Potential use of other starch sources in the treatment of glycogen storage disease type Ia - an in vitro study.

BACKGROUND: Glycogen storage disease type Ia (GSD-Ia) is one of the most common hepatic GSD. Its treatment mainly consists of a diet including a high intake of slow-digestion carbohydrates such as raw cornstarch and the restriction of simple sugars. This enables the maintenance of euglycemia and prevents secondary metabolic disorders. Starch is a glucose polymer formed by amylose and amylopectin, which can be obtained from distinct sources. Although uncooked cornstarch has been successfully used in the treatment of GSD-Ia, it can lead to hyperglycemia and weight gain. in vitro andin vivo tests indicated that sweet manioc starch can be potentially used in the treatment of GSD-Ia. RESULTS: The moisture analysis revealed a variation from 10.3 to 12.8% in the sweet manioc starch samples, whereas the moisture content of uncooked cornstarch ranged from 7.3 to 11.1%. Quantifiable sugar was detected in 3/5 samples of sweet manioc starch and 1/3 samples of uncooked cornstarch. Notably, this uncooked cornstarch brand is widely employed in GSD-Ia treatment in Brazil. Products B and E had higher values of amylopectin and undetectable levels of sugars. A clinical trial is warranted to compare samples F and G and determine the impact of sugar trace in the same dietary source of starch. CONCLUSIONS: Collectively, the results demonstrated possible therapeutic alternatives for GSD-Ia in addition to traditional uncooked cornstarch.

In vitro digestion of starches in a dynamic gastrointestinal model: an innovative study to optimize dietary management of patients with hepatic glycogen storage diseases.

Uncooked cornstarch (UCCS) is a widely used treatment strategy for patients with hepatic glycogen storage disease (GSD). It has been observed that GSD-patients display different metabolic responses to different cornstarches. The objective was to characterize starch fractions and analyze the digestion of different starches in a dynamic gastrointestinal in vitro model. The following brands of UCCS were studied: Argo and Great Value from the United States of America; Brazilian Maizena Duryea and Yoki from Brazil; Dutch Maizena Duryea from the Netherlands. Glycosade, a modified starch, and sweet polvilho, a Brazilian starch extracted from cassava, were also studied. The starch fractions were analyzed by glycemic TNO index method and digestion analyses were determined by the TIM-1 system, a dynamic, computer-controlled, in vitro gastrointestinal model, which simulates the stomach and small intestine. The final digested amounts were between 84 and 86% for the UCCS and Glycosade, but was 75.5% for sweet povilho. At 180 min of the experiment, an important time-point for GSD patients, the digested amount of the starches corresponded to 67.9-71.5 for the UCCS and Glycosade, while it was 55.5% for sweet povilho. In an experiment with a mixture of sweet polvilho and Brazilian Maizena Duryea, a final digested amount of 78.4% was found, while the value at 180 min was 61.7%. Sweet polvilho seems to have a slower and extended release of glucose and looks like an interesting product to be further studied as it might lead to extended normoglycemia in GSD-patients.

Glycogen storage disease type I: clinical and laboratory profile / Doença de depósito de glicogênio tipo I: perfil clínico e laboratorial

OBJECTIVES: To characterize the clinical, laboratory, and anthropometric profile of a sample of Brazilian patients with glycogen storage disease type I managed at an outpatient referral clinic for inborn errors of metabolism. METHODS: This was a cross-sectional outpatient study based on a convenience sampling strategy. Data on diagnosis, management, anthropometric parameters, and follow-up were assessed. RESULTS: Twenty-one patients were included (median age 10 years, range 1-25 years), all using uncooked cornstarch therapy. Median age at diagnosis was 7 months (range, 1-132 months), and 19 patients underwent liver biopsy for diagnostic confirmation. Overweight, short stature, hepatomegaly, and liver nodules were present in 16 of 21, four of 21, nine of 14, and three of 14 patients, respectively. A correlation was found between height-for-age and BMI-for-age Z-scores (r = 0.561; p = 0.008). CONCLUSIONS: Diagnosis of glycogen storage disease type I is delayed in Brazil. Most patients undergo liver biopsy for diagnostic confirmation, even though the combination of a characteristic clinical presentation and molecular methods can provide a definitive diagnosis in a less invasive manner. Obesity is a side effect of cornstarch therapy, and appears to be associated with growth in these patients. .

OBJETIVOS: Caracterizar o perfil clínico, laboratorial e antropométrico de uma amostra de pacientes brasileiros com doença de depósito de glicogênio tipo I tratados em um ambulatório de referência para erros inatos do metabolismo. MÉTODOS: Este foi um estudo ambulatorial transversal com base em uma estratégia de amostragem de conveniência. Foram avaliados os dados com relação ao diagnóstico, tratamento, parâmetros antropométricos e acompanhamento. RESULTADOS: Foram incluídos 21 pacientes (idade média de 10 anos, faixa 1-25 anos de idade), e todos se encontravam em terapia de amido de milho cru. A idade média na época do diagnóstico foi de sete meses (faixa, 1-32 meses), e 19 pacientes foram submetidos a biópsia hepática para confirmação do diagnóstico. Sobrepeso, baixa estatura, hepatomegalia e nódulos hepáticos foram fatores presentes em 16 de 21, quatro de 21, nove de 14 e três de 14 pacientes, respectivamente. Foi encontrada uma correlação entre os escores z para peso para idade e IMC para idade (r = 0,561; p = 0,008). CONCLUSÕES: O diagnóstico da doença de depósito de glicogênio tipo I tem sido tardio no Brasil. A maioria dos pacientes foi submetida a confirmação do diagnóstico, apesar de o quadro clínico característico e os métodos moleculares poderem fornecer um diagnóstico definitivo de forma menos invasiva. Obesidade é um efeito colateral da terapia com amido de milho e parece estar associada a crescimento nesses pacientes. .

