were examined in each patient in random order, 2 days apart. Blood glucose was measured by an automated glucose monitor every 2 min. Short-term glucose fluctuations of the two observations were analyzed by two-way ANOVA for repeated measurements with a post hoc t test (p < 0.05). Data were expressed as mean +/- SD. RESULTS: Daily glucose profiles of the two groups showed that their glycemic controls on the days of observation were good and that the two glucose profile curves were superimposable. A transient decrease in glucose (nadir 62 +/- 6 mg/dl) was observed at 6-10 min of meal ingestion in the 30-min regimen, which was significantly different from the glucose fluctuations during the 15-min regimen. The 2-h postprandial glucose levels were similar in both experiments. CONCLUSIONS: In women with tightly controlled GDM during the third trimester, insulin-meal intervals of 15 min are beneficial when compared with 30-min intervals, in that they avoid preprandial hypoglycemia without increasing 2-h postprandial hyperglycemia.