Thyroid Diseases: Abalovich M

Abalovich M, Amino N, Barbour LA, Cobin RH, De Groot LJ, Glinoer D, Mandel SJ, Stagnaro-Green A. · Endocrinology Division, Durand Hospital, Buenos Aires, Argentina. · J Clin Endocrinol Metab. · Pubmed #17948378 links to  free full text

Abstract: OBJECTIVE: The objective is to provide clinical guidelines for the management of thyroid problems present during pregnancy and in the postpartum. PARTICIPANTS: The Chair was selected by the Clinical Guidelines Subcommittee (CGS) of The Endocrine Society. The Chair requested participation by the Latin American Thyroid Society, the Asia and Oceania Thyroid Society, the American Thyroid Association, the European Thyroid Association, and the American Association of Clinical Endocrinologists, and each organization appointed a member to the task force. Two members of The Endocrine Society were also asked to participate. The group worked on the guidelines for 2 yr and held two meetings. There was no corporate funding, and no members received remuneration. EVIDENCE: Applicable published and peer-reviewed literature of the last two decades was reviewed, with a concentration on original investigations. The grading of evidence was done using the United States Preventive Services Task Force system and, where possible, the GRADE system. CONSENSUS PROCESS: Consensus was achieved through conference calls, two group meetings, and exchange of many drafts by E-mail. The manuscript was reviewed concurrently by the Society's CGS, Clinical Affairs Committee, members of The Endocrine Society, and members of each of the collaborating societies. Many valuable suggestions were received and incorporated into the final document. Each of the societies endorsed the guidelines. CONCLUSIONS: Management of thyroid diseases during pregnancy requires special considerations because pregnancy induces major changes in thyroid function, and maternal thyroid disease can have adverse effects on the pregnancy and the fetus. Care requires coordination among several healthcare professionals. Avoiding maternal (and fetal) hypothyroidism is of major importance because of potential damage to fetal neural development, an increased incidence of miscarriage, and preterm delivery. Maternal hyperthyroidism and its treatment may be accompanied by coincident problems in fetal thyroid function. Autoimmune thyroid disease is associated with both increased rates of miscarriage, for which the appropriate medical response is uncertain at this time, and postpartum thyroiditis. Fine-needle aspiration cytology should be performed for dominant thyroid nodules discovered in pregnancy. Radioactive isotopes must be avoided during pregnancy and lactation. Universal screening of pregnant women for thyroid disease is not yet supported by adequate studies, but case finding targeted to specific groups of patients who are at increased risk is strongly supported.

Glinoer D, Abalovich M. · Division of Endocrinology, Department of Internal Medicine, University Hospital Saint Pierre, B-1000 Brussels, Belgium. · BMJ. · Pubmed #17690371 No free full text.

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Abalovich M, Mitelberg L, Allami C, Gutierrez S, Alcaraz G, Otero P, Levalle O. · Human Reproduction and Thyroid Sections, Endocrinology Division, Hospital Carlos Durand, Buenos Aires, Argentina. · Gynecol Endocrinol. · Pubmed #17558686 No free full text.

Abstract: OBJECTIVE: To determine the prevalence of different subclinical hypothyroidism (SH) grades and thyroid autoimmunity (TAI) in infertile women. DESIGN: Retrospective study. Setting. Endocrinology division of a public hospital in Argentina. PATIENTS: Group I comprised 244 women consulting on infertility (>1 year without pregnancy); Group C (controls) comprised 155 healthy women with confirmed fertility. INTERVENTION: Thyroid-stimulating hormone and thyroid peroxidase antibodies were measured in all patients, and a thyrotropin-releasing hormone (TRH) stimulation test was performed in 71 patients to diagnose SH grade 1. The pregnancy rate in hypothyroid women on levothyroxine treatment was also evaluated. RESULTS: SH was diagnosed in 13.9% of the patients in Group I and in 3.9% of Group C (p < 0.002). The TRH stimulation test was useful to detect SH grade 1 in 12.7% of the infertile patients. Patients with precocious ovarian failure, tubal disturbances and ovulatory dysfunction presented higher SH rates (40.0, 18.2 and 15.4%, respectively) than control patients (p < 0.0001, p < 0.002 and p < 0.003). No significant difference in TAI prevalence was shown in Group I relative to Group C. Pregnancy rate of 44.1% was achieved under levothyroxine treatment. CONCLUSIONS: We observed a higher prevalence of SH, but not of TAI, in patients with infertility. Our results support thyroid screening in women with reproductive failure.

