Urine Toxic Metals:
collection instructions | sample report
Analysis of elements in urine provides diagnostic information on potentially toxic elements such
as lead, mercury, cadmium, nickel, beryllium, arsenic and aluminum, and assessment of the
efficiency of renal resorption of essential elements such as magnesium, calcium, sodium and
potassium.
Urine element analysis is an invaluable tool for the diagnosis or confirmation of toxic element burden and
monitoring of detoxification therapy. For diagnosis of the presence of certain toxic element burdens, a
challenge consisting of pre and post provocation testing is recommended.
A pre-provocation urine elements analysis requires a urine collection prior to administration of a chelating
or complexing agent to establish baseline elemental levels. It is highly recommended that a creatinine
clearance test be ordered at this time to assess glomerular filtration as currently available chelation
agents are excreted as metal complexes that pass through the kidneys. A creatinine clearance test can
be used to determine patient candidacy and appropriate chelation agent dosages. This test requires a 24
hour unprovoked urine specimen and a serum sample drawn during the 24 hour urine collection period.
A single unprovoked 24 hour urine collection can be used to perform both the urine elements analysis
and the creatinine clearance test (also requires a serum collection). The second part of a challenge test
is the post-provocation urine elements analysis. This involves urine collection following oral or
intravenous administration of chelating or complexing agents that mobilize elements from otherwise
slowly exchanging tissue pools. For example, non-provoked levels of cadmium, mercury, and lead may
not be indicative of deep tissue stores and only reflect ongoing or very recent exposure. Collection
periods for provocation agents are dictated by the active half life of the specific agent:
Common Agents
EDTA
DMPS (IV)
DMPS (oral)
DMSA
Half Life
~1 hr
~1 hr
~9 hrs
4 hrs
Collection Period
6 – 24 hrs
2 – 6 hrs
6 – 9 hrs
6 – 9 hrs
Unprovoked urinary levels of essential elements such as magnesium, calcium, sodium, and potassium
may be indicative of renal wasting conditions and provide early warning of renal dysfunction. Magnesium
loading tests can also be performed using urine elements testing. Provoked urinary levels of elements
that chelation agents have an affinity for can provide valuable information as to the efficacy of the
provocation. For example, a DMPS challenge with a copper value that is not elevated usually indicates
improper infusion or urine collection techniques, or low effective strength of the agent. It may also indicate
extremely low copper status within the patient. Blood levels are better indicators of nutritional
element status.
Urine elements results are reported in standardized units that allows variable collection periods and ease
of comparison between tests. For example, a pre-provocation test using a 24 hour urine collection will be
reported in both units per 24 hours and units per mg creatinine. A post-provocation 6 hour collection will
be reported in units per mg creatinine. Less than 24 hour collections are expressed per mg creatinine to
account for urine dilution variations.