Pathophysiological aspects of calcium metabolism in spasmophilia.

In order to clarify the pathophysiological mechanisms of spasmophilia, 34 subjects (31 females and 3 males) with spasmophilia were studied. The diagnosis of spasmophilia was based on a specific clinical protocol and electromyographic criteria. In the study, markedly reduced plasma ionized calcium and serum magnesium concentrations were observed together with slightly and non-significantly reduced plasma calcium and phosphate levels. An impairment of intestinal radiocalcium absorption was also noticed. Parathyroid secretion did not show any significant disturbance, but circulating calcitonin levels were found to be significantly lower than in normal subjects. The mean value of serum 25OHD was within the normal range, while a slight reduction in bone Gla protein, an index of osteoblastic activity, was detected. No difference between patients with spasmophilia and normal subjects was observed concerning 47Ca kinetics in red blood cells. The studies indicated that an impaired intestinal calcium transport together with low levels of circulating calcitonin represent the most important pathophysiological determinants of spasmophilia.