Another group of factors under consideration was related to estrogen levels. The first factor was the age at which the first menstruation occurred. The mean age at menarche for allergic students did not differ from that in students without allergies. The subjects were divided into three groups: early onset of puberty (age at menarche lower than the 25th centile), average onset of puberty (age at menarche ranging from the 25th to 75th centile), and late onset of puberty (age at menarche higher than the 75th centile). In the group of girls with early onset of adolescence slightly more subjects reported allergic rhinitis than in groups with the average or late onset of puberty, although the difference was not statistically significant. Also other factors under analysis which may be indicative of estrogen levels, such as WHR and menstrual cycle regularity, were not significantly correlated with the prevalence of allergic rhinitis (Table 2).

The final stage of the analysis involved verifying the relationship between indicators of abnormal amount of adipose tissue and the prevalence of allergic rhinitis. No statistically significant differences in the incidence of allergic rhinitis between underweight, normal-weight, overweight, and obese students were reported; the same was also true of students with and without abdominal obesity (Table 2). Moreover, no significant differences in the mean values of BMI, waist circumference, and WHtR between students with and without allergies were found (Table 3).