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The decline of many freshwater mussel populations in the United States has brought about the need for facilities in which mussels can be held for purposes of relocation, research, and propagation. The Aquatic Wildlife Conservation Center (AWCC) of the Virginia Department of Game and Inland Fisheries (VDGIF) serves as a freshwater mussel conservation facility in southwest Virginia. The goals of this study were: (1) to determine whether adult freshwater mussels could maintain energy reserves at AWCC (2) to determine whether adults could produce mature gametes at AWCC and (3) to establish suitable rearing conditions for juvenile mussels at the AWCC. In fall 2002, four species of mussels, Villosa iris, V. vanuxemensis, Amblema plicata, and Pleurobema oviforme, served as surrogates for endangered species and were relocated to the AWCC. Three energy reserves (glycogen, protein, and lipid) were measured seasonally (fall 2002 to summer 2004) from mantle tissue and compared between AWCC specimens and those from their wild source populations. The gametogenic stage of each species was also compared to determine whether gametogenesis was occurring in captivity. In summer 2003, the first of two juvenile experiments tested the effects of three rates of water flow (1 L/min, 3 L/min, and 7 L/min) on the survival and growth of V. iris and Epioblasma capsaeformis reared in flow-through troughs. In summer 2004, round flow-through tanks were used to assess the effects of three sizes of substrate (fine sediment, fine sand, and coarse sand) and sampling frequency on the survival and growth of V. iris. Gut content analyses also were conducted at the end of each experiment to determine which algal species were being consumed. Overall survival rates were as follows: A. plicata, 100 %; V. vanuxemensis, 86 %; V. iris, 79 %; P. oviforme (2002 collection), 53 %; and P. oviforme (2003 collection), 50 %. All energy reserves varied among seasons, but every species except P. oviforme (2003 collection) had levels higher than those in source populations at the end of this experiment. Glycogen appeared to be the best indicator of condition in these species, with protein also being important in the 2003 collection of P. oviforme. Mature gametes were found in all four captive species in 2003 and 2004, with lipids appearing to fuel gametogenesis. Additionally, gametogenesis was occurring earlier in captive long-term brooders than in the wild, possibly due to warmer water temperatures at AWCC. The first juvenile experiment resulted in 15 % overall survival, with 1 L/min having the greatest survival (18 %), and the 3 L/min having the greatest growth (656 μm). In the second experiment, dishes left unsampled had significantly greater survival (40 %) (P<0.05) of juveniles than those which were sampled (27 %). The unsampled fine sand treatment had significantly greater survival than the other two unsampled treatments (52 %) (P<0.001). Sampled juveniles in fine sediment had the greatest growth (887 μm). Also, juveniles from Experiment 1 were consuming primarily Navicula, with Coelastrum and Chlorella consumed in greatest abundance in Experiment 2. Results indicate that most adult mussels maintained energy reserves and produced mature gametes, and that juveniles of V. iris had good survival and growth. Only P. oviforme had survival rates lower than expected and did not appear to maintain condition at AWCC. Based on results of the species tested, environmental conditions at AWCC appear suitable for the survival of most adult and juvenile freshwater mussels. / Master of Science

This project evaluated the feasibility of salvaging zebra mussel-infested freshwater mussels from their native habitat by determining 1) how zebra mussel infestation affects unionid feeding and body condition, 2) how starvation in quarantine affects body condition of unionids, and 3) what feeding regime maintain unionid condition in quarantine. The effects of zebra mussel infestation on two mussel species were evaluated through glycogen analyses of mantle tissue and gut content analysis. Specimens of Amblema p. plicata (Say, 1817) and Quadrula p. pustulosa (I. Lea, 1831), collected from a heavily infested reach of the Ohio River in 1996, had significantly lower (p<0.05) glycogen levels than specimens collected from a low-infestation reach upstream. In 1996 and 1997, heavily infested Amblema p. plicata and Quadrula