Effects of red blood cell transfusion on resting energy expenditure in adolescents with sickle cell anemia

Resting Energy Expenditure in the Critically Ill and Healthy Elderly-A Retrospective Matched Cohort Study

The use of indirect calorimetry to measure resting energy expenditure (mREE) is widely recommended as opposed to calculating REE (cREE) by predictive equations (PE). The aim of this study was to compare mREE with cREE in critically ill, mechanically ventilated patients aged ≥ 75 years and a healthy control group matched by age, gender and body mass index. The primary outcome was the PE accuracy rate of mREE/cREE, derived using Bland Altman plots. Secondary analyses included linear regression analyses for determinants of intraindividual mREE/cREE differences in the critically ill and interindividual mREE differences in the matched healthy cohort. In this retrospective study, 90 critically ill patients (median age 80 years) and 58 matched healthy persons were included. Median mREE was significantly higher in the critically ill (1457 kcal/d) versus the healthy cohort (1351 kcal/d), with low PE accuracy rates (21% to 49%). Independent predictors of mREE/cREE differences in the critically ill were body temperature, heart rate, FiO₂, hematocrit, serum sodium and urea. Body temperature, respiratory rate, and FiO₂ were independent predictors of interindividual mREE differences (critically ill versus healthy control). In conclusion, the commonly used PE in the elderly critically ill are inaccurate. Respiratory, metabolic and energy homeostasis variables may explain intraindividual mREE/cREE as well as interindividual mREE differences.

Wasting and stunting are still prevalent in children with sickle cell anaemia in Lagos, Nigeria

Background

Sickle cell anaemia (SCA) is associated with growth failure. However, recent reports indicate high rates of overweight or obesity among children with SCA in developed countries. It is unclear whether overweight or obesity is also common in children with SCA in developing countries. The objectives of the study were to determine the prevalence of overweight or obesity, wasting and stunting and identify predictors of wasting and stunting among children with SCA in Nigeria.

Method

Children with SCA attending a public-funded tertiary hospital clinic were studied. Weight, height, haemoglobin, haemoglobin fractions and white cell count were measured. Anthropometric values were converted to z scores and referenced to the WHO Child Growth Standards and WHO Reference 2007. The proportions with wasting, stunting and overweight or obesity were determined. Regression analysis was used to identify the predictors of wasting and stunting.

Results

Two hundred and thirty-three children [mean (±SD) age of 9.0 (±4.0) years, 60.9 % males] participated in the study. Wasting, stunting and overweight or obesity rates were 22.7 %, 11.6 % and 1.7 %, respectively. Boys and children from low socioeconomic class were 3.25 (1.45-7.29) and 2.42 (1.14-5.18) times more likely to be wasted respectively, while both wasting and stunting were more common with increasing age [adjusted OR of 1.33 (1.18-1.51) and 1.15 (1.01-1.32) respectively]. Sickle cell-related complications and intake of oral penicillin and hydroxyurea were not associated with wasting and stunting.

Conclusion

Overweight or obesity is uncommon while wasting and stunting are still prevalent in children with SCA in Lagos. The strongest predictors of wasting and stunting were older age, male gender and low socioeconomic status.

Selenium and Vitamin E as antioxidants in chronic hemolytic anemia: Are they deficient? A case-control study in a group of Egyptian children

Accelerated oxidative damage is one of the hallmarks in both sickle cell disease (SCD) and thalassemia major (TM). A decreased antioxidant level is found in both diseases. Our study was carried out to evaluate the variation in serum levels of Selenium and Vitamin E among a group of transfusion dependant Egyptian SCD and TM patients, further more to correlate these levels with iron overload status or transfusion requirements. A case-control study was conducted at the Cairo University Pediatric Hospital to assess the serum levels of Selenium using Atomic Absorption Spectrometer and Vitamin E using commercially available ELISA Kit in transfusion dependent children, 30 with beta thalassemia and 30 with SCD in a steady state aged from 6 to 18 years, these findings were compared to 30 age/sex matched healthy controls. Our results revealed a depleted antioxidants level in the studied group of Egyptian children with TM and SCD relative to healthy controls (P < 0.05). A significant positive correlation was found between Vitamin E levels and ferritin (r = 0.26, p = 0.047) in SCD and TM patients. Nonsignificant correlation was detected between serum Selenium and Vitamin E. Moreover, values of these antioxidants did not correlate with indices of hemolysis nor with those of inflammation in chronically transfused TM and SCD patients.

