Houston Area Pediatric Specialists

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Friday, January 23, 2015

Urine toxic metal tests & autism. Read more about provoked testing for autism.

How the "Urine Toxic Metals" Test
Is Used to Defraud Patients

Urine toxic metal tests and autism. Read more about provoked testing. 

Stephen Barrett, M.D.

Many patients are falsely told that their body has dangerously high levels of lead, mercury, or other heavy metals and should be "detoxified" to reduce these levels. This article explains how a urine test is used to defraud patients.

The report pictured to the right is a "urine toxic metals" test ...the patient who gave it to me was told by his doctor that his mercury and lead levels were high and should be reduced with EDTA chelation therapy.

The report classifies the man's lead and mercury levels as "elevated because they are twice as high as the upper limit of their "reference ranges." However, this classification is misleading because:
  • The report states that the specimen was obtained after patient was given a "provoking agent," but the reference range is based on non-provoked tests.
  • The levels, whether provoked or not, are not high enough to conclude that the patient has a problem that requires attention.
  • Even if a problem exists, chelation may not be the best course of action.

Why Provoked Testing Is a Scam

Mercury is found in the earth's crust and is ubiquitous in the environment. Because of this, it is common to find small amounts in people's urine. The body reaches a steady state in which tiny amounts are absorbed and excreted. Large-scale population studies have shown that the general population has urine-mercury levels below 10 micrograms/liter, with most people between zero and 5 [1]. Similarly, many people circulate trivial amounts of lead.

Urine lead and mercury levels can be artificially raised by administering a scavenger (chelating agent) such as DMPS or DMSA, which attaches to lead and mercury molecules in the blood and forces them to be excreted. In other words, some molecules that would normally recirculate within the body are bound and exit through the kidneys. As a result, their urine levels are artificially and temporarily raised. How much the levels are raised depends on how the test is administered. The standard way to measure urinary mercury and lead levels is by collecting a non-provoked urine sample over a 24-hour period. Because most of the extra excretion takes place within a few hours after the chelating agent is administered, using a shorter collection period will yield a higher concentration.

When testing is performed, the levels are expressed as micrograms of lead or mercury per grams of creatinine (µg/g) and compared to the laboratory's "reference range." Well-designed experiments have demonstrated how provocation artificially raises urinary output.
  • One experiment involved ten healthy people whose urine was examined before and after receiving a 1-hour infusion of calcium disodium EDTA. The infusion increased the excretion of lead about 6 times over the baseline level [2].
  • Another experiment tested workers who had industrial exposure to mercury. The researchers reported that provocation with DMSA raised the 24-hour average urine mercury level from 4.3 µg/g before chelation to 7.8 µg/g after chelation [3].
Both of these studies used a 24-hour urine collection period. Because most of the extra excretion occurs toward the beginning of the test, it is safe to assume that the provoked levels would have been much higher if a 6-hour collection period had been used.

Practitioners who use the urine toxic metals test typically tell patients that provocation is needed to discover "hidden body stores" of mercury or lead, which they also refer to as "body burden" or "mercury efflux disorder." However, the above experiment proved that provocation raises urine levels as much in exposed workers as in unexposed control subjects and that rise is temporary, should be expected, and is not evidence of "hidden stores." The scientific community does not recognize "mercury efflux disorder" as a diagnosis or even as a theoretical possibility.
The "hidden stores" notion was further debunked by a study that compared non-provoked and DMSA-provoked urine specimens from 15 children with autism and 4 normally developing children who ranged from 3 to 7 years old. After a baseline specimen from each child was collected, the DMSA was given in three doses over a 16-hour period, and the specimens were collected for 24 hours and tested for lead, mercury, arsenic, and cadmium. The testing was performed by the Mayo Clinic's laboratory, which used reference ranges of 80 ug/liter as the upper limit of normal and over 400 µg/liter for the lower limit of the potentially toxic range for lead and 10 µg/liter as the upper limit of normal and over 50 µg/liter for the lower limit of the potentially toxic range for mercury. All of the normal children and 12 of the autistic children excreted no detectable amount of any of the tested materials. In one child, DMSA provocation raised the urine lead level from undetectable to 6 µg/liter, which the researchers said was far too low to be of concern. In another child, the mercury level rose from undetectable to 23 µg/liter, but after fish was removed from that child's diet for more than a month, it fell to 5. The study showed that when laboratory measurements are accurate and proper reference standards are used, neither autistic nor normal children are likely to have problematic levels of lead or mercury, even when provoked testing is used, but fish-eaters might consume enough mercury to enable provocation to produce an inflated value. The authors concluded that the proportion of autistic participants in this study whose DMSA-provoked excretion results demonstrated an excess chelatable body burden of Arsenic, Cadmium, Lead or mercury was zero [4].

Neither Mayo Clinic, nor any other legitimate national laboratory, has reference ranges for “provoked” specimens. Further, the references ranges for normal urine heavy metal levels used by Mayo Clinic and the largest national reference lab, Quest Diagnostics, are the same.

Full article here