Patients with congestive heart failure are four times more likely to sustain a serious fracture than those who have acute cardiovascular conditions, a study published Monday said.
The study, which was published Monday in Circulation, the journal of the American Heart Association, looked at 2,041 patients with heart failure and more than 14,000 people who had presented themselves for emergency cardiovascular care at facilities in Alberta, Canada between 1998 and 2001.
One year after their visit to the emergency room, 4.6 percent of the patients with congestive heart failure, defined as a condition where the heart can't pump enough blood to the body's other organs, had suffered a fracture, compared to only one percent of the control group.
Even when the researchers adjusted for medications known to affect bone density, such as bisphosphonates, which are often prescribed for sufferers of the bone-crumbling disease of osteoporosis, the risk of fracture remained proportionally elevated for heart failure victims compared to the others.
"This is the first study to link heart failure patients to a higher risk of fractures," said Justin Ezekowitz, senior author of the study and assistant professor of medicine at the University of Alberta in Canada.
Ezekowitz said the reasons for the higher incidence of fractures among chronic heart failure patients were unclear but posited that it could be that the patients were not getting enough calcium or vitamin D.
Another possible reason might be that raised levels of the hormone aldosterone in heart failure patients might stimulate calcium excretion by the body, causing the parathyroid gland to react by increasing levels of the hormone it produces, to try to regulate calcium in the blood.
When parathyroid hormone is released into the blood, it increases the amount of calcium in the blood, which is like removing the mineral from bones.
Another possible reason for the increased risk of fracture is a reduced level of exercise because the "failing" heart is unable to work as well as it should, meaning that sufferers cannot exert themselves.
Bones are highly sensitive to lack of stress, and many chronic heart disease patients are unable to do much exercise, which leads to bone mass loss.
Chronic heart failure affects 2.2 percent of people in North America and 8.4 percent of people over the age of 75, while osteoporosis affects some 10 million Americans, including a quarter of women over the age of 50, according to the study.
Around one-third of people who are affected by what the study calls "the most devastating complication of osteoporosis, hip fracture," die a year after sustaining the fracture, while survivors usually suffer a loss of function and independence which requires admission to long-term care, the study says.
Ezekowitz called for better screening for osteoporosis for heart failure patients and further research to determine the link between heart failure and fractures.