Following radiotherapy, patients have decreased bone mass and increased risk of fragility fractures. Diabetes mellitus (DM) is also reported to have detrimental effects on bone architecture and quality. However, no clinical or experimental study has systematically characterized the bone phenotype of the diabetic patients following radiotherapy. After one month of streptozotocin injection, three-month-old male rats were subjected to focal radiotherapy (8 Gy, twice, at days 1 and 3), and then bone mass, microarchitecture, and turnover as well as bone cell activities were evaluated at 2 months post-irradiation. Microcomputed tomography results demonstrated that DM rats exhibited greater deterioration in trabecular bone mass and microarchitecture following irradiation compared with the damage to bone structure induced by DM or radiotherapy. The serum biochemical, bone histomorphometric, and gene expression assays revealed that DM combined with radiotherapy showed lower bone formation rate, osteoblast number on bone surface, and expression of osteoblast-related markers (ALP, Runx2, Osx, and Col-1) compared with DM or irradiation alone. DM plus irradiation also caused higher bone resorption rate, osteoclast number on bone surface, and expression of osteoclast-specific markers (TRAP, cathepsin K, and calcitonin receptor) than DM or irradiation treatment alone. Moreover, lower osteocyte survival and higher expression of Sost and DKK1 genes (two negative modulators of Wnt signaling) were observed in rats with combined DM and radiotherapy. Together, these findings revealed a higher deterioration of the diabetic skeleton following radiotherapy, and emphasized the clinical importance of health maintenance.

Purpose: Although many researches have indicated the anticoagulant effect of warfarin and rivaroxaban in atrial fibrillation (AF) patients, the comparison of these drugs on safety and efficacy in northern Chinese patients with different CHA2DS2-VASc Score is unclear. We aim to compare the safety and efficacy of warfarin versus rivaroxaban in northern Chinese AF patients with different CHA2DS2-VASc Score subgroups. Methods: 387 AF patients were recruited in the study. Of these, one group patients (n=194) were receiving warfarin, and the other group patients (n=193) were receiving rivaroxaban. Follow-up data were collected for one year, which included adherence, bleeding and ischemic stroke (IS) events. Results: There was better adherence in rivaroxaban-treated group than warfarin-treated group. The events of bleeding decreased with increased score in warfarin-treated group. Patients with score 2-3, had better adherence and less stroke events in warfarin-treated group. The events of bleeding and stroke was not significantly different in rivaroxaban-treated group at different score. Conclusions: We found that there was better adherence and less bleeding and stroke events in rivaroxaban-treated group than warfarin-treated group with different CHA2DS2-VASc score. There is better choice for northern Chinese patients to select rivaroxaban in the anticoagulative treatment of AF, regardless of economic factors.