Related Experiment Videos
Interpretation of serum aluminum values in dialysis patients
Insights
Serum aluminum levels in dialysis patients are primarily determined by aluminum-based phosphate binders, not dialysis type. High levels indicate aluminum-associated osteomalacia, but lower levels may still suggest bone disease.
Area of Science:
- Nephrology
- Clinical Chemistry
- Bone Metabolism
Background:
- Dialysis patients are at risk for aluminum toxicity due to impaired renal excretion.
- Aluminum exposure can lead to serious bone disease and neurological complications.
- Understanding serum aluminum levels is crucial for managing dialysis patients.
Purpose of the Study:
- To investigate the determinants of serum aluminum levels in patients undergoing maintenance hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD).
- To establish the correlation between serum aluminum levels and bone disease in dialysis patients.
- To assess the utility of serum aluminum levels and parathyroid hormone (iPTH) in diagnosing bone disorders.
Main Methods:
- Retrospective analysis of serum aluminum levels in HD and CAPD patients.
- Correlation analysis with patient demographics, diabetes, vitamin D intake, and medication dosage.
- Bone biopsy analysis for histochemical aluminum staining and bone aluminum content.
- Measurement of serum immunoreactive parathyroid hormone (iPTH) levels.
Main Results:
- Serum aluminum levels did not differ significantly between HD and CAPD patients and were unrelated to age, sex, diabetes, or vitamin D intake.
- The primary determinant of serum aluminum levels in HD patients was the dose of aluminum-containing phosphate-binding medication.
- Serum aluminum levels above 100 ng/mL reliably indicated aluminum-associated osteomalacia; lower levels suggested other bone disorders.
- Elevated iPTH aided in detecting hyperparathyroidism in the presence of high serum aluminum.
Conclusions:
- Aluminum-containing phosphate binders are the main source of elevated serum aluminum in dialysis patients.
- Serum aluminum levels are a valuable indicator for diagnosing aluminum-associated osteomalacia.
- Further investigation is needed to differentiate other bone disorders in dialysis patients with varying aluminum levels.
Abstract:
To determine the significance of serum aluminum levels in dialysis patients, the authors retrospectively analyzed a series of patients on maintenance hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). All patients had always been treated with a dialysate containing negligible amounts of aluminum. The serum aluminum levels of hemodialysis and CAPD patients were not significantly different, not related to age or sex, and not affected by the presence of diabetes or vitamin D intake. The most important determinant of serum aluminum level in the hemodialysis patients was the current dose of aluminum-containing phosphate-binding medication. This relationship was most striking in the compliant patients. In hemodialysis patients, after an increase during the first one to two years, the aluminum levels plateaued. Aluminum levels remained stable more than five years in CAPD patients. Red blood cell mean corpuscular volume was negatively correlated with serum aluminum level. In 28 dialysis patients who had bone biopsy, aluminum levels were positively correlated to histochemical aluminum staining and bone aluminum content. A level greater than 100 ng/mL was a reliable indicator of aluminum-associated osteomalacia, although a lower level did not exclude the presence of low turnover bone disease or mixed uremic osteodystrophy--two disorders possibly related to aluminum. In the presence of a high serum aluminum, elevated levels of immunoreactive parathyroid hormone (iPTH) were useful in detecting the presence of hyperparathyroidism; low levels of iPTH did not allow the authors to distinguish between other subtypes of uremic osteodystrophy.