THE EFFECT OF SPLENECTOMY FOR HYPERSPLENISM ON WHOLE-BODY PROTEIN-TURNOVER, RESTING METABOLIC-RATE AND GROWTH IN SICKLE-CELL DISEASE

Objective: To determine whether, in the same individual, an observed f all in whole body protein turnover following splenectomy in children w ith hypersplenism and homozygous sickle cell (SS) disease is associate d with a measurable fall in resting metabolic rate (RMR) and an increa se in rate of growth. Subjects: Six children (5 SS disease, 1 S beta d egrees thalassaemia), aged 68 to 126 months, were studied before and a fter splenectomy for hypersplenism. Design: Protein turnover was measu red by the end product method using prime/intermittent oral doses of N -15-glycine and RMR by indirect calorimetry before preoperative transf usion and repeated at least eight weeks after splenectomy. Height and weight velocities were measured over six month periods before and afte r splenectomy. Setting: University Hospital of the West Indies in Jama ica and the Medical Research Laboratories (Jamaica). Results: After sp lenectomy protein turnover fell significantly by 30% and RMR by 34 kJ/ kg/d. Mean weight velocity which was below normal before surgery, z=-2 .3, improved significantly after surgery, z=0.7, (P=0.03). Height velo city increased in two children but the mean height velocity did not ch ange following splenectomy. The reduction in protein turnover was esti mated to account for 62% of the fall in RMR. Conclusion: This study co nfirms that there is a significant reduction in energy expenditure fol lowing splenectomy for hypersplenism in SS disease. A reduction in pro tein turnover was a major contributor to the saving in energy, althoug h it is not clear whether it accounted for all. In the present group o f children the energy saved was associated with an improvement in the wasting present before splenectomy.