Mevorach et al1 report that the specific gravity of the first urine specimen of the morning is significantly lower in children with nocturnal enuresis compared with that of children without this problem. Based on this information, Mevorach et al suggest that a trial of desmopressin acetate "is likely to fail in a child who already concentrates urine adequately." This statement is not supported by their data or a review of the literature.2,3 The article by Moffatt et al,4 cited by Mevorach et al in defense of this statement, is a review article and does not provide any original data. The only mention of urine concentration in the article by Moffatt et al is the citation of two references that report on the urine osmolality after treatment with desmopressin. There are no data on pretreatment urine osmolality in these articles.
Evans and Meadow2 reported that the nocturnal