Randomized Trial Comparing Two Algorithms for Levothyroxine Dose Adjustment in Pregnant Women With Primary Hypothyroidism.

Context: Regulation of maternal thyroid hormones during pregnancy is crucial for optimal maternal and fetal outcomes. There are no specific guidelines addressing maternal levothyroxine (LT4) dose adjustments throughout pregnancy. Objective: To compare two LT4 dose-adjustment algorithms in hypothyroid pregnant women. Design: Thirty-three women on stable LT4 doses were recruited at <10 weeks gestation during 38 pregnancies and randomized to one of two dose-adjustment groups. Group 1 (G1) used an empiric two-pill/week dose increase followed by subsequent pill-per-week dose adjustments. In group 2 (G2), LT4 dose was adjusted in an ongoing approach in micrograms per day based on current thyroid stimulating hormone (TSH) level and LT4 dose. TSH was monitored every 2 weeks in trimesters 1 and 2 and every 4 weeks in trimester 3. Setting: Academic endocrinology clinics in Washington, DC. Main Outcome Measure: Proportion of TSH values within trimester-specific goal ranges. Results: Mean gestational age at study entry was 6.4 ± 2.1 weeks. Seventy-five percent of TSH values were within trimester-specific goal ranges in G1 compared with 81% in G2 (P = 0.09). Similar numbers of LT4 dose adjustments per pregnancy were required in both groups (G1, 3.1 ± 2.0 vs G2, 4.1 ± 3.2; P = 0.27). Women in G1 were more likely to have suppressed TSH <0.1 mIU/L in trimester 1 (P = 0.01). Etiology of hypothyroidism, but not thyroid antibody status, was associated with proportion of goal TSH values. Conclusions: We compared two options for LT4 dose adjustment and showed that an ongoing adjustment approach is as effective as empiric dose increase for maintaining goal TSH in hypothyroid women during pregnancy.

A diagnostic scoring system for myxedema coma.

OBJECTIVE: To develop diagnostic criteria for myxedema coma (MC), a decompensated state of extreme hypothyroidism with a high mortality rate if untreated, in order to facilitate its early recognition and treatment. METHODS: The frequencies of characteristics associated with MC were assessed retrospectively in patients from our institutions in order to derive a semiquantitative diagnostic point scale that was further applied on selected patients whose data were retrieved from the literature. Logistic regression analysis was used to test the predictive power of the score. Receiver operating characteristic (ROC) curve analysis was performed to test the discriminative power of the score. RESULTS: Of the 21 patients examined, 7 were reclassified as not having MC (non-MC), and they were used as controls. The scoring system included a composite of alterations of thermoregulatory, central nervous, cardiovascular, gastrointestinal, and metabolic systems, and presence or absence of a precipitating event. All 14 of our MC patients had a score of ≥60, whereas 6 of 7 non-MC patients had scores of 25 to 50. A total of 16 of 22 MC patients whose data were retrieved from the literature had a score ≥60, and 6 of 22 of these patients scored between 45 and 55. The odds ratio per each score unit increase as a continuum was 1.09 (95% confidence interval [CI], 1.01 to 1.16; P = .019); a score of 60 identified coma, with an odds ratio of 1.22. The area under the ROC curve was 0.88 (95% CI, 0.65 to 1.00), and the score of 60 had 100% sensitivity and 85.71% specificity. CONCLUSION: A score ≥60 in the proposed scoring system is potentially diagnostic for MC, whereas scores between 45 and 59 could classify patients at risk for MC.

Thyroid nodules.

Thyroid nodules are common entities, clinically important primarily because of their malignant potential. Serum thyrotropin and thyroid ultrasonography are pivotal in evaluating thyroid nodules. Fine-needle aspiration biopsy is the most accurate tool for diagnosing malignancy and selecting candidates for surgery. An approach to the initial evaluation and management of single nodules, functioning nodules, multinodular glands, incidental nodules, and cysts is discussed, as are therapeutic interventions for benign nodules. Thyroid cancer discovered during pregnancy is also discussed.

Graves' disease and thymic hyperplasia: the relationship of thymic volume to thyroid function.

BACKGROUND: Thymic hyperplasia is associated with Graves' disease, particularly in young patients. The degree of thymic transformation is minimal in most but not all patients. In the latter group radiological measurements of thyroid size and their change with treatment have rarely been reported. We present two patients with Graves' disease and relatively rapid resolution of thymic enlargement after successful treatment of their hyperthyroidism. SUMMARY: Three patients with thyrotoxicosis secondary to Graves' disease and marked thymic enlargement were seen at our institution during a 2-year period. On computed tomography (CT) studies their volumes were 67, 81, and 54 cm(3). Thymic hyperplasia in the setting of Graves' disease was the diagnosis of exclusion. Two of the patients returned for follow-up after successful treatment of thyrotoxicosis as requested. On repeat CT their thymic volumes had decreased by 72% and 78%, respectively. Two types of histological modifications of the thymus have been described in association with Graves' disease, namely, thymic parenchyma hyperplasia and medullary lymphoid hyperplasia. The mechanisms underlying thymic transformation in patients with Graves' hyperthyroidism are not completely elucidated, but autoimmune processes underlying Graves' disease are presumed to play a role. The clinical course of our patients is consistent with earlier literature, indicating that thymic enlargement may occur in conjunction with Graves' hyperthyroidism, and that it usually resolves as hyperthyroidism is treated, but there is little quantitative pre- and posttreatment of hyperthyroidism data. CONCLUSION: Although every patient must be individually considered, it appears that thymic hyperplasia can be diagnosed in most Graves' hyperthyroid patients by considering the clinical context and appropriate radiologic studies such as CT. Raising awareness of the association of thymic hyperplasia in patients with Graves' hyperthyroidism and its resolution with the reversibility of the hyperthyroid state should prevent unnecessary thymic evaluation and surgery with its attendant risks.

Malignant melanoma in African-Americans.

Although relatively uncommon, malignant melanoma in African-Americans and other minority ethnic populations represents an aggressive disease highly associated with invasive lesions and a more advanced stage of disease at diagnosis, and consequently with a decreased survival compared with Caucasians. Data on biology of melanoma in African-Americans is very limited, which complicates the analysis of epidemiological information, as well as identification of accurate prognostic variables. This review article explores critical features of melanoma in African-Americans that distinguish it from disease seen in Caucasians, including the clinical presentation, histological patterns, prognostic indicators, and etiology. Emerging data from biologic and genetic studies will also be discussed, raising the possibility that melanoma in pigmented skin may represent molecular distinct cancers that are inherently more aggressive. Improved understanding of the unique manifestations of melanoma in African-Americans, and its underlying tumor biology, will help improve clinical detection, optimize preventative measures through public health education, and potentially lead to the development of novel targeted therapeutic approaches.