Acid maltase deficiency in an adult. Evidence for improvement in respiratory function with high-protein dietary therapy.

Acid maltase deficiency (AMD) in the adult is associated with progressive ventilatory muscle weakness and death from respiratory failure, but effective therapy is not available at present. Because recent evidence suggests that muscle catabolism may contribute to muscle weakness in AMD, we treated a 55-yr-old man with AMD and severe ventilatory muscle weakness with a high-protein (1.6 g/kg), weight-reducing diet for 27 months. High-protein dietary therapy was associated with striking improvement in respiratory function, including measures of ventilatory muscle strength and endurance. We suggest that high-protein dietary therapy may be useful in adults with AMD and respiratory insufficiency.