TNFRSF11A and systemic lupus erythematosus: However, no association of OPG 1181G>C, OPG 163A>G, and RANK A>G polymorphisms was found between BMD and vertebral fractures in premenopausal SLE patients [27], although these genetic variations were associated with lower BMD and a higher risk of osteoporosis in postmenopausal women [15, 28, 29].