ABSTRACT
Adult-onset acid maltase deficiency is an inherited lysosomal skeletal-muscle disease characterized by progressive myopathy and respiratory failure, for which there is no known therapy. In an uncontrolled, prospective study, we evaluated whether adherence to high-protein and low-carbohydrate nutrition and exercise therapy (NET) can slow the progressive deterioration of muscle function in this disease. Thirty-four patients have been treated with NET for periods of 2-10 years (mean 4.5 +/- 2.5). Pre-NET rate of muscle function deterioration, as measured by the Walton scale, was compared to post-NET rate. Twenty-six patients were deemed to be consistently compliant with NET. Difference between pre-NET slope of muscle function deterioration to that of post-NET slope in compliant patients was -0.29 (95% CI -0.19, 0.39) (P < 0.0001). We conclude that compliance with NET can slow deterioration of muscle function and improve the natural history of adult-onset acid maltase deficiency. Muscle Nerve, 2006.
Subject(s)
Exercise Therapy/methods , Glycogen Storage Disease Type II/therapy , Muscular Diseases/therapy , Nutrition Therapy/methods , Adult , Aged , Dietary Carbohydrates/metabolism , Dietary Carbohydrates/therapeutic use , Dietary Proteins/metabolism , Dietary Proteins/therapeutic use , Disease Progression , Female , Food, Formulated , Glycogen Storage Disease Type II/metabolism , Glycogen Storage Disease Type II/physiopathology , Humans , Male , Middle Aged , Muscle, Skeletal/metabolism , Muscle, Skeletal/physiopathology , Muscular Diseases/metabolism , Muscular Diseases/physiopathology , Patient Compliance , Physical Fitness/physiology , Prospective Studies , Respiratory Function Tests , Respiratory Insufficiency/metabolism , Respiratory Insufficiency/physiopathology , Respiratory Insufficiency/therapy , Treatment Outcome , Vital Capacity/physiologyABSTRACT
Two brothers with the childhood variant of type II glycogenosis (GSD-IIb) treated with nutrition and exercise therapy (NET) from a young age showed an unusually benign course. Muscle biopsy from the older brother, which showed characteristic vacuolar glycogen accumulation at age 2, had reverted to normal by age 16. A muscle biopsy from the younger brother was normal at 5 years. It is uncertain whether this anomalous evolution was spontaneous (nature) or due to the symptomatic therapy (nurture), but NET should be considered in patients with GSD-IIb until enzyme replacement or gene therapy become generally available.
