To assess (1) plasma levels of antidiuretic hormone (ADH) and brain natriuretic peptide (BNP) and urinary levels of electrolytes in children with sleep disordered breathing (SDB), with or without nocturnal enuresis (NE), and (2) the effect of adenotonsillectomy (T&A) on urinary electrolytes and the secretion of ADH and BNP in children with NE and SDB. We previously reported post-T&A improvements in plasma levels of BNP and ADH in children with SDB and NE. However, the differences in plasma concentration of these hormones in SDB children with and without NE, and their relationships with urinary electrolytes, have not yet been addressed.
This prospective study compared concentrations of urinary electrolytes and plasma ADH and BNP in (1) children with SDB and NE (study group) and an age- and sex-matched control group of children with SDB without NE, and (2) the study group before and 1-month after T&A.
Compared with the control group (n = 31), the study group (n = 37) exhibited significantly lower ADH (P =.04) and higher BNP (P =.009) plasma levels. The differences in urinary electrolytes were not significant. Post-T&A, the study group showed significantly decreased BNP (P =.018), urinary sodium-to-creatinine ratio (P =.02), and urinary calcium-to-creatinine ratio (P =.007) compared with the pre-T&A values. Post-T&A changes in urinary calcium were significantly correlated with changes in sodium excretion (P =.002) and in plasma levels of BNP (P <.001).
The presence of NE is associated with altered ADH and BNP levels in children with SDB. T&A led to normalization of ADH and BNP, probably through a calcium- and sodium-dependent mechanism.