Carole A. Spencer

Bio: Carole A. Spencer is an academic researcher from University of Southern California. The author has contributed to research in topics: Thyroid & Thyroglobulin. The author has an hindex of 49, co-authored 100 publications receiving 12820 citations. Previous affiliations of Carole A. Spencer include Boston Medical Center & University of Western Australia.

Serum TSH, T4, and Thyroid Antibodies in the United States Population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III)

Abstract: NHANES III measured serum TSH, total serum T(4), antithyroperoxidase (TPOAb), and antithyroglobulin (TgAb) antibodies from a sample of 17,353 people aged > or =12 yr representing the geographic and ethnic distribution of the U.S. population. These data provide a reference for other studies of these analytes in the U.S. For the 16,533 people who did not report thyroid disease, goiter, or taking thyroid medications (disease-free population), we determined mean concentrations of TSH, T(4), TgAb, and TPOAb. A reference population of 13,344 people was selected from the disease-free population by excluding, in addition, those who were pregnant, taking androgens or estrogens, who had thyroid antibodies, or biochemical hypothyroidism or hyperthyroidism. The influence of demographics on TSH, T(4), and antibodies was examined. Hypothyroidism was found in 4.6% of the U.S. population (0.3% clinical and 4.3% subclinical) and hyperthyroidism in 1.3% (0.5% clinical and 0.7% subclinical). (Subclinical hypothyroidism is used in this paper to mean mild hypothyroidism, the term now preferred by the American Thyroid Association for the laboratory findings described.) For the disease-free population, mean serum TSH was 1.50 (95% confidence interval, 1.46-1.54) mIU/liter, was higher in females than males, and higher in white non-Hispanics (whites) [1.57 (1.52-1.62) mIU/liter] than black non-Hispanics (blacks) [1.18 (1.14-1.21) mIU/liter] (P < 0.001) or Mexican Americans [1.43 (1.40-1.46) mIU/liter] (P < 0.001). TgAb were positive in 10.4 +/- 0.5% and TPOAb, in 11.3 +/- 0.4%; positive antibodies were more prevalent in women than men, increased with age, and TPOAb were less prevalent in blacks (4.5 +/- 0.3%) than in whites (12.3 +/- 0.5%) (P < 0.001). TPOAb were significantly associated with hypo or hyperthyroidism, but TgAb were not. Using the reference population, geometric mean TSH was 1.40 +/- 0.02 mIU/liter and increased with age, and was significantly lower in blacks (1.18 +/- 0.02 mIU/liter) than whites (1.45 +/- 0.02 mIU/liter) (P < 0.001) and Mexican Americans (1.37 +/- 0.02 mIU/liter) (P < 0.001). Arithmetic mean total T(4) was 112.3 +/- 0.7 nmol/liter in the disease-free population and was consistently higher among Mexican Americans in all populations. In the reference population, mean total T(4) in Mexican Americans was (116.3 +/- 0.7 nmol/liter), significantly higher than whites (110.0 +/- 0.8 nmol/liter) or blacks (109.4 +/- 0.8 nmol/liter) (P < 0.0001). The difference persisted in all age groups. In summary, TSH and the prevalence of antithyroid antibodies are greater in females, increase with age, and are greater in whites and Mexican Americans than in blacks. TgAb alone in the absence of TPOAb is not significantly associated with thyroid disease. The lower prevalence of thyroid antibodies and lower TSH concentrations in blacks need more research to relate these findings to clinical status. A large proportion of the U.S. population unknowingly have laboratory evidence of thyroid disease, which supports the usefulness of screening for early detection.

A consensus report of the role of serum thyroglobulin as a monitoring method for low-risk patients with papillary thyroid carcinoma.

