Evaluation of food intake in patients with mucopolysaccharidosis

Background: Mucopoly saccharidosis (MPS) are inborn errors of metabolism (IEM) recognized by deficient enzymes enrolled in glycosaminoglycans catabolism. The resulting accumulation of glycosaminoglycans leads to clinical progressive and generalized manifestations. Considering the severity of MPS and the relevance of establishing dietetic strategies to these patients, the present study was tailored to evaluate the food intake in patients with MPS types I, II, and VI. Methods: Food intake in patients with MPS I, II, and VI was assessed. A descriptive cross-sectional study was conducted. Energetic demand based on estimated necessity of energy equations and reported food intake was analyzed. Total energetic value and nutrients (vitamins B1, B2, C, calcium, iron, and phosphate) were analyzed inaccordance with the standardized interval for macronutrient distribution and the method of apparent adequacy for nutrient intake. Results: Food intake of 17 patients (6- to 30-year-olds) was considered adequate regarding macronutrients. Children and adolescents failed in presenting this parameter. Macronutrients were satisfactory in both groups. Children and adolescents displayed increased intake of iron and vitamins B1 (p< 0.05), B2, B3, and C (p< 0.077)and probability of adequacy≥50%. Calcium and phosphorus intake was greater in adults. Conclusions: The results obtained demonstrated that patients with MPS have nutrition deficiency in their diet, which may directly or indirectly influence the course of the disease.

Metabolic adaptations to interrupted glycosaminoglycan recycling.

Lysosomal storage diseases (LSD) are metabolic disorders characterized by accumulation of undegraded material. The mucopolysaccharidoses (MPS) are LSDs defined by the storage of glycosaminoglycans. Previously, we hypothesized that cells affected with LSD have increased energy expenditure for biosynthesis because of deficiencies of raw materials sequestered within the lysosome. Thus, LSDs can be characterized as diseases of deficiency as well as overabundance (lysosomal storage). In this study, metabolite analysis identified deficiencies in simple sugars, nucleotides, and lipids in the livers of MPSI mice. In contrast, most amino acids, amino acid derivatives, dipeptides, and urea were elevated. These data suggest that protein catabolism, perhaps because of increased autophagy, is at least partially fulfilling intermediary metabolism. Thus, maintaining glycosaminoglycan synthesis in the absence of recycled precursors results in major shifts in the energy utilization of the cells. A high fat diet increased simple sugars and some fats and lowered the apparent protein catabolism. Interestingly, autophagy, which is increased in several LSDs, is responsive to dietary intervention and is reduced in MPSVII and MPSI mice fed a high fat diet. Although long term dietary treatment improved body weight in MPSVII mice, it failed to improve life span or retinal function. In addition, the ventricular hypertrophy and proximal aorta dilation observed in MPSVII mice were unchanged by a high fat, simple sugar diet. As the mechanism of this energy imbalance is better understood, a more targeted nutrient approach may yet prove beneficial as an adjunct therapy to traditional approaches.