Catch-up growth in height and cognitive function: Why definitions matter.

Area of Science:

• Child Development
• Nutritional Science
• Cognitive Psychology

Background:

• Early growth retardation (stunting) is linked to impaired cognitive function in children.
• Research on catch-up growth and cognitive recovery in previously stunted children yields contradictory findings.
• Discrepancies may stem from varied definitions of catch-up growth (timing and extent).

Purpose of the Study:

• To investigate how different definitions of catch-up growth affect conclusions about cognitive outcomes in stunted children.
• To analyze the impact of varying the starting age for measuring catch-up growth.
• To examine cognitive performance based on five different criteria for catch-up growth.

Main Methods:

• Utilized South African cohort data with repeated early childhood length measurements.
• Analyzed cognitive outcomes by varying the age from which catch-up growth was measured (1 vs. 2 years).
• Applied five distinct definitions of catch-up growth, from lenient to strict, to assess cognitive function.

Main Results:

• The age chosen to measure catch-up growth significantly influences study conclusions, especially as stunting prevalence peaks around age 2.
• Except for the strictest definition, children experiencing catch-up growth after stunting at age 2 performed worse cognitively than never-stunted children.
• Cognitive scores for children with catch-up growth were nearly as low as those who remained stunted.

Conclusions:

• The definition of catch-up growth critically impacts observed associations with cognitive function.
• Interventions during the first two years of life are crucial for preventing stunting and associated cognitive deficits.
• Early developmental timing is paramount for optimizing both linear growth and cognitive development.