This study aims to integrate bone measurements (including bone turnover markers (BTM), bone mineral density (BMD) measurement, vertebral fracture assessment (VFA), trabecular bone score (TBS) ) commonly used in the general population for primary osteoporosis evaluation to enhance the assessment of CKD-MBD.

Prospective observational study that will evaluate differences in bone (BMD, TBS, VFA and BTMs, serum calcium and phosphate) parameters in hemodialysis (HD) patients and kidney transplant recipients (KTR), compared to general population osteopenia/osteoporosis patients, at baseline and after one year of monitoring, with or without therapeutic intervention for CKD-MBD (KTR and HD groups).

Inclusion Criteria:

1. HD group: Patients undergoing HD for at least 12 months, aged 20-70 years, after signing an informed consent.
2. KTR group: Patients with successful KTx performed at least 12 months prior to their enrollment, aged 20-70 years old, after signing an informed consent. Subjects will be eligible for inclusion regardless of KTx immunosuppression regimen, pre-transplantation history, history of pre-transplant dialysis, or whether the kidney donation was from a living or deceased donor.
3. GPO group: men and postmenopausal women diagnosed with primary osteopenia or osteoporosis, aged 50-70 years old, after signing an informed consent.

Exclusion Criteria:

1. HD group: Treatment with active bone therapies (excluding calcium and vitamin D); ongoing cancer treatment or recent history of malignancy, cirrhosis, recent major fractures, patients who have received transplants other than kidney, secondary causes of osteoporosis (other than CKD or transplant-related: primary hyperparathyroidism, hyperthyroidism, congenital bone disorders, sarcoidosis, severe bone trauma, malignant tumors, inflammatory bowel disease, endogenous Cushing syndrome, anti-estrogen/anti-androgen therapy, and anorexia nervosa), pregnancy and breast-feeding.
2. KTR group: The same as for HD + return to dialysis + acute graft rejection.
3. GPO group: The same as for HD + diabetes mellitus + prolonged glucocorticoid therapy (>7.5 mg Prednisone or equivalent for at least 3 months).

Men and postmenopausal women diagnosed with primary osteopenia or osteoporosis, aged 50-70 years old and patients undergoing HD or KTR, aged 20-70 years old.

Individual participant data will not be shared due to privacy concerns and data protection regulations.