Age at Menarche Is Associated With Leg-Length Components Among the Adolescent Girls in West Bengal, India

The relationship between early age at menarche (AAM) and body height (HT), including its different segments has not been extensively studied among non Western populations. Lengths of the lower (distal) part of the leg, such as knee HT (KH) and tibial length (TbL), are considered to be sensitive indicators of living conditions during early growth and development. Life history theory predicts that within a survival challenge the growth of vital parts of the body shall be prioritized over less essential parts. The present study hypothesized that earlier age at menarche would be associated with shorter tibial length in resource constrained settings.

To investigate the potential associations of menarcheal age with HT, KH, TbL, and other linear components of HT among the Bengalee schoolgirls aged 10-13 years.

Among the 208 girls aged 10-13 years, menarcheal status and age at menarche were determined by status quo and retrospective methods, respectively. Lower leg length was represented by two measures, KH and the supracutaneous measure of TbL. The differences in HT, sitting HT (SH), total leg length (LL), thigh length (TL), KH, and TbL, between pre-menarcheal-(PMG) and post-menarcheal girls (POMG), as well as between earlier menarcheal-(EMG) and later menarcheal girls (LMG), were assessed by student t-test and analysis of covariance.

The POMG were heavier, taller and had higher adiposity than their PMG peers, without showing any significant age-difference. HT, knee HT, TbL, and TbL to HT ratio showed significant differences between the EMG and LMG. The EMG showed lower values for all of those measures and the strongest difference was observed for TbL. However, there were no significant differences in SH and SHR between EMG and LMG.

The study indicated a possible effect of early AAM on growth of distal body parts in a resource poor socioeconomic condition. Further studies on the relationship between growth and AAM among different populations living in different socio-ecological conditions could be worth conducting.