Patients with polymyalgia rheumatica (PMR) and giant-cell arteritis (GCA) have similarly increased risks of fracture, compared with the general population, according to a study published in the journal BMC Medicine.

"It is of surprise that patients with GCA have a similar fracture risk to those with PMR,” said Dr. Zoe Paskins from Keele University, in Staffordshire.

“I would expect it to be higher, as GCA is typically treated with twice the cumulative dose of steroid over the course of the condition. One explanation for this is that PMR is overtreated, and the real-life doses of steroids used in PMR needs further evaluation.”

GCA and PMR, which overlap in many patients, are typically treated with glucocorticoids, which are a well-established cause of osteoporosis and fragility fracture.

Dr. Paskins’s team used data from the UK's Clinical Practice Research Datalink database to quantify separately the risks of fracture among patients with PMR and GCA and to assess the impact of age, sex, glucocorticoids, and methotrexate on those risks.

Their retrospective study included 12,136 PMR and 2,673 GCA patients (735 patients had both conditions), matched to 46,238 and 10,423 nonexposed patients (controls), respectively.

Compared with their separate control populations, the risk of fracture was 63% higher in patients with PMR (148 fractures per 10,000 person-years) and 67% higher in patients with GCA (147 fractures per 10,000 person-years).

The risks were similar for both sexes, and the relative risks were even higher among individuals age 50 to 60 (2.23-fold higher for PMR and 2.27-fold higher for GCA, compared with their respective controls).

The fracture risk was increased at all sites in PMR patients, whereas GCA patients had an increased risk of wrist, vertebral and hip fractures, but not of humeral fractures.

Higher doses of glucocorticoids were associated with higher fracture risks, whereas methotrexate prescription was not associated with the risk of fracture in either group.

Even among GCA and PMR patients with at least two prescriptions for glucocorticoids, only 12.6% and 10.1%, respectively, were prescribed bisphosphonates.

“In view of the increased fracture risk in both conditions, the results highlight the importance of using bone protection in these patients, and assessing and managing falls risk,” Dr. Paskins said.

The researchers say "more research is needed into optimal glucocorticoid tapering regimes to identify whether lower starting doses and/or aggressive dose reduction reduces fracture risk, particularly in PMR, and to explore the safety and benefit of using non-glucocorticoid treatments and glucocorticoid sparing agents in the treatment of these conditions.”