Fracture Risk Increases with Declining Kidney Function
Individuals older than 65 years are more likely to suffer a fracture, regardless of eGFR.
Many patients with chronic kidney disease (CKD) will suffer fractures within 3 years, with the risk of fracture increasing with decreasing kidney function, new study findings suggest.
A Canadian team led by Amit X. Garg, MD, of the London Health Sciences Centre in London, Ontario, studied 679,114 individuals aged 40 years and older. The cohort had a mean age of 62 years.
At study entry, the researchers stratified subjects according to estimated glomerular filtration rate (eGFR), gender, and age. The primary outcome was the 3-year cumulative incidence of fracture: the proportion of subjects who fractured their hip, forearm, pelvis, or proximal humorus at least once within 3 years of follow-up.
Results showed that the 3-year incidence of fracture among women older than 65 years was 4.3%, 5.8%, 6.5%, 7.8%, and 9.6% for those with an eGFR (in mL/min/1.73 m2) of 60 or higher, 45-59, 30-44, 15-29, and below 15, respectively, according to findings published in Kidney International (2014;86:810-818).
Among men older than 65 years, the corresponding incidences were 1.6%, 2.0%, 2.7%, 3.8%, and 5.0%, respectively. According to the researchers' estimates, 1 in 10 women and 1 in 20 men older than 65 with an eGFR below 15 experienced at least 1 fracture in the subsequent 3 years. Fracture was significantly more likely to occur in subjects older than 65 than in those aged 40-65 across all eGFR categories.
The researchers also found that the 3-year cumulative incidence of falls with hospitalization also increased as kidney function decreased in both sexes. For example, among women older than 65, the incidences were 3.8%, 5.9%, 7.6%, 9.1%, and 13.1% for those with an eGFR of 60 or higher, 45-59, 30-44, 15-29, and below 15.
Additionally, Dr. Garg's group estimated the incidence rates of fracture per 1,000 person-years. Women older than 65 who had an eGFR of 60 or higher, 45-59, 30-44, 15-29, and less than 15 had an incidence rate of 15.0, 20.5, 24.2, 31.2, and 46.3 per 1,000 person-years, respectively. The corresponding rates for men older than 65 were 5.7, 7.3, 10.1, 15.3, and 24.3, respectively.
“The results of this study are a call to develop and test interventions to reduce the burden of fracture in this population,” the authors concluded.
The researchers commented that the higher risk of fracture observed among individuals with diminished kidney function compared with those who had normal kidney was particularly striking.
For example, among women older than 65, the rate of fracture was 3 times higher among those with an eGFR below 15 than among those with an eGFR of 60 or higher. Among men aged 40-65, the rate was 5 times higher among those with an eGFR below 15 compared with an eGFR of 60 or higher.