Measurement of serum thyroperoxidase autoantibodies (TPOAb) during gestation as a classical marker for the risk of postpartum thyroiditis (PPT) predicts PPT in 1/3 to 1/2 of women. Very few studies ...have measured serum thyroid hormone Ab (THAb) during gestation, and none as a possible marker for PPT.
In 412 women who were followed up from 7 to 11 weeks of gestation through 12 months after delivery, we measured THAb (T3.IgM, T3.IgG, T4.IgM, T4.IgG), thyroglobulin autoantibodies (TgAb) and TPOAb at study entry (7–11 week of gestation).
Sixty-three women (15.3%) developed PPT, which progressed to permanent hypothyroidism (PH) in 34/63 (54%). THAb+ve were 21/412 women (5.1%), the frequency being greater in those who then developed PPT (12/63 19.0% vs. 9/349 2.6%, P = 4.6 × 10−8), and in the PH subgroup (26.5% 9/34 vs. 10.3% 10/29, P = 0.12). THAb positivity occurred in 9/76 women (11.8%) who were TgAb and/or TPOAb+ve compared to 12/336 women who were TgAb and TPOAb negative (3.6%, P = 0.0031). Of these 9 THAb+ve, TgAb and/or TPOAb+ve women, all (100%) developed PPT compared to 3/11 (27.3%, P = 0.0011) THAb+ve, TgAb and/or TPOAb negative women. Of these 9 and 3 PPT women, 8 and 1 progressed to PH (88.9% and 33.3%, respectively, P = 0.12).
Gestational positivity of THAb enhance enormously the predictivity for PPT of gestational positivity of TPOAb/TgAb. However, their low frequency (5.1%) and their sensitivity (17.5% 21/63) go against their application in lieu of TPOAb/TgAb.
The use of thyrotropin and free thyroid hormone assays to evaluate thyroid function is widespread, but in some situations the results are inconsistent with the patient's thyroid status.
A 35-year-old ...woman with a known diagnosis of chronic autoimmune thyroiditis was referred to the authors' clinic at week 26 of her second pregnancy. The patient was clinically euthyroid. Consistent with this, her serum thyrotropin (TSH) was normal (0.79 mIU/L), but she had elevated free thyroid hormones-free triiodothyronine (fT3) and free thyroxine (fT4)-as determined by a one-step chemiluminescent assay. The patient was taking levothyroxine replacement therapy (125 μg/day), and the dose was confirmed. Previous blood tests showed concordance between TSH and free thyroid hormone values. The patient was followed up throughout gestation and at 12 months postpartum. During gestation, her free thyroid hormones remained high using one-step methods, while the total thyroid hormone concentration values were within the reference range, in agreement with the TSH values. Postpartum fT4 and fT3 values returned progressively to normality, in agreement with the TSH values. The presence of circulating thyroid hormone autoantibodies (THAb) was hypothesized, which are known to interfere, although to a variable extent, with thyroid hormone one-step assays. Using stored frozen sera, this hypothesis was confirmed indirectly by measuring normal levels of fT3 and fT4 with a two-step method, and directly by demonstrating THAb against the two hormones.
Despite their relative rarity, circulating THAb may be suspected when laboratory data are not consistent and contrast with the clinical picture. To the authors' knowledge, no previous case of transient appearance of THAb in pregnancy has been described.
Summary
Objective
Adipocytes, regulated by insulin, represent the major peripheral source of prolactin (PRL), which play a pivotal role in energy balance, acting on adipogenesis and lipolysis. The ...aim of this study was to investigate whether PRL was associated with obesity‐related inflammatory status and metabolic parameters. The diagnostic and prognostic role of PRL for metabolic syndrome (MS) was assessed. The effects of short‐term lifestyle therapy on PRL levels were evaluated.
Subjects
Prolactin was assessed in 94 obese patients and compared with 40 healthy children (HS).Patients were followed up for 1 year. Receiver operating characteristics (ROC) analysis was employed to find the best cut‐off values capable of identifying MS in obese children for PRL, IL‐6 and TNF‐α. Kaplan–Meier curves were also generated. Adjusted risk estimates for MS were calculated using Cox proportional hazard regression analysis. An obesity intervention programme was administered for 12 months.
