Osteoporosis International

, Volume 20, Issue 4, pp 577–583 | Cite as

Heritability of impaired balance: a nationwide cohort study in twins

  • H. Wagner
  • H. Melhus
  • N. L. Pedersen
  • K. Michaëlsson
Original Article



In this large population-based twin study, a self-estimated impaired balance, an important risk factor for osteoporotic fractures, had a modest heritability of 0.27. Individual-specific environmental influences seem to be the dominating cause for impaired balance.


The principal causal components of an osteoporotic fracture are falls and weakened bone strength. While bone strength has a strong genetic origin, the heritable influences on impaired balance that contribute to the risk of injurious falls at older age are uncertain.


To evaluate the heritability and environmental influence on self-reported impaired balance in older men and women, we used data from a sample of 22,998 Swedish twins, 55 to 99 years of age.


An impaired balance was reported by 2,890 (12.3%) of the twins. The tetrachoric correlation for impaired balance was only slightly lower for like-sex dizygotic twins (0.31) compared to monozygotic twins (0.36). These correlations indicate a modest familial (genetic and shared environmental) influence. Model fitting results indicate that the age- and sex-adjusted heritability for impaired balance was 0.27 (95%CI = 0.01–0.45). Individual-specific environmental influences differed only slightly by sex and age.


These results imply that a self-reported impaired balance, an independent risk factor for osteoporotic fractures, has a modestly heritable etiology in older subjects. Our observation can partly explain the previously observed modest heritability for osteoporotic fractures even though there is a high heritability for bone mineral density.


Balance Environment Heritability Muscular weakness Osteoporotic fractures Twin study 


