Induction of low-T3 syndrome in exercising women occurs at a threshold of energy availability

1994 ◽  
Vol 266 (3) ◽  
pp. R817-R823 ◽  
Author(s):  
A. B. Loucks ◽  
E. M. Heath

To investigate the relationship between energy availability (dietary energy intake minus energy expended during exercise) and thyroid metabolism, we studied 27 untrained, regularly menstruating women who performed approximately 30 kcal.kg lean body mass (LBM)-1.day-1 of supervised ergometer exercise at 70% of aerobic capacity for 4 days in the early follicular phase. A clinical dietary product was used to set energy availability in four groups (10.8, 19.0, 25.0, 40.4 kcal.kg LBM-1.day-1). For 9 days beginning 3 days before treatments, blood was sampled once daily at 8 A.M. Initially, thyroxine (T4) and free T4 (fT4), 3,5,3'-triiodothyronine (T3) and free T3 (fT3), and reverse T3 (rT3) were in the normal range for all subjects. Repeated-measures one-way analysis of variance followed by one-sided, two-sample post hoc Fischer's least significant difference tests of changes by treatment day 4 revealed that reductions in T3 (16%, P < 0.00001) and fT3 (9%, P < 0.01) occurred abruptly between 19.0 and 25.0 kcal.kg LBM-1.day-1 and that increases in fT4 (11%, P < 0.05) and rT3 (22%, P < 0.01) occurred abruptly between 10.8 and 19.0 kcal.kg LBM-1.day-1. Changes in T4 could not be distinguished. If energy deficiency suppresses reproductive as well as thyroid function, athletic amenorrhea might be prevented or reversed by increasing energy availability through dietary reform to 25 kcal.kg LBM-1.day-1, without moderating the exercise regimen.

1993 ◽  
Vol 264 (5) ◽  
pp. R924-R930 ◽  
Author(s):  
A. B. Loucks ◽  
R. Callister

To investigate the influence of exercise on thyroid metabolism, 46 healthy young regularly menstruating sedentary women were randomly assigned to a 3 x 2 experimental design of aerobic exercise and energy availability treatments. Energy availability was defined as dietary energy intake minus energy expenditure during exercise. After 4 days of treatments, low energy availability (8 vs. 30 kcal.kg body wt-1.day-1) had reduced 3,5,3'-triiodothyronine (T3) by 15% and free T3 (fT3) by 18% and had increased thyroxine (T4) by 7% and reverse T3 (rT3) by 24% (all P < 0.01), whereas free T4 (fT4) was unchanged (P = 0.08). Exercise quantity (0 vs. 1,300 kcal/day) and intensity (40 vs. 70% of aerobic capacity) did not affect any thyroid hormone (all P > 0.10). That is, low-T3 syndrome was induced by the energy cost of exercise and was prevented in exercising women by increasing dietary energy intake. Selective observation of low-T3 syndrome in amenorrheic and not in regularly menstruating athletes suggests that exercise may compromise the availability of energy for reproductive function in humans. If so, athletic amenorrhea might be prevented or reversed through dietary reform without reducing exercise quantity or intensity.


1987 ◽  
Vol 33 (7) ◽  
pp. 1217-1219 ◽  
Author(s):  
Y Iwatani ◽  
N Amino ◽  
O Tanizawa ◽  
H Mori ◽  
M Kawashima ◽  
...  

Abstract We measured thyroid hormones and thyroxin-binding proteins in serum from 62 normal lactating and 52 nonlactating women at three months postpartum, and compared these values with those for 42 nonpregnant control women of similar age. Mean thyroxin concentrations in the lactating and nonlactating women were significantly (P less than 0.001) lower than that of the nonpregnant controls, but there was no significant difference (P greater than 0.2) in triiodothyronine concentration among these three groups. Free T4 concentration was significantly (P less than 0.01) lower in lactating women than in controls. The reverse-T3 concentrations in both lactating and nonlactating women were significantly (P less than 0.001) lower than in controls, and were significantly (P less than 0.001) lower in lactating than in nonlactating women. The concentration of thyroxin-binding globulin was significantly higher in lactating women than in controls, and the albumin concentration was significantly lower in women postpartum than in controls. Evidently, regulation of thyroid hormone in women postpartum, especially during lactation, differs from that in nonpregnant women.