Abstract: Recent studies have provided new information regarding the optimal surveillance protocols for low-risk patients with differentiated thyroid cancer (DTC). This article summarizes the main issues brought out in a consensus conference of thyroid cancer specialists who analyzed and discussed this new data. There is growing recognition of the value of serum thyroglobulin (Tg) as part of routine surveillance. An undetectable serum Tg measured during thyroid hormone suppression of TSH (THST) is often misleading. Eight studies show that 21% of 784 patients who had no clinical evidence of tumor with baseline serum Tg levels usually below 1 micro g/liter during THST had, in response to recombinant human TSH (rhTSH), a rise in serum Tg to more than 2 micro g/liter. When this happened, 36% of the patients were found to have metastases (36% at distant sites) that were identified in 91% by an rhTSH-stimulated Tg above 2 micro g/liter. Diagnostic whole body scanning, after either rhTSH or thyroid hormone withdrawal, identified only 19% of the cases of metastases. Ten studies comprising 1599 patients demonstrate that a TSH-stimulated Tg test using a Tg cutoff of 2 micro g/liter (either after thyroid hormone withdrawal or 72 h after rhTSH) is sufficiently sensitive to be used as the principal test in the follow-up management of low-risk patients with DTC and that the routine use of diagnostic whole body scanning in follow-up should be discouraged. On the basis of the foregoing, we propose a surveillance guideline using TSH-stimulated Tg levels for patients who have undergone total or near-total thyroidectomy and (131)I ablation for DTC and have no clinical evidence of residual tumor with a serum Tg below 1 micro g/liter during THST.

Laboratory medicine practice guidelines: laboratory support for the diagnosis and monitoring of thyroid disease

Abstract: Quality thyroid tests are essential for diagnosing and managing thyroid conditions. Indeed, mild (subclinical) hypoand hyperthyroidism are by definition conditions that are recognized by their biochemical profile, typified by an abnormal serum TSH concentration associated with normal range free thyroid hormone (FT4 and FT3) levels. The National Academy of Clinical Biochemistry (NACB) has recently published a consensus monograph entitled Laboratory Medicine Practice Guidelines: Laboratory Support for the Diagnosis and Monitoring of Thyroid Disease that reviews the clinical utility and technical performance of current thyroid tests (Demers & Spencer, 2002). The current scientific literature abounds with articles relating to thyroid conditions, strategies for thyroid testing and the technical performance of different thyroid methodologies. This monograph was prompted by the need to develop a consensus concerning these issues as well as to address the unusual thyroid problems that challenge the diagnostic accuracy of the thyroid tests currently available. These atypical presentations account for a disproportionately large expenditure of laboratory resources to determine the correct diagnosis (Kricka, 2000). In ambulatory patients these unusual presentations include: binding protein abnormalities that affect the diagnostic accuracy of FT4 tests; the presence of thyroglobulin (Tg) autoantibodies that interfere with serum Tg measurements; and medications that compromise the in vivo and in vitro metabolism of thyroid hormones and influence the diagnostic accuracy of TSH measurements. In addition, severe forms of non-thyroidal illnesses (NTI) have a myriad of effects on thyroid test results. This monograph is unique because it contains consensus guidelines that were developed by a process of global review. The review process was initiated at the International Thyroid Congress in Kyoto in October 2000, after which the guidelines were displayed electronically in addition to being distributed to more than 100 thyroid specialists, representing diverse professional associations worldwide, for consensus-building. The information contained in the monograph is presented in discrete chapters. Each chapter covers the clinical utility of a specific test, and contains focused guidelines that describe the physiological strengths and limitations of the test together with its optimal technical performance parameters. Most of the guidelines appeared to have greater than 95% consensus; however, there were some geographically sensitive differences in practice patterns.

A comparison of recombinant human thyrotropin and thyroid hormone withdrawal for the detection of thyroid remnant or cancer.

