Weight and mid-upper arm circumference gain velocities during treatment of young children with severe acute malnutrition, a prospective study in Uganda

BACKGROUND: Weight gain is routinely monitored to assess hydration and growth during treatment of children with complicated severe acute malnutrition (SAM). However, changes in weight and mid-upper arm circumference (MUAC) gain velocities over time are scarcely described. We assessed weight and MUAC gain velocities in 6–59 mo-old children with complicated SAM by treatment phase and edema status. METHODS: This was a prospective study, nested in a randomized/probiotic trial (ISRCTN16454889). Weight and MUAC gain velocities were assessed by treatment phase and edema at admission using linear mixed-effects models. RESULTS: Among 400 children enrolled, the median (IQR) age was 15.0 (11.2;19.2) months, 58% were males, and 65% presented with edema. During inpatient therapeutic care (ITC), children with edema vs no edema at admission had negative weight gain velocity in the stabilization phase [differences at day 3 and 4 were − 11.26 (95% CI: − 20.73; − 1.79) g/kg/d and − 13.09 (95% CI: − 23.15; − 3.02) g/kg/d, respectively]. This gradually changed into positive weight gain velocity in transition and eventually peaked at 12 g/kg/d early in the rehabilitation phase, with no difference by edema status (P > 0.9). During outpatient therapeutic care (OTC), overall, weight gain velocity showed a decreasing trend over time (from 5 to 2 g/kg/d), [difference between edema and non-edema groups at week 2 was 2.1 (95% CI: 1.0;3.2) g/kg/d]. MUAC gain velocity results mirrored those of weight gain velocity [differences were − 2.30 (95% CI: − 3.6; − 0.97) mm/week at week 1 in ITC and 0.65 (95% CI: − 0.07;1.37) mm/week at week 2 in OTC]. CONCLUSIONS: Weight and MUAC gain velocities among Ugandan children with complicated SAM showed an increasing trend during transition and early in the rehabilitation phase, and a decreasing trend thereafter, but, overall, catch-up growth was prolonged. Further research to establish specific cut-offs to assess weight and MUAC gain velocities during different periods of rehabilitation is needed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40795-021-00428-0.