Influence of anti-osteoporosis treatments on the incidence of COVID-19 in patients with non-inflammatory rheumatic conditions.

Coronavirus disease 19 (COVID-19) is currently a global pandemic that affects patients with other pathologies. Here, we investigated the influence of treatments for osteoporosis and other non-inflammatory rheumatic conditions, such as osteoarthritis and fibromyalgia, on COVID-19 incidence. To this end, we conducted a cross-sectional study of 2,102 patients being treated at the Rheumatology Service of Hospital del Mar (Barcelona, Spain). In our cohort, COVID-19 cumulative incidence from March 1 to May 3, 2020 was compared to population estimates for the same city. We used Poisson regression models to determine the adjusted relative risk ratios for COVID-19 associated with different treatments and comorbidities. Denosumab, zoledronate and calcium were negatively associated with COVID-19 incidence. Some analgesics, particularly pregabalin and most of the studied antidepressants, were positively associated with COVID-19 incidence, whereas duloxetine presented a negative association. Oral bisphosphonates, vitamin D, thiazide diuretics, anti-hypertensive drugs and chronic non-steroidal anti-inflammatory drugs had no effect on COVID-19 incidence in the studied population. Our results provide novel evidence to support the maintenance of the main anti-osteoporosis treatments in COVID-19 patients, which may be of particular relevance to elderly patients affected by the SARS-CoV-2 pandemic.

Reduced proliferation and osteocalcin expression in osteoblasts of male idiopathic osteoporosis.

Osteoporosis is characterized by low bone mineral density (BMD), resulting in increasing susceptibility to bone fractures. In men, it has been related to some diseases and toxic habits, but in some instances the cause of the primary--or idiopathic--osteoporosis is not apparent. In a previous study, our group compared histomorphometric measurements in cortical and cancellous bones from male idiopathic osteoporosis (MIO) patients to those of control subjects and found reduced bone formation without major differences in bone resorption. To confirm these results, this study analyzed the etiology of this pathology, examining the osteoblast behavior in vitro. We compared two parameters of osteoblast activity in MIO patients and controls: osteoblastic proliferation and gene expression of COL1A1 and osteocalcin, in basal conditions and with vitamin D(3) added. All these experiments were performed from a first-passage osteoblastic culture, obtained from osteoblasts that had migrated from the transiliac explants to the plate. The results suggested that the MIO osteoblast has a slower proliferation rate and decreased expression of genes related to matrix formation, probably due to a lesser or slower response to some stimulus. We concluded that, contrary to female osteoporosis, in which loss of BMD is predominantly due to increased resorption, low BMD in MIO seems to be due to an osteoblastic defect.

Bone histomorphometry in 22 male patients with normocalciuric idiopathic osteoporosis.

Osteoporosis is associated with increased bone resorption together with a decrease in bone formation. In women, there is an increase of resorption surfaces and in the number of osteoclasts. These changes, however, are not found in males. This purpose of this study was to examine clinical, laboratory, and histomorphometric data in a series of 22 male patients with primary osteoporosis and normocalciuria undergoing transiliac bone biopsy. All of them gave written informed consent for bone biopsy. Automated biochemical profile, urinary calcium excretion, and bone marker assays were performed. Histomorphometric studies were carried out in transiliac bone biopsies obtained with a Bordier-Lepine needle with previous tetracycline labeling. The histomorphometric values of cancellous bone showed significantly lower values of bone volume and values of osteoid surface (OS/BS) and osteoblast surface (Ob.S/BS), and a modest increase in osteoid thickness (O.Th) without changes in the mineralization lag time or eroded surface in patients compared with controls. In cortical bone, there was a low cortical volume (Ct.V/TV) and cortical width (Ct.Wi) in patients compared with controls, without differences in cortical porosity (Po.V/TV). These results suggest that normocalciuric idiopathic osteoporosis in men is characterized by decreased cancellous osteoblasts and bone turnover.