Fracture prevalence and relationship to endocrinopathy in iron overloaded patients with sickle cell disease and thalassemia.
Transfusional iron overload leads to gonadal failure and low bone mass in patients with thalassemia (Thal). However, gonadal failure is rarely reported in transfused patients with sickle cell disease (SCD) and the literature regarding fracture prevalence in SCD is limited. The objective of this study was to assess self-reported fracture prevalence and its relationship to endocrinopathy in transfused Thal or SCD subjects and compare to non-transfused subjects with SCD (NonTxSCD). Eligibility was based on age> or =12 years and liver iron concentration> or =10 mg/g dry wt or serum ferritin> or =2000 ng/mL (Thal or TxSCD) or for NonTxSCD, ferritin<500 ng/mL. Data were collected by patient interview and chart review at 31 clinical centers in the U.S., Canada and the U.K. 152 subjects with Thal (52% Male; 25.6+/-0.7 years), 203 subjects with TxSCD (44% Male, 24.7+/-0.9 years: Mean+/-SE), and 65 NonTxSCD (50% Male, 22.2+/-1.3 years) were enrolled. Overall, male subjects with Thal were more likely to have sustained a fracture in their lifetime (51%) compared to TxSCD (28%) or NonTxSCD (32%) (p=0.005). There was no difference in fracture prevalence among women (Thal: 26%, TxSCD 17%, NonTxSCD: 16%). Fracture was most frequently reported in the upper extremities (53.3% of all fractures) while spine and pelvic fractures were relatively common for such a young cohort: 10.6%. Though overall fracture prevalence was not distinctly different from published healthy cohorts, fewer fractures occurred during the adolescent years. In multivariate analysis, the significant predictors of fracture prevalence were Thal diagnosis (Odds Ratio: 2.3; 1.2-4.6; 95%CI), male gender (OR: 2.6; 1.5-4.5), hypothyroidism (OR: 3.3; 1.1-9.8) and age (OR: 1.1; 1.03-1.08). These data suggest that despite similar iron burden, transfused patients with Thal are at greater risk for fracture than subjects with SCD. Male subjects with Thal and hypothyroidism are at particular risk for fracture, in contrast, transfused subjects with SCD had no greater risk of fracture compared to non-transfused SCD. Though ethnic differences in fracture risk cannot be ignored, endocrinopathy is rare in TxSCD which may also provide some protection from fracture.
Fung
Ellen B
EB
Department of Hematology at the Children's Hospital & Research Center, Oakland, CA, USA. Electronic address: efung@mail.cho.org.
Harmatz
Paul R
PR
Department of Gastroenterology at the Children's Hospital & Research Center, Oakland, CA, USA.
Milet
Meredith
M
Pediatric Clinical Research Center at the Children's Hospital and Research Center at Oakland, CA, USA.
Coates
Thomas D
TD
Departments of Hematology at the Children Hospital Los Angeles, CA, USA.
Thompson
Alexis A
AA
Children's Memorial Hospital, Chicago, IL, USA.
Ranalli
Mark
M
Nationwide Children's Hospital, Columbus, OH, USA.
Mignaca
Robert
R
Children's Hospital of Central California, CA, USA.
Scher
Charles
C
Tulane University Medical Center, New Orleans, LA, USA.
Giardina
Patricia
P
Weill Medical College of Cornell University, NY, USA.
Robertson
Shanda
S
Department of Hematology at the Children's Hospital & Research Center, Oakland, CA, USA.
Neumayr
Lynne
L
Department of Hematology at the Children's Hospital & Research Center, Oakland, CA, USA.
Vichinsky
Elliott P
EP
Department of Hematology at the Children's Hospital & Research Center, Oakland, CA, USA.
D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications / Q000378:metabolism*; D004700:Endocrine System Diseases / Q000150:complications*; D005260:Female; D050723:Fractures, Bone / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D015995:Prevalence; D013789:Thalassemia / Q000150:complications / Q000378:metabolism*
D007501:Iron