Abstract: Recombinant human TSH has been developed to facilitate monitoring for thyroid carcinoma recurrence or persistence without the attendant morbidity of hypothyroidism seen after thyroid hormone withdrawal. The objectives of this study were to compare the effect of administered recombinant human TSH with thyroid hormone withdrawal on the results of radioiodine whole body scanning (WBS) and serum thyroglobulin (Tg) levels. Two hundred and twenty-nine adult patients with differentiated thyroid cancer requiring radioiodine WBS were studied. Radioiodine WBS and serum Tg measurements were performed after administration of recombinant human TSH and again after thyroid hormone withdrawal in each patient. Radioiodine whole body scans were concordant between the recombinant TSH-stimulated and thyroid hormone withdrawal phases in 195 of 220 (89%) patients. Of the discordant scans, 8 (4%) had superior scans after recombinant human TSH administration, and 17 (8%) had superior scans after thyroid hormone withdrawal (P = 0.108). Based on a serum Tg level of 2 ng/mL or more, thyroid tissue or cancer was detected during thyroid hormone therapy in 22%, after recombinant human TSH stimulation in 52%, and after thyroid hormone withdrawal in 56% of patients with disease or tissue limited to the thyroid bed and in 80%, 100%, and 100% of patients, respectively, with metastatic disease. A combination of radioiodine WBS and serum Tg after recombinant human TSH stimulation detected thyroid tissue or cancer in 93% of patients with disease or tissue limited to the thyroid bed and 100% of patients with metastatic disease. In conclusion, recombinant human TSH administration is a safe and effective means of stimulating radioiodine uptake and serum Tg levels in patients undergoing evaluation for thyroid cancer persistence and recurrence.

Population based randomised controlled trial on impact of screening on mortality from abdominal aortic aneurysm

Abstract: Objective To assess whether screening for abdominal aortic aneurysms in men reduces mortality. Design Population based randomised controlled trial of ultrasound screening, with intention to treat analysis of age standardised mortality. Setting Community based screening programme in Western Australia. Participants 41 000 men aged 65-83 years randomised to intervention and control groups. Intervention Invitation to ultrasound screening. Main outcome measure Deaths from abdominal aortic aneurysm in the five years after the start of screening. Results The corrected response to invitation to screening was 70%. The crude prevalence was 7.2% for aortic diameter ≥ 30 mm and 0.5% for diameter ≥ 55 mm. Twice as many men in the intervention group than in the control group underwent elective surgery for abdominal aortic aneurysm (107 v 54, P = 0.002, χ2 test). Between scheduled screening and the end of follow up 18 men in the intervention group and 25 in the control group died from abdominal aortic aneurysm, yielding a mortality ratio of 0.61 (95% confidence interval 0.33 to 1.11). Any benefit was almost entirely in men aged between 65 and 75 years, where the ratio was reduced to 0.19 (0.04 to 0.89). Conclusions At a whole population level screening for abdominal aortic aneurysms was not effective in men aged 65-83 years and did not reduce overall death rates. The success of screening depends on choice of target age group and the exclusion of ineligible men. It is also important to assess the current rate of elective surgery for abdominal aortic aneurysm as in some communities this may already approach a level that reduces the potential benefit of population based screening.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer.

Abstract: Background: Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer. Methods: The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Gr...

Revised American Thyroid Association Management Guidelines for Patients with Thyroid Nodules and Differentiated Thyroid Cancer

Abstract: Background: Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the publication of the American Thyroid Association's guidelines for the management of these disorders was published in 2006, a large amount of new information has become available, prompting a revision of the guidelines. Methods: Relevant articles through December 2008 were reviewed by the task force and categorized by topic and level of evidence according to a modified schema used by the United States Preventative Services Task Force. Results: The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to optimal surgical management, radioiodine remnant ablation, a...

A systematic review of the literature

Abstract: OBJECTIVE — To systematically review the incidence of posttransplantation diabetes (PTD), risk factors for its development, prognostic implications, and optimal management. RESEARCH DESIGN AND METHODS — We searched databases (MEDLINE, EMBASE, the Cochrane Library, and others) from inception to September 2000, reviewed bibliographies in reports retrieved, contacted transplantation experts, and reviewed specialty journals. Two reviewers independently determined report inclusion (original studies, in all languages, of PTD in adults with no history of diabetes before transplantation), assessed study methods, and extracted data using a standardized form. Meta-regression was used to explain between-study differences in incidence. RESULTS — Nineteen studies with 3,611 patients were included. The 12-month cumulative incidence of PTD is lower (10% in most studies) than it was 3 decades ago. The type of immunosuppression explained 74% of the variability in incidence (P 0.0004). Risk factors were patient age, nonwhite ethnicity, glucocorticoid treatment for rejection, and immunosuppression with high-dose cyclosporine and tacrolimus. PTD was associated with decreased graft and patient survival in earlier studies; later studies showed improved outcomes. Randomized trials of treatment regimens have not been conducted. CONCLUSIONS — Physicians should consider modification of immunosuppressive regimens to decrease the risk of PTD in high-risk transplant recipients. Randomized trials are needed to evaluate the use of oral glucose-lowering agents in transplant recipients, paying particular attention to interactions with immunosuppressive drugs. Diabetes Care 25:583–592, 2002