Abalovich M, Llesuy S, Gutierrez S, Repetto M. · Endocrinological Division, Durand Hospital and General and Inorganic Chemistry Division, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. · Clin Endocrinol (Oxf). · Pubmed #12919155 No free full text.

Abstract: BACKGROUND: Increased oxidative stress, with elevated levels of free radicals, together with diminished antioxidation have been described previously in models of hyperthyroidism and in patients with Graves' disease. However, controversial results have been found about the antioxidant status and its response to treatment. AIM: To evaluate the antioxidant/oxidant balance in active Graves' disease and the effects of treatment with methimazole (MMI) and 131 iodine (131I). PATIENTS AND METHODS: We studied 69 hyperthyroid (H) patients, 58 female and 11 male, 16-50 years old; total T3: 8 +/- 2 nmol/l, total T4: 264 +/- 65 nmol/l (all mean +/- SD), TSH: 0.1 +/- 0.1 mIU/l, TSH receptor antibody 41 +/- 21%, highest 131Iodine uptake: 67 +/- 16%. As a control group (C), 19 normal adults were studied. DESIGN: Parameters evaluated were: tert-butyl hydroperoxide initiated chemiluminiscence (CL), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx) and total reactive antioxidant potential (TRAP). RESULTS: In patients vs. controls there was an increase in CL levels (6207 +/- 1434 vs. 3000 +/- 851 cpm/mg of haemoglobin, P < 0.001), decrease in SOD (0.4 +/- 0.1 vs. 0.7 +/- 0.2 U/mg prot, P < 0.05; corresponding to 0.15 micro g/ml), CAT (2.8 +/- 0.6 vs. 3.8 +/- 0.7 pmol/mg prot, P < 0.001) and GSH (1.2 +/- 0.4 vs. 2 +/- 0.7 mmol/l erythrocytes, P < 0.05). The decrease in GPx and TRAP did not show significant differences. The parameters were also recorded in 30 patients who became euthyroid after treatment: 20 of them under MMI therapy (2-12 months) and the rest 3-6 months after 131Iodine administration. All the parameters evaluated were normalized after MMI; however, CL levels stayed high after 131I and only CAT and GSH levels returned to normal values. CONCLUSION: Our results confirm the imbalance of the antioxidant/oxidant status in hyperthyroid patients. MMI treatment was more effective than 131I therapy to improve that balance. We speculate on the benefits of antioxidant therapy administrated together with the habitual treatment of hyperthyroidism, especially in patients after 131I therapy.

Abalovich M, Gutierrez S, Alcaraz G, Maccallini G, Garcia A, Levalle O. · División Endocrinología, Hospital C. Durand, Buenos Aires, Argentina. · Thyroid. · Pubmed #11838732 No free full text.

Abstract: We studied the evolution of 150 pregnancies corresponding to 114 women (16-39 years old) with primary hypothyroidism. Fifty-one pregnancies (34%) were conceived under hypothyroidism: 16 overt (X +/- standard deviation [SD], thyroxine [T4]: 2.44 +/- 0.7 microg/dL; thyrotropin [TSH]: 33.4 +/- 8.82 mIU/L), and 35 subclinical hypothyroidism (T4: 6.93 +/- 1.88 microg/dL; TSH: 12.87 +/- 8.43 mIU/L); 99 pregnancies were conceived under euthyroidism while undergoing thyroid therapy. When treatment with levothyroxine was inadequate, the outcome of pregnancy was abortion in 60% of overtly hypothyroid patients and in 71.4% of subclinically hypothyroid patients, premature delivery in 20% and 7.2% respectively, and term delivery in 20% and 21.4%, respectively. When treatment was adequate, 100% of overtly hypothyroid patients and 90.5% of subclinically hypothyroid patients carried pregnancies to term; there were no abortions in any of the groups. Abortions, premature and term deliveries in patients who were euthyroid on levothyroxine at the time of conception were 4%, 11.1% and 84.9% respectively. Of the patients receiving levothyroxine therapy before conception, 69.5% had to increase the dose (mean increase 46.2 +/- 29.6 microg/d). Of 126 evaluated newborns, 110 were delivered at term while 16 were premature. Eight newborns, 4 were premature, had congenital malformations (6.3%), and 4 died. Our results show that the evolution of pregnancies did not depend on whether the hypothyroidism was overt or subclinical but mainly on the treatment received. The adequate treatment of hypothyroidism during gestation minimizes risks and generally, makes it possible for pregnancies to be carried to term without complications.

