Abstract 
Background:  Pediatric obstructive sleep apnea (OSA) is associated with cognitive dysfunction, suggesting altered neurotransmitter function. We therefore explored overnight changes in neurotransmitters in the urine of children with and without OSA.
Subjects and Methods:  Urine samples were collected in children with OSA and controls before and after sleep studies. A neurocognitive battery assessing general cognitive ability (GCA) was administered to a subset of children with OSA. Samples were subjected to multiple ELISA assays for 12 neurotransmitters, and adjusted for creatinine concentrations.
Results:  50 children with OSA and 20 controls were studied. Of the children with OSA, 20 had normal GCA (101.2±14.5) and 16 had reduced GCA (87.3±13.9; p<0 .001=".001" 0.923="0.923" 0.977="0.977" 4="4" alterations="alterations" and="and" approaches="approaches" as="as" changes="changes" children="children" combinatorial="combinatorial" cut-off="cut-off" decreases="decreases" discriminated="discriminated" emerged="emerged" enabled="enabled" epinephrine="epinephrine" for="for" furthermore="furthermore" gaba="gaba" gca="gca" in="in" increases="increases" levels.="levels." levels="levels" low="low" more="more" neurotransmitters="neurotransmitters" nor-epinephrine="nor-epinephrine" normal="normal" of="of" osa="osa" overnight="overnight" p="p" phenylethylamine="phenylethylamine" prediction="prediction" prominent="prominent" reductions="reductions" reliably="reliably" span="span" status="status" taurine="taurine" than="than" these="these" using="using" values="values" well="well" were="were" with="with">
Conclusions:  Pediatric OSA is associated with overnight increases in urinary concentrations of catecholamines indicative of heightened sympathetic outflow. Increases in GABA and decreases in taurine could underlie mechanisms of neuronal excitotoxicity and dysfunction. Combinatorial approaches using defined cut-offs in overnight changes of selected neurotransmitters in urine may not only predict OSA, but also the presence of cognitive deficits. Larger cohort studies appear warranted to confirm these findings.