Serum zinc levels as a predictor of clinical features and outcome of paediatric acute lower respiratory infections in Nigeria

Background : Malnutrition, especially macronutrient deficiency, has been shown to be interrelated with ALRI-related morbidity and mortality. However the import of zinc deficiency has only recently become the focus of research attention. Objective : The current study was carried out in Ilorin, Kwara State, Nigeria to determine the relationship between serum zinc levels, clinical features and outcome in hospitalized children with acute lower respiratory infections (ALRI). Method : A descriptive crosssectional hospital-based study involving 120 children aged two months to five years with ALRI. Socio-demographic, clinical and laboratory data were obtained. The serum zinc was analyzed with a Jenway™ spectrophotometer after initial preparation with the QuantiChrom™ zinc assay kit. Results : Children with tachypnoea and crepitations had significantly lower mean serum zinc levels compared to the corresponding values in those without these features (each p<0.05). Significantly higher mean serum zinc level was recorded in children with grunting respiration compared with those without grunting (p=0.028). Agerelated tachypnoea, grunting, and crepitations remained significant (each p<0.05) following a linear  regression analysis. The mean serum zinc level in children with multiple complications was significantly lower than the corresponding level recorded in children who had one complication, p=0.020. No significant difference was found between the mean serum zinc level of the children who were discharged compared with the corresponding level recorded in those that died, p=0.589. Conclusion : The presence of crepitations had the strongest clinical association with a low serum zinc level. Children managed for ALRI would benefit from post-treatment zinc supplements and appropriate zinc-rich sources of food at discharge. Keywords : Children zinc respiratory infections