Association of childhood obesity with pubertal development in boys: A systematic review and meta-analysis

Childhood obesity leads to early puberty development in girls, but its effect in boys remains unclear. We conducted a systematic review and meta-analysis to study the association between childhood obesity and puberty development in boys. We included 14 cohort studies with 114,822 boys. Meta-analysis showed that childhood overweight (RR, 1.44; 95%CI, 1.08-1.93; the number of studies [N] = 4) and obesity (RR, 1.35; 95%CI, 1.11-1.64; N = 5) were associated with the earlier occurrence of testicular volume ≥4 mL (Tanner stage 2). Age reaching Tanner stage 2 in overweight boys was earlier than normal-weight boys (mean difference: -0.23 years, 95% CI: -0.37 to -0.08; N = 2); a similar trend was observed in obese boys, but the effect estimate did not reach significance level (mean difference: -0.27 years, 95% CI: -0.59 to 0.05; N = 3). Similarly, the age at pubarche in boys with overweight/obesity was earlier than those with normal weight. Qualitative analysis shows first nocturnal emission; change in voice and peak height velocity in boys with overweight/obesity appeared to develop earlier than those with normal weight. These findings suggest overweight/obesity is associated with earlier pubertal development in boys. Due to the limited number of studies identified in this review, further studies are warranted to confirm these associations.