Publication Date:
2008-11-16
Description:
Background: SCD is characterized by HbS polymerization, chronic hemolytic anemia, and recurrent acute painful episodes. Recent data have established that SCD patients have chronic inflammation, with endothelium activation related to hypoxia/reoxygenation cycles and reperfusion injury, increased inflammatory markers, and enhanced endothelium adhesion of red cells and leukocytes. The bone is a key target of SCD, being the site of both acute events (painful crises and infections) and chronic changes. Osteopenia and osteoporosis are reported in 30 to 40% of adults with SCD. By analogy with thalassemia, bone marrow hyperplasia secondary to chronic anemia has been hypothesized to be a causative factor. The prevalence of low bone mineral density (BMD) is not known in children. Aim: We assessed BMD in a cohort of SCD children and looked for correlations between BMD and age, gender, SCD severity, growth and pubertal development, serum vitamin D, calcium intake, and markers of bone turnover. Methods: Fifty-three children (45 SS, 4 SC, 4 Sb-thalassemia), 27 females, and 26 males, with a mean age of 12.8±2.4 y (9–19 y) were enrolled between 2002 and 2006. They originated from: West and Central Africa (n=41), the Caribbean (n=8), North Africa (n=3), and Brazil (n=1). We assessed height; weight; sexual maturation (Tanner); number of hospitalizations and of painful crises and of transfusions in the last 3 years; calcium intake; steady-state hemoglobin (Hb) and leukocyte count; calcemia, phosphatemia, calciuria/creatinuria; 25-OH D and PTH concentrations; osteocalcin, urinary deoxypyridinolin (DPD) and C-terminal component of pro-collagen type I (CTX). BMD was assessed using a dual X-ray absorptiometry (DXA). Results: In the overall population, mean lumbar spine z-score was −1.1±1.3 (−3.9–1.8), females had non-significantly lower values (−1.42±0.29) than males (−0.77±0.28). In prepubertal children, lumbar spine z-score was lower in females (−1.74±0.27) than in males (−0.53±0.31) (p=0.01). BMD did not correlate with hospitalization and transfusion episodes, Hb, or leukocytes counts. Hb and leukocyte count were inversely correlated (p=0.02) and leukocytosis was correlated to the number of hospitalizations (p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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