The use of continuous glucose monitoring in the practical management of glycogen storage disorders.

Continuous glucose monitoring systems (CGMS) are now in widespread use in diabetes management with an increasing evidence base. There are few reports of their use in GSD. Liver glycogen storage disorders (GSDs) are most often managed by intensive dietary regimens. Risks of over and under-treatment remain. We describe our use of CGMS in a cohort of GSD patients, the results obtained and the frequency of complications. Our experience is that CGM is a reliable, well accepted and valid tool in the monitoring of GSD patients and allows for assessment of blood sugar control in the 'real-life' setting, unlike hospital admissions. Combining CGM with urine ketone and / or blood lactate measurements, again at home, improves the investigation yet further. It is possible to perform CGM for periods including both schooldays and weekends, and also to change the dietary regimen during the period of monitoring to reduce the frequency of assessments. Risks of decreased reliability in the low range of blood sugars may be outweighed by the increased validity of the patient being in the home environment, with a normal diet and activity schedule.