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Biomedical subjects

W E Szpunar

Publications and source records attributed to W E Szpunar.

At least 19 recordsLinked to original sources
PubMed1990

How does levothyroxine therapy affect thyroid function studies?

Are thyroid function test results affected by the timing of the previous levothyroxine dose? To answer this question, the authors asked 101 consecutive patients when they took the last dose and then correlated the time elapsed with the results of thyroid assays. Their findings are discussed in this article.

Administration, Oral↗
PubMed1987

Clinical evaluation of a thyroxine binding globulin assay in calculating a free thyroxine index in normal, thyroid disease, and sick euthyroid patients.

As assay for thyroxine binding globulin (TBG) that measures the thyroxine binding capacity of TBG and other proteins was used to calculate a free thyroxine index (FTI) in 108 consecutive thyroid patients, 2,559 normal patients, and 152 sick euthyroid patients. The TBG assay compared favorably with the triiodothyronine (T3) uptake test in producing a FTI for the clinical evaluation of thyroid patients. In addition, it did not suffer the disadvantages inherent in assays specific for only TBG. In the sick euthyroid population, the TBG assay produced an FTI that was more consistent with the clinical evaluation than did the T3 uptake test.

Humans↗
PubMed1984

Potency of levothyroxine products.

Recently, the company that manufactures the levothyroxine product that we use most often in our practice switched to high-pressure liquid chromotography (HPLC) to monitor their product. As a result, the brand name product now contains 100% of expected potency as determined in our laboratory by radioimmunoassay. Previous studies in our laboratory demonstrated that this product had only 78% of expected potency. This year our patients have a higher mean serum free thyroxine index (FTI) than they have had in the past. In addition, there were more elevated serum FTI levels and fewer elevated serum thyroid-stimulating hormone levels this year. Physicians should be aware of possible product changes being made by manufacturers of levothyroxine products over the next year or so as more companies switch to the HPLC method. The thyroid function studies of patients receiving levothyroxine products should be rather carefully monitored during this transitional period. We suspect that the new products will be more consistent and have a more reliable shelf life.

Adult↗
PubMed1983

Screening for minimal hypothyroidism. How sensitive is the free thyroxine assay?

The free thyroxine index (FTI) and a free thyroxine (FT4) assay were compared with the thyrotropin-releasing hormone stimulation test in 98 consecutive patients to determine whether the FT4 assay is more sensitive than the FTI in screening patients for minimal hypothyroidism. FTI and FT4 values did not agree with the clinical evaluation in 20% (3/15) of the patients with a transitional thyroid-stimulating hormone (TSH) response (21 to 35 microU/ml) and in 64.3% (9/14) of the patients with an augmented TSH response (greater than 35 microU/ml). From these results we conclude that the FT4 assay is no more sensitive than the FTI in detection of such minimal thyroid dysfunction.

Humans↗
PubMed1983

Faster assessment of patients receiving unnecessary thyroid treatment: concise communication.

Forty-five consecutive patients on thyroid hormone treatment without obvious indication were evaluated. Twenty-five of these cases were found to have no evidence of thyroid disease. Biochemical testing was not helpful in making the diagnosis of hypothyroidism in the majority of thyroid-treated hypothyroid patients. Normal technetium images were obtained in 25 patients, 22 of which had no thyroid disease. In contrast, abnormal technetium images were obtained in 20 patients, 16 of whom were thought to be hypothyroid, and one of whom developed a goiter within 2 mo after discontinuing levothyroxine. The use of technetium imaging seems useful for the rapid (20 min) evaluation of those patients likely to benefit from discontinuing thyroid medication.

Adult↗
PubMed1982

Hyperparathyroidism and thyroid disease. A study of their association.

The incidence of hyperparathyroidism was prospectively evaluated in a group of patients with thyroid disease, and the incidence of thyroid disease was retrospectively evaluated in a group of patients specifically referred for evaluation of hyperparathyroidism. Hyperparathyroidism was ten times more frequent in thyroid patients than expected in a general medical population and was especially prevalent in patients with nodular goiter. The incidence of thyroid disease in patients with hyperparathyroidism was 38.8%. Although radiation therapy was shown to be a factor in these associations, it alone could not explain the observed frequency.

Goiter, Nodular↗