2004 ◽  
Vol 62 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Luiz Augusto Casulari ◽  
Paola Mangieri ◽  
Luciana A. Naves ◽  
Kunio Suzuki ◽  
Moema Ferreira ◽  
...  

We have previously reported that subarachnoid hemorrhage due to ruptured intracranial aneurysm (SH) is associated with changes in the hormonal profile in the first 24 hours after the event. We proposed that the hormonal changes observed are due to the intense stress to which the patients are exposed. However, the thyroidal hormonal profile is indicative of the presence of a nonthyroidal illness syndrome (NTIS). In this paper, we examined whether the change in the thyroid hormone profile is compatible with a NTIS. Two groups of patients were included in the study: A) 30 patients with SH (21 females and 9 males; 41.7±11.4 years) and B) a control group including 25 patients with benign diseases of the spine (BDS) (lumbar disc hernia or stable spinal trauma) (8 females and 17 males; 41.3±14.2 years). In a subgroup of eight patients of each group serum triiodothyronine (T3) and reverse T3 levels were measured. The blood samples were obtained between 8:00 and 9:00 AM. The following results were obtained: The SH group had smaller serum T3 and free T4 levels than the BDS group (p<0.05): T3 (ng/mL): SH = 58.7±1.1 and BDS = 74.5±13.9; free T4 (ng/dL): SH = 0.9±0.2 and BDS = 1.1±0.3. There was no significant difference in the serum levels of total thyroxine (T4) and thyroid-stimulating hormone (TSH) between the two groups: T4 (µg/dL): SH = 6.9±1.1 and BDS = 7.4±2.1; TSH (µUI/mL): SH = 1.5±0.8 and BDS = 1.8±1,0. In the sample of eight patients of each group we had the following results: T3 (ng/mL): SH = 66.8±3.8 and BDS = 77.2±1.1 (p <0.05); reverse T3 (ng/dL): SH = 32.8±8 and BDS = 24.7±2.2 (NS); T3/ reverse T3 ratio: SH = 2.6±0.3 and BDS = 3.3±0.4 (NS). Thyreoglobulin and microsomal antibodies were not detectable, except in one patient in the SH group. In conclusion, the SH patients present serum levels of T3 and free T4 significantly lower than that of BDS patients; the thyroidal hormone profile suggests that SH patients have developed the nonthyroidal illness syndrome.


2020 ◽  
Vol 16 (8) ◽  
pp. 895-899 ◽  
Author(s):  
Shahin Safian ◽  
Farzaneh Esna-Ashari ◽  
Shiva Borzouei

Aims: Investigation thyroid dysfunction and autoimmunity in pregnant women with gestational diabetes mellitus. Background: This article was written to evaluate the thyroid function and anti-thyroid peroxidase (anti- TPO) antibodies in pregnant women with gestational diabetes mellitus (GDM). Method: A total of 252 women with GDM and 252 healthy pregnant women were enrolled. Thyroid tests, including TSH, FreeT3, Free T4, and anti-TPO were performed for all women at 24–28 weeks of gestation. Data analysis was then carried out using SPSS ver. 22. Result: There was a significant difference between the experimental group (38.4%) and the control group (14.06%) in terms of the prevalence of subclinical hypothyroidism (p= 0.016). The frequency of anti-TPO was higher in the experimental group than the control group and positive anti-TPO was observed in 18.6% of women with GDM and 10.3% of healthy pregnant women (P= 0.008). Conclusion: Thyroid disorders are observed in pregnant women with GDM more frequently than healthy individuals and it may be thus reasonable to perform thyroid tests routinely.


2020 ◽  
Vol 16 (2) ◽  
pp. 152-159
Author(s):  
Arezoo Shayan ◽  
Mansoureh Refaei ◽  
Farkhondeh Jamshidi

