Researchers enrolled 160 older women (ages, 70-90 y) with minimal trauma hip fractures (MTHFs) and 160 age-matched women without fracture serving as controls, and the results of the test showed that the subjects in the MTHFs group had lower serum irisin levels compared to the control group, indicating that increased risk of hip fracture in older adults at low serum irisin levels, suggesting that irisin may be a useful indicator to help identify the risk of MTHFs in older women (100). Here, FNDC5 is linked to hip fracture.