Clinical and Biochemical Markers of Risk in Uncomplicated Severe Acute Malnutrition

Background and objectives: Use of mid-upper arm circumference (MUAC) as a single screening tool for severe acute malnutrition (SAM) assumes that children with a low weight-for-height z score (WHZ) and normal MUAC have lower risks of morbidity and mortality. However, the pathophysiology and functional severity associated with different anthropometric phenotypes of SAM have never been well characterized. We compared clinical characteristics, biochemical features, and health and nutrition histories of nonedematous children with SAM who had (1) low WHZ only, (2) both low WHZ and low MUAC, or (3) low MUAC only.

Methods: In Bangladesh, Burkina Faso, and Liberia, we conducted a multicentric cohort study in uncomplicated, nonedematous children with SAM and low MUAC only (n = 161), low WHZ only (n = 138), or a combination of low MUAC and low WHZ (n = 152). Alongside routine anthropometric measurements, we collected a wide range of critical indicators of clinical and nutritional status and viability; these included serum leptin, an adipocytokine negatively associated with mortality risk in SAM.

Results: Median leptin levels at diagnosis were lower in children with low WHZ only (215.8 pg/mL; P < .001) and in those with combined WHZ and MUAC deficits (180.1 pg/mL; P < .001) than in children with low MUAC only (331.50 pg/mL). The same pattern emerged on a wide range of clinical indicators, including signs of severe wasting, dehydration, serum ferritin levels, and caretaker-reported health deterioration, and was replicated across study sites.

Conclusions: Illustrative of the likely heterogeneous functional severity of the different anthropometric phenotypes of SAM, our results confirm the need to retain low WHZ as an independent diagnostic criterion.