Background: Treatment of breast cancer can be accompanied by long-term consequences affecting women’s participation in many tasks. Objective: This study aimed to assess the effect of cognitive behavioral stress management (CBSM) program on occupational performance of women with breast cancer. Methods: In this randomized clinical trial, conducted between Feb 3 and Oct 26, 2016, 104 women with breast cancer who had referred to Imam Khomeini clinic in Hamadan, and who fulfilled the inclusion criteria (20-60 years old, married, suffering from grade 1-3 breast cancer with a history of recent surgery) were enrolled. They were randomly divided into two groups of 52 using a permuted block size of four. The intervention group took part in four 60-minute sessions of CBSM over four weeks. The study data were collected using a demographic information form and the Canadian Occupational Performance Measure. The statistical analyst was masked to intervention allocation. The data were analyzed using descriptive statistics, paired t-test, and repeated measures ANOVA. Results: A significant difference was observed between the two groups regarding the mean scores of occupational performance (p=0.02) and satisfaction (p=0.005) after the intervention. Each variable was measured at three time points (before the intervention, immediately and 2 weeks after intervention). A significant difference was observed in the two groups’ mean scores of performance (p=0.026) and satisfaction (p=0.01), irrespective of the time of assessment. Conclusion: The CBSM program promoted the occupational performance immediately and two weeks after the intervention in women with breast cancer. This technique can be used as a complementary method alongside medical therapies in oncology centers.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ferdiye Küçük ◽  
Sibel Yıldırım ◽  
Serap Çetiner

Abstract Background The purpose of this study was to assess the cytotoxicity of various concentrations of ozonated water (OW) on human primary dental pulp cells. Methods Human primary dental pulp cells were isolated from exfoliated primary canine teeth of an 11-year-old patient with good systemic and oral health. Afterwards, cells were divided into 6 experimental groups; four groups of OW in concentrations of 2 mg/L, 4 mg/L, 8 mg/L, and 16 mg/L, untreated control group, and cell culture without cells. Cytotoxicity was evaluated after exposure for 5-min exposure using Mosmann’s Tetrazolium Toxicity (MTT) assay at 0 h and 48 h time points. Data were analyzed using a repeated measures analysis of variance and Post-hoc tests were performed using Bonferroni correction for multiple comparisons. Results All experimental groups showed proliferation at 0 h time point. However, all groups also experienced a decrease in overtime at 48 h time point (p < 0.05). At both time points 2 mg/L OW showed the highest cell viability as well as proliferation. At 0 h time point, the increase in cell viability for all experimental groups was found statistically significant when compared to positive control group (p < 0.05). At 48 h time point, although 8 mg/L and 16 mg/L OW showed statistically significant reduction in compare to 0 h time point, 2 mg/L and 4 mg/L OW groups didn’t experience any statistically significant difference (p < 0.05). Conclusion Considering our findings, due to ozonated water's induced a higher proliferation rate of dental pulp cells, indicating their biocompatibility and a possible adjuvant on irrigating agent in regenerative endodontic procedures.


2017 ◽  
Vol 38 (5) ◽  
pp. 485-495 ◽  
Author(s):  
Riccardo D’Ambrosi ◽  
Camilla Maccario ◽  
Chiara Ursino ◽  
Nicola Serra ◽  
Federico Giuseppe Usuelli

Background: The purpose of this study was to evaluate the clinical and radiologic outcomes of patients younger than 20 years, treated with the arthroscopic-talus autologous matrix-induced chondrogenesis (AT-AMIC) technique and autologous bone graft for osteochondral lesion of the talus (OLT). Methods: Eleven patients under 20 years (range 13.3-20.0) underwent the AT-AMIC procedure and autologous bone graft for OLTs. Patients were evaluated preoperatively (T0) and at 6 (T1), 12 (T2), and 24 (T3) months postoperatively, using the American Orthopaedic Foot & Ankle Society Ankle and Hindfoot (AOFAS) score, the visual analog scale and the SF-12 respectively in its Mental and Physical Component Scores. Radiologic assessment included computed tomographic (CT) scan, magnetic resonance imaging (MRI) and intraoperative measurement of the lesion. A multivariate statistical analysis was performed. Results: Mean lesion size measured during surgery was 1.1 cm3 ± 0.5 cm3. We found a significant difference in clinical and radiologic parameters with analysis of variance for repeated measures ( P < .001). All clinical scores significantly improved ( P < .05) from T0 to T3. Lesion area significantly reduced from 119.1 ± 29.1 mm2 preoperatively to 77.9 ± 15.8 mm2 ( P < .05) at final follow-up as assessed by CT, and from 132.2 ± 31.3 mm2 to 85.3 ± 14.5 mm2 ( P < .05) as assessed by MRI. Moreover, we noted an important correlation between intraoperative size of the lesion and body mass index (BMI) ( P = .011). Conclusions: The technique can be considered safe and effective with early good results in young patients. Moreover, we demonstrated a significant correlation between BMI and lesion size and a significant impact of OLTs on quality of life. Level of Evidence: Level IV, retrospective case series.


