The relationship between PTH (though not directly a reflection of bone turnover) and the risk of fracture is linear in the early stages of CKD, but at more advanced stages, it becomes an inverted J curve, suggesting that the conditions associated with decreased PTH (malnutrition, inflammation, elderly patients, DM, etc.)could per se be the cause of the increased risk of fracture [71]. Here, PTH is linked to diabetes mellitus.