Sources of cadmium exposure:
(1) environmental: Cadmium and other heavy metals contaminate the soil and water with eventual incorporation into rice and other foods.
(2) occupational
Clinical features:
(1) The patient has a chronic exposure to cadmium, which accumulates in the kidneys, liver and other organs.
(2) The patient develops a nephropathy with glomerular and proximal tubular dysfunction. Initially this is associated with proteinuria involving low molecular weight proteins including beta-2 microglobulin. With time the renal damage can progress to end-stage renal failure which may include polyuria.
(3) Renal damage affects vitamin D metabolism and results in osteomalacia.
(4) People with risk factors for osteoporosis such as post-menopausal women are more likely to develop clinical osteoporosis.
(5) There is increased risk for renal stone disease.
(6) Severe anemia may be present, which may be due to bone marrow damage and/or reduced erythropoietin from the kidney.
Urinalysis may show:
(1) low-molecular weight proteins
(2) high-molecular weight proteins
(3) amino acids (aminoaciduria)
(4) glucose (glucosuria)
(5) calcium (hypercalcuria)
(6) uric acid
(7) cadmium
(8) phosphate (phosphaturia)
The risk of progression to renal failure increases with:
(1) higher levels of cadmium exposure
(2) diabetes
(3) hypertension
