Reference values for serum nitric oxide metabolites in an adult population.
OBJECTIVE
To determine reference values for serum nitric oxide metabolites (nitrite+nitrate=NO(x)) concentrations in adult subjects.


METHODS
Serum NO(x) concentration was measured, using the Griess method, in 694 non-smoking apparently healthy subjects, randomly selected from a population-based study. The International Federation of Clinical Chemistry guidelines and the robust method were used for determining reference values.


RESULTS
The 95% reference values for serum NO(x) concentration and serum NO(x)/creatinine ratio were 11.5 to 76.4 micromol/L and 0.111 to 0.729 in men and 10.1 to 65.6 micromol/L and 0.121 to 0.777 in women, respectively. With increasing body mass index, upper limits of serum NO(x) and the NO(x)/creatinine ratio increased in women and decreased in men. Serum NO(x) levels above upper limits predicted both diabetes and metabolic syndrome in women.


CONCLUSIONS
This study reports the first set of reference values for serum NO(x) concentration and NO(x)/creatinine ratio in a relatively large healthy non-smoking population.
Endocrine Physiology Laboratory, Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, PO Box 19395-4763, Tehran, Iran.
Asghar
A
Ghasemi
Saleh
S
Zahediasl
Fereidoun
F
Azizi
D000328:Adult; D000886:Anthropometry; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000097:blood*; D011247:Pregnancy; D012016:Reference Values; D012907:Smoking; D055815:Young Adult
D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide