Severe acute malnutrition (SAM) is a major cause of child mortality and morbidity. Children treated for SAM are at risk of refeeding hypophosphataemia (HP). The study was done to find out the incidence and various predictors of moderate/severe HP in SAM among North Indian children. This prospective observational study was conducted from August 2014 to July 2015 in the inpatients’ department of Department of Paediatrics at King George’s Medical University, Lucknow, Uttar Pradesh, North India, a tertiary care teaching hospital. Before inclusion, ethical approval and written informed consent was obtained. Included in the study were sixty-five children aged 6–59 months of age, who were admitted to the hospital with SAM as per the WHO guidelines. SAM was defined as a mid-upper arm circumference <115 mm and/or weight-for-height/length <–3 z-scores of the WHO growth standards and/or have bilateral oedema. Serum P levels were measured on admission and for five consecutive days after starting feed. HP was defined as mild, moderate and severe with a cut-off of 1·19–0·65, 0·65–0·32 and <0·32 mmol/l, respectively. About 60 % children had HP, with 20 % having moderate/severe HP at admission. The proportion of HP increased to 83·1 %, with 38·5 % having moderate/severe HP on day 3 after feeding. It was concluded that HP is a common biochemical abnormality in SAM. Considering its impact on the health of the child, serum P levels should be monitored in patients with SAM who are treated with enteral feeding.

Refeeding syndrome is difficult to diagnose since the guidelines for identifying those at risk are largely based on subjective clinical parameters and there are no predictive biochemical markers. We examined the suitability of insulin-like growth factor 1 (IGF1) and leptin as markers to identify patients at risk of the refeeding syndrome before initiation of parenteral nutrition (PN). A total of thirty-five consecutive patients referred for commencement of PN were included. Serum leptin and IGF1 were measured before starting PN. Electrolytes, liver and renal function tests were conducted before and daily for 1 week after initiating PN. The primary outcome was a decrease in phosphate 12–36 h after initiating PN. ‘Refeeding index’ (RI) was defined as leptin × IGF1 divided by 2800 to produce a ratio of 1·0 in patients who are well nourished. RI had better sensitivity (78 %; 95 % CI 40, 97 %) and specificity (78 %; 95 % CI 40, 97 %) with a likelihood ratio of 3·4, at a cut-off value of 0·19 for predicting a ≥ 30 % decrease in phosphate concentration within 12–36 h after starting PN, compared with IGF1 or leptin alone. However, IGF1 was a better predictor of mortality than either leptin or the RI. The present study is the first to derive and test the ‘RI’, and find that it is a sensitive and specific predictor of the refeeding syndrome in hospitalised patients before starting PN.