Blood asymmetric dimethylarginine and nitrite/nitrate concentrations in short-stature children born small for gestational age with and without growth hormone therapy

OBJECTIVE: To investigate the basal amino acid metabolism and impact of growth hormone (GH) therapy in short-stature children born small for gestational age (short SGA children). METHODS: In this age-matched case-control study, the basal blood levels of amino acids, asymmetric dimethylarginine (ADMA), and nitrite/nitrate (NOx) were compared between 24 short SGA children and 25 age-matched normal children. Changes in these parameters were assessed for 12 months in 12 short SGA children initiating GH therapy (Group A) and 12 age-matched short SGA children without GH therapy (Group B). RESULTS: The arginine levels were significantly lower in the short SGA than in normal children. The ADMA levels were significantly higher and NOx levels were significantly lower in the short SGA than normal children. In Group A, the ADMA level was significantly lower and NOx level was significantly higher at 6 months than at baseline. At 12 months, the ADMA level in Group A began to increase, but the NOx level remained the same. Group B showed no significant changes. CONCLUSIONS: This study is the first to show that ADMA is promoted and nitric oxide is suppressed in short SGA children and that GH therapy affects the production of ADMA and nitric oxide.