PTH and diabetes mellitus: As expected and consistent with the pathophysiology and prognosis of later stage CKD, patients with earlier CKD stages tended to be slightly older, have a higher BMI, have a higher haemoglobin and HbA1c, have a lower phosphate and PTH, and have a lesser need for treatment for CKD metabolic bone disease, compared to later CKD Stages (Additional file 1: Appendix: Table S2: Characteristics and medication usage of patients with diabetes and CKD stratified by CKD stage).