A study that includes twins finds that the risk of hip fracture was significantly increased following a diagnosis of cardiovascular disease (CVD), with analysis also suggesting a genetic predisposition to the development of CVD and fractures, according to a study in the October 21 issue of JAMA.
CVD and osteoporosis, which are common in elderly individuals, have been regarded as independent age-related disorders. Research has suggested that there may be common mechanisms that cause these diseases. Stroke is a well-documented risk factor for hip fracture, but it is uncertain whether other CVDs may increase the risk of future hip fracture, according to background information in the article. "It is also unknown whether the risk for hip fracture differs depending on CVD diagnosis and sex, as well as whether the risk reflects lifestyle and individual environmental influences or genetic constitution," the authors write.
Ulf Sennerby, M.D., of Uppsala University, Uppsala, Sweden, and colleagues used information from 31,936 twins in the Swedish Twin Registry to investigate the association between cardiovascular events and future hip fracture risk and to examine to what extent the relation was attributable to genes or associated with other lifestyle factors. The researchers note that a study that includes twins provides a framework for an ordinary group analysis while simultaneously examining whether the relation between cardiovascular events and hip fracture is explained by genetic and early environmental factors. The twins, born from 1914-1944, were followed up from the age of 50 years. The National Patient Registry identified twins with CVD and fractures from 1964 through 2005.
The researchers found that the crude absolute rate of hip fractures was highest after a diagnosis of heart failure or stroke, compared to after a diagnosis of peripheral atherosclerosis or ischemic heart disease and lowest for those without a CVD diagnosis. In comparison with individuals without CVD, patients with heart failure had about a 4-fold increased rate of hip fracture and individuals with a stroke had 5 times the risk. The elevated hip fracture rate was also present after ischemic stroke, hemorrhagic stroke, peripheral atherosclerosis and ischemic heart disease.