Osteoporosis and heart failure are prevalent conditions, particularly among the elderly.1–3
Worldwide, over 1.7 million hip fractures, the most serious fracture related to osteoporosis, occur annually with over 340 000 occurring in the USA alone.1,2
In the USA, heart failure is the most common cause of hospitalization in patients aged >65.3
However, whether hip fracture rates are increased in persons with heart failure compared with healthy persons is a subject of ongoing debate. One report, limited to women, suggested that the odds ratio for hip fractures was increased 2–3-fold in heart failure patients compared with healthy controls matched to the expected hip fracture age distribution.4
In a population-based study in Canada including over 16 000 men and women aged 65 years and older, patients with heart failure had an ~4-fold increased risk for any fractures and a 6-fold increased risk for hip fractures. However, in this study, the comparator group was patients with cardiovascular disease without heart failure, and not healthy controls.5
Thus, whether there is an increased risk for hip fractures in men and women with heart failure compared with healthy controls and if so, whether the risk of fractures in heart failure is a function of the disease itself, or underlying shared risk factors, is less clear.
There are a number of shared risk factors for hip fractures and heart failure. These include, among others, decreased exercise tolerance,6,7
low levels of 25 hydroxyvitamin D,8,9
advancing age, renal disease,10–12
and, among women, postmenopausal status.15
In addition, medications used by persons with heart failure, including thiazide diuretics,16
angiotensin-converting enzyme (ACE) inhibitors18
have been positively associated with bone metabolism. Conversely, loop diuretics have been associated with loss of bone mineral density (BMD), a risk for fractures in some20
but not all studies.21
Importantly, poor self-reported health status has also been identified to be a risk factor for both heart failure and low BMD.22–24
Theoretically, the pathophysiology of heart failure and osteoporotic fractures may share some common components. Experimental studies suggest that aldosteronism, a key component in heart failure,25
may also be operative in bone loss.26,27
Another potential common pathophysiological mechanism for heart failure and osteoporotic fractures is that of shared matrix proteins.28
Up-regulation of putative cytokines may also underlie the pathogenesis of both heart failure and osteoporosis.28
Finally, one study reported that inflammatory markers are elevated in heart failure,29
and inflammation has been associated with fractures.30,31
No study to date has compared hip fracture rates and mortality rates, following these fractures in those with and without heart failure within the context of a large prospective study of ambulatory, multiethnic, non-institutionalized women and men that uniformly collected data on hip fractures, mortality, and heart failure status. Moreover, no study to date has examined whether any relationship between hip fractures and heart failure is independent of shared risk factors. The primary objective of this study was to examine the association between heart failure and hip fractures and to determine whether this was dependent or independent of shared risk factors. The secondary purposes were to examine the association between heart failure and hip fractures in those with systolic compared with diastolic dysfunction, and to estimate the contribution of hip fractures to mortality in persons with heart failure.
We hypothesized that relative to persons without heart failure, that rates of hip fractures in those with heart failure would be increased. However, we suspected that these increased rates of hip fractures would be explained at least in part by shared risk factors. Finally, since mortality is increased following a hip fracture in healthy persons,32
we hypothesized that there would be a substantial association of hip fractures with mortality in persons with heart failure.
To test these hypotheses, we utilized data from a well-characterized community-based longitudinal cohort study of older men and women, the Cardiovascular Health Study (CHS). We determined the risk for incident hip fractures in men and women with heart failure and by the type of heart failure compared with those without heart failure with and without adjustments for potential covariates. We estimated the mortality due to incident hip fractures in men and women with heart failure.