Study Links Kidney Stones to Fracture Risk in Older Adults

Calyani Ganesan, MD

Could the presence of kidney stones help clinicians identify patients at risk for osteoporosis? A new study from Stanford University has uncovered a possible link between kidney stone disease and risk of osteoporosis or bone fracture.

An analysis of more than half a million patients with kidney stones disease, results indicate nearly 1-in-4 patients received a diagnosis of osteoporosis or suffered a bone fracture and suggest screening of these patients for increased risk remains subpar.

"We hope this work raises awareness regarding the possibility of reduced bone strength in patients with kidney stones. In our future work, we hope to identify which patients with kidney stones are at higher risk for osteoporosis or fracture to help guide bone density screening efforts by clinicians in this population," said lead investigator Calyani Ganesan, MD, a nephrology fellow at Stanford University, in a statement.

With osteoporosis and fractures posing a serious threat to the well-being and quality of life of aging adults, Ganesan and colleagues from Stanford University sought to determine whether kidney stone disease was associated with increased risk of osteoporosis. Investigators designed their analysis as a retrospective cohort study using data from the Veterans Health Administration database.

Patients were considered to have kidney stone disease if they had at least one inpatient encounter that included ICD-9 and ICD-10 codes for kidney or ureteral stones. In total, investigates identified 531,431 patients with kidney stone disease treated. Between January 1, 2007-December 31, 2015. Of these, 125,427 had a diagnosis of osteoporosis or fracture in the 5 years preceding or 5 years following index stone diagnosis. Of the 125,527, 32,613 (6.1%) were diagnosed with osteoporosis.

In adjusted models, results suggested presence of type 2 diabetes (OR, 1.07; 95% CI, 1.05-1.09), metastatic cancer (OR, 1.15; 95% CI, 1.11-1.20), enteric disease (OR, 1.19; 95% CI, 1.08-1.31), hypogonadism (OR, 1.22; 95% CI, 1.14-1.29), and primary hyperparathyroidism (OR, 1.59; 95% CI, 1.43-1.76) were associated with increased risk of receiving a diagnosis of fracture or osteoporosis after index stone diagnosis.

When assessing rates of dual-energy X-ray absorptiometry (DXA) among those with no history of osteoporosis or fracture before a kidney stone diagnosis, investigators found just 9.1% (n=42,329) of patients meeting these criteria underwent DXA in the 5 years following their initial diagnosis. Of those who did undergo DXA, 20% were subsequently diagnosed with osteoporosis, 19% (n=8055) were diagnosed with a non-hip fracture, and 2.4% (n=1008) were diagnosed with a hip fracture. Investigators pointed out 85% of patients who were screened and later diagnosed with osteoporosis were men.

Further analysis indicated odds of being screened with DXA were greater among patients with a history of hypogonadism (OR = 2.07; 95% CI 1.95–2.20) or primary hyperparathyroidism (OR = 4.99; 95% CI 4.57–5.44). Additionally, results suggested patients had decreased odds of undergoing DXA if they had a history of metastatic cancer (OR, 0.93; 95% CI, 0.88-0.98).

“Our findings provide support for wider use of bone mineral density screening in patients with kidney stone disease, including middle-aged and older men, for whom efforts to mitigate risks of osteoporosis and fractures are not commonly emphasized,” wrote investigators.

This study, “Osteoporosis, Fractures, and Bone Mineral Density Screening in Veterans With Kidney Stone Disease,” was published in the Journal of Bone and Mineral Research.