Obesity Is Associated With Earlier Pubertal Onset in Boys

Alexander S. Busch; Brigitte Højgaard; Casper P. Hagen; Grete Teilmann


J Clin Endocrinol Metab. 2020;105(4) 

In This Article


In the clinical study cohort of obese children, initial pubertal milestones, that is, testicular volume ≥ 4 mL, genital stage ≥ 2, and pubarche occurred at 11.3 years (11.0–11.6), 11.6 years (11.3–11.9), and 11.9 years (11.5–12.3), respectively. Detailed timing of pubertal milestones for both the study cohort as well as the population-based controls are shown in Table 1 and Figure 1. Pubertal milestones in obese boys occurred at the same age or earlier compared to the population-based controls. We observed a significant difference in timing of testicular enlargement between the controls and the obese study cohort (P = 0.01). However, timing of the genital stage ≥ 2 and pubarche did not differ significantly (P = 0.94 and 0.06, respectively). Further, comparing overweight controls (+1SD < zBMI ≤ +2SD) to obese (zBMI > +2SD) boys, we did not observe a significant difference in the timing of either testicular enlargement (P = 0.54), genital stage ≥ 2 (P = 0.62), or pubarche (P = 0.78). In addition, comparing obese boys (+2SD < zBMI ≤ +3SD) with very obese boys (zBMI > +3SD), we did not observe a significant difference in the timing of either testicular enlargement (P = 0.19) or the genital stage ≥2 (P = 0.15). However, pubarche occurred significantly earlier in very obese boys (zBMI > +3SD) compared to obese boys (+2SD < zBMI ≤ +3SD) (P = 0.002). Visualizing the entire dataset, we plotted the timing of pubertal events into puberty nomograms of a previously published Danish population reference (Figure 2),[14] indicating normal progression of puberty in obese boys.

Figure 1.

Timing of pubertal milestones in obese boys compared to population-based reference cohort. Timing of testicular enlargement ≥ 4 mL (diamond), genital stage ≥ 2 (triangle), and pubarche (square) stratified by zBMI score. Left panel, COPENHAGEN puberty study (blues); right panel, Hillerød obesity cohort (red: +2SD < zBMI ≤ +3SD; black: zBMI > +3SD). [From (5, 21).]

Figure 2.

Pubertal development in obese boys compared to population-based reference puberty nomograms. Upper panel, genital stage (G1–5); middle panel, testicular volume (in mL); lower panel, pubic hair (PH1–5). Black or red symbols represent pubertal development in subjects with a zBMI > +3SD or +2SD < zBMI ≤ +3SD, respectively. White areas represent the 95% CI, while the light and dark grey areas extend to the 1st and 99th percentile and < 1st and > 99th percentile, respectively. Figures include all measurements, including data from the longitudinal part.