p. pustulosa had significantly less (p<0.01) organic matter and fewer algal cells in their guts than lightly infested specimens. In addition, gut contents of individual A. p. plicata contained significantly less (p<0.05) organic matter and fewer algal cells than the combined gut contents of all zebra mussels (18-33 mm in length) attached to their shells. Gut analyses also revealed significant diet overlap between native unionids and infesting zebra mussels. Thus, competitive interactions or interference by zebra mussels likely reduced unionid ingestion and consequently reduced glycogen stores. During quarantine, unionids salvaged from a lightly infested area and starved for 30 days had glycogen levels that declined dramatically. After 30 days without supplemental feeding, mean glycogen levels of A. p. plicata declined 85%, and mean glycogen levels of Q. p. pustulosa declined 70%. Thus, feeding of unionids is necessary to maintain their condition during lengthy quarantine. To determine the best feeding regime for unionids in quarantine, assimilation efficiencies and carbon budgets were established for the rainbow mussel, Villosa iris (Lea, 1829), using radio-labelled cultures of Neochloris oleoabundans (Chantanachat and Bold 1962) at three cell concentrations. Assimilation efficiencies for Villosa iris at 100,000cells/ml, 10,000 cells/ml, and 1,000 cells/ml were similar (45-56%); however, regardless of these similarities, assimilation efficiencies from this study indicate that Neochloris oleoabundans is readily assimilated (~50% AE) by Villosa iris . In addition, total assimilation was maximized at 100,000cells/ml, which indicates that Villosa iris has the greatest amount of energy available for growth, reproduction, and maintenance of condition in captivity at this cell concentration. During a second quarantine experiment, specimens were provided with 100,000cells/ml of N. oleoabundans twice per day. Initial mean glycogen levels for Amblema p. plicata (9.4 + 2.4 mg/g) and Quadrula p. pustulosa collected from ORM 175.5 in July 1997 were not significantly different (p>0.3) than the mean glycogen levels of A. p. plicata and Q. p. pustulosa collected from the same site in July 1996. Glycogen stores of unionids entering quarantine, therefore, were similar in both the starvation and controlled feeding experiments. After 7, 14, and 30 days of controlled feeding in quarantine, mean glycogen levels of A. p. plicata and Q. p. pustulosa did not change significantly (p>0.1). Thus, quarantine protocol for salvaged native mussels should include the feeding of algae to captive specimens to sustain glycogen levels prior to relocation. / Master of Science

Due to the increasing need to provide refugia for freshwater mussels impacted by anthropogenic activities and exotic species, facilities should be identified and protocols developed for holding mussels in captivity. White Sulphur Springs National Fish Hatchery (WSSNFH), White Sulphur Springs, WV, has held freshwater mussels for nearly eight years, and has the potential to become an important refugium and propagation facility for conservation of mussels in the Ohio River Basin and elsewhere. The goal of this study was to determine the feasibility of holding adult freshwater mussels in long-term captivity at WSSNFH by evaluating survival, energy reserves, and gametogenesis of captive mussels in a recirculating pond system. I relocated three mussel species in the summer of 2001 and 10 mussel species in the summer of 2002 to a recirculating pond system (reservoir and raceway) at the hatchery. Water quality parameters of pH, alkalinity, hardness, temperature, and dissolved oxygen; and algal concentrations were measured periodically from summer 2001 to summer 2003. Annual survival rates of 10 species were estimated (August 2002 to August 2003) using the program MARK. Glycogen, protein, and lipid concentrations in mantle tissue of three captive species (Actinonaias ligamentina, Cyclonaias tuberculata, and Tritogonia verrucosa) were compared to those of wild mussels in the New River. Gametogenic activity and synchrony in A. ligamentina and C. tuberculata were compared between captive and wild mussels. Water quality parameters, with the exception of temperature, were within desirable ranges for most of the study. Temperatures of > 28° C were observed for several days during summers 2002 and 2003. Algal concentrations averaged 1903 cells ml-1 in the raceway (range: 300 to 4658 cells ml-1), which is comparable to algal concentrations reported for nearby rivers. The overall survival rate for 10 freshwater mussel species held in the raceway for one year was 77%. Villosa vanuxemensis had the highest survival rate (96%), and Lampsilis cardium had the lowest survival rate (31%). Although there were fluctuations in glycogen, protein, and lipid levels over 2 yr, there were no overall differences in energy substrates between captive and wild mussels at the end of the study. Captivity did not appear to have a negative affect on gametogenesis. Captive C. tuberculata spawned within the expected time frame between January and June, but slightly earlier than their wild counterparts in the New River. Due to the infestation of the gonads of both captive and wild A. ligamentina by digenean trematodes, little gametogenesis was observed. However, captive holding did not appear to have an effect on trematode infestation rates. From these results, I conclude that captive holding conditions in the recirculating pond system at WSSNFH were adequate for long-term holding of a wide range of mussel taxa. I recommend that WSSNFH continue to be used as an adult holding facility. Further research should be conducted to determine food and habitat preferences of freshwater mussel species in captivity so that optimal holding conditions can be provided for each species. / Master of Science

The slime mold Dictyostelium discoideum has two developmentally regulated forms of the enzyme glycogen phosphorylase. The inactive ’b’ form requires 5'AMP for activity and is present in early development, whereas the active ’a’ form is 5'AMP independent and is present in late development. Polyclonal antibodies raised to purified forms of the enzyme show low cross-reactivity. The anti-’a’ is specific for a 104 kd protein associated with phosphorylase ‘a’ activity; the anti-’b’ is specific for a 92 kd protein associated with the ’b’ activity. The two antibodies inhibit the activities of their corresponding antigens, furthermore, each antibody recognizes the proteolytic products of its corresponding antigen. In the presence of exogenously added Mn²⁺ and ATP, the ‘b’ form shows apparent conversion to a 5'AMP independent form as detected spectrophotometrically. This apparent conversion is accompanied by in vitro phosphorylation of the ’b’ enzyme by a Mn²⁺ dependent protein kinase. The ’b’ kinase also phosphorylates casein in the presence of Mg²⁺ or Mn²⁺. In vivo phosphorylation of the ’b’ form was observed in early development. Phosphorylation of the ’b’ form did not result in the appearance of the 104 kd protein. At this point, it is unclear whether Dictyostelium phosphorylase ’a’ represents a phosphorylated and activated form of the ’b’ form, or whether it represents a separate gene product. / Ph. D.

Two weeks of sprint interval training (SIT) increased maximal aerobic power (VO2peak), however maximal anaerobic power (Wmax; 30-sec “all out” Wingate test) was unaffected, possibly due to chronic fatigue induced by 14 daily training bouts (Rodas et al. Eur. J. Appl. Physiol. 82:480-86,2000). The effect of fewer SIT bouts on these parameters is unknown, and no study has assessed changes in performance or muscle metabolism during intense aerobic exercise after SIT. PURPOSE: We examined whether 6 bouts of SIT, performed over 2 wks with 1-2 d rest between bouts, elicited changes in endurance performance or metabolism during a “challenge ride” to exhaustion @ ~80% VO2peak· METHODS: 8 subjects (6 men; 23±2 yr) were studied before and 2-3 d following the SIT protocol (6 bouts x 4-8 Wingate tests, 4 min rest). RESULTS: VO2peak was unchanged by SIT (Post: 45.5 ± 5 vs. Pre: 44.6 ±3.2 ml/kg/min) as was mean power during 4 repeated Wingate tests (Post: 574.8 ± 29.9 vs. Pre: 569.8 ±31.3 W). Wmax during 4 repeated Wingate tests increased by 14% following SIT (Post: 1067.0 ± 234 vs. Pre: 934.3 ± 173.6 W; p < 0.05). Most strikingly, cycle time to exhaustion increased by 101% after SIT (Post: 51.1 ± 30.8 vs. Pre: 25.4 ± 14.4 min, p < 0.01). Biopsies obtained prior to, and during the challenge rides revealed that resting muscle glycogen was higher after SIT (Post: 614 ± 39 vs. Pre: 489 ± 57 mmol/kg dry wt., p < 0.02), and glycogen degradation during exercise was attenuated (p < 0.05). The maximal activity of CS was 29% higher following training (Post: 16.7 ± 2.3 vs. Pre: 11.5 ± 1.8 mmol/kg wet wt., p < 0.05) which is indicative of a higher muscle oxidative potential. CONCLUSION: 6 bouts of SIT (~15 min total exercise time) markedly increased intense aerobic cycling performance and peak anaerobic power. The physiological mechanisms that account for these improvements remain to be fully elucidated, but include alterations in glycogen metabolism and an increased muscle oxidative potential. / Thesis / Master of Science (MS)

