When was tsh test invented

Also, the mean total cholesterol and low-density lipoprotein cholesterol levels of subjects with TSH values between 5. Symptoms were reported more often in hypothyroid vs euthyroid individuals, but individual symptom sensitivities were low. Conclusions The prevalence of abnormal biochemical thyroid function reported here is substantial and confirms previous reports in smaller populations.

Modest elevations of TSH corresponded to changes in lipid levels that may affect cardiovascular health. Individual symptoms were not very sensitive, but patients who report multiple thyroid symptoms warrant serum thyroid testing.

These results confirm that thyroid dysfunction is common, may often go undetected, and may be associated with adverse health outcomes that can be avoided by serum TSH measurement. Numerous studies from various countries differ in their prevalence estimates for both hypothyroidism and hyperthyroidism. The difficulty with many of these studies lies in the variable definitions of disease states, the poorly defined and diverse populations studied, and the historically insensitive measures of thyroid function.

In perhaps the best longitudinal study conducted to date, Tunbridge et al 1 found that 7. Several factors may affect prevalence. The Framingham Study showed that Abnormal thyroid function has important public health consequences.

Suppressed TSH levels have been associated with decreased bone density in some but not all studies 9 , 10 and with an increased risk of atrial fibrillation 11 and premature atrial beats. Identifying thyroid disease clinically can be challenging. Symptoms often develop so insidiously that they go unnoticed.

In the present study, a large cohort provided a unique opportunity to conduct a cross-sectional study of abnormal thyroid function. The principal inquiries were 1 the prevalence of abnormal thyroid function, 2 the relationship of abnormal thyroid function to abnormal serum lipid concentrations, and 3 the relationship between abnormal thyroid function and symptoms of hypothyroidism using modern and sensitive tests of thyroid function.

The Colorado 9Health Fair is an annual statewide event that provides testing for such disorders as hypertension, colon cancer, glaucoma, and skin cancer, with optional blood analysis available at a nominal fee. Participants also complete a demographic survey at the time of their screening. In , sensitive tests of thyroid function were added to the menu of blood analyses, and a questionnaire for hypothyroid symptoms was included with the survey.

The Thyroid Health Survey is available upon request from the authors. Written informed consent was obtained from all participants. Questions on personal history, family history, and demographic characteristics were included. There were also 14 questions on symptoms of hypothyroidism, which were chosen based on the results of a previous study.

Was the symptom new from the previous year "changed" symptom? Subjects who opted for blood analysis were requested to fast for 12 hours prior to having their blood drawn. Serum TSH concentrations were measured by a third-generation immunochemiluminescent procedure having a functional detection limit of 0.

Serum lipid levels were determined using the autoanalyzer method. Age- and sex-adjusted reference ranges were used to define the limits of normality for serum lipid levels. Thyroid status was defined as follows:. Euthyroid TSH level within the normal range, 0.

Because total T 4 and not free FT 4 thyroxine levels were used in this study, some total T 4 concentrations may have been slightly elevated because of increases in thyroid hormone binding proteins in patients who were receiving certain concomitant medications; for example, estrogens. We therefore categorized hyperthyroid states according to TSH levels alone, as above, assuming that virtually all hyperthyroid patients have undetectable serum TSH levels.

Similarly, the population of patients with subclinical hypothyroidism may be overestimated because of concomitant estrogen administration. Data were entered directly from the Colorado 9Health Fair Survey forms and verified using double entry. Laboratory results collected by the Colorado 9Health Fair were later linked to survey information by site and subject identification number.

The Colorado Medical Society, Englewood, provided appropriate medical follow-up for participants with abnormal laboratory test results identified through the Colorado 9Health Fair. The Pearson correlation coefficient was calculated between the TSH level and the percentage of reported symptoms in order to relate symptoms to progressively worsening thyroid function.

Logistic regression was used to determine which symptoms were independent predictors of a disease state, while controlling for other symptoms. Centor and J. Keightley, University of Alabama, Birmingham. The symptom index was calculated in the manner of Billewicz et al. For each patient, the numerical weights of the patient's reported symptoms, present and absent, were summed to calculate the Billewicz score.

These patient scores may discriminate between hypothyroid and euthyroid persons better than individual symptoms. In our study population, symptom weights were calculated using the overt hypothyroid group relative to a randomly chosen subset of the euthyroid group.

This subgroup, of equal size to the hypothyroid group, was matched with the hypothyroid group for age, sex, and whether or not the individual was taking thyroid medication. There were 33, subjects who presented to the Colorado 9Health Fair screening sites. We excluded subjects for not returning the Thyroid Health Survey, nonevaluable responses, or inconsistent demographic data that made matching survey responses to laboratory data potentially inaccurate.

Another subjects did not have blood drawn. Demographic data on the remaining 25, individuals, representing testing sites, are shown in Table 1. When compared with the general population of Colorado, the study population was older and had more women, a greater proportion who were white, and more high school and college graduates. Similar population characteristics have been reported by other community health fairs.

Based on the above definitions of thyroid status, an abnormal serum TSH concentration was found in There were subjects 9. The distribution of subjects with an elevated TSH level is shown by age and sex in Figure 1. There were participants with a low TSH concentration 2. The remaining 22, participants Among patients not taking thyroid medication, 8. Thus, 9. Cognitive outcomes depend on the timing and adequacy of treatment.

