The effect of early menarche on later body composition and fat distribution in female adolescents: role of birth weight.

BACKGROUND

To examine the effect of early menarche (EM) on adolescent body composition and fat distribution, and to explore the possible contribution of birth weight (BW) to this relationship.

METHODS

From the cross-sectional AVENA study, 788 girls (aged 13-18.5 years) were selected. Post-menarcheal body composition was estimated by anthropometric methods.

RESULTS

BW Z-score was associated with age at menarche (beta = 0.496, p < 0.001). EM (age of menarche <12 years) adolescents were shorter, had a higher body mass index (BMI), fat free mass index (FFMI), fat mass index (FMI) and waist circumference (all p < 0.01). BW was associated with height (p < 0.001), BMI Z-score (p < 0.01), FFMI (p < 0.01) and FMI (p < 0.05). These relationships did not change when the analysis was controlled for age of menarche. Height and FFM were lower in EM (p < 0.01), but these effects seem to be due to the BW (p < 0.01).

CONCLUSION

EM was strongly associated with unhealthy body composition in female adolescents, but these relationships seem to be due to the programming effect of BW.