The effect of a high protein diet on leucine and alanine turnover in acid maltase deficiency.

Abstract

SUMMARY Leucine and alanine production rate was measured in 5 patients with acid maltase deficiency in the postabsorptive state, following 6 months on a normal diet with placebo and 6 months on an isocaloric high protein diet (16-22% protein). Whole body leucine production rate, a measure of protein degradation, expressed in terms of lean body mass was significantly greater than in five control subjects. Following the high protein diet, leucine production rate was decreased in four of the five patients but this was not statistically significant. Alanine production rate expressed in terms of lean body mass was significantly greater than in control subjects. After the high protein diet, alanine production rate and concentration were significantly decreased (p < 0O05). There were no significant improvements in any ofthe clinically relevant variables measured in these patients. It is possible that a larger increase in protein intake over a longer time period may have a clinical effect.Type II glycogenosis (acid alpha-1,4-glucosidase deficiency) presents either in infancy, or in juvenile or adult forms.' Infants are floppy and develop gross cardiomegaly and hepatomegaly before perishing in the first few years of life.2 Adults tend to present in their late 'teens or twenties with marked truncal and pelvic girdle weakness and impressive paraspinal muscle wasting. However, the key clinical feature is the presence of respiratory insufficiency which is chiefly caused by diaphragmatic weakness or paralysis.34 The diagnosis can be confirmed by finding absent or low levels of acid maltase in muscle,5 cultured skin fibroblasts6 and leucocytes.78The muscle wasting and weakness in the adult-onset disease has been attributed to the disruption of muscle fibres caused by accumulation of glycogen in the sarcoplasm.9 Measurement of protein turnover in a patient with this disorder has demonstrated an increase in whole body protein degradation which suggests that the myopathy may be due to increased muscle breakdown.'" Treatment of the patient with a

Physical therapy management of Pompe disease

“…14 Protein catabolism and abnormal protein metabolism may occur, due to or exacerbated by poor nutrition, with more rapid clearance of branched chain amino acids that normally have a role in muscle protein synthesis. [15][16][17][18] Muscle function may be impaired by loss of contractile mass, decreased contractile function due to clusters of non-contractile material (glycogen) impeding force transmission by interrupting or displacing myofibrils, 12,19,20 decreased oxidative capacity resulting in decreased adenosine-5=-triphosphate (ATP) availability for contraction, and impaired innervation. 21 Clinical presentation and distribution of muscle weakness Weakness in Pompe disease is greater in proximal muscles than distal, greater in lower extremities (LE's) than upper extremities (UE's), and generally symmetrical but imbalanced across joints.…”

Fat and carbohydrate metabolism during exercise in late-onset Pompe disease

“…Clinically, Pompe disease belongs to the second group. However, even though protein metabolism and dietary interventions in combination with exercise have been investigated in a few patients, fat and carbohydrate metabolism during exercise is unknown in Pompe disease [5][6][7][8][9].…”

Management and treatment of glycogenosis type II

“…That the intralysosomal accumulation of glycogen in muscles fibers is not the only pathophysiologic mechanism of progressive muscle damage is supported by the observation that the severity of the myopathy is often out of proportion to the degree of glycogen muscle deposition. 37,40 Diametrically opposite results have been found by the same authors through two different studies. A high-protein diet would counteract muscle protein depletion by supplying amino acid substrates for protein synthesis, 35 thus improving the net protein balance.…”

“…38 The causes of increased muscle protein breakdown, however, remain uncertain although it is likely that the amino acids derived from proteolysis are used as an alternative source of muscle fuel. 37,39,40 Patients with glycogenosis type II who improve after stopping the high-protein diet 40 or who worsen simultaneously with amino acid supplementation 41 are also reported. 28,29 Previously, treatment with high-protein diets, with or without amino acid supplementation, has given dramatic but controversial results.…”