In reply
The interesting patients described by Milionis et al provide further evidence that hypernatremia may not infrequently be associated with normal or increased body water. Others have noted that patients with volume depletion may become overloaded with salt and water for days when given large volumes of fluid containing both salt and glucose.1,2 The development of hypernatremia in such cases may reflect primarily excessive salt retention, possibly at a site not associated with much water reabsorption, such as the distal convoluted tubule. Less than maximal production and/or action of antidiuretic hormones in this setting may be physiologically appropriate to prevent fluid overload. This condition may be the opposite of that which occurs in cases of hyponatremia with "renal salt wasting," in which antidiuretic hormone levels are high to maintain volume despite low serum osmolality.3