Dietary Effects of Nitrates and Nitrites on Illness Severity in Children with Sickle Cell Disease Ramsay A. Singer, BA, MBBS1, Diana Cardona-Grau, BA2, Deidre Dexter, RD3, and Philippa Sprinz, MD4 1Royal Free Hospital, London, United Kingdom 2Boston Unversity School of Medicine/Boston Medical Center, Boston, MA 3 Nutritional Services, Boston Medical Center, Boston, MA 4Division of Pediatric Hematology/Oncology, Boston University School of Medicine/Boston Medical Center, Boston, MA M di i /B t M di l C t B t BACKGROUND • Sickle cell anemia is an autosomally inherited disease in which mutations in the two genes for hemoglobin encode (most commonly) for a substitution of Val or Lys for Glu in the 6th AA of beta globin chain beta-globin producing HbSS or the HbSC variant. CONT’D BACKGROUND CONT D • Under stress HbS polymerizes and forms rigid rods which causes sickling of the red vaso occlusive blood cells and can lead to vaso-occlusive episodes. vasodilator, • Nitric oxide (NO) acts as a vasodilator is an anti-oxidant and anti-inflammatory, and contributes to the inhibition of platelet aggregation. OBJECTIVE • This study sought to investigate whether a diet high in nitrates or nitrites ameliorated sickle cell disease severity in patients ages 2-21. 2 21 METHODS Forty four patients, • Forty-four pediatric patients with the help of their parents, completed a 94-question modified version of the National Institutes of Health 12 month food frequency questionnaire. • 23 foods included in the questionnaire were determined to be high in nitrates and nitrites and were used in this analysis. (CONT’D) METHODS (CONT D) • The analysis compared the values of nitrate and nitrite intake, in mg/kg/yr, with the patient’s sickle cell disease severity index patient s score, using the validated tool from Sebastiani et al. • Pearson’s Product Moment Correlation was analysis used for statistical analysis. RESULTS Correlation R Score Yearly intake of nitrates versus -0.22 severity index score Yearly intake of nitrites versus -0.23 severity index score Yearly intake of nitrates versus severity index score 1 erity Index Score 0.8 x 06 0.6 0.4 02 0.2 Seve 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Total Nitrate Intake (mg/kg/yr) Yearly intake of nitrites versus severity index score 1 erity Index Score 0.8 x 06 0.6 0.4 0.2 02 Seve 0 0 5 10 15 20 25 30 Total Nitrite Intake (mg/kg/yr) RESULTS • Sickle cell severity scores ranged from 0.02 to 0.9 with a median score of 0.16 Nitrate i t k df 8 12 /k / t • Nit t intake ranged from 8.12 mg/kg/yr to 4085 mg/kg/yr with a median value of /k / 560 mg/kg/yr. • Nitrite intake ranged from .108 mg/kg/yr to g g gy 24.31 mg/kg/yr with a median value of 8.21 mg/kg/yr. g gy LIMITATIONS • Small sample size. • Accuracy of patients’ and parents’ dietary recall. • Lack of knowledge of exact nitrate and nitrite content of foods considered to be rich in these nutrients. • A single unified source for the known nitrate g and nitrite content in analyzed foods was not available. CONCLUSIONS • A negative correlation was found between increased consumption of nitrates and i d ti f it t d nitrites and sickle cell severity index score. FUTURE DIRECTIONS • Enrollment of more subjects to improve the statistical power of this study. Design • D i an i t ti l t d ith interventional study with nitrate/nitrite supplemented diets to further analyze the benefit of these nutrients in sickle cell disease.
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