Effect of letrozole on characteristics and linear growth of boys in early and middle youth period

Objective To analyze the effect of aromatase inhibitor letrozole on the characteristics and linear growth of boys in early and middle youth period. Methods Thirty children in early-middle youth period who were to be impaired in adult height and treated in our hospital from January, 2016 to January, 2018 were enrolled as a study group. They were treated with letrozole, 1.5 mg/m2 per day. And 30 healthy boys in the early and middle youth stage taking physical examination during the same time period were selected as a control group, and took no drug intervention. The growth characteristics and linear growth changes of the two groups before treatment and after 1 year’s treatment were compared. Results There were no statistical differences in bone age, age, BMI, testicular volume, and height between the study group and the control group before the intervention(all P>0.05). After the intervention, the bone age of the study group was significantly inhibited (P<0.05); the testicular volume of the study group was (7.3±2.8)ml, which was significantly higher than that of the control group [(4.5±1.2) ml, P<0.05]; The study group’s predicted adult height and insulin growth factor 1 (IGF-1) were significantly different from the control group’s (both P<0.05). Conclusion The used of letrozole in boys in early and middle youth stage can effectively inhibit bone age, improve their final height, and achieve their linear growth. Key words: Growth characteristics; Letrozole; Bone growth; Aromatase inhibitor; Linear growth