title: Bone and fat relationships in postadolescent black females: a pQCT study.
abstract: Despite adolescent black females experiencing the highest rates of obesity, the effect of excess fat mass on bone structure and strength in this population is unknown. Our findings in postadolescent black females suggest that excess weight in the form of fat mass may adversely influence cortical bone structure and strength.
  
  
  BACKGROUND
  Although adolescent obesity has been associated with reduced bone structure and strength in white females, this relationship has not been studied in adolescent black females, a population experiencing the highest rates of obesity. Our objective was to compare bone structure and strength between postadolescent black females with normal and high levels of adiposity.
  
  
  METHODS
  Black females with ≤ 32% body fat were classified as normal body fat (NF; n = 33, aged 19.3 ± 1.3 years); females exceeding this cutoff were classified as high body fat (HF; n = 15, aged 19.0 ± 1.1 years). Using peripheral quantitative computed tomography, tibial and radial bones were scanned at the 4% (trabecular) and 20% (cortical) sites from the distal metaphyses. Fat-free soft-tissue mass (FFST) and %body fat were assessed by dual-energy X-ray absorptiometry.
  
  
  RESULTS
  After controlling for either FFST or body weight, the HF vs. NF group had lower total cross-sectional area (CSA; 9-17%), cortical CSA (6-15%), and strength-strain index (SSI; 13-24%) at the cortical site of the tibia (all p < 0.05). At the cortical site of the radius, the HF vs. NF group had lower total CSA (14%, p = 0.03), cortical CSA (9%, p = 0.04), and SSI (15%, p = 0.07) after control for body weight. There were no group differences in either the FFST-adjusted cortical bone values at the radius or in the trabecular bone parameters (body weight- or FFST-adjusted) at the tibia and radius.
  
