Mediation analysis showed that in UL patients, bone mineral density (mediator ratio: FinnGen:49.68%; UKB:56.45%) and SHBG (mediator ratio: FinnGen:2.406%; UKB:2.595%) levels partially mediated the risk of osteoporosis, indicating that these two mediators may be involved in the mechanism by which UL induced OP. The gene discussed is SHBG; the disease is osteoporosis.