A Comparative Study of Blood Glucose Measurements Using Glucometer Readings and the Standard Method in the Diagnosis of Neonatal Hypoglycemia

Hypoglycemia is one of the most common neonatal disorders, associated with severe complications. There has been a great deal of controversy regarding the definition and screening of hypoglycemia. Therefore, in this study, we aimed to determine a cut-off value for blood glucose level in glucometer readings.
This cross-sectional study was conducted on 238 newborns at risk of hypoglycemia, admitted to Baqiyatallah Hospital of Tehran, Iran in 2012; the subjects were selected via simple sampling. After obtaining informed consents from the newborns’ parents, 1 cc blood samples were sent to the laboratory for measuring the blood glucose level. Moreover, venous blood samples, as well as heel-stick blood samples, were obtained for glucometer measurements. Blood glucose measurements were used to determine the cut-off value by the receiver operating characteristic (ROC) curve and make comparisons with the diagnostic criteria for hypoglycemia in the literature.
A total of 238 infants with the mean weight of 2869±821.9 g were enrolled in this study. The mean (±SD) blood glucose levels were 65.1±22.9, 82.9±24.7, and 84.4±24.8 mg/dl, based on the standard laboratory method, glucometer reading of venous blood samples, and glucometer reading of heel-stick capillary blood samples, respectively. The optimal cut-off point for hypoglycemia was determined as 65 mg/dl, using glucometer-based assessment of heel-stick blood samples.
The significant difference in blood glucose levels measured by the laboratory method and outpatient glucometer readings highlights the importance of a cut-off value for rapid assessment and control of blood glucose and timely detection of hypoglycemia. In fact, the cut-off value introduced in the present study could facilitate such measurements.