Abalovich M, Levalle O, Hermes R, Scaglia H, Aranda C, Zylbersztein C, Oneto A, Aquilano D, Gutierrez S. · División Endocrinology, Hospital Carlos Durand, Buenos Aires, Argentina. · Thyroid. · Pubmed #10524563 No free full text.

Abstract: Information on the effect of abnormal thyroid function on male reproduction is less available than that for the female. To assess the effects of hyperthyroidism on hypothalamic-pituitary-testicular axis and on spermogram parameters, 25 male patients (19-47 years old) suffering from active Graves' disease were studied. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), and prolactin (PRL) were measured before and after administration of 100 microg GnRH plus 200 microg thyrotropin-releasing hormone (TRH). Testosterone (T), estradiol (E2), and 17-hydroxyprogesterone (17-OHP) were determined before and after 5000 IU human chorionic gonadotropin (HCG) administration. Serum sex hormone-binding globulin (SHBG), cortisol-binding globulin (CBG), androstenedione and bioavailable testosterone (bioT), and bioavailable estradiol (bioE2) were also measured. Spermograms according to World Health Organization (WHO) criteria were determined in 21 patients. Hormonal and seminal studies were repeated in six patients after 7 to 19 months of euthyroidism achieved after treatment for hyperthyroidism. As a control group, 10 normal men were evaluated. Impaired sexual function, gynecomastia, and low testicular volume were found in 12, 6, and 3 hyperthyroid patients. Mean basal LH was significantly higher than the control group (7.8 +/- 4.7 vs. 5.0 +/- 1.9 mIU/mL, respectively, p < 0.02), with hyperresponse to GnRH. The response of PRL to TRH was lower in patients versus control group (30 minutes: 3.9 +/- 3.4 and 12.0 +/- 2.8 ng/mL, p < 0.01). Basal levels of steroids and SHBG were significantly higher in patients than in normal men (T: 9.3 +/- 3.3 vs. 5.4 +/- 1.6 ng/mL, p < 0.005; E2: 62.2 +/- 25.2 vs. 32.1 +/- 11.0 pg/mL, p < 0.005; 17-OHP: 2.4 +/- 0.9 vs. 1.1 +/- 0.5 ng/mL, p < 0.001; SHBG: 102.3 +/- 37.3 vs. 19.0 +/- 5.0 nmol/L, p < 0.01). The maximal increment of T and 17-OHP after HCG was lower in hyperthyroid patients than in normal men (p < 0.019 and p < 0.001, respectively). Basal bioT was lower in patients than controls (1.7 +/- 0.8 and 3.1 +/- 1.9 ng/mL, p < 0.02). The following incidence of abnormal semen parameters was found: asthenospermia 85.7%, hypospermia 61.9%, oligospermia 42.9%, necrospermia 42.9% and teratospermia 19.0%. In euthyroidism, a normalization of 85% of seminal alterations was observed in the limited number of patients evaluated. Our results confirm that hyperthyroidism causes marked alterations of the gonadotropic and PRL axis and dramatically affects spermatic function. BioT measurement was useful to identify hypoandrogenism in these patients in spite of the high concentration of total testosterone. The restoration of most semen parameters when euthyroidism was achieved suggests that the alterations were induced by the Graves' disease.