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Florian J. Segerer, Johannes Biko, Christoph Reiners, Clemens Wirth and Helge Hebestreit

Purpose:

Exercise-induced arterial hypoxemia (EIAH) has been reported in patients with juvenile thyroid cancer treated with radioiodine for lung metastases. This retrospective study tested the hypothesis that EIAH is due to ventilation-perfusion-mismatch in this rare pulmonary condition.

Method:

50 patients (age 13–23 years) treated for juvenile thyroid carcinoma and lung metastasis with 131I and 24 controls with thyroid cancer but without lung metastases and prior 131I-treatment were assessed in a state of acute hypothyroidism by com-puted tomography of the lungs, pulmonary function testing, cardiopulmonary exercise test with measurements of gas exchange, oxygen saturation, alveolar-arterial difference in pO2 (p(A-a)O2) and pCO2 (p(ET-a)CO2).

Results:

10 of the 50 patients with lung metastases showed EIAH. They had more pronounced pulmonary fibrosis on computed tomography, a widened p(A-a)O2, and p(ET-a)CO2, a lower DVE/DVCO2-slope, a lower respiratory rate and no increased dead space ventilation. A more pronounced EIAH was associated with male gender, younger age, lower diffusion capacity, higher p(ET-a)CO2 during exercise and a higher peak exercise tidal volume over vital capacity ratio.

Conclusion:

EIAH in patients with thyroid carcinoma and pulmonary metastases is not related to ventilation-perfusion mismatch but to alveolar hypoventilation, possibly related to an increased work of breathing with pulmonary fibrosis.

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Michael C. Scally and Andrew Hodge

Prior to presentation, two physically fit adults, a 39-year-old male and 40-year-old female, began supplementation with an over-the-counter thyroid preparation marketed as a metabolic accelerator and fat loss aid, tiratricol. Both participants took the supplement for 5 weeks (3000–4000 mcg/d) and 3 weeks (6000 mcg/d), respectively. At presentation, both complained of lethargy, loss of appetite, and muscle weakness. Upon initial laboratory evaluation, results revealed low thyroid stimulating hormone with profoundly elevated T3 values in both patients. After an extensive review of the literature, the cause of the problem was found to be the nutritional supplement they consumed contained tiratricol. After discontinuation of the supplement, thyroid levels slowly returned to baseline 40 days and 5 months later, respectively.

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Penny Harris Rosenzweig and Stella L. Volpe

Iron plays an important role in thyroid hormone metabolism; thus, iron deficiency anemia may lead to alterations in resting metabolic rate (RMR). Based on this premise, two iron-deficient-anemic female athletes, 18 (A 1) and 21 (A2) years of age, were supplemented with 23 mg/day of elemental iron to assess its effects on iron and thyroid hormone status and RMR at 0, 8, and 16 weeks. Anemia was clinically corrected in both subjects (hemoglobin: Al = 11.0 to 13.0 to 12.6 g/dL and A2 = 11.5 to 13.9 to 12.6 g/dL, 0 to 8 to 16 weeks, respectively). Serum ferritin (SF) concentration also improved in both subjects (Al: 5.0 to 11.0 to 15.0 ng/dL and A2: 5.0 to 16.0 to 20.0 ng/dL; 0 to 8 to 16 weeks, respectively); however, 16 weeks of iron supplementation did not fully replete iron stores. A2 increased dietary iron and ascorbic acid intakes from 8 to 16 weeks, possibly accounting for her higher SF concentrations. RMR and total thyroxine changed over time: Al increased while A2 decreased in these variables. Although clinical correction of iron deficiency anemia occurred after 16 weeks of low-level iron supplementation, RMR and thyroid hormone metabolism were oppositely affected in the two subjects.

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Kirsty J. Elliott-Sale, Adam S. Tenforde, Allyson L. Parziale, Bryan Holtzman and Kathryn E. Ackerman

 cortisol ↑ Ackerman et al. ( 2013 ), Laughlin and Yen ( 1996 ), Loucks et al. ( 1989 , 1998 ), Loucks and Thuma ( 2003 ), Rickenlund et al. ( 2004 ), and Tornberg et al. ( 2017 ) ↔ Hooper et al. ( 2017 ) ↔ De Souza et al. ( 1994 ), Laughlin and Yen ( 1996 ), and Schaal et al. ( 2011 ) Hypothalamic–pituitary–thyroid

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Nathan A. Lewis, Ann Redgrave, Mark Homer, Richard Burden, Wendy Martinson, Brian Moore and Charles R. Pedlar

