TNF and osteoporosis: Interestingly, patients with chronic inflammatory diseases have a higher incidence of osteoporotic fractures (24) and high levels of pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) inhibit osteoblast function and promote osteoclast function, thereby having a detrimental effect on osteoporosis (1, 25).