Gender-, age- and time-dependent dosing of growth hormone in adults – real-world data from a decade of clinical practice in Germany

We evaluated treatment patterns and gender-dependent dosing of growth hormone (GH) substitution in adults with GH deficiency (AGHD). Data on GH dose were collected (2003–2013) from 509 GH-treated patients (mean age: 48.9 years; 47% female) enroled in the observational German NordiWin study (NCT01543880). The impact of gender, age, treatment duration and calendar year on GH treatment patterns was evaluated by multiple regression analysis. Mean (SD) baseline GH dose (mg/day) was similar between females (0.25 [0.19] and males (0.24 [0.15]), but increased with treatment duration (at year 10, 0.55 [0.48] and 0.31 [0.09] in females and males, respectively), reflecting patient dose titration. GH dose increased more in females than males during treatment; this was statistically significant in years 2–6 (p < 0.05). Over the 10-year study period, a time trend of an overall estimated GH dose increase by 0.06 mg/day (females) and decrease by 0.07 mg/day (males) was shown; this interaction of gender and calendar year was significant (p < 0.0001). In both genders, overall GH dose decreased with increasing age (p < 0.0001). Our study confirms that females and younger patients require higher GH doses compared with males and older patients.