Health-associated reference values for arginine, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) measured with high-performance liquid chromatography.

OBJECTIVE: Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide production. It has been implicated in various pathological processes, especially processes involving the cardiovascular system. Plasma concentration of ADMA (p-ADMA) has been measured in several studies with different techniques, and a wide range of normal values has been published. With use of high performance liquid chromatography (HPLC) with fluorescence detection, we have established health-associated reference values for p-ADMA, p-arginine, p-SDMA and the p-arginine/p-ADMA and p-arginine/p-SDMA ratios.
MATERIAL AND METHODS: Blood samples were taken from 238 blood donors (112 F and 126 M). HPLC was used to analyse arginine, ADMA and SDMA. Reference values are presented as 2.5 and 97.5 percentiles estimated by the bootstrap method.
RESULTS: The reference interval for p-ADMA is 0.40-0.77 micromol/L for the whole population, 0.41-0.79 micromol/L for men, 0.38-0.73 micromol/L for women 45 years or less, and 0.41-0.84 micromol/L for women >45 years.
CONCLUSIONS: Age affects p-ADMA in healthy women, but not in men.