Osteoporosis International

, Volume 22, Issue 5, pp 1377–1388 | Cite as

Ethnic differences in femur geometry in the women's health initiative observational study

  • D. A. Nelson
  • T. J. Beck
  • G. Wu
  • C. E. Lewis
  • T. Bassford
  • J. A. Cauley
  • M. S. LeBoff
  • S. B. Going
  • Z. Chen
Original Article

Abstract

Summary

Participants in the observational study of the Women's Health Initiative (WHI) were studied to determine if ethnic differences in femur geometry can help to explain differences in hip fracture rates. Structural differences in femurs of African and Mexican-American women appear to be consistent with lower rates of hip fractures vs. whites.

Introduction

Ethnic origin has a major influence on hip fractures, but the underlying etiology is unknown. We evaluated ethnic differences in hip fracture rates among 159,579 postmenopausal participants in the WHI then compared femur bone mineral density (BMD) and geometry among a subset with dual X-ray absorptiometry (DXA) scans of the hip and total body.

Methods

The subset included 8,206 non-Hispanic whites, 1,476 African-American (AA), 704 Mexican-American (MA), and 130 Native Americans (NA). Femur geometry derived from hip DXA using hip-structure analysis (HSA) in whites was compared to minority groups after adjustment for age, height, weight, percent lean mass, neck-shaft angle and neck length, hormone use, chronic disease (e.g., diabetes, rheumatoid arthritis, cancer), bone active medications (e.g., corticosteroids, osteoporosis therapies), and clinical center.

Results

Both AA and MA women suffered hip fractures at half the rate of whites while NA appeared to be similar to whites. The structural advantage among AA appears to be due to a slightly narrower femur that requires more bone tissue to achieve similar or lower section moduli (SM) vs. whites. This also underlies their higher BMD (reduces region area) and lower buckling ratios (buckling susceptibility). Both MA and NA women had similar advantages vs. whites at the intertrochanter region where cross-sectional area and SM were higher but with no differences at the neck. NA and MA had smaller bending moments vs. whites acting in a fall on the hip (not significant in small NA sample). Buckling ratios of MA did not differ from whites at any region although NA had 4% lower values at the IT region.

Conclusion

Differences in the geometry at the proximal femur are consistent with the lower hip fracture rates among AA and MA women compared to whites.

Keywords

African American Cross-sectional geometry Ethnic differences Hip structure analysis Local buckling Mexican American Native American Proximal femur 