G6Pase-alpha and G6Pase-beta share kinetic properties and active site structures, which lie on the luminal side of the endoplasmic reticulum (ER). For hydrolysis of G6P to glucose, G6Pase-alpha or G6Pase-beta must couple with an ubiquitously expressed ER-transmembrane protein, the G6P transporter (G6PT) that translocates G6P from the cytoplasm into the lumen of the ER. The primary role of the G6Pase/G6PT complex is therefore to provide endogenous glucose to the ER lumen. The essential role of the G6Pase-alpha/G6PT complex in glucose homeostasis has been well established, and the deficiencies in G6Pase-alpha and G6PT cause glycogen storage disease type Ia (GSD-Ia) and GSD-Ib, respectively. Both patients manifest the same metabolic phenotype of disturbed glucose homeostasis. While the metabolic abnormalities of GSD-Ia and GSD-Ib are almost identical, GSD-Ib patients exhibit neutropenia and myeloid dysfunctions which are not observed in GSD-Ia patients. Since G6Pase-beta and G6PT share an ubiquitous expression pattern, we hypothesized that the G6Pase-beta/G6PT complex might be functional in neutrophils and that the myeloid defects in GSD-Ib are due to the loss of activity of that complex. To test this hypothesis, we generated G6Pase-beta-deficient (G6pc3 --/--) mouse strains and showed that G6pc3--/-- mice manifest neutropenia; defects in neutrophil respiratory burst, chemotaxis, and calcium flux; and increased susceptibility to bacterial infection mimicking GSD-Ib patients. Consistent with this, G6pc3--/-- neutrophils exhibit enhanced ER stress and apoptosis. Taken together, the results demonstrate that endogenous glucose production in the ER via G6P translocation and metabolism are critical for normal neutrophil functions and that an ER stress-mediated neutrophil apoptosis is one mechanism underlying myeloid dysfunctions in the G6pc3--/-- mice. / Macrophages are the abundant leukocytes in the decidua throughout pregnancy and were thought to play a vital role in decidual homeostasis, placental development, and maintenance of a successful pregnancy. We hypothesized that endogenous glucose production in the ER might also be critical for normal macrophage function and G6pc3--/-- females manifesting neutropenia, neutrophil and macrophage dysfunctions might suffer from pregnancy-associated complications. Here we show that G6pc3--/-- macrophages exhibited impaired respiratory burst activity and repressed trafficking in vivo during an inflammatory response. The litter size and pregnancy frequency were markedly reduced in female G6pc3--/-- matings as compared to female G6pc3+/--/G6pc3+/+ matings, indicative of reduced fertility. The pregnancy-associated mortality risk was greatly increased in G6pc3--/--. Pathological analyses revealed that the sick or dying G6pc3--/-- mothers were emaciated and suffered from dental dysplasia and otitis media. Consistent with this, parental male and female G6pc3--/-- mice were more neutropenic than their age-matched virgin G6pc3 --/-- mice. Taken together, our results show that macrophage dysfunction, defective macrophage trafficking, neutrophil dysfunction, and enhanced neutropenia underlie the reduced fertility and increased mortality of G6pc3--/-- mothers. / Cheung, Yuk Yin. / Advisers: Janice Chou; Kam Bo Wong. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 92-107). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Introdução: A glicogenose hepática tipo 1 (GSD I) é um erro inato do metabolismo (EIM), ocasionada pela presença de mutações patogênicas em genes que codificam enzimas envolvidas no catabolismo do glicogênio, levando ao acúmulo desse substrato e de gordura no fígado, rins e mucosa intestinal, ocasionando alterações metabólicas importantes que comprometem significativamente a qualidade de vida do indivíduo. O tratamento da GSD I é essencialmente dietético, e objetiva proporcionar uma fonte contínua de glicose para evitar a hipoglicemia e prevenir distúrbios metabólicos secundários, através da administração frequente de amido de milho cru (AMC) e/ou dieta contínua noturna administrada por sonda nasogástrica ou gastrostomia, além da restrição de frutose, sacarose e lactose, bem como suplementação de vitaminas e minerais. Em pacientes com complicações graves, o transplante hepático pode ser indicado. A não adesão aos tratamentos é um problema de saúde pública de magnitude mundial e sabe-se que a baixa adesão às intervenções prescritas é um problema complexo e presente especialmente em pacientes com doenças crônicas. Não foram encontrados estudos sobre adesão ao tratamento em glicogenoses hepáticas. Estudos realizados sobre adesão relacionada à fenilcetonúria (EIM com tratamento com restrição alimentar semelhante, sob alguns aspectos, às glicogenoses) indicaram, para essa doença, que o nível de adesão depende de múltiplos fatores e também foi evidenciado um alto nível de não adesão. Objetivo: Caracterizar a adesão ao tratamento de pacientes com GSD I e identificar os fatores que influenciam a adesão desses pacientes. Métodos: Estudo transversal cuja amostra foi selecionada por conveniência, incluindo indivíduos com diagnóstico de GSD Ia e GSD Ib acompanhados no ambulatório de EIM do Serviço de Genética Médica do Hospital de Clínicas de Porto Alegre. Os dados foram coletados através de revisão de prontuário e entrevista com pacientes ou familiares. Dois questionários foram aplicados a eles contendo questões sobre hábitos de vida, suporte social, percepção da dieta e conhecimento sobre a doença. A adesão foi avaliada por meio dos marcadores biológicos de tratamento e as variáveis foram analisadas estatisticamente para verificar possíveis associações. Resultados: Dezoito pacientes foram incluídos. A mediana de idade foi de 6,5 anos (IQ = 9 a 34 anos). Onze pacientes foram classificados como aderentes ao tratamento. A totalidade dos pacientes de GSD subtipo Ib foi aderente. O convívio com o pai e a mãe foi um dos fatores associados à adesão (p=0,049). Três pacientes tiveram um ótimo nível de 6 adesão. A maioria apresentou conhecimento satisfatório sobre a doença. Restrição dietética, acordar durante a madrugada, palatabilidade do AMC, custo da dieta e a distância da residência do paciente ao ambulatório foram as dificuldades mais relatadas. Conclusão: O estudo teve um índice maior de adesão do que o referenciado pela literatura para doenças crônicas. A adesão ao tratamento em GSD I é um tema complexo e que necessita de mais estudos. Compreender os fatores associados à adesão é necessário para a efetividade do tratamento. Nesse estudo, obtiveram-se informações importantes que possibilitam melhor compreensão sobre possíveis fatores que podem contribuir para não adesão ao tratamento das GSD I. Estratégias devem ser elaboradas pelo sistema de saúde e pelos profissionais com o intuito de que as dificuldades associadas ao tratamento sejam trabalhadas e minimizadas em conjunto com os pacientes ou familiares. / Introduction: Glycogen Storage Disease type I (GSDI) is an inborn error of metabolism (IEM) due to the presence of pathological mutations on genes that code enzymes involved in glycogen’s metabolism that leads to the accumulation of this substrate and fat in the liver, kidneys and intestinal mucosa and causes important metabolic alterations that significantly compromise the individual's quality of life. The treatment for GSDI is essentially dietetic and aims to provide a continuous source of glucose to avoid hypoglycemia and also to prevent secondary metabolic disorders, through the frequent administration of uncooked cornstarch (UCCS) and/or continuous nocturnal nasogastric feeding or gastrostomy, restricting fructose, saccharose and lactose besides supplementation of vitamins and minerals. Liver transplant may be indicated for more severely acute patients. Non-adherence to treatments is a world-wide public health matter and it is known that low adherence to prescribed interventions is a complex problem that is present especially in chronic disease patients. To date, no studies were found on adherence to treatment on hepatic glycogen storage disease. Studies on adherence to treatment related to phenylketonuria (EIM with dietetic restriction) indicate that, for this disease, the adherence level depends on multiple factors and a high level of non-adherence has been evidenced. Objective: To characterize adherence to treatment of GSDI patients and identify the factors that influence those patients' adherence. Methods: Convenience sampled