Osteoporosis International

, Volume 14, Issue 8, pp 694–700 | Cite as

Influence of reproductive factors on hip fracture risk in Chinese women

Original Article


To assess the relationships between reproductive factors and the risk of hip fractures in postmenopausal Chinese women, the authors analyzed data from a matched case-control study conducted in the Beijing metropolitan area among women aged 50 years and older. One hundred and fifty-six cases who sustained a hip fracture after minor trauma between January 1994 and May 1996 were identified from hospital records, of whom 121 could be located (78%). All cases agreed to be interviewed. Two controls were selected from the neighbors of each hip fracture case and matched to the cases by age within a 5-year range. Information on reproductive factors and potential confounders was obtained through personal interviews. Multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed using conditional logistic regression. Multiple imputation procedure was also employed to account for item non-response. Although univariate analyses revealed that later age at menopause, parity and breastfeeding were protective factors, only breastfeeding was statistically associated with risk of hip fracture after adjusting for potential confounding in multivariable logistic models. As compared with women with average duration of breastfeeding per child ≤6 months, women with average duration of breastfeeding per child 7–12 months, 13–23 months, and ≥24 months had odds ratios of 1.14 (95% CI: 0.48, 2.72), 0.28 (95% CI: 0.10, 0.82) and 0.34 (95% CI: 0.13, 0.92), respectively. Among parous women, 13% reduced risk was associated with every 6 months increase in breastfeeding per child. The authors conclude that extended breastfeeding is associated with a reduced hip fracture risk among Chinese women in Beijing.


