Secular trends in physical growth and maturation in 7 to 21 year-old Bengali boys and girls from Kolkata, India, over six decades of time interval

Published in Int. Journal of Anthropology – Vol. 30 – n.3-4 – 2016

KEY WORDS: Adolescent growth spurt, standing height, sitting height, subischial leg length, biacromial diameter, bi-iliocristal diameter, secular trends.

Abstract
In the backdrop of ongoing socioeconomic transition in India, a cross-sectional growth and socioeconomic survey was under-taken in the families of 4194 Bengali children, adolescents and youth of both sexes aged 7.0 to 21.0 years from Kolkata city, India during 1999-2011.The objective of the study was to in-vestigate secular trends phenomena in the measures of physical growth and maturation of three linear and two width measures (standing height, sitting height, subischial leg length, biacromial and bi-iliocristal diameters) through comparisons of results of the present study with two earlier growth studies (1952-66 and 1982-83) carried out in the same population during the pre-transitional period of the country (before 1990s). The possible influences of socioeconomic, demographic and public health related factors have also been investigated. Approximately over six decades of time difference, mean values of anthropometric measures increased in both sexes and that was more evident during ado-lescent years than at maturity. In standing height, the highest increase of mean value was 14.4 cm for boys at 13.0 years and 11.8 cm for girls at 10.0 and 11.0 years of age. In adulthood, averages of four body dimensions (except bi-iliocristal diam-eter) increased in a lesser magnitude than the increase found during adolescent years. Mean of adult standing height in males increased by 3.0 cm of which increase in mean of subischial leg length was greater (1.8 cm) than the increment in mean sit-ting height (1.2 cm). Increased standard deviation values over time indicated early initiation of adolescent growth spurt of the contemporary children. Time of reaching peak of the spurt esti-mated by fitting Preece-Baines model 1, was found to be about two years ahead as recorded in the contemporary population compared to the children of earlier study periods. Finally, mean age at menarche (11.80 years) of the contemporary Kolkata girls was observed to have declined by 1.10 years over about four decades of time span.
Among the probable factors responsible for positive secular trends, came into the discussion, were improvements in sev-eral socioeconomic factors including maternal education level, monthly family expenditure per capita and decline in sibship size of the families. In addition, improvements in several im-portant parameters of public health, namely decline in infant mortality and morbidity rates, increase in life expectancy, child immunization rate and overall Human Development Index of Kolkata population appeared to be the secondary contributing factors for the observed trends.

 

Das, R.
Biological Anthropology Unit, Indian Statistical Institute, Kolkata, India.

Das, S.
Department of Anthropology,
North Bengal University.

Datta Banik,
S. Department of Human Ecology.
Centro de Investigación y de Estudios Avanzados (Cinvestav del IPN),
Merida. Yucatan, Mexico.

Saha, R.
Dinabandhu Mahavidyalaya,
Bongaon,West Bengal.

Chakraborty, A.
Haltu High School for Girls, Kolkata.

Dasgupta, P.
Biological Anthropology Unit, Indian Statistical Institute,
Kolkata, India. 203, B.T. Road, Kolkata 700108, India
Email: paras@isical.ac.in; paras709@gmail.com