Hypophosphataemic Osteomalacia and Myopathy: Studies with Nuclear Magnetic Resonance Spectroscopy

Publisher Website
Google Scholar
Abstract
A patient with familial adult-onset hypophosphatemia, whose myopathy was closely related to the plasma phosphate concentration, was investigted by 31P NMR in vivo of the right flexor digitorum superficialis muscle. During hypophosphatemia induced by stopping oral phosphate a significant reduction in measured muscle strength occurred, but the ratios of the intramyocellular levels of phosphocreatine (PCr), ATP and Pi remained unchanged at rest. During exercise these levels changed, as did the intramyocellular pH, but they did not differ from the pattern previously recorded in normal subjects. In 4 adults with inherited infantile-onset hypophosphatemia (vitamin D-resistant rickets, VDRR) without myopathy, the NMR measurements were normal at rest and during exercise. In 1 patient with inherited hyperphosphatemia (tumoral calcinosis) the resting PCr: Pi ratio was significantly reduced.