Case-control study Hip fracture Lactation Parity 


  1. 1.
    Cooper C, Campion G, Melton LJ III et al. (1992) Hip fracture in the elderly: a world-wide projection. Osteoporos Int 2:285–289PubMedGoogle Scholar
  2. 2.
    Xu L, Lu A, Zhao X et al. (1996) Very low rates of hip fracture in Beijing, People's Republic of China the Beijing Osteoporosis Project. Am J Epidemiol 144:901–907PubMedGoogle Scholar
  3. 3.
    Yan L, Zhou B, Prentice A et al. (1999) Epidemiological study of hip fracture in Shenyang, People's Republic of China. Bone 24:151–155CrossRefPubMedGoogle Scholar
  4. 4.
    Zhang L, Cheng A, Bai Z et al. (2000) Epidemiology of cervical and trochanteric fractures of the proximal femur in 1994 in Tangshan, China. J Bone Miner Metab 18:84–88CrossRefGoogle Scholar
  5. 5.
    Schwartz AV, Kelsey JL, Maggi S et al. (1999) International variation in the incidence of hip fractures: Cross-national project on osteoporosis for the World Health Organization program for research on aging. Osteoporos Int 9:242–253CrossRefPubMedGoogle Scholar
  6. 6.
    Cumming RG, Nevitt MC, Cummings SR (1997) Epidemiology of hip fractures. Epidemiol Rev 19:244–257PubMedGoogle Scholar
  7. 7.
    Faulkner KG, Cummings SR, Black D et al. (1993) Simple measurement of femoral geometry predicts hip fracture: the study of osteoporotic fractures. J Bone Miner Res 8:1211–1217Google Scholar
  8. 8.
    Huo D, Li L (2000) [A case-control study on risk factors for hip fracture in the middle-aged and elderly in Beijing] (in Chinese). Zhonghua Liu Xing Bing Xue Za Zhi 21:37–40PubMedGoogle Scholar
  9. 9.
    Sowers M (1996) Pregnancy and lactation as risk factors for subsequent bone loss and osteoporosis. J Bone Miner Res 11:1052–1060PubMedGoogle Scholar
  10. 10.
    Cummings SR, Cauley JA, Palermo L et al. (1994) Racial differences in hip axis lengths might explain racial differences in rates of hip fracture. Study of Osteoporotic Fractures Research Group. Osteoporos Int 4:226–229PubMedGoogle Scholar
  11. 11.
    Rubin DB (1987) Multiple imputation for nonresponse in surveys. Wiley, New YorkGoogle Scholar
  12. 12.
    Schafer JL (1997) Analysis of incomplete multivariate data. Chapman & Hall, LondonGoogle Scholar
  13. 13.
    Cumming RG, Klineberg R (1993) Breastfeeding and other reproductive factors and the risk of hip fracture in elderly women. Int J Epidemiol 22:684–691PubMedGoogle Scholar
  14. 14.
    Kreiger N, Kelsey JL, Holford TR et al. (1982) An epidemiologic study of hip fracture in postmenopausal women. Am J Epidemiol 116:141–148PubMedGoogle Scholar
  15. 15.
    Boonyaratavej N, Suriyawongpaisal P, Takkinsatien A et al. (2001) Physical activity and risk factors for hip fractures in Thai women. Osteoporos Int 12:244–248CrossRefPubMedGoogle Scholar
  16. 16.
    Alderman BW, Weiss NS, Daling JR et al. (1986) Reproductive history and postmenopausal risk of hip and forearm fracture. Am J Epidemiol 124:262–267PubMedGoogle Scholar
  17. 17.
    Kreiger N, Gross A, Hunter G (1992) Dietary factors and fracture in postmenopausal women: a case-control study. Int J Epidemiol 21:953–958PubMedGoogle Scholar
  18. 18.
    Hoffman S, Grisso JA, Kelsey JL et al. (1993) Parity, lactation and hip fracture. Osteoporos Int 3:171–176PubMedGoogle Scholar
  19. 19.
    Cummings SR, Nevitt MC, Browner WS et al. (1995) Risk factors for hip fracture in white women. Study of Osteoporotic Fractures Research Group. N Engl J Med 332:767–773PubMedGoogle Scholar
  20. 20.
    Michaelsson K, Baron JA, Farahmand BY et al. (2001) Influence of parity and lactation on hip fracture risk. Am J Epidemiol 153:1166–1172CrossRefPubMedGoogle Scholar
  21. 21.
    Kovacs CS (2001) Calcium and bone metabolism in pregnancy and lactation. J Clin Endocrinol Metab 86:2344–2348PubMedGoogle Scholar
  22. 22.
    Sowers MF, Hollis BW, Shapiro B et al. (1996) Elevated parathyroid hormone-related peptide associated with lactation and bone density loss. JAMA 276:549–554PubMedGoogle Scholar
  23. 23.
    Lopez JM, Gonzales G, Reyes V et al. (1996) Bone turnover and density in healthy women during breastfeeding and after weaning. Osteoporos Int 6:153–159PubMedGoogle Scholar
  24. 24.
    Sowers M, Randolph JF, Shapiro B et al. (1995) A prospective study of bone density and pregnancy after an extended period of lactation with bone loss. Obstet Gynecol 85:285–289CrossRefPubMedGoogle Scholar
  25. 25.
    Kalkwarf HJ, Specker BL, Bianchi DC, Ranz J, Ho M (1997) The effect of calcium supplementation on bone density during lactation and after weaning. N Engl J Med 337:523–528CrossRefPubMedGoogle Scholar
  26. 26.
    Polatti F, Capuzzo E, Viazzo F et al. (1999) Bone mineral changes during and after lactation. Obstet Gynecol 94:52–56CrossRefPubMedGoogle Scholar
  27. 27.
    Prentice A, Jarjou LM, Cole TJ et al. (1995) Calcium requirements of lactating Gambian mothers: effects of a calcium supplement on breast-milk calcium concentration, maternal bone mineral content, and urinary calcium excretion. Am J Clin Nutr 62:58–67PubMedGoogle Scholar
  28. 28.
    Paganini-Hill A, Chao A, Ross RK et al. (1991) Exercise and other factors in the prevention of hip fracture: the Leisure World study. Epidemiology 2:16–25PubMedGoogle Scholar
  29. 29.
    Johnell O, Gullberg B, Kanis JA et al. (1995) Risk factors for hip fracture in European women: the MEDOS study. Mediterranean Osteoporosis Study. J Bone Miner Res 10:1802–1815PubMedGoogle Scholar
  30. 30.
    Raisz LG, Prestwood KM (1998) Estrogen and the risk of fracture—new data, new questions. N Engl J Med 339:767–768CrossRefPubMedGoogle Scholar
  31. 31.
    Parazzini F, Tavani A, Ricci E et al. (1996) Menstrual and reproductive factors and hip fractures in postmenopausal women. Maturitas 24:191–196PubMedGoogle Scholar
  32. 32.
    Cummings SR (1991) Epidemiologic studies of osteoporotic fractures: methodologic issues. Calcif Tissue Int 49;S15–20Google Scholar

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2003

Authors and Affiliations

  1. 1.Department of Health StudiesUniversity of ChicagoChicagoUSA
  2. 2.Center for Disease Control and PreventionBeijingChina

Personalised recommendations