Results
Prolactin levels were lower in obese patients than controls (P < 0·0001). PRL was found to be inversely correlated with BMI, IL‐6 and HOMA‐IR, whereas a direct correlation was found with HDL values. At ROC analysis, PRL showed higher sensitivity and specificity than IL‐6 and TNF‐α in identifying MS in obese children. Cox proportional hazard regression analysis showed that PRL predicted MS independently of other potential confounders. The lifestyle intervention improved PRL and metabolic parameters.
Conclusions
Prolactin represents a prognostic marker for obese children and a predictive factor for progression to MS. PRL measurement may be useful as part of the endocrine work‐up of obese children.
Context: Mild to moderate iodine deficiency during pregnancy can cause transient maternal hypothyroidism and impaired mental development of the progeny. These unfavorable effects are preventable by ...iodine supplementation. In Europe, however, less than 50% pregnant women receive iodine-containing supplements, thus representing dietary iodized salt the only carrier of iodine for most women in this life stage.
Objective/Design: This longitudinal study is aimed to investigate the effects of long-term iodized salt consumption on maternal thyroid function during gestation.
Participants/Outcome Measures: We prospectively evaluated thyroid function in 100 consecutive thyroperoxidase antibody-negative pregnant women from a mildly iodine-deficient area. Sixty-two women who had regularly used iodized salt for at least 2 yr prior to becoming pregnant and 38 who commenced iodized salt consumption upon becoming pregnant were classified as long-term (LT) and short-term (ST) iodine supplemented, respectively.
Results: Long-term iodized salt consumption resulted in a very low prevalence of maternal thyroid failure (MTF) in LT women. Conversely, short-term iodine prophylaxis does not seem to protect against the risk of MTF, the prevalence of which was almost 6-fold higher in ST than LT women (36.8% vs. 6.4%; χ2 14.7, P < 0.0005; relative risk 5.7, 95% confidence interval 2.03–16.08, P < 0.001). The relative risk reduction amounted to 82.5%, this measure indicating the extent to which long-term iodine prophylaxis using iodized salt would reduce the risk of MTF in ST women.
Conclusions: Prolonged iodized salt significantly improves maternal thyroid economy and reduces the risk of maternal thyroid insufficiency during gestation, probably because of a nearly restoring intrathyroidal iodine stores.
Summary
objective We prospectively evaluated the effects of 12 months thyrotropin suppressive levo‐thyroxine (L‐T4) therapy in terms of changes in both thyroid nodule size and cytological features ...and considered whether thyroid nodule size changes actually resulted in (or were the result of) cytological changes.
design and patients We studied 142 consecutive patients with benign ‘cold’ solitary thyroid nodules. For the purposes of the study, we divided our patients into three groups according to their initial cytological nodule classification as follows: group 1, including 88 colloid nodules (CN); group 2, including 30 hyperplastic nodules (HN); and group 3, including 24 adenomatous nodules (AN).
measurements The effects of TSH suppressive L‐T4 treatment on both nodule volume and cytological characteristics were evaluated by ultrasonography and fine‐needle aspiration (FNA) before and 12 months after the onset of therapy.
results Twelve months of TSH suppressive L‐T4 treatment were effective in shrinking about one‐third to one‐quarter (31·8% CN, 26·7% HN and 25% AN) of thyroid nodules, irrespective of their initial cytological characteristics. Similarly, there was no difference in the prevalence of ‘non‐responders’ (increasing nodules) to L‐T4, which accounted for about one‐fifth or less (20·5% CN, 13·3% HN and 20·8% AN) of all nodules. We found also that cytological features changed in 33·8% nodules after 12 months of L‐T4 treatment. These changes were most commonly observed in HN and AN and consisted largely (∼80%) of cytological characteristics resembling colloid features, not only in shrinking but also in stable nodules, thus indicating that cytology changes might be the very first indicator of nodule sensitivity to L‐T4 therapy even in the continued absence of nodule shrinkage. When nodules were divided into three subgroups according to variations in size (shrinking, stable and increasing nodules), we observed that the distribution of the three cytological types showed a trend towards colloid lesions in shrinking nodules (χ2 3·8, P < 0·005) and towards an augmentation of hypercellular, adenomatous and suspicious characteristics in increasing nodules (χ2 3·6, P < 0·005).
conclusion The frequency of shrinking nodules was not different between colloid, hyperplastic and adenomatous nodules. Repeat FNA should be advisable for thyroid nodules which increase in volume despite L‐T4 therapy and might also provide useful information about nodule sensitivity to L‐T4 treatment for both HN and AN, even where nodule size remains stable.
PDF
