Impact of hip fracture on mortality: a cohort study in hip fracture discordant identical twins
2014 (English)In: Journal of Bone and Mineral Research, ISSN 0884-0431, E-ISSN 1523-4681, Vol. 29, no 2, 424-431 p.Article in journal (Refereed) Published
Several studies have shown a long-lasting higher mortality after hip fracture but the reasons of the excess risk is not well understood. We aimed to determine whether there exists a higher mortality after hip fracture when controlling for genetic constitution, shared environment, comorbidity and lifestyle by use of a nation-wide cohort study in hip fracture discordant monozygotic twins. All 286 identical Swedish twin pairs discordant for hip fracture (1972-2010) were identified. Comorbidity and lifestyle information was retrieved by registers and questionnaire information. We used intrapair Cox regression to compute multivariable-adjusted hazard ratios (HRs) for death. During follow-up, 143 twins with a hip fracture died (50%) compared to 101 twins (35%) without a hip fracture. Through the first year after hip fracture, the rate of death increased four-fold in women (HR 3.71; 95% confidence interval (CI) 1.32-10.40) and seven-fold in men (HR 6.67; 95% CI 1.47-30.13). The increased rate in women only persisted during the first year after hip fracture (HR after 1 year 0.99; 95% CI 0.66-1.50), whereas the corresponding HR in men was 2.58 (95% CI 1.02-6.62). The higher risk in men after the hip fracture event was successively attenuated during follow-up. After 5 years, the hazard ratio in men with a hip fracture was 1.19 (95% CI 0.29-4.90). On average, the hip fracture contributed to 0.9 years of life lost in women (95% CI 0.06-1.7) and 2.7 years in men (95% CI 1.7-3.7). The potential years of life lost associated with the hip fracture was especially pronounced in older men (>75 years), with an average loss of 47% (95% CI 31-61) of the expected remaining lifetime. We conclude that both women and men display a higher mortality after hip fracture independent of genes, comorbidity and lifestyle.
Place, publisher, year, edition, pages
Wiley-Blackwell, 2014. Vol. 29, no 2, 424-431 p.
GENETIC RESEARCH, EPIDEMIOLOGY, HIP FRACTURE, MORTALITY, TWIN
IdentifiersURN: urn:nbn:se:umu:diva-79212DOI: 10.1002/jbmr.2029PubMedID: 23821464OAI: oai:DiVA.org:umu-79212DiVA: diva2:640275
FunderSwedish Research Council