Serum nitric oxide metabolite levels in general healthy population: relation to sex and age

Abstract Background: Interest in measuring of serum nitrite/nitrate (NOx) concentration has increased during recent years as there are reports indicating that NOx levels affected by some diseases. Objective: This study was aimed at determining the serum NOx levels in healthy subjects within the framework of a population-based study. Methods: This was a descriptive analytical study carried out within the framework of Tehran lipid and glucose study participant. Serum NOx concentration was measured in 3505 subjects aged 20 years and over. The exclusion criteria were high blood pressure, impaired carbohydrate metabolism, dyslipidemia, and renal dysfunction. Afterthat 786 non-smoker healty subjects were in cluded in the analysis. Serum NOx concentration was determined in all samples obtained following an overnight fasting period. The serum level of NOx in different age groups was further compared. Later, comparison between the lowest and highest quartiles of NOx levels was performed for both genders. Findings: The mean±SD serum NOx concentration was 26.0±12.9 µmol/l with insignificant difference between men (25.6±11.8) and women (26.1±13.3 µmol/l). No age-related change in serum NOx concentration was observed in either sex. Women and not men with high serum NOx had significantly higher weight, waist circumferences, and systolic blood pressure even after adjustment for menopausal status (p<0.05). Conclusions: Based on data found in present study it seems that the serum NOx concentration in healthy subjects to be strongly controlled, thus, any significant change in serum level of NOx could be considered as a reflection of altered physiological status.