Underweight children over 5 years with sickle cell anemia are at risk for early mortality in a low-resource setting

Abstract

Undernutrition is a risk factor for under 5 mortality and is also postulated to be a risk factor for mortality in older children and adults with sickle cell anemia. We tested the hypothesis that underweight (weight-for-age z-score <-1) is associated with mortality in children aged 5-12 years with sickle cell anemia. We performed a secondary analysis of participants in the Primary Prevention of Stroke in Children with Sickle Cell Disease in Nigeria trial, a double-blind, parallel-group randomized controlled trial for low-dose (n=109) or moderate-dose (n=111) hydroxyurea in children with abnormal transcranial Doppler velocities and a comparison group (n=211) of participants with non-elevated transcranial Doppler velocities in northern Nigeria (NCT02560935). Nutritional status was classified as underweight (weight-for-age z-score), stunting (height-for-age z-score), and wasting (body mass index z-score) using the World Health Organization growth reference. The mean weight-for-age z-score was lower in children who died during the study than in those who survived (-2.6 vs. -2.1, p=0.016). Otherwise, the baseline characteristics of children who died during the study were not significantly different from those who survived. A pooled analysis of participants demonstrated that a lower weight-for-age z-score was associated with an increased hazard of death (HR=0.580, p=0.004, 95%CI 0.399-0.843). Underweight participants (weight-for-age z-score <-1) had a greater probability of death during follow-up than those not underweight (p=0.043). Underweight status in school-aged children with sickle cell anemia is a previously unrecognized risk factor for early mortality in Nigeria and can be easily applied to screen children at risk for death.