gms | German Medical Science

Question: The aim of the work is to study correlation dependence of the QT interval and glucose levels in blood in Type I diabetic children and adolescents.

Method: Simultaneous monitoring of glucose levels using MiniMed Continuous Glucose Monitoring System and monitoring of QT intervals using Holier digital system "DMS Advanced Technologies” with automatic processing QT interval values were made in 13 children and adolescents at the age of 9-17. The glucose level was determined every 5 minutes during 3 days. Monitoring was performed in three leads: MV5, MAVF, MV3 during one-three days with automatic calculation of QT, QTc, RT and RTc values for 5 minutes with simultaneous glucose monitoring. Correlation analysis was made for QTñ and RTñ and glucose levels.

Results: In two patients, hypoglycemia with glucose levels lower than 4 mmol/l lasted from 5 to 12 hours while in the other patients from 40 minutes to 2 hours. The state of hypoglycemia was detected mainly in sleeping. With long hypoglycemia, inverse correlation dependence of QTc and RTc values on glucose levels was revealed. The correlation factor was -0.6 and -0.65 with p <0.05. With developing hypoglycemia and at the end of it, QTc interval change was somewhat delayed. If the points corresponding to transitional states are ignored the correction factor with p<0.95 will be -0,8. In the remaining 11 cases no distinct correlation between changes in glucose levels and QTc intervals was observed. The correlation factor during 24 hours remained within -0.1 and -0.45 which is evidence of stable recurrent of weak correlation dependence between glycemia and QTc interval.

Conclusion: With developing hypoglycemia there is inverse proportional dependence between the level of hypoglycemia and QTc length. Prolonged QTc interval occurs with long and expressed hypoglycemia. This index can be used as one of the markers of detection of unrevealed latent hypoglycemia states.