Apart from hypertension and diabetes mellitus, one of SLE's major complications is premature atherosclerosis.
Previous studies have reported a biological link between atherosclerosis and osteoporosis, and nitrogen-containing bisphosphonates (BP) have been said to inhibit this by interfering with intimal plaque formation.
Additionally, progress in treating SLE has seen the main cause of morbidity and mortality in its patients shift from lupus-related organ failure to cardiovascular disease, for which vitamin D deficiency is a novel risk factor.
A combination worth considering?
However, whether BP or vitamin D can fight atherosclerosis is still unclear, as there has been no data to show a correlation between atherosclerosis development or progression and treatment with BP and / or vitamin D, both of which are often prescribed to lupus sufferers.
Based on this, researchers at Hokkaido University conducted a study to investigate the correlation. They recruited 117 SLE patients who had undergone carotid ultrasonography and retrospectively analysed them using propensity scoring.
They then noted that 42 (36%) of the patients were receiving BP and vitamin D, 30 (26%) were receiving vitamin D alone, and 27 (23%) were receiving BP alone.
Subsequently, they observed that carotid plaque was "statistically significantly less prevalent" across all strata among those taking both BP and vitamin D, compared to the other treatment groups.
This led the researchers to state: "Combined treatment with bisphosphonate and vitamin D may have a role in preventing atherosclerosis in patients with SLE."
Preliminary results require prospective research
They added, however, that the study involved only Japanese SLE patients, and its retrospective design meant the anti-osteoporotic drugs consumed were selected by the patients' doctors, which could have resulted in grouping bias.
They added RCTs are necessary to confirm the current study's results. A lack of data on diet and supplementation also meant the researchers were unable to calculate the patients' daily calcium intake, and serological data on biomarkers related to osteoporosis (such as vitamin D status) were unavailable as a result.
The researchers concluded: "This study provides some preliminary evidence to support the use of combination therapy with bisphosphonates and vitamin D to prevent atherosclerosis in patients with SLE.
"Both bisphosphonates and vitamin D supplementation are already recommended for osteoporosis, and their combination may prevent the development and progression of atherosclerotic plaques better than either agent alone.
"Further large-scale prospective studies are warranted to confirm the results of this analysis."
Source: Arthritis Research & Therapy
https://doi.org/10.1186/s13075-018-1589-9
"Effect of combined treatment with bisphosphonate and vitamin D on atherosclerosis in patients with systemic lupus erythematosus: a propensity score-based analysis"
Authors: Kazumasa Ohmura, et al.