title: The effect of gonadal status on body composition and bone mineral density in transfusion-dependent thalassemia.
abstract: Patients with transfusion-dependent thalassemia have abnormal growth, hormonal deficits, and increased bone loss. We investigated the relationship between skeletal muscle mass, fat mass, and bone mineral density in adult subjects with transfusion-dependent thalassemia based on their gonadal status. Our findings show that hypogonadism attenuates the strength of the muscle-bone relationship in males but strengthens the positive correlation of skeletal muscle mass and fat mass in female subjects.
  
  
  BACKGROUND
  Transfusion-dependent thalassemia is associated with a high prevalence of fractures. Multiple hormonal complications, in particular hypogonadism, can lead to changes in body composition and bone mineral density (BMD). We investigated for the first time the relationship between skeletal muscle mass (SMM), fat mass, and BMD in adult subjects with transfusion-dependent thalassemia based on their gonadal status.
  
  
  METHODS
  A retrospective cohort study of 186 adults with transfusion-dependent thalassemia was analyzed. Body composition and BMD were measured using dual energy X-ray absorptiometry. The association between skeletal muscle, fat, and BMD was investigated through uni-, multi-, and stepwise regression analyses after adjusting for multicollinearity. SMM was derived using the formula, SMM = 1.19 × ALST-1.65, where ALST is equivalent to the sum of both arm and leg lean tissue mass.
  
  
  RESULTS
  There were 186 subjects, males (43.5 %) and females (56.5 %), with a median age of 36.5. Hypogonadism was reported in 44.4 % of males and 44.7 % of females. SMM and BMD were positively correlated and strongest in eugonadal males (0.36 ≤ R (2) ≤ 0.59), but the association was attenuated in hypogonadal males. SMM (0.27 ≤ R (2) ≤ 0.69) and total fat mass (0.26 ≤ R (2) ≤ 0.55) were positively correlated with BMD in hypogonadal females, but the correlation was less pronounced in eugonadal females. Leg lean tissue mass and arm lean tissue mass in males and females, respectively, were most highly correlated to BMD in the stepwise regression analysis.
  
  
  CONCLUSIONS
  Hypogonadism attenuates the strength of the muscle-bone relationship in males but strengthens the positive correlation of skeletal muscle mass and fat mass in female subjects. This study supports the notion that exercise is important for maintaining BMD and the need to optimize treatment of hypogonadism in patients with transfusion-dependent thalassemia.
authors.affiliation: Prince Henry's Institute, PO Box 5152, Clayton, VIC, 3168, Australia, phillip.wong@princehenrys.org.
authors.forename: P
authors.initials: P
authors.lastname: Wong
authors.forename: P J
authors.initials: PJ
authors.lastname: Fuller
authors.forename: M T
authors.initials: MT
authors.lastname: Gillespie
authors.forename: V
authors.initials: V
authors.lastname: Kartsogiannis
authors.forename: F
authors.initials: F
authors.lastname: Milat
authors.forename: D K
authors.initials: DK
authors.lastname: Bowden
authors.forename: B J
authors.initials: BJ
authors.lastname: Strauss
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D001803:Blood Transfusion; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D006801:Humans; D007006:Hypogonadism / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D009929:Organ Size / Q000502:physiology; D012189:Retrospective Studies; D013789:Thalassemia / Q000150:complications / Q000503:physiopathology* / Q000628:therapy
references.citation: J Bone Miner Res. 1996 Jun;11(6):857-63
references.pmid: 8725184
references.citation: Bone. 2001 Aug;29(2):114-20
references.pmid: 11502471
references.citation: J Bone Miner Res. 2002 Sep;17(9):1563-9
references.pmid: 12211425
references.citation: Maturitas. 2002 Dec 10;43(4):239-44
references.pmid: 12468131
references.citation: J Clin Invest. 2000 Dec;106(12):1553-60
references.pmid: 11120762
references.citation: J Bone Miner Res. 2008 Feb;23(2):189-98
references.pmid: 17922610
references.citation: Biochem Biophys Res Commun. 1995 Feb 6;207(1):133-9
references.pmid: 7857256
references.citation: Arch Biochem Biophys. 2010 Nov 1;503(1):20-7
references.pmid: 20599663
references.citation: J Bone Miner Res. 2011 Jan;26(1):79-87
references.pmid: 20658559
references.citation: J Clin Endocrinol Metab. 1999 Aug;84(8):2647-53
references.pmid: 10443654
references.citation: Calcif Tissue Int. 2004 Jan;74(1):68-71
references.pmid: 14523599
references.citation: Eur J Pediatr. 1997 Oct;156(10):777-83
references.pmid: 9365067
references.citation: Pediatr Endocrinol Rev. 2008 Oct;6 Suppl 1:158-69
references.pmid: 19337172
references.citation: Bone. 2004 Sep;35(3):792-8
references.pmid: 15336618
references.citation: Clin Endocrinol (Oxf). 1995 Jun;42(6):587-92
references.pmid: 7634498
references.citation: J Pediatr. 2010 Oct;157(4):641-7, 647.e1-2
references.pmid: 20547400
references.citation: Clin Endocrinol (Oxf). 1992 Nov;37(5):426-31
references.pmid: 1486693
references.citation: J Clin Endocrinol Metab. 1992 Jul;75(1):45-51
references.pmid: 1619030
references.citation: BMC Endocr Disord. 2003 Aug 12;3(1):4
references.pmid: 12914670
references.citation: J Clin Endocrinol Metab. 1992 Sep;75(3):779-82
references.pmid: 1517366
references.citation: J Clin Endocrinol Metab. 1995 Jun;80(6):1764-8
references.pmid: 7775619
references.citation: J Clin Densitom. 2007 Jul-Sep;10(3):319-26
references.pmid: 17574465
references.citation: J Appl Physiol (1985). 2004 Aug;97(2):655-60
references.pmid: 15090482
references.citation: J Bone Miner Res. 2009 Mar;24(3):543-57
references.pmid: 18505376