Obesity increases the risk of early hip fracture in postmenopausal women

December 01, 2020

Obese women have an increased risk of hip fracture earlier than others, already well before the age of 70, a new study from the University of Eastern Finland shows. The study followed 12,715 women for a period of 25 years. The new findings from the Osteoporosis Risk Factor and Prevention (OSTPRE) study were published in Osteoporosis International.

Launched at the University of Eastern Finland in 1989, the OSTPRE study is a population-based cohort study that recruited all women born in Kuopio Province, Eastern Finland, between 1932 and 1941. In the 25-year follow-up, the researchers analysed the association of body mass index (BMI) at the age of 58 with the risk of early hip fracture up until the age of 70. They also analysed the association of body mass index at the age of 70 with the risk of hip fracture later in life, up until the age of 83. The risk of hip fracture was examined in groups of normal-weight, overweight and obese women. Data on hip fractures, mechanisms of injury, and mortality were obtained from national health registers.

Normal weight was defined as a BMI of 25 or less, overweight as a BMI of 25-29.9, and obesity as a BMI of 30 or over (kg/m2). At baseline, 39.6 per cent of the women were normal-weight, 40 per cent were overweight, and 19.9 per cent were obese. A small fraction of the women (n=59, 0.5%) had a BMI below the normal range, i.e. less than 18.5 kg/m2. Ageing was associated with some increase in the BMI: at 70 years of age, 33.4% of the women were normal-weight, 40.9% were overweight, and 25.7% were obese.

As expected, the risk of hip fracture increased with age in all of the groups; however, the risk of early hip fracture increased faster in obese women, and slower in overweight women, than in others. In obese women, the probability of hip fracture was at 1% already at the age of 66.7, while in overweight women the 1% probability was reached 5.1 years later, at the age of 71.8. Obese women had a 2% probability of hip fracture 2.1 years earlier than overweight women, and a 4% probability 1.3 years earlier. The differences between the groups became smaller with ageing.

In obese women, hip fracture related mortality in five years after the incident was approximately 1.5 times higher than in others.

After around 75 years of age, the risk of hip fracture increased fastest in slender women whose BMI was at the lower end of normal weight. Women at the borderline between normal weight and overweight had the smallest risk all the way until old age.

The study also included a DXA bone density measurement of the hip and a related follow-up of a sub-sample of 3,136 women. At baseline, obese women had on average the highest bone density, but their bone loss was significantly faster than in others. Indeed, obese women in the lowest bone density tertile at baseline had a particularly high risk of hip fracture.

Some earlier studies have suggested that obesity could also be a factor that protects against hip fracture. However, the contradictory findings on the association of BMI with hip fracture seem to be dependent on which age group is being studied. Typically, follow-up times have been significantly shorter than those in the OSTPRE study.

"Based on this study, the risk of early hip fracture occurring before the age of 70 is clearly highest in obese women - and especially in obese women who have a below-average bone density. Later, after around 75 years of age, the risk increases fastest in slender women. Ageing women at the borderline between normal weight and overweight seem to have the lowest risk," Senior Researcher Toni Rikkonen from the University of Eastern Finland says.
-end-
For further information, please contact:

Senior Researcher, Docent Toni Rikkonen, toni.rikkonen@uef.fi, tel. +358504752356, https://uefconnect.uef.fi/en/person/toni.rikkonen/

Research article:

Rikkonen, T., Sund, R., Sirola, J. et al. Obesity is associated with early hip fracture risk in postmenopausal women: a 25-year follow-up. Osteoporos Int (2020). https://link.springer.com/article/10.1007/s00198-020-05665-w

University of Eastern Finland

Related Science Articles from Brightsurf:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.

Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.

Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.

Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.

World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.

PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.

Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.

Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.

Read More: Science News and Science Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.