Sodium excess in postmenopausal osteoporosis.

The sodium excess (Naes) which represents the nonexchangeable sodium compartment of bone was calculated from the total body sodium and total body chlorine of 95 women with vertebral crush fracture syndrome. No evidence was found for a subpopulation with increased or decreased Naes or Naes:TBCa ratio (TBCa is total body calcium which reflects total skeletal mass). Correlations in the osteoporotic women were found between the Naes and serum alkaline phosphatase (r = 0.31), PTH (r = 0.53), urinary hydroxyproline excretion (r = 0.42) and serum 250H vitamin D (r = -0.32). These data suggest that the state of vitamin D nutrition as well as parathyroid hormone levels may influence the quantity of sodium in bone in osteoporotic women. It is of great interest that these relationships were not observed in two control populations consisting of elderly women and women who recently underwent spontaneous menopause.