in cross-sectional study, including individuals diagnosed with GSDIa and GSDIb followed by the IEM Ambulatory of the Medical Genetics Service of the Hospital de Clínicas de Porto Alegre. The data was collected through medical records review and interviews with patients and/or family members. Two questionnaires were administered with questions about life habits, social support, diet perception and knowledge about the disease. Adherence was evaluated by biochemical biomarkers and the variables were statistically analysed to verify possible associations. Results: 18 patients were included. The median age was 6,5 years. Eleven patients were classified as adherents to treatment. All the GSD patients with subtype Ib were adherent. Living with both parents was one of the factors associated to adherence. Three patients had an optimal level of adherence. Most patients showed satisfying knowledge about the disease. The most reported difficulties were dietetic restriction, waking up in the middle of the night, UCCS 8 palatability, diet cost and distance from the patient’s residence to the ambulatory clinic. Conclusions: The study had a higher index of adherence than referenced by the literature for chronic diseases. Adherence to treatment in GSDI is a complex theme that needs more research. It is necessary to understand the factors associated with adherence to result in effect treatment. In this study, important data was obtained that provides better comprehension of the possible factors that can contribute to non-adherence for the treatment of the GSDI types. Strategies must be considered and incorporated into standards of care by the Health Care System and health professionals to insure that patients and their families understand requirements needed to improve and minimize the difficulties associated with the treatment.

Thesis (Ph. D.)--University of Missouri--Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 143-155). Also available on the Internet.

Introdução: A glicogenose hepática tipo 1 (GSD I) é um erro inato do metabolismo (EIM), ocasionada pela presença de mutações patogênicas em genes que codificam enzimas envolvidas no catabolismo do glicogênio, levando ao acúmulo desse substrato e de gordura no fígado, rins e mucosa intestinal, ocasionando alterações metabólicas importantes que comprometem significativamente a qualidade de vida do indivíduo. O tratamento da GSD I é essencialmente dietético, e objetiva proporcionar uma fonte contínua de glicose para evitar a hipoglicemia e prevenir distúrbios metabólicos secundários, através da administração frequente de amido de milho cru (AMC) e/ou dieta contínua noturna administrada por sonda nasogástrica ou gastrostomia, além da restrição de frutose, sacarose e lactose, bem como suplementação de vitaminas e minerais. Em pacientes com complicações graves, o transplante hepático pode ser indicado. A não adesão aos tratamentos é um problema de saúde pública de magnitude mundial e sabe-se que a baixa adesão às intervenções prescritas é um problema complexo e presente especialmente em pacientes com doenças crônicas. Não foram encontrados estudos sobre adesão ao tratamento em glicogenoses hepáticas. Estudos realizados sobre adesão relacionada à fenilcetonúria (EIM com tratamento com restrição alimentar semelhante, sob alguns aspectos, às glicogenoses) indicaram, para essa doença, que o nível de adesão depende de múltiplos fatores e também foi evidenciado um alto nível de não adesão. Objetivo: Caracterizar a adesão ao tratamento de pacientes com GSD I e identificar os fatores que influenciam a adesão desses pacientes. Métodos: Estudo transversal cuja amostra foi selecionada por conveniência, incluindo indivíduos com diagnóstico de GSD Ia e GSD Ib acompanhados no ambulatório de EIM do Serviço de Genética Médica do Hospital de Clínicas de Porto Alegre. Os dados foram coletados através de revisão de prontuário e entrevista com pacientes ou familiares. Dois questionários foram aplicados a eles contendo questões sobre hábitos de vida, suporte social, percepção da dieta e conhecimento sobre a doença. A adesão foi avaliada por meio dos marcadores biológicos de tratamento e as variáveis foram analisadas estatisticamente para verificar possíveis associações. Resultados: Dezoito pacientes foram incluídos. A mediana de idade foi de 6,5 anos (IQ = 9 a 34 anos). Onze pacientes foram classificados como aderentes ao tratamento. A totalidade dos pacientes de GSD subtipo