Clinical and biochemical responses to treatment of uncomplicated severe acute malnutrition: a multicenter observational cohort from the OptiDiag study

Background: Severe acute malnutrition (SAM) can be diagnosed using weight-for-height Z-score (WHZ) and/or mid-upper arm circumference (MUAC). Although some favor using MUAC alone, valuing its presumed ability to identify children at greatest need for nutritional care, the functional severity and physiological responses to treatment in children with varying deficits in WHZ and MUAC remain inadequately characterized.

Objective: We aimed to compare clinical and biochemical responses to treatment in children with 1) both low MUAC and low WHZ, 2) low MUAC-only, and 3) low WHZ-only.

Methods: A multicenter, observational cohort study was conducted in children aged 6-59 mo with nonedematous, uncomplicated SAM in Bangladesh, Burkina Faso, and Liberia. Anthropometric measurements and critical indicators were collected 3 times during treatment; metrics included clinical status, nutritional status, viability, and serum leptin, a biomarker of mortality risk in SAM.

Results: Children with combined MUAC and WHZ deficits had greater increases in leptin levels during treatment than those with low MUAC alone, showing a 34.4% greater increase on the second visit (95% confidence interval [CI]: 7.6%, 43.6%; P = 0.02) and a 34.3% greater increase on the third visit (95% CI: 13.2%, 50.3%; P = 0.01). Similarly, weight gain velocity was higher by 1.56 g/kg/d in the combined deficit group (95% CI: 0.38, 2.75; P = 0.03) compared with children with low MUAC-only. Children with combined deficits had higher rates of iron deficiency and wasting while those with low WHZ alone and combined deficits had higher rates of tachypnea and pneumonia during treatment.

Conclusions: Given the comparable treatment responses of children with low WHZ alone and those with low MUAC alone, and the greater vulnerability at admission and during treatment in those with combined deficits, our findings support retaining WHZ as an independent diagnostic and admission criterion of SAM, alongside MUAC. This trial was registered at www.

Clinicaltrials: gov/study/NCT03400930 as NCT03400930.