NEW YORK (Reuters Health) - Bisphosphonate use is associated with better survival in patients admitted to the intensive care unit (ICU), according to Australian researchers.
As Dr. Paul Lee told Reuters Health by email, "Bone loss in critical illness may have wider effects on the body beyond bone itself, and bisphosphonates, by reducing bone loss, may attenuate these potentially adverse effects on the body."
Increased bone resorption is known to predict mortality in the community setting, Dr. Lee of the Gavan Institute of Medical Research in Sydney and colleagues note in the Journal of Clinical Endocrinology and Metabolism, online January 18. The team theorized that mortality would be lower among patients treated with bisphosphonates prior to their acute illness.
To investigate, they examined data on more than 7,800 patients admitted to the ICU between 2003 and 2014; 245 had received bisphosphonates before admission.
The bisphosphonate users were older and had more co-morbidities, yet their in-hospital mortality rate was significantly lower than that of non-users(mortality rate ratio, 0.41; p<0.01). The difference remained significant after adjusting for factors including age, sex, and principal diagnosis.
Bisphosphonate-associated survival benefit was independent of vitamin D use, but bisphosphonate and vitamin D co-use was associated with a further reduction in mortality (MRR, 0.38).
A substudy involving CT scans of 37 patients with preadmission bisphosphonate use and 74 matched patients without such use found that baseline bone density was significantly lower among bisphosphonate users. However, all users survived admission whereas six of the non-users died.
The researchers speculate that the apparent benefits of bisphosphonate "may be partly related to modulation of systemic inflammation through antibone resorption."
However, Dr. Lee made it clear that "causality is not proven in the study, and prospective intervention trials are required to evaluate effects of bisphosphonates in critical illness."