References

  1. 1.
    Cauley JA, Wu L, Wampler NS, Barnhart JM, Allison M, Chen Z, Jackson R, Robbins J (2007) Clinical risk factors for fractures in multi-ethnic women: the women's health initiative. J Bone Miner Res 22:1816–1826PubMedCrossRefGoogle Scholar
  2. 2.
    De Laet C, Kanis JA, Oden A, Johanson H, Johnell O, Delmas P, Eisman JA, Kroger H, Fujiwara S, Garnero P, McCloskey EV, Mellstrom D, Melton LJ 3rd, Meunier PJ, Pols HA, Reeve J, Silman A, Tenenhouse A (2005) Body mass index as a predictor of fracture risk: a meta-analysis. Osteoporos Int 16:1330–1338PubMedCrossRefGoogle Scholar
  3. 3.
    Beck TJ, Petit MA, Wu G, LeBoff MS, Cauley JA, Chen Z (2009) Does obesity really make the femur stronger? BMD, geometry, and fracture incidence in the women's health initiative-observational study. J Bone Miner Res 24:1369–1379PubMedCrossRefGoogle Scholar
  4. 4.
    Verhulp E, van Rietbergen B, Huiskes R (2008) Load distribution in the healthy and osteoporotic human proximal femur during a fall to the side. Bone 42:30–35PubMedCrossRefGoogle Scholar
  5. 5.
    Martin R (1991) Determinants of the mechanical properties of bones. J Biomech 24:79–88PubMedCrossRefGoogle Scholar
  6. 6.
    Martin RB, Burr DB (1984) Non-invasive measurement of long bone cross-sectional moment of inertia by photon absorptiometry. J Biomech 17:195–201PubMedCrossRefGoogle Scholar
  7. 7.
    Kaptoge S, Beck TJ, Reeve J, Stone KL, Hillier TA, Cauley JA, Cummings SR (2008) Prediction of incident hip fracture risk by femur geometry variables measured by hip structural analysis in the study of osteoporotic fractures. J Bone Miner Res 23:1892–1904PubMedCrossRefGoogle Scholar
  8. 8.
    Rivadeneira F, Zillikens MC, De Laet CE, Hofman A, Uitterlinden AG, Beck TJ, Pols HA (2007) Femoral neck BMD is a strong predictor of hip fracture susceptibility in elderly men and women because it detects cortical bone instability: the Rotterdam Study. J Bone Miner Res 22:1781–1790PubMedCrossRefGoogle Scholar
  9. 9.
    Gnudi S, Ripamonti C, Lisi L, Fini M, Giardino R, Giavaresi G (2002) Proximal femur geometry to detect and distinguish femoral neck fractures from trochanteric fractures in postmenopausal women. Osteoporos Int 13:69–73PubMedCrossRefGoogle Scholar
  10. 10.
    de Bakker PM, Manske SL, Ebacher V, Oxland TR, Cripton PA, Guy P (2009) During sideways falls proximal femur fractures initiate in the superolateral cortex: evidence from high-speed video of simulated fractures. J Biomech 42:1917–1925PubMedCrossRefGoogle Scholar
  11. 11.
    Nelson DA, Barondess DA, Hendrix SL, Beck TJ (2000) Cross-sectional geometry, bone strength, and bone mass in the proximal femur in black and white postmenopausal women. J Bone Miner Res 15:1992–1997PubMedCrossRefGoogle Scholar
  12. 12.
    Nelson D, Pettifor J, Barondess D, Cody D, Uusi-Rasi K, Beck T (2004) Comparison of cross-sectional geometry of the proximal femur in white and black women from Detroit and Johannesburg. J Bone Miner Res 19:560–565PubMedCrossRefGoogle Scholar
  13. 13.
    Travison TG, Beck TJ, Esche GR, Araujo AB, McKinlay JB (2008) Age trends in proximal femur geometry in men: variation by race and ethnicity. Osteoporos Int 19:277–287PubMedCrossRefGoogle Scholar
  14. 14.
    Rossouw JE, Anderson GL, Prentice RL, LaCroix AZ, Kooperberg C, Stefanick ML, Jackson RD, Beresford SA, Howard BV, Johnson KC, Kotchen JM, Ockene J (2002) Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the women's health initiative randomized controlled trial. JAMA 288:321–333PubMedCrossRefGoogle Scholar
  15. 15.
    Anderson GL, Limacher M, Assaf AR, Bassford T, Beresford SA, Black H, Bonds D, Brunner R, Brzyski R, Caan B, Chlebowski R, Curb D, Gass M, Hays J, Heiss G, Hendrix S, Howard BV, Hsia J, Hubbell A, Jackson R, Johnson KC, Judd H, Kotchen JM, Kuller L, LaCroix AZ, Lane D, Langer RD, Lasser N, Lewis CE, Manson J, Margolis K, Ockene J, O'Sullivan MJ, Phillips L, Prentice RL, Ritenbaugh C, Robbins J, Rossouw JE, Sarto G, Stefanick ML, Van Horn L, Wactawski-Wende J, Wallace R, Wassertheil-Smoller S (2004) Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the women's health initiative randomized controlled trial. JAMA 291:1701–1712PubMedCrossRefGoogle Scholar
  16. 16.
    Curb JD, McTiernan A, Heckbert SR, Kooperberg C, Stanford J, Nevitt M, Johnson KC, Proulx-Burns L, Pastore L, Criqui M, Daugherty S (2003) Outcomes ascertainment and adjudication methods in the women's health initiative. Ann Epidemiol 13:S122–S128PubMedCrossRefGoogle Scholar