2021 ◽  
pp. 1-9
Author(s):  
Evan V. Papa ◽  
Rita M. Patterson ◽  
Nicoleta Bugnariu

BACKGROUND: Nearly half of persons with Parkinson disease (PD) report fatigue as a factor in their fall history. However, it is unknown whether these self-reported falls are caused by a sensation of fatigue or performance fatigue. OBJECTIVE: We sought to investigate the influences of performance fatigue and age on postural control in persons with PD. METHODS: Individuals with PD (n = 14) underwent postural control assessments before (T0) and immediately after (T1) fatiguing exercise. Biomechanical data were gathered on participants completing a treadmill-induced, posterior-directed fall. Performance fatigue was produced using lower extremity resistance exercise on an isokinetic ergometer. Repeated measures ANCOVAs were used with age as a covariate to determine the effects of performance fatigue on biomechanical variables. RESULTS: After adjustment for age, there was a statistically significant difference in peak center of pressure (COP) latency during the support phase of recovery. Pairwise comparisons demonstrated a decrease in peak ankle displacement from T0 to T1. Age was also found to be significantly related to reaction time and peak knee displacement while participants were fatigued. CONCLUSIONS: The decreased peak COP latency, along with decreased ankle angular displacement, suggest that persons with PD adopt a stiffening strategy in response to backward directed falls. Postural stiffening is not uncommon in persons with PD and could be a risk factor for falls. Older individuals with PD demonstrate slower mobility scores and decreased reaction times in the setting of fatigue, suggesting a combined effect of the aging and fatigue processes.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Tomomi Yamazaki ◽  
Sae Maruyama ◽  
Yuki Sato ◽  
Yukako Suzuki ◽  
Sohei Shimizu ◽  
...  

Abstract Background The purpose of the present study was to examine the relationship between ankle joint laxity and general joint laxity (GJL) in relation to the menstrual cycle, which was divided into four phases based on basal body temperature and ovulation, assessed using an ovulation kit. Methods Participants were 14 female college students (21–22 years) with normal menstrual cycles (cis gender). Anterior drawer stress to a magnitude of 120 N was applied for all participants. Anterior talofibular ligament (ATFL) length was measured as the linear distance (mm) between its points of attachment on the lateral malleolus and talus using ultrasonography. Data on ATFL length from each subject were used to calculate each subject’s normalized length change with anterior drawer stress (AD%). The University of Tokyo method was used for evaluation of GJL. AD% and GJL were measured once in each menstrual phase. Results There was no statistically significant difference between AD% in each phase. GJL score was significantly higher in the ovulation and luteal phases compared with the early follicular phase. AD% and GJL showed a positive correlation with each other in the ovulation phase. Conclusions Although it is unclear whether estrogen receptors are present in the ATFL, the present study suggests that women with high GJL scores might be more sensitive to the effects of estrogen, resulting in ATFL length change in the ovulation phase.


2021 ◽  
Vol 13 (7) ◽  
pp. 3631
Author(s):  
Alfonso Penichet-Tomas ◽  
Basilio Pueo ◽  
Marta Abad-Lopez ◽  
Jose M. Jimenez-Olmedo

Rowers’ anthropometric characteristics and flexibility are fundamental to increase stroke amplitude and optimize power transfer. The aim of the present study was to analyze the effect of foam rolling and static stretching on the range of motion over time. Eight university rowers (24.8 ± 3.4 yrs., height 182.3 ± 6.5 cm, body mass 79.3 ± 4.6 kg) participated in an alternating treatment design study with two-way repeated measures ANOVA. The sit and reach test was used to measure the range of motion. Both in the foam rolling and in the static stretching method, a pre-test (T0), a post-test (T1), and a post-15-min test (T2) were performed. A significant effect was observed on the range of motion over time (p < 0.001), but not for time x method interaction (p = 0.680). Significant differences were found between T0 and T1 with foam rolling and static stretching (p < 0.001, d = 0.4); p < 0.001, d = 0.6). The differences between T0 and T2 were also significant with both methods (p = 0.001, d = 0.4; p < 0.001, d = 0.4). However, no significant difference was observed between T1 and T2 (p = 1.000, d = 0.1; p = 0.089, d = 0.2). Foam roller and static stretching seem to be effective methods to improve the range of motion but there seems to be no differences between them.


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