Magnitude of hypophosphatemia in children under five years with kwashiorkor and marasmic kwashiorkor at Kenyatta National Hospital

Abstract

Background: A number of biochemical changes in blood and tissues have been described in protein-energy malnutrition (PEM), the main one being electrolyte depletion. Hypophosphatemia is the main feature of refeeding syndrome. It is a recognized cause of morbidity and mortality among children with severe malnutrition. Worldwide, data on prevalence of hypophosphatemia in children with severe PEM is scanty, and especially so in developing countries which bear the highest burden of childhood malnutrition. Methodology: We carried out a short longitudinal survey at Kenyatta National Hospital (K.NH) Paediatric wards to determine the frequency of hypophosphatemia in children under 5 years of age with kwashiorkor and marasmic kwashiorkor, before and during nutritional intervention and to relate hypophosphatemia to outcome in the first week. Subjects were recruited on admission into the wards. Consecutive sampling of children with kwashiorkor and marasmic kwashiorkor whose mothers/ guardians gave informed consent and met the inclusion criteria was carried out. Blood samples were taken on admission, then days I. 2 and 4 thereafter. Serum phosphate level was determined on all the four days but serum albumin, calcium and magnesium levels were only determined on admission. Demographic, clinical and laboratory data were collected. Hypophosphatemia was defined as serum phosphate lex el below 1.20 mmol/l and severe hypophosphatemia as serum phosphate level below O.33mmol/1. Results: A total of 165 children vxere enrolled into the study between June 2005 and February 2006. Of the 165 children. 107 (64%) had kwashiorkor and 58 (36%) had marasmic kwashiorkor. They were of mean age 20 months (range, 3 - 60 months), and majority. 95 (58%) were male. The prevalence of hypophosphatemia was 86% on admission, increased to 90% on day one and 93% on day two. and then declined slightly to 90% on day four. The prevalence of severe hypophosphatemia was 6° o on admission, increased to 18% on day one and 22% on day two, and then declined to 11% on day four. On admission, mean serum 10 phosphate level was below normal at 0.91mmol/l, declined significantly to 0.67mmol/l and to a nadir of 0.63mmol/l on the first and second day after treatment initiation respectively, then rose slightly to O.“5mmol/I on the fourth day (p <0.001 comparing each follow-up mean level with the admission level). There was a positive association between severity of nadir serum phosphate level and mortality. There were no deaths among children with normal nadir serum phosphate levels. However, among children with mild, moderate and severe hypophosphatemia 8%. 14% and 21% died respectively (p =0.028). There was no significant association between hypophosphatemia and the various demographic, clinical and laboratory correlates. However, those children with dermatosis and hypomagnesaemia showed a trend for association (p =0.082 and 0.099 respectively). Conclusion: Hypophosphatemia is frequent among children with kwashiorkor and marasmic kwashiorkor presenting at K.NH. Phosphate levels decline significantly during the first two days following nutritional intervention, and severity of hypophosphatemia is positively associated with mortality.