Serum TSH, T4, and Thyroid Antibodies in the United States Population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III)

Abstract: NHANES III measured serum TSH, total serum T(4), antithyroperoxidase (TPOAb), and antithyroglobulin (TgAb) antibodies from a sample of 17,353 people aged > or =12 yr representing the geographic and ethnic distribution of the U.S. population. These data provide a reference for other studies of these analytes in the U.S. For the 16,533 people who did not report thyroid disease, goiter, or taking thyroid medications (disease-free population), we determined mean concentrations of TSH, T(4), TgAb, and TPOAb. A reference population of 13,344 people was selected from the disease-free population by excluding, in addition, those who were pregnant, taking androgens or estrogens, who had thyroid antibodies, or biochemical hypothyroidism or hyperthyroidism. The influence of demographics on TSH, T(4), and antibodies was examined. Hypothyroidism was found in 4.6% of the U.S. population (0.3% clinical and 4.3% subclinical) and hyperthyroidism in 1.3% (0.5% clinical and 0.7% subclinical). (Subclinical hypothyroidism is used in this paper to mean mild hypothyroidism, the term now preferred by the American Thyroid Association for the laboratory findings described.) For the disease-free population, mean serum TSH was 1.50 (95% confidence interval, 1.46-1.54) mIU/liter, was higher in females than males, and higher in white non-Hispanics (whites) [1.57 (1.52-1.62) mIU/liter] than black non-Hispanics (blacks) [1.18 (1.14-1.21) mIU/liter] (P < 0.001) or Mexican Americans [1.43 (1.40-1.46) mIU/liter] (P < 0.001). TgAb were positive in 10.4 +/- 0.5% and TPOAb, in 11.3 +/- 0.4%; positive antibodies were more prevalent in women than men, increased with age, and TPOAb were less prevalent in blacks (4.5 +/- 0.3%) than in whites (12.3 +/- 0.5%) (P < 0.001). TPOAb were significantly associated with hypo or hyperthyroidism, but TgAb were not. Using the reference population, geometric mean TSH was 1.40 +/- 0.02 mIU/liter and increased with age, and was significantly lower in blacks (1.18 +/- 0.02 mIU/liter) than whites (1.45 +/- 0.02 mIU/liter) (P < 0.001) and Mexican Americans (1.37 +/- 0.02 mIU/liter) (P < 0.001). Arithmetic mean total T(4) was 112.3 +/- 0.7 nmol/liter in the disease-free population and was consistently higher among Mexican Americans in all populations. In the reference population, mean total T(4) in Mexican Americans was (116.3 +/- 0.7 nmol/liter), significantly higher than whites (110.0 +/- 0.8 nmol/liter) or blacks (109.4 +/- 0.8 nmol/liter) (P < 0.0001). The difference persisted in all age groups. In summary, TSH and the prevalence of antithyroid antibodies are greater in females, increase with age, and are greater in whites and Mexican Americans than in blacks. TgAb alone in the absence of TPOAb is not significantly associated with thyroid disease. The lower prevalence of thyroid antibodies and lower TSH concentrations in blacks need more research to relate these findings to clinical status. A large proportion of the U.S. population unknowingly have laboratory evidence of thyroid disease, which supports the usefulness of screening for early detection.

ACC/AHA 2005 Practice Guidelines for the Management of Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic)

Abstract: Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic) A Collaborative Report from the American Association for Vascular Surgery/Society for Vascular Surgery,* Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease) Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation