Objective   To investigate the influence of osteoarthritis (OA) at different sites and of different degrees on the prevalence of osteoporosis (OP) and lumbar bone mineral density (L-BMD) in men, and thereby to analyze the relationship between OA and OP.

  Methods   We collected information on the age, height, body mass, the course of pain, smoking status, exercise status, and history of hypertension and diabetes of 1206 male patients who received treatment for bone and joint pain at the Department of Osteoporosis and Rheumatology, West China Fourth Hospital, Sichuan University between January 2017 and December 2020. The patients' L-BMD was determined with dual-energy X-ray absorptiometry. The sites and the degrees of OA were evaluated by digital radiography and CT or MRI. χ² test was performed to compare the OP prevalence of different groups. Analysis of covariance was carried out to compare the L-BMD of different groups. Binary logistic regression was conducted to analyze the risk factors of OP.

  Results   OP prevalence of the OA group was significantly lower than that of the non-OA group (P<0.05). OP prevalence of the lumbar vertebra OA group was significantly lower than that of the non-OA group (P<0.05). In addition, OP prevalence of the mild OA group and moderate OA group was significantly lower than of the non-OA group (P<0.05). The L-BMD of the OA group was significantly higher than that of the non-OA group (P<0.05). In addition, there were significant differences in L-BMD between groups with OA at different sites (P<0.05). Furthermore, the L-BMD of the lumbar vertebra OA group and the multi-site OA group was significantly higher than that of the non-OA group (P<0.05). There were significant differences in L-BMD between groups with different degrees of OA (P<0.05). Furthermore, the L-BMD of the mild OA group and moderate OA group was significantly higher than that of the non-OA group (P<0.05). OA and exercise were found to be protective factors for OP (odds ratio OR=0.715 and 0.625, 95% confidence interval CI: 0.550-0.928 and 0.481-0.814, P<0.05). Age and BMI were found to be risk factors for OP in men (OR=1.018 and 1.081, 95% CI: 1.008-1.028 and 1.042-1.122, P<0.05).

  Conclusion   Lumbar vertebra OA and mild and moderate OA decrease OP prevalence in men, while lumbar vertebra OA, multi-site OA, and mild and moderate OA increase L-BMD in men. OA and exercise decrease the occurrence of OP in men, while age and BMI increase the risk of OP in men.