The association of transfusion status with antioxidant enzymes and malondialdehyde level in Nigerians with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) often leads to chronic hemolytic anemia of varying severity, and blood transfusion may be employed in the management of SCD complications.

OBJECTIVE

The aim of the study was to evaluate the effect of blood transfusion on the activities of some antioxidant enzymes as well as lipid peroxide and to relate transfusion status to these enzymes and malondialdehyde (MDA) in SCD patients.

MATERIALS AND METHODS

Glutathione peroxidase (GPX), superoxide dismutase, catalase, MDA, and lipoproteins were assayed in 87 SCD and 20 age- and sex-matched subjects with normal hemoglobin. Of the 87 SCD patients, 30 had multiple transfusions, 21 had been transfused once while 36 had not been transfused within the last 3 months.

RESULTS

Statistically significant decrease in the mean levels of GPX (P = 0.045) and Cu/Zn SOD (P = 0.001) and increased (P = 0.001) MDA were observed in the transfused compared to non-transfused patients. Similarly, significant decrease (P = 0.001) in Cu/Zn SOD and increase (P = 0.01) in MDA were observed in multi transfused compared to those who had been transfused once. Transfusion status correlated (P <0.047) inversely with Cu/Zn SOD and positively with MDA.

CONCLUSION

Reduced activity levels of serum antioxidant enzymes and increased mean levels of MDA were observed in transfused compared to non-transfused SCD patients and these changes correlated with transfusion status.

Nutritional deficiencies in iron overloaded patients with hemoglobinopathies

One of the hallmarks of both sickle cell disease (SCD) and thalassemia major (TM) is accelerated oxidative damage. Decreased antioxidant levels and increased oxidant stress biomarkers are found in both diseases. Although isolated vitamin deficiencies have been reported in TM and nontransfused SCD patients, a comprehensive evaluation of vitamin and trace mineral levels has never been performed in chronically transfused SCD or TM patients. As vitamins and trace minerals may be consumed as a result of chronic oxidative stress; we hypothesized that levels of these compounds would correlate with surrogates of iron overload, hemolysis, and inflammation in chronically transfused patients. Using a convenience sample of our group of chronically transfused patients we studied 43 patients with SCD (17 male, 26 female) and 24 patients with TM (13 male and 11 female). The age range for our patients varied from 1.5 to 31.4 years. Levels of vitamins A, thiamin, B6, B12, C, D, E as well as selenium, zinc, copper, and ceruloplasmin were measured. We found that 40-75% of the patients were deficient in A, C, D and selenium and 28-38% of the patients had low levels of B vitamins and folate. There was little association with iron overload, hemolysis, or inflammation. Although the precise mechanism of these deficiencies is unclear, they may contribute to the morbidity of chronically transfused hemoglobinopathy patients.

Erythropoiesis and myocardial energy requirements contribute to the hypermetabolism of childhood sickle cell anemia

OBJECTIVES

We hypothesized that an elevated hemoglobin synthesis rate (SynHb) and myocardial oxygen consumption (MVO2) contribute to the excess protein and energy metabolism reported in children with sickle cell anemia.

PATIENTS AND METHODS

Twelve children (6-12 years old) with asymptomatic sickle cell and 9 healthy children matched for age and sex were studied. Measurements were whole-body protein turnover by [1-C]leucine, SynHb by [N]glycine, resting energy expenditure by indirect calorimetry and the systolic blood pressure-heart rate product used as an index of MVO2. Protein energy cost was calculated from protein turnover. Statistical analysis included Spearman correlations and partial correlation analyses.

RESULTS

Although body mass index was significantly lower for sickle cell versus controls (P < 0.02), children with asymptomatic sickle cell had 52% higher protein turnover (P < 0.0005). Proportional reticulocyte count, SynHb, MVO2 and resting energy expenditure were also significantly higher in children with sickle cell (P < 0.01). Protein turnover correlated significantly with both SynHb (r = 0.63, P < 0.01) and reticulocyte percentage (r = 0.83, P < 0.0001). Partial correlation of these 3 variables showed reticulocyte percentage as the only variable to be significantly associated with protein turnover, even after adjusting for sickle cell anemia (P = 0.03). Partial correlation of log resting energy expenditure on MVO2 was significant, controlling for protein energy cost, sex and age (P = 0.03).

