Related Experiment Video
Updated: Apr 30, 2026
Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants
Published on: March 14, 2013
Brain mass estimation by head circumference and body mass methods in neonatal glycaemic modelling and control
Cameron Allan Gunn1, Jennifer L Dickson1, Christopher G Pretty1
1Department of Mechanical Engineering, University of Canterbury, Private Bag, Christchurch, Canterbury 8140, New Zealand.
Insights
A new head circumference model improves accuracy for estimating brain glucose uptake in extremely low-birth-weight infants, offering better insulin therapy and particularly benefiting small-for-gestational-age infants.
Area of Science:
- Neonatalogy
- Pediatric Endocrinology
- Computational Biology
Background:
- Hyperglycemia is a frequent complication in extremely low-birth-weight infants due to stress and prematurity.
- Model-based insulin therapy can optimize glycemic control in this vulnerable population.
- Current models often rely on body weight to estimate brain glucose uptake, which may lack precision.
Purpose of the Study:
- To compare a novel head circumference-based model with traditional body weight models for estimating non-insulin-mediated brain glucose uptake.
- To evaluate the impact of these models on insulin sensitivity (SI) and projected glycemic control in extremely low-birth-weight infants.
- To specifically assess the performance of the head circumference model in small-for-gestational-age (SGA) infants.
Main Methods:
- Retrospective analysis of 48 extremely low-birth-weight infants (median birth weight 750g, median gestational age 25 weeks).
- Comparison of brain mass estimation and insulin sensitivity (SI) profiles between a head circumference model and a body weight model.
- Separate analysis of a cohort of 5 small-for-gestational-age (SGA) infants.
Main Results:
- The head circumference model showed significantly less deviation in estimated brain mass (median 10% vs. higher in SGA) and insulin sensitivity (median 3.5% vs. 13.7% in SGA) compared to the body weight model.
- Virtual trials indicated that the head circumference method resulted in 87-93% of recommended insulin rates being equal or slightly reduced.
- Glycemic control outcomes demonstrated minimal changes between the models.
Conclusions:
- Head circumference-based modeling offers superior accuracy for estimating brain glucose uptake compared to body weight methods in extremely low-birth-weight infants.
- This improved accuracy may lead to a slight reduction in insulin administration, especially beneficial for SGA infants.
- The findings support the clinical utility of head circumference for refining insulin therapy protocols in neonatal intensive care.
Introduction:
Hyperglycaemia is a common complication of stress and prematurity in extremely low-birth-weight infants. Model-based insulin therapy protocols have the ability to safely improve glycaemic control for this group. Estimating non-insulin-mediated brain glucose uptake by the central nervous system in these models is typically done using population-based body weight models, which may not be ideal.
Method:
A head circumference-based model that separately treats small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) infants is compared to a body weight model in a retrospective analysis of 48 patients with a median birth weight of 750g and median gestational age of 25 weeks. Estimated brain mass, model-based insulin sensitivity (SI) profiles, and projected glycaemic control outcomes are investigated. SGA infants (5) are also analyzed as a separate cohort.
Results:
Across the entire cohort, estimated brain mass deviated by a median 10% between models, with a per-patient median difference in SI of 3.5%. For the SGA group, brain mass deviation was 42%, and per-patient SI deviation 13.7%. In virtual trials, 87-93% of recommended insulin rates were equal or slightly reduced (Δ<0.16mU/h) under the head circumference method, while glycaemic control outcomes showed little change.
Conclusion:
The results suggest that body weight methods are not as accurate as head circumference methods. Head circumference-based estimates may offer improved modelling accuracy and a small reduction in insulin administration, particularly for SGA infants.
