Aromatase inhibitors: a useful additional therapeutic option for slowing down advanced bone age in boys with growth hormone deficiency.

Abstract

Aromatase inhibitors (AIs) have been used to slow down estrogen-dependent skeletal maturation in pubertal boys with short stature. In the literature, few data evaluate the effectiveness and safety of AIs in boys with growth hormone deficiency (GHD). This study aimed to evaluate the auxologic effects and short-term laboratory profiles of combined AI and rhGH therapy for 1year in adolescent males with GHD. Male subjects between the ages of 10 and 16 with GHD from two different centers were included in the study. Patients were divided into two groups: (i) those who only used recombinant human growth hormone (rhGH) therapy (Group I; G-I) and (ii) those who also used AI therapy (anastrozole or letrozole) along with rhGH (Group II; G-II). Forty-one patients (G-I, 46%; G-II, 54%) were included in the study. All the subjects had isolated GHD. At the beginning of the treatment, the chronological ages (CAs) of the patients in the G-I and G-II groups were 11.8 (10.9-13.7) and 12.8 (12.0-14.3) years, respectively. The ratios of bone age (BA)/CA for the two groups were 0.8 (0.8-0.9) and 1.0 (0.9-1.1), respectively (p < 0.001). After the treatment, the height standard deviation (SD) scores and predicted adult height (PAH) significantly increased from baseline in all subjects in the G-I and G-II groups (p < 0.001; p < 0.001, respectively). There was no significant change in the ratio of BA/CA post-therapy in the G-I group (p = 0.1), while there was a significant decrease in the G-II group (p < 0.001). The growth velocities of the patients in the G-I and G-II groups were 9.1 (7.4-10.1) cm/year [1.5 (0.8-5.0) SD score] and 8.7 (7.5-9.9) cm/year [1.1 (0.3-3.1) SD score], respectively (p = 0.6). While post-therapy serum testosterone concentrations were seen to increase in the G-II group, none of the patients exhibited hematocrit above 50 percent, and the fasting glucose concentrations were normal. When used in addition to rhGH therapy in boys with GHD and advanced BA, AIs were observed to slow down the tempo of BA maturation after 1year, compared to those who received rhGH treatment alone. AI therapy was found to be safe during the 1-year observation period and thus could be considered for preserving growth potential in these patients.