title: Bone Mineral Content as a Driver of Energy Expenditure in Prepubertal and Early Pubertal Boys.
abstract: OBJECTIVE
  To examine the associations of bone and bone-secreted factors with measures of energy metabolism in prepubertal and early pubertal boys.
  
  
  METHODS
  Participants in this cross-sectional, observational study included 37 (69% black, 31% white) boys, aged 7-12 years (Tanner stage <III). Dual-energy X-ray absorptiometry was used to measure bone mineral content (BMC) and percent body fat. Indirect calorimetry was used to assess resting energy expenditure (REE). Fasting blood levels of osteocalcin (OCN), fibroblast growth factor 23 (FGF23), insulin, glucose, precursor product of type I collagen (N-terminal pro-peptide) and type I collagen, and C-terminal cross-linked telopeptide were measured. Pearson correlations were performed to evaluate relationships among BMC, OCN, FGF23, fasting insulin and glucose, and REE. Multiple linear regression models were used to test associations between OCN and BMC (independent variables) with fasting insulin and glucose and with REE, adjusting for bone turnover markers and further adjusted for percent body fat.
  
  
  RESULTS
  BMC was correlated with REE and insulin. OCN was correlated with glucose in blacks only (r = 0.45, P < .05). FGF23 was not correlated with any markers of energy metabolism. BMC was associated with insulin level in blacks (β = 0.95, P = .001), which was attenuated by percent body fat (β = 0.47, P = .081). BMC was associated with REE in whites (β = 0.496.7, P < .05) and blacks (β = 619.5, P < .0001); but accounting for percent body fat attenuated the association in whites (β = 413.2, P = .078).
  
  
  CONCLUSIONS
  Our findings suggest that BMC is a determinant of fasting insulin and REE, and that the contribution of body fat appears to be race-specific. Endocrine effects of FGF23 and OCN on energy metabolism were not apparent.
  
