Reference urinary LTE4 levels in normal individuals: a pilot study.

Abstract The definition of reference normal values for urinary LTE4 still represents an open question. AIM: to assess the influence of gender and age on urinary LTE4 levels in normal individuals. METHODS: after their informed consent, urinary LTE4 was measured in 124 well matched, non smoker, non atopic subjects (mean age 49.5 y +/- 20.1 sd; range 4-85 y, 57 m;) without any clinically evident disease and not taking any drug for several months. In all subjects, urine were collected in the morning, and processed by an immunoenzimatic method (Cayman Chem, Mi, USA) via the Triturus system (Grifols, Spain). STATISTICS: t test, anova, linear regression, assuming p < 0.05. RESULTS: mean urinary LTE4 were 57.3 pg/ml in males (mean age 51.2 y +/- 21.3 sd) and 57.0 pg/ml in females (mean age 48.1 y + 19.1 sd), p = ns. Linear regression showed no relationship between urinary LTE4 levels and subjects' age in the whole sample of subjects. When subjects were divided according to 4 different classes of age (0-14; 15-40; 41-60; > 60), anova proved that mean urinary LTE4 levels were significantly different in the different classes of age, being higher in younger subjects (67.1 pg/ml +/- 33.4 sd; 69.8 pg/ml +/- 27.5 sd; 57.1 pg/ml +/- 25.4 sd, and 45.1 pg/ml +/- 24.9, respectively) (anova p < .002; Welch test p < .005). CONCLUSIONS: 1) gender does not affect urinary LTE4 levels in normals; 2) mean urinary LTE4 concentrations tend to a slight, but significant, decrease with the increase of the subjects' age, and this is clear in those over-60; 3) reference values for younger and older normal subjects (such as, under- and over-60 years) should be assumed accordingly.