The impact of rickets on growth and morbidity during recovery among children with complicated severe acute malnutrition in Kenya: A cohort study

Background: The effects of rickets on children recovery from severe acute malnutrition (SAM) is unknown. Rickets may affect growth and susceptibility to infectious diseases. We investigated the associations of clinically diagnosed rickets with life-threatening events and anthropometric recovery during one year following inpatient treatment for complicated SAM. Methods: Secondary analysis of clinical trial data amongst non-HIV infected Kenyan children with complicated SAM (2-59 months) followed for one year post-hospital discharge (ClinicalTrials.gov ID NCT00934492). The outcomes were mortality, hospital re-admissions and growth during 12 months. The main exposure was clinically diagnosed rickets at baseline. Results: Of 1,778 children recruited, 230 (12.9% (95% CI 11.4 to 14 .6%) had clinical signs of rickets at baseline. Enrolment at an urban site, height-for-age and head circumference-for-age z scores were associated with rickets. Rickets was associated with increased mortality; adjusted Hazard Ratio (aHR) 1.61 (95% CI 1.14-2.27), any re-admission to hospital; aHR 1.37 (95% CI 1.09-1.72); re-admission for severe pneumonia; aHR 1.37 (95% CI 1.05-1.79), but not with diarrhoea; aHR 1.05 (95% CI 0.73-1.51). Rickets was associated with increased height gain; adjusted regression co-efficient 0.19 (95% CI 0.10-0.28), but not changes in head circumference, mid-upper arm circumference (MUAC) or weight. Conclusion: Rickets was common among children with SAM at urban sites and associated with increased risks of severe pneumonia and death. Increased height gain may have resulted from vitamin D and calcium treatment. Future work should explore the possibility of other concurrent micronutrient deficiencies and optimal treatment of rickets in this high-risk population