Study of bone mineral density in patients with chronic renal failure

الملخص EN

BACKGROUND : Bone disease is a major cause of morbidity in end stage renal failure.

Renal osteodystrophy is a common finding in patients with renal insufficiency the maximum of its intensity isfuond in haemodialysis patients.

Bone mineral density (BMD) measured by dual-energy x-ray absorptiometry (DEXA) has proven to be a strong predictor of bone strength in healthy persons and in osteoporotic patients and DEXA is aprecise, rapid and noninvasive procedure to detect osteopenia.

Bone densitometry is so far the best method for noninvasive assessment of the extent of renal osteodystrophy.

OBJECTIVE : The present work aimed to study the bone mineral density in chronic renal failure patients before and after starting haemodialysis therapy.

STUDY Design : We conducted our study on 172 patients with chronic renal failure, and 20 matched normal control subjects.

The 172 patients were 150 patients on regular haemodialysis regimen thrice weekly and 22 patients in predialysis stage, under follow up in nephrology clinic.

Patients with diabetic nephropathy or under corticosteroid therapy or aged more than 50 years old, were excluded from the study.

All persons are subjected to full medical history, thorough medical examination, biochemical markers in the form of serum calcium, serum phosphorous, alkaline phosphatase, serum PTH and serum creatinine.

Bone mineral density of the distal forearm bones was measured for all subjects by single energy X-ray absorptiometer (DTX-100 SXA).

RESULTS : In the present study we found that the mean values of BMD were 0.365±0.10 in chronic renal failure patients on regular haemodialysis (Group I) 0.435±0.147 in patients with end stage renal disease in the predialysis stage (Group II) and 0.509+0.5 in controls (Group III).

There was highly statistical significant difference in BMD between the 3 groups (p<0.001).

There was no significant correlation between BMD loss and biochemical parameters (p>0.05) in normal controls (Group III).

In the other hand, in patients with end stage renal disease in predialysis stage (Group II), there was a highly significant correlation between BMD loss and biochemical parameters (p<0.001) except for serum phosphorous there was no significant correlation (p>0.05).

In patients with chronic renal failure on regular haemodialysis regimen thrice weekly (Group I), there was a significant correlation between BMD loss and biochemical parameters (p<0.05) except for serum calcium and serum phosphorous there was no significant correlation (p>0.05).

CONCLUSION: Metabolic bone disease might commence early in the course of renal failure.

The patients with chronic renal failure had significantly reduced BMD in comparison to healthy controls.

The patients on regular haemodialysis had more reduction in BMD in comparison to patients in predialysis stage.

BMD z-scores of the forearm correlates to most of the biochemical markers in patients with chronic renal failure specially to PTH level (strong correlation).