(P07-024-25) Linear Growth Velocity Varies by Severity of Thinness in Nepali Preschoolers

Objectives: Wasting and stunting malnutrition often coexist in impoverished regions of the world.  However, the influence of the degrees of antecedent wasting [weight (wt)-for-height (ht) z-score (WHZ) < -2] on preschool child linear growth velocity, and risk of becoming stunted [height-for-age z-score (HAZ) < -2] remains poorly understood.

Methods: We analyzed longitudinal data on 5,930 children ≤60 mo of age with ≥1 pair of ht and wt measurements from the PoSHAN community studies (2013–2016).  WHZ at the first measurement was stratified into decrements of ≥ 0, 0 to -1, -1 to -2, and < -2. Annualized linear growth velocities (LGV) were calculated as paired differences in ht, expressed in cm/yr, and as a LGV Z-score (Z) derived from a concatenated WHO-Tanner preschool annual LGV referent (Manohar et al. Publ Health Nutr 2023).  Primary outcomes were differences between observed LGV and the age-sex-specific median referent LGV (ΔLGV), and relative odds (95% CI) of a LGVZ < -2, we define as growth faltering (GF).  Baseline variables included child sex, age as natural splines, household socioeconomic and food security status, season and region (Terai, hills, mountains). Mixed effects models with random intercepts for child and cluster were used to explore associations between baseline thinness and subsequent LGV, ΔLGV, and odds of GF, controlling for above variables.

Results: Initial WHZ was ≥ 0, 0 to -1, -1.01 to -2, and < -2 for 14.2%, 33.1%, 34.1% and 18.5% of children, respectively. Compared to children with WHZ ≥ 0, those with 0 to -1 had a significantly lower LGV of -0.47 cm/yr (95% CI: -0.59, -0.34) and higher odds for GF of 1.54 (1.27, 1.88). Children with -1 > WHZ ≥ -2 had a lower LGV of -0.69 cm/yr (-0.82, -0.56) and odds of GF of 2.19 (1.80, 2.67). Those with WHZ < -2 exhibited the greatest LGV deficit of -1.11 cm/yr (-1.25, -0.96), and relative odds GF, of 3.24 (2.63, 4.00).

Conclusions: Among Nepali preschool-aged children, compared to having a WHZ at/above the WHO median, linear growth velocity in progressively thinner children decreased, and risk of growth faltering increased, in a dose-responsive manner.  In this undernourished population of South Asian children growing, on average, below a recently derived composite Tanner-WHO velocity reference, our findings reveal the importance of a normal weight-for-height to sustain adequate growth.

Funding Sources: USAID