What is the Most Effective Method for Predicting Adult Height in Boys with Constitutional Delay of Growth and Puberty?

Objective: Predicted adult height (PAH) can be calculated using methods such as Bayley-Pinneau (BP), Roche-Wainer-Thissen (RWT), and BoneXpert based on bone age (BA) assessment. Since these methods were developed for healthy children, varying results have been reported regarding their efficacy across different patient groups. Our aim was to determine the most accurate method for PAH by comparing the BP, RWT, and BoneXpert methods in boys with constitutional delay of growth and puberty (CDGP). Methods: Male patients with CDGP who had reached their final height (FH) were included in the study. Two experienced clinicians reassessed left-hand and wrist radiographs taken at the time of diagnosis using the Greulich-Pyle (GP) atlas to manually determine BA. Among the methods used for PAH, the GP atlas was used for BP and RWT, while we used the intrinsic GP-based application with BoneXpert. Results: For the 62 boys included, the mean age at diagnosis was 14.2±0.8 years, with 58.1% (n=36) having a similar family history. The mean height standard deviation (SD) score was -2.1±0.9, and 24.2% (n=15) of patients received low-dose testosterone induction therapy. The median (range) BAs were 12.5 (11.5-13.0) years using the GP atlas and 12.6 (11.8-13.4) years with BoneXpert (p<0.001). Boys who were or were not treated with testosterone therapy had similar mean height SD scores, median testicular volumes, and median BAs assessed by both methods. The mean target height and FH SD scores were -0.6±0.6 and -0.6±0.9, respectively (p=0.8). Almost all patients (n=60, 97%) achieved adult height within the target range, with no significant difference in the FH SD score between boys who received testosterone and those who did not (p=0.1). There was no significant difference between the FH and PAH when estimated by the BP and RWT methods (p=0.2 and p=0.6, respectively), while the BoneXpert method underestimated the FH (p<0.001). The BP and RWT methods provided better predictions in patients with BA ≤2 years compared to BoneXpert (p=0.3 and p=0.4 vs. p<0.001, respectively). Conversely, RWT and BoneXpert methods were more accurate in PAH in boys with delayed BA >2 years (p=0.1 and p=0.1, respectively), while the BP method resulted in overestimation (p=0.003). Conclusion: The RWT method was found to be a better predictor of FH compared to the BP or BoneXpert methods in boys with delayed BA ≤2 years and >2 years.