Cornstarch requirements of the adult glycogen storage disease Ia population: A retrospective review

Abstract

Cornstarch has been the primary treatment for glycogen storage disease type Ia (GSD Ia) for over 35 years. When cornstarch was first described as a treatment, few people survived beyond early childhood. As the prognosis for this population has improved, the need to ensure appropriate cornstarch dosing for different age groups has become imperative. Records from 115 patients (10‐62 years of age) with GSD Ia evaluated at our center between 2015 and 2017 were reviewed. Data collected included weight, age, genetic mutation, amount and frequency of cornstarch doses, body mass index, gender, 24‐hour glucose and lactate concentrations, and biochemical markers of metabolic control. The data demonstrate that adult treatment needs vary greatly from younger age groups, and the required cornstarch support decreases with age (P < .001). The required number of doses, however, did not change with a mean of six doses (range 4‐8) daily in all age groups. General laboratory findings across time demonstrate that significantly reducing the amount of starch required to maintain euglycemia with aging can be done without sacrificing metabolic control. Carbohydrate requirements decrease with aging, and older patients were found to require less cornstarch. Failure to lower the cornstarch doses contributes to over‐treatment in adults with GSD Ia. Not only does this lead to worsening hepatomegaly and excessive weight gain, but over‐treatment contributes to relative hyperinsulinism and rebound hypoglycemia. This knowledge is essential in designing nutritional therapies for the aging GSD population.

Glycogen Storage Disease Type Ia: Current Management Options, Burden and Unmet Needs

“…UCCS is unpalatable and may cause gastrointestinal complaints, including bloating, flatulence and diarrhoea, leading to poor compliance [20,24,48,50]. Glucose replacement therapy with UCCS can be imprecise; in many centres and homes, it is dosed by volume (e.g., tablespoons and scoops), which can lead to wide fluctuations in glucose levels and periods of hyperglycaemia and hypoglycaemia [48,49]. Accuracy of dosing may be improved by weighing UCCS during preparation; however, the composition of the daily diet can influence the absorption of UCCS, and requirements may change depending on daily activity levels.…”

“…Strict home/self-monitoring of blood glucose levels and adjustment of UCCS dosing is required to ensure appropriate glycaemic control for daily activities, e.g., when participating in sports or other physical activity or in times of acute illness [48]. CGM is an increasingly accurate and powerful tool for monitoring daily fluctuations in blood glucose levels widely used in patients with type I diabetes [49,66]. Several published studies have assessed the utility of CGM in a number of GSDs, including a clinical trial of patients with GSD type I [56,61,[66][67][68][69].…”

“…The dose may need to be adjusted during periods of increased metabolic demand, such as during exercise, puberty and pregnancy, to avoid undertreatment and the risk of hypoglycaemia [48]. Cornstarch requirements decrease with age, and the dose may need to be reduced in adults with GSDIa [49]. Failure to decrease the dose may result in overtreatment, which can lead to obesity, hyperlipidaemia and metabolic instability, worsening hepatomegaly, hyperinsulinaemia and rebound hypoglycaemia [48,49].…”

“…Cornstarch requirements decrease with age, and the dose may need to be reduced in adults with GSDIa [49]. Failure to decrease the dose may result in overtreatment, which can lead to obesity, hyperlipidaemia and metabolic instability, worsening hepatomegaly, hyperinsulinaemia and rebound hypoglycaemia [48,49]. However, there are no robust evidence-based guidelines to support age-related dosing or adjustments of the dosing interval.…”

“…Undertreatment increases the risk of hypoglycaemia and consequent serious long-term complications; overtreatment can lead to weight gain, hyperlipidaemia and metabolic instability, worsening hepatomegaly, hyperinsulinaemia and rebound hypoglycaemia [49,60]. 7.…”