, mean cell volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; RDW, red cell distribution width; N:L, neutrophil:lympocyte ratio; TSH, thyroid-stimulating hormone; EBNA, Epstein–Barr nuclear antigen; EBV, Epstein–Barr virus; VCA, viral capsid antigen. a Results

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Kathryn H. Myburgh, Claire Berman, Illana Novick, Timothy D. Noakes and Estelle V. Lambert

We studied 21 ballet dancers aged 19.4 ± 1.4 years, hypothesizing that undernu-trition was a major factor in menstrual irregularity in this population. Menstrual history was determined by questionnaire. Eight dancers had always been regular (R). Thirteen subjects had a history of menstrual irregularity (HI). Of these, 2 were currently regularly menstruating, 3 had short cycles, 6 were oligomenorrheic, and 2 were amenorrheic. Subjects completed a weighed dietary record and an Eating Attitudes Test (EAT). The following physiological parameters were measured: body composition by anthropometry, resting metabolic rate (RMR) by open-circuit indirect calorimetry, and serum thyroid hormone concentrations by radioimmunoassay. R subjects had significantly higher RMR than HI subjects. Also, HI subjects had lower RMR than predicted by fat-free mass, compared to the R subjects. Neitherreported energy intake nor serum thyroid hormone concentrations were different between R and HI subjects. EAT scores varied and were not different between groups. We concluded that in ballet dancers, low RMR is more strongly associated with menstrual irregularity than is currentreported energy intake or serum thyroid hormone concentrations.

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Kathryn A. Witt, Jean T. Snook, Thomas M. O'Dorisio, Danial Zivony and William B. Malarkey

To determine relationships among dietary carbohydrate, aerobic exercise training, the thermic effect of food (TEF), and hormonal responses to feeding, 8 trained and 7 sedentary men consumed diets providing 15, 45, or 75% of energy as carbohydrate for 5 days. On Day 6, metabolic rate was measured before as well as 30, 60, 90, and 120 min after an 868-kcal liquid iesi breakfast. Blood was sampled hourly during Day 5 and during each metabolic rate measurement. The trained group had a larger TEF (40 ±2.4 vs. 31 ±3.0 kcal/2 hrs), greater insulin sensitivity, and greater plasma prolactin and corlisol levels, As carbohydrate in the treatment diet increased, carbohydrate utilization and thyroid stimulating hormone were higher and thyroxine was lower, but TEF was not significantly different. After the test meal, trained individuals had a higher TEF but the carbohydrate content of the treatment diet did not influence TEF.

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W. Daniel Schmidt, Gerald C. Hyner, Roseann M. Lyle, Donald Corrigan, Gerald Bottoms and Christopher L. Melby

This study examined resting metabolic rate (RMR) and thermic effect of a meal (TEM) among athletes who had participated in long-term anaerobic or aerobic exercise. Nine collegiate wrestlers were matched for age, weight, and fat-free weight with 9 collegiate swimmers. Preliminary testing included maximal oxygen consumption, maximal anaerobic capacity (MAnC) for both the arms and the legs, and percent body fat. On two separate occasions, RMR and TEM were measured using indirect calorimetry. VO2max was significantly higher in the swimmers while MAnC was significantly higher in the wrestlers for both the arms and the legs. RMR adjusted for fat-free weight was not significantly different between groups. The differences in total and percentage of TEM between the groups were not statistically significant, and there were no differences in baseline thyroid hormones. These data suggest that despite significant differences in VO2max and WAnT values following long-term aerobic and anaerobic exercise training, resting energy expenditure does not differ between these college athletes.

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Gislaine S. Kogure, Cristiana L. Miranda-Furtado, Daiana C.C. Pedroso, Victor B. Ribeiro, Matheus C. Eiras, Rafael C. Silva, Lisandra C. Caetano, Rui A. Ferriani, Rodrigo T. Calado and Rosana M. dos Reis

excluded from the analysis. Biochemical Measurements The following serum concentrations were measured, as previously described 19 , 13 : prolactin, sex hormone–binding globulin, fasting insulin, testosterone, androstenedione, plasma glucose, thyroid-stimulating hormone, and 17α-OHP (17α

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D. Enette Larson-Meyer, Kathleen Woolf and Louise Burke

processed foods contain little to no iodine Recommended measure: 24-hr urinary iodine along with thyroid stimulating hormone, T3, T4, and thyroid autoantibodies j Urinary iodine j Mild deficiency 4–8 µmol/d Moderate deficiency 2–3.9 µmol/d Severe deficiency <2 µmol/d Depressed thyroid gland activity