It represents the effect of Renal failure on bone.
• Is due to disturbance in bone phosphate and calcium metabolism.
1• Hyperphosphatemia is a feature of advanced renal failure. The serum phosphate
concentration rises in patients with a GFR < 20 mL/min.
2• Calcium: - The total plasma Ca2+ concentration in patients with CRF is often
significantly lower than normal. Patients with CRF tolerate the hypocalcaemia
quite well; rarely is a patient symptomatic from the decreased Ca2+
concentration. Note that the low serum level of Ca++ is attributed to secondary
3• Reduced synthesis of 1,25 (OH)2D3 during CRD plays a key role in the
pathogenesis of hyperparathyroidism, both directly and through hypocalcaemia.
** Note :
The abnormal vitamin D metabolism may be related to the ;
1.renal disease itself
(since the active vitamin D metabolite is normally produced in the proximal
2. The hyperphosphatemia, which has a suppressive effect on the
renal 1?-hydroxylase enzyme.
Some of the resulting bony abnormalities are ;
1. Ostitis fibrosa cystica : is due to osteoclastic bone resorption of
specially terminal phalanges , long bones and distal end of clavicle
2. Renal rickets ( Osteomalacia )
3. Osteosclerosis : enhanced bone density in the upper and lower margins
1. Phosphate binder like calcium acetate (phostat), with major food like launch, dinner breakfast.
2. Active Vit D like 1,25 (OH)2 cholecalciferol .
3 . In case of patient with hypercacemia give sevlamer inplace of calcium because of calcium toxicity like calciphylaxix.
Dr Atul Chowdhury