Hip fracture risk of farmers in Sweden was assessed by a team of UK and Swedish researchers and shows that the risk rose with age, low income, low education, higher latitude, and urban location.
Sweden is one of the few countries which tracks hip fractures through a national registry. It is therefore possible to assess how hip fracture risk across the country varies according to occupation, economic status, level of education, latitude, and urban versus rural residence. Although hip fracture risk is known to be correlated to physical activity, that's one of the variables, among others, which the registries can't track.
The researchers therefore focused on farming, an occupation which is characterized by regular, long-term outdoor physical activity. Looking at the hip fracture incidence of all men and women aged 40 years or more in Sweden between 1987-2002, they found that there were 100,083 individuals who sustained a hip fracture. Of these, 4,175 were farmers.
For male farmers the risk of a hip fracture was 14% lower compared to other occupations, adjusted for age. When also adjusted for rural status of residence, the risk reduction was still 15% lower. However, when also adjusted for income, education and latitude the effect was even more marked -- at 39% lower risk.
Lead author, Dr. Helena Johansson of the Centre for Metabolic Bone Diseases, University of Sheffield Medical School, UK, stated, "We need to be concerned about hip fractures as they are the most serious and disabling osteoporosis-related fractures. Given the many, complex factors that affect fracture risk, it is not possible to pinpoint a single variable that is associated with lower hip fracture risk. However, these findings are interesting in that they suggest that a lifetime of outdoor, physical activity may be a positive factor when it comes to hip fracture risk. "