Ib foi aderente. O convívio com o pai e a mãe foi um dos fatores associados à adesão (p=0,049). Três pacientes tiveram um ótimo nível de 6 adesão. A maioria apresentou conhecimento satisfatório sobre a doença. Restrição dietética, acordar durante a madrugada, palatabilidade do AMC, custo da dieta e a distância da residência do paciente ao ambulatório foram as dificuldades mais relatadas. Conclusão: O estudo teve um índice maior de adesão do que o referenciado pela literatura para doenças crônicas. A adesão ao tratamento em GSD I é um tema complexo e que necessita de mais estudos. Compreender os fatores associados à adesão é necessário para a efetividade do tratamento. Nesse estudo, obtiveram-se informações importantes que possibilitam melhor compreensão sobre possíveis fatores que podem contribuir para não adesão ao tratamento das GSD I. Estratégias devem ser elaboradas pelo sistema de saúde e pelos profissionais com o intuito de que as dificuldades associadas ao tratamento sejam trabalhadas e minimizadas em conjunto com os pacientes ou familiares. / Introduction: Glycogen Storage Disease type I (GSDI) is an inborn error of metabolism (IEM) due to the presence of pathological mutations on genes that code enzymes involved in glycogen’s metabolism that leads to the accumulation of this substrate and fat in the liver, kidneys and intestinal mucosa and causes important metabolic alterations that significantly compromise the individual's quality of life. The treatment for GSDI is essentially dietetic and aims to provide a continuous source of glucose to avoid hypoglycemia and also to prevent secondary metabolic disorders, through the frequent administration of uncooked cornstarch (UCCS) and/or continuous nocturnal nasogastric feeding or gastrostomy, restricting fructose, saccharose and lactose besides supplementation of vitamins and minerals. Liver transplant may be indicated for more severely acute patients. Non-adherence to treatments is a world-wide public health matter and it is known that low adherence to prescribed interventions is a complex problem that is present especially in chronic disease patients. To date, no studies were found on adherence to treatment on hepatic glycogen storage disease. Studies on adherence to treatment related to phenylketonuria (EIM with dietetic restriction) indicate that, for this disease, the adherence level depends on multiple factors and a high level of non-adherence has been evidenced. Objective: To characterize adherence to treatment of GSDI patients and identify the factors that influence those patients' adherence. Methods: Convenience sampled in cross-sectional study, including individuals diagnosed with GSDIa and GSDIb followed by the IEM Ambulatory of the Medical Genetics Service of the Hospital de Clínicas de Porto Alegre. The data was collected through medical records review and interviews with patients and/or family members. Two questionnaires were administered with questions about life habits, social support, diet perception and knowledge about the disease. Adherence was evaluated by biochemical biomarkers and the variables were statistically analysed to verify possible associations. Results: 18 patients were included. The median age was 6,5 years. Eleven patients were classified as adherents to treatment. All the GSD patients with subtype Ib were adherent. Living with both parents was one of the factors associated to adherence. Three patients had an optimal level of adherence. Most patients showed satisfying knowledge about the disease. The most reported difficulties were dietetic restriction, waking up in the middle of the night, UCCS 8 palatability, diet cost and distance from the patient’s residence to the ambulatory clinic. Conclusions: The study had a higher index of adherence than referenced by the literature for chronic diseases. Adherence to treatment in GSDI is a complex theme that needs more research. It is necessary to understand the factors associated with adherence to result in effect treatment. In this study, important data was obtained that provides better comprehension of the possible factors that can contribute to non-adherence for the treatment of the GSDI types. Strategies must be considered and incorporated into standards of care by the Health Care System and health professionals to insure that patients and their families understand requirements needed to improve and minimize the difficulties associated with the treatment.