  17. 17.
    Hays J, Hunt JR, Hubbell FA, Anderson GL, Limacher M, Allen C, Rossouw JE (2003) The women's health initiative recruitment methods and results. Ann Epidemiol 13:S18–S77PubMedCrossRefGoogle Scholar
  18. 18.
    Anderson GL, Manson J, Wallace R, Lund B, Hall D, Davis S, Shumaker S, Wang CY, Stein E, Prentice RL (2003) Implementation of the women's health initiative study design. Ann Epidemiol 13:S5–S17PubMedCrossRefGoogle Scholar
  19. 19.
    Patterson RE, Kristal AR, Tinker LF, Carter RA, Bolton MP, Agurs-Collins T (1999) Measurement characteristics of the women's health initiative food frequency questionnaire. Ann Epidemiol 9:178–187PubMedCrossRefGoogle Scholar
  20. 20.
    Ainsworth BE, Jacobs DR Jr, Leon AS, Richardson MT, Montoye HJ (1993) Assessment of the accuracy of physical activity questionnaire occupational data. J Occup Med 35:1017–1027PubMedGoogle Scholar
  21. 21.
    McTiernan A, Kooperberg C, White E, Wilcox S, Coates R, Adams-Campbell LL, Woods N, Ockene J (2003) Recreational physical activity and the risk of breast cancer in postmenopausal women: the women's health initiative cohort study. JAMA 290:1331–1336PubMedCrossRefGoogle Scholar
  22. 22.
    Ware JE Jr, Sherbourne CD (1992) The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 30:473–483PubMedCrossRefGoogle Scholar
  23. 23.
    Beck TJ, Looker AC, Ruff CB, Sievanen H, Wahner HW (2000) Structural trends in the aging femoral neck and proximal shaft: analysis of the third national health and nutrition examination survey dual-energy X-ray absorptiometry data. J Bone Miner Res 15:2297–2304PubMedCrossRefGoogle Scholar
  24. 24.
    Mayhew P, Thomas C, Clement J, Loveridge N, Beck T, Bonfield W, Burgoyne C, Reeve J (2005) Relation between age, femoral neck cortical stability, and hip fracture risk. Lancet 366:129–135PubMedCrossRefGoogle Scholar
  25. 25.
    Young W (1989) Elastic stability formulas for stress and strain. In: Young WC, Budynas RG, Roark RJ (eds) Roark's Formulas for Stress and Strain. McGraw-Hill, New York, p 688Google Scholar
  26. 26.
    Cummings SR, Nevitt MC, Browner WS, Stone K, Fox KM, Ensrud KE, Cauley J, Black D, Vogt TM (1995) Risk factors for hip fracture in white women. Study of osteoporotic fractures research group [see comments]. N Engl J Med 332:767–773PubMedCrossRefGoogle Scholar
  27. 27.
    Cauley J, Lui L, Stone K, Hillier T, Zmuda J, Hochberg M, Beck T, Ensrud K (2005) Loss of hip bone mineral density is greater among Caucasian women than African American women. J Am Geriatr Soc 53:183–189PubMedCrossRefGoogle Scholar
  28. 28.
    Cauley J, Lui L, Ensrud K, Zmuda J, Stone K, Hochberg M, SR C (2005) Bone mineral density and the risk of incident nonspinal fractures in black and white women. JAMA 293:2102–2108PubMedCrossRefGoogle Scholar
  29. 29.
    Burr DB (1997) Muscle strength, bone mass and age-related bone loss. J Bone Miner Res 12:1547–1551PubMedCrossRefGoogle Scholar
  30. 30.
    Paul JP (1967) Forces at the human hip joint. In. University of GlasgowGoogle Scholar
  31. 31.
    Beck TJ (2007) Extending DXA beyond bone mineral density: understanding hip structure analysis. Curr Osteoporos Rep 5:49–55PubMedCrossRefGoogle Scholar
  32. 32.
    Khoo B, Beck T, Qiao Q, Parakh Q, Semanick L, Prince R, Singer K, Price R (2005) In vivo short-term reproducibility of hip structure analysis variables in comparison with bone mineral density using paired dual-energy X-ray absorptiometry scans from multi-centre clinical trials. Bone 37:112–121PubMedCrossRefGoogle Scholar
  33. 33.
    Ruff CB (2005) Mechanical determinants of bone form: insights from skeletal remains. J Musculoskelet Neuronal Interact 5:202–212PubMedGoogle Scholar

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2010

Authors and Affiliations

  • D. A. Nelson
    • 1
  • T. J. Beck
    • 2
  • G. Wu
    • 3
  • C. E. Lewis
    • 4
  • T. Bassford
    • 3
  • J. A. Cauley
    • 5
  • M. S. LeBoff
    • 6
  • S. B. Going
    • 3
  • Z. Chen
    • 3
  1. 1.Wayne State University School of MedicineDetroitUSA
  2. 2.Johns Hopkins University School of MedicineBaltimoreUSA
  3. 3.Mel and Enid Zuckerman College of Public HealthUniversity of ArizonaTucsonUSA
  4. 4.University of Alabama BirminghamBirminghamUSA
  5. 5.Brigham and Womens Hospital, Harvard Medical SchoolBostonUSA
  6. 6.University of Pittsburgh Graduate School of Public HealthPittsburghUSA

Personalised recommendations