Application of dynamic glucose monitoring in the diagnosis and differential diagnosis of hypoglycemia

Abstract

Objective To analyze the characteristics of dynamic blood glucose in hypoglycemia patients with different causes and explore the application value of dynamic glucose monitoring system (DGMS) in the diagnosis and differential diagnosis of hypoglycemia. Methods We used DGMS to monitor the blood glucose levels of 20 hypoglycemia patients for 3-6 days, including 6 cases of insulinoma, 7 cases of reactive hypoglycemia, 2 cases of autoimmune hypoglycemia, 3 cases of islet cell hyperplasia, 1 case of drug-induced hypoglycemia, 1 case of congenital hyperinsulinism. The blood glucose profiles of hypoglycemia patients with different causes were compared. Results The average monitoring duration was (88.9±10.8)hours. 38-936 points of hypoglycemia were detected in these patients with hypoglycemia. The average blood glucose of patients of each cause, in the order from low to high, were: congenital hyperinsulinism [(2.97±0.59)mmol/L], islet cell hyperplasia [(4.83±1.32)mmol/L], insulinoma [(4.87±1.37)mmol/L], drug-induced hypoglycemia [(5.98±0.8)mmol/L], reactive hypoglycemia [(6.38±1.99)mmol/L], and autoimmune hypoglycemia [(7.63±2.67)mmol/L]. The constituent ratio of hypoglycemia from low to high were: autoimmune hypoglycemia and drug-induced hypoglycemia (0%), reactive hypoglycemia [0.5% (0.0%, 1.6%), insulinoma [9.0% (5.2%, 16.3%), islet cell hyperplasia [9.5% (1.1%, 14.2%), congenital hyperinsulinism (58.5%). In terms of the blood glucose profiles in day and night, the night blood glucose levels were lower than those in daytime in insulinoma [(5.16±1.37)mmol/L vs. (4.44±1.24)mmol/L], reactive hypoglycemia [(6.93±2.19)mmol/L vs. (5.57±1.25)mmol/L], autoimmune hypoglycemia [(8.08±2.79)mmol/L vs. (6.95±2.31)mmol/L], islet cell hyperplasia [(5.23±1.31)mmol/L vs. (4.11±1.00)mmol/L] and congenital hyperinsulinism [(3.06±0.57)mmol/L vs. (2.83±0.59)mmol/L] (all P<0.05); while the daytime blood glucose level was lower than that at night in drug-induced hypoglycemia [(5.90±0.81)mmol/L vs. (6.11±0.77)mmol/L, P<0.05]. 62.2% and 78.9% of the hypoglycemia episodes happened at night in patients with insulinoma and islet cell hyperplasia, and 43.2% at night in patients with congenital hyperinsulinism. The highest standard deviation of blood glucose (2.67 mmol/L), largest amplitude of glycemic excursions (9.2 mmol/L)and coefficient of variation (35%) were found in patients with autoimmune hypoglycemia. The largest range of blood glucose (20.4 mmol/L) was found in patients with reactive hypoglycemia. The day-night differences in coefficient of variation (31.6% vs. 22.4%) and range of blood glucose (20.4 mmol/L vs. 6.8 mmol/L) were most prominent in patients with reactive hypoglycemia. Conclusion The dynamic monitoring of blood glucose and the analysis of the parameters such as average blood glucose, blood glucose profiles and variability of blood glucose may be helpful for the diagnosis of hypoglycemia and differential diagnosis of causes of hypoglycemia. Key words: Hypoglycemia; Insulinoma; Dynamic glucose monitoring system; Continuous glucose monitoring system; Reactive hypoglycemia; Differential diagnosis