Growth patterns and secular trends over four decades in the dynamics of height growth of Indian boys and girls in Sri Aurobindo Ashram: A cohort study

Background: Growth parameters are widely used in the assessment of health, nutrition and physical characteristics of a population, however, there still exist uncertainties regarding ethnic variation and the influence of physical activity on growth. Due to the paucity of longitudinal data, the dynamics of the adolescent growth spurt have not been satisfactorily examined in most populations. Aim: The main purpose of this longitudinal study is to present the secular trends in the dynamics of height growth over four decades. In the process, this paper also aims to establish current norms for some biological parameters of growth and to address issues concerning ethnic variation and the effect of childhood physical activity on growth. Methodology: Three hundred and one boys and 235 girls of Indian origin who had been enrolled in the Sri Aurobindo International Centre of Education (SAICE) by age 6 and remained for at least 3 uninterrupted years were divided into four birth cohort periods. Cross-sectional and longitudinal analyses were carried out to derive distance, velocity and acceleration curves. Results: No significant differences were found between ethnic groups in any of the growth parameters. Over the 40-year span of this study, SAICE children prove to be taller than their Indian peers. A significant positive secular trend was seen in the height attained at all velocity turning points over the first two decades. Most pre-pubertal growth parameters in these children resemble those from developed nations. Conclusions: Children from most parts of India have similar genetic growth potential. After a significant positive secular trend in height attained over the first 20 years, the adult height has now plateaued. The significant difference in post-pubertal stature between the current generation and those of European origin indicates a genetic difference. Regular and graded physical activities have a salutary effect on growth. The data provide norms for healthy, active Indian child growing up in a satisfactory environment.