  
  BACKGROUND
  Registered with ClinicalTrials.gov: NCT02040740, NCT02040727, and NCT01410643.
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL. Electronic address: hankslj@uab.edu.
authors.forename: Lynae J
authors.initials: LJ
authors.lastname: Hanks
authors.affiliation: Department of Medicine, University of Alabama at Birmingham, Birmingham, AL.
authors.forename: Orlando M
authors.initials: OM
authors.lastname: Gutiérrez
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL.
authors.forename: Ambika P
authors.initials: AP
authors.lastname: Ashraf
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL.
authors.forename: Krista
authors.initials: K
authors.lastname: Casazza
mesh_terms: D001741:Black or African American; D015519:Bone Density / Q000502:physiology*; D002648:Child; D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology*; D000089703:Fibroblast Growth Factor-23; D006801:Humans; D008297:Male; D011627:Puberty / Q000378:metabolism*; D044465:White People
references.citation: J Clin Endocrinol Metab. 1999 Dec;84(12):4702-12
references.pmid: 10599739
references.citation: J Clin Endocrinol Metab. 2011 Jul;96(7):E1092-9
references.pmid: 21508147
references.citation: Clin Endocrinol (Oxf). 2015 Apr;82(4):550-6
references.pmid: 25039824
references.citation: J Clin Endocrinol Metab. 2011 May;96(5):1450-5
references.pmid: 21325461
references.citation: Nature. 2012 Jan 19;481(7381):314-20
references.pmid: 22258610
references.citation: J Pediatr Endocrinol Metab. 2012;25(7-8):687-90
references.pmid: 23155694
references.citation: Bone. 2002 Dec;31(6):703-8
references.pmid: 12531565
references.citation: World J Diabetes. 2013 Aug 15;4(4):145-50
references.pmid: 23961325
references.citation: Bonekey Rep. 2013 Apr 10;2:315
references.pmid: 23951544
references.citation: J Clin Endocrinol Metab. 2014 Jan;99(1):178-83
references.pmid: 24170105
references.citation: J Bone Miner Res. 2003 May;18(5):859-67
references.pmid: 12733725
references.citation: J Bone Miner Res. 1993 Sep;8(9):1111-5
references.pmid: 8237481
references.citation: J Adolesc. 2002 Oct;25(5):535-50
references.pmid: 12234559
references.citation: Cell. 2007 Aug 10;130(3):456-69
references.pmid: 17693256
references.citation: Diabetes. 1996 Jun;45(6):742-8
references.pmid: 8635647
references.citation: J Bone Miner Res. 1995 May;10(5):829-33
references.pmid: 7639119
references.citation: J Bone Miner Res. 2012 Feb;27(2):283-93
references.pmid: 22068892
references.citation: J Clin Endocrinol Metab. 2009 May;94(5):1602-7
references.pmid: 19258409
references.citation: J Clin Endocrinol Metab. 1991 Mar;72(3):703-10
references.pmid: 1997523
references.citation: Eur J Clin Nutr. 2013 Dec;67(12):1331-3
references.pmid: 24169463
references.citation: Diabetes. 1999 Aug;48(8):1515-21
references.pmid: 10426367
references.citation: Semin Nephrol. 2013 Sep;33(5):448-56
references.pmid: 24119850
references.citation: Pediatrics. 2002 Nov;110(5):911-9
references.pmid: 12415029
references.citation: Mol Cell Endocrinol. 2014 Nov;397(1-2):4-14
references.pmid: 25289807
references.citation: Arterioscler Thromb Vasc Biol. 2010 Jul;30(7):1474-8
references.pmid: 20395593
references.citation: Int J Androl. 2006 Feb;29(1):241-6; discussion 286-90
references.pmid: 16466545
references.citation: J Diabetes Complications. 2014 Jan-Feb;28(1):61-5
references.pmid: 24125760
references.citation: Biomarkers. 2009 May;14(3):181-202
references.pmid: 19399662
references.citation: Med Sport Sci. 2010;55:114-27
references.pmid: 20956864
references.citation: J Clin Endocrinol Metab. 2009 Mar;94(3):827-32
references.pmid: 19088165
references.citation: Endocr Rev. 2005 Feb;26(1):114-46
references.pmid: 15689575
references.citation: PLoS One. 2013;8(3):e58961
references.pmid: 23555610
references.citation: Int J Obes (Lond). 2010 May;34(5):852-8
references.pmid: 20065970
references.citation: J Bone Miner Res. 1997 Apr;12(4):676-82
references.pmid: 9101380
references.citation: J Bone Miner Res. 2010 Jul;25(7):1527-35
references.pmid: 20200959
references.citation: J Clin Endocrinol Metab. 2007 Sep;92(9):3453-7
references.pmid: 17579203
references.citation: Diabetes Metab Res Rev. 2009 Nov;25(8):768-72
references.pmid: 19877133
references.citation: Horm Res. 2002;57(5-6):170-9
references.pmid: 12053089
references.citation: J Lab Clin Med. 1996 Jan;127(1):67-70
references.pmid: 8592098
references.citation: J Clin Endocrinol Metab. 2009 Jan;94(1):237-45
references.pmid: 18854399
references.citation: Am J Clin Nutr. 2010 Apr;91(4):907-12
references.pmid: 20164308
references.citation: J Clin Endocrinol Metab. 2008 Jul;93(7):2610-5
references.pmid: 18349063
references.citation: J Clin Densitom. 2012 Oct-Dec;15(4):399-404
references.pmid: 22542222
references.citation: Osteoporos Int. 2012 Apr;23(4):1337-42
references.pmid: 21656264
references.citation: N Engl J Med. 2006 May 25;354(21):2250-61
references.pmid: 16723616
references.citation: Diabetes. 2002 Oct;51(10):3014-9
references.pmid: 12351441
references.citation: Am J Clin Nutr. 2002 Apr;75(4):705-13
references.pmid: 11916757
references.citation: J Clin Endocrinol Metab. 1995 Aug;80(8):2291-7
references.pmid: 7543111
references.citation: Clin Endocrinol (Oxf). 2002 Jul;57(1):107-16
references.pmid: 12100078
references.citation: Diabetes. 2001 Nov;50(11):2444-50
references.pmid: 11679420