Catch-up growth and growth deficits: Nine-year annual panel child growth for native Amazonians in Bolivia

Background: Childhood growth stunting is negatively associated with cognitive and health outcomes, and is claimed to be irreversible after age 2. Aim: To estimate growth rates for children aged 2-7 who were stunted (sex-age standardised z-score [HAZ] < -2), marginally-stunted (-2 <= HAZ <= -1) or not-stunted (HAZ > -1) at baseline and tracked annually until age 11; frequency of movement among height categories; and variation in height predicted by early childhood height. Subjects and methods: This study used a 9-year annual panel (2002-2010) from a native Amazonian society of horticulturalists-foragers (Tsimane'; n = 174 girls; 179 boys at baseline). Descriptive statistics and random-effect regressions were used. Results: This study found some evidence of catch-up growth in HAZ, but persistent height deficits. Children stunted at baseline improved 1 HAZ unit by age 11 and had higher annual growth rates than non-stunted children. Marginally-stunted boys had a 0.1 HAZ units higher annual growth rate than nonstunted boys. Despite some catch up, similar to 80% of marginally-stunted children at baseline remained marginally-stunted by age 11. The height deficit increased from age 2 to 11. Modest year-to-year movement was found between height categories. Conclusions: The prevalence of growth faltering among the Tsimane' has declined, but hurdles still substantially lock children into height categories.