Glycogen storage disease type I: clinical and laboratory profile.

OBJECTIVES: To characterize the clinical, laboratory, and anthropometric profile of a sample of Brazilian patients with glycogen storage disease type I managed at an outpatient referral clinic for inborn errors of metabolism. METHODS: This was a cross-sectional outpatient study based on a convenience sampling strategy. Data on diagnosis, management, anthropometric parameters, and follow-up were assessed. RESULTS: Twenty-one patients were included (median age 10 years, range 1-25 years), all using uncooked cornstarch therapy. Median age at diagnosis was 7 months (range, 1-132 months), and 19 patients underwent liver biopsy for diagnostic confirmation. Overweight, short stature, hepatomegaly, and liver nodules were present in 16 of 21, four of 21, nine of 14, and three of 14 patients, respectively. A correlation was found between height-for-age and BMI-for-age Z-scores (r=0.561; p=0.008). CONCLUSIONS: Diagnosis of glycogen storage disease type I is delayed in Brazil. Most patients undergo liver biopsy for diagnostic confirmation, even though the combination of a characteristic clinical presentation and molecular methods can provide a definitive diagnosis in a less invasive manner. Obesity is a side effect of cornstarch therapy, and appears to be associated with growth in these patients.

Hyperlipidemia and fatty acid composition in patients treated for type IA glycogen storage disease.

Because glycogen storage disease type IA (GSD-IA) is characterized by recurrent episodes of hypoglycemia that promote a marked elevation in blood triglyceride levels, we evaluated plasma lipid levels in 12 patients with GSD-IA on a regular basis. Six of the 12 patients had plasma fatty acid composition measured; because of possible essential fatty acid deficiency, urinary prostaglandin excretion was also measured. All patients had triglyceride levels between 1440 and 6120 mg/dl (16.25 to 69.09 mmol/L) before treatment. After treatment to promote blood glucose levels of 75 to 85 mg/dl (4.2 to 4.7 mmol/L), triglyceride levels in each of 11 patients were between 189 +/- 31 (2.13 +/- 0.35 mmol/L) and 510 +/- 60 mg/dl (5.76 +/- 0.68 mmol/L). The lipoprotein fatty acid composition in six patients showed a substantial elevation in C16:0, C16:1 omega 7, and C18:1 omega 9, but no increase in C20:3 omega 9 (the fatty acid that characteristically increases in essential fatty acid deficiency). In addition, each of the six patients had normal 24-hour urinary excretion of prostaglandin. One patient, whose triglyceride levels remained elevated despite dietary treatment, was given either clofibrate, lovastatin, niacin, or fish oil. With the exception of lovastatin, these agents produced a decrease in triglyceride values for 1 to 2 months; however, by 3 months triglycerides reached pretreatment levels. Combined treatment with clofibrate and niacin resulted in a sustained decrease in plasma triglyceride levels for 4 months. The findings indicate that dietary management of GSD-IA is usually associated with improvements in triglyceride levels; however, patients maintain triglyceride values between 300 and 500 mg/dl (3.38 to 5.65 mmol/L). No patient had biochemical evidence of essential fatty acid deficiency.

Glucose therapy for glycogenosis type 1 in infants: comparison of intermittent uncooked cornstarch and continuous overnight glucose feedings.

This study was undertaken to test the glycemic response of five infants with glycogen storage disease type 1, aged 0.7 to 1.5 years, to uncooked cornstarch under various dietary conditions, and to evaluate the long-term effects of a dietary regimen consisting of uncooked cornstarch in milk every 4 hours, in addition to three meals daily, on biochemical values and physical growth. The results were compared with previous experience in treating six infants with continuous overnight glucose infusion via gastrostomy plus multiple daily feedings containing an adequate source of glucose. A test dose of cornstarch (1.6 to 1.8 gm/kg) providing four times the calculated hourly glucose production rate, when given in water 15 to 30 minutes after a continuous overnight intragastric glucose infusion was stopped, did not maintain normoglycemia. When the same dose was given in 2% cow milk 4 hours later, mean blood glucose levels remained greater than 68 mg/dl (3.8 mmol/L) for up to 4 hours. A regimen of uncooked cornstarch in 2% cow milk at 4-hour intervals in addition to three meals daily prevented hypoglycemia, and maintained blood lactate at nearly normal levels and serum uric acid and cholesterol within the normal range; triglyceride levels were increased only modestly. Overnight blood glucose levels were comparable to those achieved with continuous intragastric glucose infusion. With this regimen the five infants have maintained linear growth rates normal for their age and genetic potential; the mean percentage of ideal body weight for length percentile did not change significantly, although two of the five patients were overweight (123% and 124% of ideal body weight respectively) after 3 years of treatment. We conclude that a trial of uncooked cornstarch in feedings of milk every 4 hours should be attempted as soon as a more frequent feeding schedule with dextrose-containing formulas proves ineffective, because the former has the potential to provide the continuous glucose required by infants with glycogen storage disease type 1 in a safer and less invasive fashion than continuous intragastric glucose infusion.