Effect of the menstrual cycle on serum diamine oxidase levels in healthy women

ObjectivesSerum diamine oxidase (DAO) level is employed as a useful marker of intestinal mucosal integrity. As reported previously, the range of serum DAO levels in women is wider than that in men. We hypothesized that the menstrual cycle may affect DAO levels.Design and methodsThirty-six women of Japanese descent were recruited. All participants, aged 20–29 years, were healthy. Food surveys utilized in this study were based on questionnaires validated by dietitians. Complete blood counts, biochemical parameters, female hormones, and serum DAO levels during the follicular and luteal phases were measured in each subject.ResultsBiochemical parameters, except for DAO levels, were comparable between the two phases. However, serum DAO levels during the luteal phase were significantly higher than those during the follicular phase.ConclusionsSerum DAO levels were influenced by the menstrual cycle. Furthermore, our findings suggest that serum DAO levels should be interpreted cautiously in premenopausal women.

► DAO activity is employed as a useful marker of intestinal mucosal integrity.
► We investigated the influence of menstrual cycle on DAO levels in healthy women.
► DAO activity was significantly higher during the luteal phase than follicular phase.
► Serum DAO levels are influenced by the menstrual cycle.