Aims: Growth stunting is prevalent in developing countries. The prevalence of stunting ranges from 10-80% or more. The critical period for growth faltering in length is between six and 18 months. The aims of this study were 1) to investigate the association between the age at onset of the childhood component and growth stunting in early life; 2) to develop a screening method for identifying any individual infant subject to stunting in early life.
Materials & methods: This community-based longitudinal study was carried out in Lahore, Pakistan. Three studied areas and one local control group were included in the study. There were 425 subjects for whom data were available for determining the age at onset of the childhood component. The onset was defined as an abrupt increase in length velocity. It was determined individually using the infancy-childhood-puberty growth model.
Results: The medians of the age at onset of childhood component were 15, 13, 10 and 9 months in the periurban, village, urban and control groups, respectively. The onset was significantly related to both length and length velocity during the critical period of stunting. Based on the distribution of individual length increment from 12 to 15 months, 2.0 and 3.0 cm were chosen as the cut-off points to identify a stunting infant. In the normal onset group, 84% of the children were identified as growing normally; in the delayed onset group, 61% were identified as stunting. Using this screening method, 97% of children have a delayed onset if their length increase is below 2 cm from 12 to 15 months; 99% of them have a normal onset if the increase is above 3 cm over the same period.
Conclusions: The age at onset of the childhood component can significantly explain the variations in both length and length velocity in early life. The stunting screening method reported here is simple. It can be used in almost any situation, such as a pediatric clinic or community-based survey.