Rural–urban variations in age at menarche, adult height, leg-length and abdominal adiposity in black South African women in transitioning South Africa

Abstract

Background: The pre-pubertal socioeconomic environment may be an important determinant of age at menarche, adult height, body proportions and adiposity: traits closely linked to adolescent and adult health.

Aims: This study explored differences in age at menarche, adult height, relative leg-length and waist circumference between rural and urban black South African young adult women, who are at different stages of the nutrition and epidemiologic transitions.

Subjects and methods: We compared 18–23 year-old black South African women, 482 urban-dwelling from Soweto and 509 from the rural Mpumalanga province. Age at menarche, obstetric history and household socio-demographic and economic information were recorded using interview-administered questionnaires. Height, sitting-height, hip and waist circumference were measured using standardised techniques.

Results: Urban and rural black South African women differed in their age at menarche (at ages 12.7 and 14.5 years, respectively). In urban women, a one-year increase in age at menarche was associated with a 0.65 cm and 0.16% increase in height and relative leg-length ratio, respectively. In both settings, earlier age at menarche and shorter relative leg-length were independently associated with an increase in waist circumference.

Conclusions: In black South African women, the earlier onset of puberty, and consequently an earlier growth cessation process, may lead to central fat mass accumulation in adulthood.

Keywords:

• Age at menarche
• height
• body proportions
• adiposity
• nutrition transition

Acknowledgements

We would like to thank the participants of the Birth-to-twenty cohort and of the Ntshembo cross-sectional survey for their time and for contributing to these studies. The MRC/Wits Agincourt Unit is supported by the South African Medical Research Council and the Wellcome Trust. The support of the DST-NRF Centre of Excellence in Human Development towards a series of workshops on the Evolutionary Biology of Human Development and Growth at the University of the Witwatersrand is hereby acknowledged. Opinions expressed and conclusions arrived at are those of the authors and are not necessarily to be attributed to the CoE in Human Development.

Disclosure statement

The views expressed in the submitted article are our own and not an official position of the affiliated institutions or funder. The authors have no financial relationships relevant to this article to disclose. The authors have no conflicts of interest to disclose.

Additional information

Funding

RSM and SAN are supported by the UK MRC DfID African Research Leader Scheme and by the DST-NRF Centre of Excellence in Human Development at the University of the Witwatersrand, Johannesburg. Birth to Twenty data collection was supported by the Wellcome Trust under Grant [092097/Z/10/Z]. The MRC/Wits- Agincourt Unit is supported by the South African Medical Research Council, and the Wellcome Trust under Grants [058893/Z/99/A, 069683/Z/02/Z, 085477/Z/08/Z, 085477/B/08/Z].