Resting energy expenditure in patients with thalassemia major

The effect of non-iron-deficiency anemia was studied in seven patients with thalassemia major (β thalassemia) ages 22-30 y. Each patient was studied before and 3 days after blood transfusion. Hemoglobin concentrations increased significantly after blood transfusion (111-153 vs 81-102 g/L, P < 0.02). Heart rate decreased from 96 ± 12 to 81 ± 7 beats/min (x̄ ± SD; P < 0.05). No significant difference was found in venous blood pH, bicarbonate concentrations, or lactic acid concentrations before and after blood transfusion. Resting energy expenditure (REE) was greater before blood transfusion in absolute numbers and as a percentage of the predicted value, and returned to normal range thereafter (6138 ± 112 vs 5678 ± 738 kJ · kg^-1 · d^-1 and 111.7 ± 11.3% vs 103.2 ± 7.8%, respectively). Protein contribution to REE was low before blood transfusion (9.7 ± 4.2%) and returned to normal range thereafter 115.3 ± 5.2%) (P < 0.09). This finding may indicate that increased protein turnover as well as increased cardiac work contribute to the observed increase in REE.