The preferred treatment is LT 4 ; triiodothyronine should not be used. An initial dosage of 10 to 15 mcg per kg per day has been recommended, depending on the severity of the condition. Soy, fiber, and iron can impair T 4 bioavailability and should be avoided. T 4 should increase to greater than 10 mcg per dL and FT 4 to greater than 2 ng per dL 26 pmol per L within two weeks after starting therapy, and TSH should normalize within one month.

Use of a higher initial dosage i. FT 4 measurement at one week can confirm appropriate serum concentration increase. In the first three years, serum total T 4 and FT 4 values should be in the upper half of the reference range, and serum TSH levels should be between 0.

Relative pituitary resistance may delay normalization of serum TSH, resulting in a normal or increased serum T 4 concentration with an inappropriately high TSH level. In these cases, the dose should be titrated based on the T 4 value after first ruling out nonadherence to treatment.

Laboratory and clinical evaluations must be performed regularly in infants with congenital hypothyroidism during the first three years to ensure optimal dosing of and adherence to therapy. Serum T 4 and TSH should be measured at two and four weeks after treatment initiation, then every one to two months until six months of age, every three to four months from six months to three years of age, every six to 12 months until growth is completed, and four weeks after any dosage change.

Measurements should be performed more frequently if non-compliance is suspected or abnormal results are found. Ongoing counseling of parents is important because of the serious consequences of poor compliance.

To ensure normal growth and development, serum T 4 concentrations should be maintained in the upper half of the reference range in the first year, and serum TSH measurements should be kept in the reference range. If serum FT 4 concentration does not increase to the upper half of the reference range by two weeks or if the TSH concentration does not fall below 20 mU per L within four weeks, physicians should evaluate compliance, dosage, and administration method. The adverse effects of excessive medication should always be taken into account, and physicians should be prepared to monitor blood FT 4 concentrations at close intervals.

An ectopic gland or absent thyroid tissue on thyroid scan or an increase in serum TSH to above 10 mU per L after one year of age indicates permanent congenital hypothyroidism. If no sign of permanence is found, therapy should be discontinued for 30 days after three years of age, and measurements of FT 4 and TSH should be obtained. A diagnosis of transient hypothyroidism can be made if results are in the reference range; otherwise, treatment should be resumed.

An alternative option is to first reduce the dosage by one half for 30 days, at which time a TSH level above 20 mU per L confirms permanent congenital hypothyroidism. Physicians should carefully monitor the child, and thyroid function tests should be repeated at any suspicion of recurrence. Inconclusive results warrant careful follow-up and further testing. Already a member or subscriber?

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This was the thyroid hormone uptake test. In conjunction with a total T4 result, the two tests could be amalgamated to produce what was claimed was an estimate of FT4. This thyroid testing method is still used today; e. However, it is not based on sound principles and does not work properly, especially for people with extreme differences in TBG from the average.

In the remainder of the s, commercial firms were set up to provide readymade tests for the clinical chemistry labs to use. In about , commercial TSH and T3 tests were developed and sold. The TSH test was the first generation — that is, it could only measure and detect hypothyroidism the depressed levels in hyperthyroidism were too low to be measured directly.

Such was the growing demand for thyroid testing that the various companies competed with one another for business in the labs. Since the method of measurement radioactivity was the same in all tests, the competition was such that no company would have a monopoly of business in the labs. This competition produced faster and slicker tests with shorter and shorter times — giving quicker turnover and more tests done in a given time.

In the late s the shortcomings of the thyroid hormone uptake test, arising from the variation in TBG levels in patients, were very apparent. The demand for properly formulated and soundly developed FT4 and FT3 tests was very great. As a response, companies and individuals produced various forms of thyroid testing claiming to measure these fractions. Many of the offerings were not soundly based, and slowly disappeared into obscurity and obsolescence.

Two methods did however prevail and form the basis of FT4 and FT3 testing today. The London researcher now a distinguished professor — Nobel Laureate just failed , who had developed the pioneering total test 20 years earlier invented a validly based test for FT4. At the same time, I invented and my company developed and offered a method based on a different principle, but also soundly based.

The London professor and his group decided to try to destroy the validity and reputation of the rival test and those who had developed it. So began a long series of aggressive, long and detailed theoretical arguments as to why the test I had invented was, in its present form, unfit for purpose and could not and did not work. In vain did we show that the practical working of our test bore no resemblance whatever to his theoretical predictions — this only invited more and more vituperative denunciation.

The individuality of the patient is lost, and therefore misjudgments are continually made as to the success of the treatment. So this is a matter of Education. I think clinical training has to change very very very much. Because there are an awful lot of misapprehensions about how you treat numbers and how you relate them to patient presentation.

They refused to allow desiccated thyroid to be licensed or used in this country for a very strange reason. So there is no real evidence and no reason not to be quite liberal in the choice of treatments that you offer patients according to their requirements and according to their responses to the treatments. This site uses Akismet to reduce spam. Learn how your comment data is processed. It commits the sin of categorization. By categorization I mean it puts you or, the diagnosis and treatment is aimed putting you into the normal range — Now the normal range is a wide range.

That is wrong.