Concentrations of silicon in plasma increase with decreasing glomerular filtration
rate in ESRD patients who are at risk for development of silicon toxicity or what is
called Si-related syndrome. The aim of the current study was to investigate silicon
toxicity in ESRD and in renal insufficiency of unknown aetiology and to assess its
possible effect on calcium metabolism and its role in the pathogenesis of arthropathy.
The study included 4 groups: patients of ESRD on regular haemodialysis, patients of
ESRD on conservative treatment, patients of renal insufficiency of unknown
aetiology, and a control group. Participants in the study were subjected to full clinical
examination including musculoskeletal and neurological examination, laboratory
investigations including plasma silicon, plasma aluminum and parathormone levels.
For patients with joint complaints, examinations for CRP, anti-nuclear antibody,
anti-double strands DNA anti-body and rheumatoid factor were done. The 4 groups
differed significantly from each other in mean plasma silicon and aluminum levels.
The serum parathyroid hormone level was significantly suppressed across the 3
groups of patients. Plasma silicon levels correlated well with serum phosphorus and
with parathormone levels. Of the patient groups, 83.3 % had high plasma silicon
levels compared to 45.0 % of controls. The high silicon group of patients suffered
more from joint affection. The elevated serum silicon level in ESRD may be
considered as a one of the retained toxins in renal failure that may affect the
parathyroid gland and lead to suppression of release of parathormone. It was
associated with more joint affection and with immunological system dysregulation as
evidenced by the presence of antinuclear antibodies. Monitoring of the silicon levels
in serum, tap water, and dialysis fluid, especially in renal failure patients, was
recommended. |