  
  CONCLUSIONS
  Consistent with our adiposity and bone data in late-adolescent white females, our findings in black females entering adulthood also suggest that obesity may adversely influence cortical bone strength.
authors.affiliation: Department of Pediatrics, Medical College of Georgia, Augusta, GA, USA. NPOLLOCK@mail.mcg.edu
authors.forename: N K
authors.initials: NK
authors.lastname: Pollock
authors.forename: E M
authors.initials: EM
authors.lastname: Laing
authors.forename: M W
authors.initials: MW
authors.lastname: Hamrick
authors.forename: C A
authors.initials: CA
authors.lastname: Baile
authors.forename: D B
authors.initials: DB
authors.lastname: Hall
authors.forename: R D
authors.initials: RD
authors.lastname: Lewis
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000293:Adolescent; D001741:Black or African American; D015519:Bone Density / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D009765:Obesity / Q000150:complications; D011884:Radius / Q000000981:diagnostic imaging*; D013977:Tibia / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
references.citation: J Musculoskelet Neuronal Interact. 2005 Jul-Sep;5(3):213-24
references.pmid: 16172512
references.citation: J Clin Endocrinol Metab. 2009 Jul;94(7):2325-31
references.pmid: 19401374
references.citation: Bone. 2009 May;44(5):970-5
references.pmid: 19442622
references.citation: Arteriosclerosis. 1982 Jul-Aug;2(4):325-34
references.pmid: 6981403
references.citation: Am J Public Health. 1992 Mar;82(3):358-63
references.pmid: 1536350
references.citation: J Clin Endocrinol Metab. 2005 Sep;90(9):5096-103
references.pmid: 15998772
references.citation: J Clin Densitom. 2008 Jan-Mar;11(1):43-58
references.pmid: 18442752
references.citation: J Bone Miner Res. 2005 Feb;20(2):185-94
references.pmid: 15647811
references.citation: Endocrinology. 2007 Jul;148(7):3419-25
references.pmid: 17431002
references.citation: J Bone Miner Res. 1998 Jan;13(1):143-8
references.pmid: 9443800
references.citation: J Bone Miner Res. 2005 May;20(5):730-40
references.pmid: 15824845
references.citation: Int J Obes Relat Metab Disord. 2000 May;24(5):627-32
references.pmid: 10849586
references.citation: Nat Med. 1995 Nov;1(11):1155-61
references.pmid: 7584987
references.citation: J Clin Endocrinol Metab. 1998 Oct;83(10):3469-75
references.pmid: 9768648
references.citation: N Engl J Med. 1991 Dec 5;325(23):1597-600
references.pmid: 1944449
references.citation: Inj Prev. 2008 Dec;14(6):366-71
references.pmid: 19074241
references.citation: Bone. 2005 Oct;37(4):474-81
references.pmid: 16040285
references.citation: J Clin Endocrinol Metab. 1998 May;83(5):1420-7
references.pmid: 9589632
references.citation: J Musculoskelet Neuronal Interact. 2005 Jul-Sep;5(3):232-8
references.pmid: 16172514
references.citation: J Bone Miner Res. 2008 Dec;23(12):1946-53
references.pmid: 18684083
references.citation: Nutr Metab (Lond). 2005 Apr 07;2(1):9
references.pmid: 15817133
references.citation: Am J Clin Nutr. 2004 Aug;80(2):514-23
references.pmid: 15277178
references.citation: Bone. 2002 Nov;31(5):547-55
references.pmid: 12477567
references.citation: N Engl J Med. 2002 Sep 5;347(10):709-15
references.pmid: 12213941
references.citation: J Bone Miner Res. 2001 Jul;16(7):1337-42
references.pmid: 11450710
references.citation: Arterioscler Thromb Vasc Biol. 1997 Apr;17(4):680-7
references.pmid: 9108780
references.citation: Calcif Tissue Int. 2006 Dec;79(6):383-8
references.pmid: 17115240
references.citation: J Bone Miner Res. 2009 Aug;24(8):1369-79
references.pmid: 19292617
references.citation: J Clin Endocrinol Metab. 1992 Jul;75(1):45-51
references.pmid: 1619030
references.citation: Bone. 2005 Mar;36(3):568-76
references.pmid: 15777684
references.citation: Am J Clin Nutr. 2009 Oct;90(4):1104-11
references.pmid: 19710192
references.citation: Osteoporos Int. 2002 Oct;13(10):835-40
references.pmid: 12378374
references.citation: J Bone Miner Res. 2000 Oct;15(10):2011-8
references.pmid: 11028455
references.citation: Osteoporos Int. 2008 May;19(5):595-606
references.pmid: 17965817
references.citation: J Biomech. 1991;24 Suppl 1:79-88
references.pmid: 1842337
references.citation: Anat Rec. 1987 Sep;219(1):1-9
references.pmid: 3688455
references.citation: J Clin Endocrinol Metab. 2006 Jul;91(7):2534-41
references.pmid: 16621904
references.citation: JAMA. 2008 May 28;299(20):2401-5
references.pmid: 18505949
references.citation: J Clin Endocrinol Metab. 1998 May;83(5):1414-9
references.pmid: 9589631
references.citation: Acta Diabetol. 2003 Oct;40 Suppl 1:S274-7
references.pmid: 14618492
references.citation: Am J Clin Nutr. 2007 Nov;86(5):1530-8
references.pmid: 17991669
references.citation: Obesity (Silver Spring). 2006 May;14(5):819-25
references.pmid: 16855191
references.citation: Pediatrics. 2006 Jun;117(6):2167-74
references.pmid: 16740861
references.citation: Circulation. 1984 May;69(5):895-904
references.pmid: 6705165
references.citation: J Bone Miner Res. 2010 Mar;25(3):527-36
references.pmid: 19778184
references.citation: Bone. 1998 Jan;22(1):1-6
references.pmid: 9437507
references.citation: J Clin Endocrinol Metab. 2007 Feb;92(2):430-6
references.pmid: 17118995
references.citation: J Musculoskelet Neuronal Interact. 2008 Oct-Dec;8(4):401-9
references.pmid: 19147978
references.citation: J Clin Endocrinol Metab. 2007 Jan;92(1):143-7
references.pmid: 17047019
references.citation: J Bone Miner Res. 2005 Dec;20(12):2090-6
references.pmid: 16294262
references.citation: J Clin Endocrinol Metab. 2007 May;92(5):1640-6
references.pmid: 17299077
references.citation: J Bone Miner Res. 2005 Dec;20(12):2075-81
references.pmid: 16294260
references.citation: Acta Paediatr. 1995 Mar;84(3):313-5
references.pmid: 7780255