CONCLUSION

These results indicate that metabolic demands of increased erythropoiesis and cardiac energy consumption account for much of the excess protein and energy metabolism in children with sickle cell anemia.

Effect of long-term transfusion on growth in children with sickle cell anemia: results of the STOP trial

OBJECTIVE

To determine whether long-term transfusion improves growth in children with sickle cell anemia.

STUDY DESIGN

In the Stroke Prevention Trial for Sickle Cell Anemia Study, patients were randomized to receive long-term transfusion (CTX) or standard care (STC). Transfusions were administered every 3 to 5 weeks, and hemoglobin S levels were maintained at 30% pretransfusion for an average of 2 years. Serial height and weight measurements (obtained every 3 months), body mass index (BMI) values, and growth z-scores were analyzed.

RESULTS

Children in the CTX (n=53) and STC (n=41) groups were similar at baseline. After 24 months, the z-scores for height, weight, and BMI of those receiving CTX had improved significantly, whereas no changes occurred in the STC group. Patients in the CTX group approached normal height-for-age and weight-for-age z-scores. Patients from a large historical control group had significantly lower weight and height growth velocities than patients in the CTX group.

CONCLUSIONS

Patients in the Stroke Prevention Trial for Sickle Cell Anemia Study who received CTX had improved height and weight and BMI over a 2-year period. Higher hemoglobin levels resulting from transfusion may improve growth by lowering energy expenditure. In addition to the prevention of vasoocclusive events, CTX results in significant improvement in the growth of children with sickle cell disease.

Correction of anemia in patients with congestive heart failure increases resting energy expenditure

BACKGROUND & AIM

Congestive heart failure (CHF) and anemia were reported to affect resting energy expenditure (REE). The aim of this study was to evaluate the effect of the correction of anemia on REE in subjects with CHF.

PATIENTS AND METHODS

Nine anemic patients with compensated CHF and CRF were studied before and after correction of anemia. REE was studied by an open circuit indirect calorimeter, body composition by dual-energy-X-ray absorption and total body and extracellular water by multi-frequency bioelectrical impedence. Four anemic and 5 non-anemic CHF patients who did not receive any new treatment served as controls.

RESULTS

After the correction of their anemia patients tended to increase weight (P<0.06), but no significant changes were observed in body composition. Daily caloric intake increased significantly (P<0.02). Ejection fraction increased (P<0.05) and pulse rate decreased significantly (P<0.001). REE and REEPP were in the normal range before correction but increased significantly afterwards (1402+/-256 vs. 1496+/-206 kcal/d, and 101+/-9 vs. 109+/-8, P<0.023 and P<0.006, respectively).

CONCLUSION

Correction of anemia in patients with CHF increases their REE. This can be related either to improved tissue oxygenation and/or to increased caloric intake.

Energy intake and resting metabolic rate in preschool Jamaican children with homozygous sickle cell disease

BACKGROUND

A relative energy deficiency consequent to a high resting metabolic rate (RMR) may contribute to growth impairment in persons with homozygous (SS genotype) sickle cell disease (SCD). The growth deficit in SCD emerges at an early age, but few studies have addressed the adequacy of energy intake relative to RMR in young children.

OBJECTIVE

Our objective was to test the hypothesis that energy intake relative to RMR is lower in children with SCD than in control subjects.

DESIGN

The dietary intake of 41 children with SCD and 31 control subjects with a normal hemoglobin genotype (AA) aged 3-6 y was assessed by weighing all food consumed during 3 d. RMR was determined with the use of indirect calorimetry.

RESULTS

The RMR in the children with SCD ( +/- SD: 5.47 +/- 0.93 MJ/d) was higher than that in the control subjects (5.19 +/- 1.3 MJ/d) after adjustment for sex and weight (P = 0.04). Energy intake did not differ significantly between the 2 genotype groups. The ratio of energy intake to RMR was lower in the children with SCD ( +/- SD: 1.13 +/- 0.33) than in the control subjects (1.35 +/- 0.38) after adjustment for sex and weight (P = 0.005).

CONCLUSIONS

Prepubertal children with SCD fail to compensate for their higher RMR by increasing their energy intake. This observation is consistent with a hypothesis of a relative energy deficiency in SCD.