  1. 1.
    Ahlborg HG, Johnell O, Turner CH et al (2003) Bone loss and bone size after menopause. N Engl J Med 349:327–334PubMedCrossRefGoogle Scholar
  2. 2.
    Peacock M, Turner CH, Econs MJ et al (2002) Genetics of osteoporosis. Endocr Rev 23:303–326PubMedCrossRefGoogle Scholar
  3. 3.
    Kannus P, Palvanen M, Kaprio J, Parkkari J, Koskenvuo M (1999) Genetic factors and osteoporotic fractures in elderly people: prospective 25 year follow up of a nationwide cohort of elderly Finnish twins. BMJ 319:1334–1337PubMedGoogle Scholar
  4. 4.
    Michaëlsson K, Melhus H, Ferm H et al (2005) Genetic liability to fractures in the elderly. Arch Intern Med 165:1825–1830PubMedCrossRefGoogle Scholar
  5. 5.
    El Haber N, Hill KD, Cassano AM et al (2006) Genetic and environmental influences on variation in balance performance among female twin pairs aged 21–82 years. Am J Epidemiol 164:246–256PubMedCrossRefGoogle Scholar
  6. 6.
    Pajala S, Era P, Koskenvuo M et al (2007) Genetic and environmental contribution to postural balance of older women in single and dual task situations. Neurobiol Aging 28:947–954PubMedCrossRefGoogle Scholar
  7. 7.
    Pajala S, Era P, Koskenvuo M et al (2004) Contribution of genetic and environmental effects to postural balance in older female twins. J Appl Physiol 96:308–315PubMedCrossRefGoogle Scholar
  8. 8.
    Baloh RW, Spain S, Socotch TM et al (1995) Posturography and balance problems in older people. J Am Geriatr Soc 43:638–644PubMedGoogle Scholar
  9. 9.
    Vellas BJ, Wayne SJ, Romero LJ et al (1997) Fear of falling and restriction of mobility in elderly fallers. Age Ageing 26:189–193PubMedCrossRefGoogle Scholar
  10. 10.
    Alexander NB, Guire KE, Thelen DG et al (2000) Self-reported walking ability predicts functional mobility performance in frail older adults. J Am Geriatr Soc 48:1408–1413PubMedGoogle Scholar
  11. 11.
    Rathouz PJ, Kasper JD, Zeger SL et al (1998) Short-term consistency in self-reported physical functioning among elderly women: the Women’s Health and Aging Study. Am J Epidemiol 147:764–773PubMedGoogle Scholar
  12. 12.
    Guralnik JM, Simonsick EM, Ferrucci L et al (1994) A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission. J Gerontol 49:M85–M94PubMedGoogle Scholar
  13. 13.
    Ferrer M, Lamarca R, Orfila F et al (1999) Comparison of performance-based and self-rated functional capacity in Spanish elderly. Am J Epidemiol 149:228–235PubMedGoogle Scholar
  14. 14.
    Cummings SR, Nevitt MC (1994) Falls. N Engl J Med 331:872–873PubMedCrossRefGoogle Scholar
  15. 15.
    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 332:767–773PubMedCrossRefGoogle Scholar
  16. 16.
    Dargent-Molina P, Favier F et al (1996) Fall-related factors and risk of hip fracture: the EPIDOS prospective study. Lancet 348:145–149PubMedCrossRefGoogle Scholar
  17. 17.
    Nguyen ND, Pongchaiyakul C, Center JR et al (2005) Identification of high-risk individuals for hip fracture: a 14-year prospective study. J Bone Miner Res 20:1921–1928PubMedCrossRefGoogle Scholar
  18. 18.
    Wagner H, Melhus H, Gedeborg R, Pedersen NL, Michaëlsson K (2008) Simply ask them about their balance—future fracture risk in a nationwide cohort study in twins. Am J Epidemiol (in press)Google Scholar
  19. 19.
    Pedersen NL, Lichtenstein P, Svedberg P (2002) The Swedish Twin Registry in the third millenium. Twin Res 5:427–432PubMedCrossRefGoogle Scholar
  20. 20.
    Lichtenstein P, De Faire U, Floderus B et al (2002) The Swedish Twin Regsitry: a unique resource for clinical, epidemiologic and genetic studies. J Intern Med 252:184–205PubMedCrossRefGoogle Scholar
  21. 21.
    Boomsma D, Busjahn A, Peltonen L (2002) Classical twin studies and beyond. Nat Genet 3:872–882CrossRefGoogle Scholar
  22. 22.
    Neale MC (1997) MX: statistical modeling. Department of Psychiatry, Virginia Commonwealth University, Richmond, VAGoogle Scholar
  23. 23.
    Rankinen T, Bray MS, Hagberg JM et al (2006) The human gene map for performance and health-related fitness phenotypes: the 2005 update. Med Sci Sports Exerc 38:1863–1888PubMedCrossRefGoogle Scholar
  24. 24.
    Evans WJ (1999) Exercise training guidelines for the elderly. Med Sci Sports Exerc 31:12–17PubMedCrossRefGoogle Scholar
  25. 25.
    Fiatarone MA, O’Neill EF, Ryan ND et al (1994) Exercise training and nutritional supplementation for physical frailty in very elderly people. N Engl J Med 330:1769–1775PubMedCrossRefGoogle Scholar
  26. 26.
    Buchner DM, Cress ME, de Lateur BJ et al (1997) A comparison of the effects of three types of endurance training on balance and other fall risk factors in older adults. Aging 9:112–119PubMedGoogle Scholar
  27. 27.
    Szulc P, Beck TJ, Marchand F et al (2005) Low skeletal muscle mass is associated with poor structural parameters of bone and impaired balance in elderly men—the MINOS study. J Bone Miner Res 20:721–729PubMedCrossRefGoogle Scholar
  28. 28.
    Province MA, Hadley EC, Hornbrook MC et al (1995) The effects of exercise on falls in elderly patients. A preplanned meta-analysis of the FICSIT trials. JAMA 273:1341–1347PubMedCrossRefGoogle Scholar
  29. 29.
    Pahor M, Blair SN, Espeland M et al (2006) Effects of a physical activity intervention on measures of physical performance: results of the lifestyle interventions and independence for Elders Pilot (LIFE-P) study. J Gerontol A Biol Sci Med Sci 61:1157–1165PubMedGoogle Scholar
  30. 30.
    Shumway-Cook A, Patla A, Stewart AL et al (2005) Assessing environmentally determined mobility disability: self-report versus observed community mobility. J Am Geriatr Soc 53:700–704PubMedCrossRefGoogle Scholar

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2008

Authors and Affiliations

  • H. Wagner
    • 1
  • H. Melhus
    • 2
  • N. L. Pedersen
    • 3
  • K. Michaëlsson
    • 1
    • 4
  1. 1.Department of Surgical Sciences, Section of OrthopaedicsUniversity HospitalUppsalaSweden
  2. 2.Department of Medical Sciences, Section of Clinical PharmacologyUniversity HospitalUppsalaSweden
  3. 3.Department of Medical Epidemiology and BiostatisticsKarolinska InstitutetStockholmSweden
  4. 4.Uppsala Clinical Research CenterUniversity HospitalUppsalaSweden

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