Thyroid hormones and thermogenesis: A microcalorimetric study of overall cell metabolism in lymphocytes from patients with different degrees of thyroid dysfunction

1990 ◽  
Vol 123 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Stig Valdemarsson ◽  
Julie Ikomi-Kumm ◽  
Mario Monti

Abstract. We used microcalorimetry to measure lymphocyte heat production rate in patients with clinical and laboratoy hyperthyroidism (serum TSH ↓, serum FT4 ↑, serum FT3 ↑ ), subclinical hyperthyroidism (serum TSH ↓, serum FT4 ↑, serum FT3=), and subclinical hypothyroidism (serum TSH ↑, serum FT4 ↓, serum FT3=) compared with healthy controls (N= 13). The lymphocyte heat production rate was significantly correlated to the free thyroxine level (r=0.53, p<0.01) and to the free triiodothyronine level (r=0.51, p<0.01) when calculated from pooled data for the three patients groups. The hyperthyroid patients (N = 8) had a significantly increased lymphocyte heat production rate, 3.43±0.25 pW/cell, as compared with 2.31±0.12 pW/cell in the control group (p<0.001). The groups with subclinical hyperthyroidism (N = 7) and subclinical hypothyroidism (N=9) had lymphocyte heat production rates of 2.14±0.11 and 2.56±0.15 pW/cell, respectively, not significantly different from that in the controls. Consistently, there was no significant difference between patients with subclinical hyperthyroidism (N=5) and controls (N=5) with regard to lymphocyte energy production as calculated from separately measured oxygen comsumption rates in vitro, 1.36±0.20 and 1.56±0.12 pW/cell, respectively. Thus microcalorimetry seems to be suitable for studying the influence of thyroid hormones on cellular metabolism. Subclinical thyroid dysfunction does not seem to alter the overall rate of lymphocyte metabolism.

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A979-A980
Author(s):  
Sayaka Yamada ◽  
Yasuyo Nakajima ◽  
Ayaka Nishikido ◽  
Masako Akuzawa ◽  
Koji Sakamaki ◽  
...  

Abstract Objective: Thyroid hormones have various effects on cardiac and circulatory systems, leading to arrhythmias and heart failure. In Europe and the United States, it has been reported that elevated thyroid hormones within the normal range have been reported to be associated with a risk of atrial fibrillation, however, there was no report on Japanese cases, a country that differs in iodine intake and ethnicity from the West. Therefore, we evaluated the abnormality of thyroid function in a large number of cases of atrial fibrillation (AF) who received catheter ablation (RFCA) in Japan. Methods: We evaluated 2,937 cases of atrial fibrillation (2,084 males, mean age 64.1±10.7 years and 853 females, 69.0±8.5 years) who underwent RFCA at the Gunma Prefectural Cardiovascular Center between 2012 and 2018. As a control we used a total of 15,660 participants for health check-up (9,176 males, mean age 49.7±9.8 years and 6,484 females, 48.9±10.3 years) from 2006 to 2013, and we evaluated thyroid function after adjusting for gender-specific age. Results: The prevalence of overt hyperthyroidism was significantly higher in the RFCA-treated male group (0.43%) than in the control group (0.07%), even after adjusting for age (p&lt;0.01). Similarly, the prevalence of subclinical hyperthyroidism was also significantly higher in the RFCA-treated male group (3.12%) than in the control group (0.94%) after adjusting for age (p&lt;0.01). On the other hand, subclinical hypothyroidism was significantly lower in the RFCA-treated group after adjusting for age (2.97% in the RFCA-treated group and 3.93% in the control group, p&lt;0.01). Females showed the same results as males. Conclusions: In an iodine rich country Japan, not only overt hyperthyroidism but also subclinical hyperthyroidism is an obvious risk factor for severe atrial fibrillation in Japan. Intriguingly, subclinical hypothyroidism might contribute to the prevention of atrial fibrillation, suggesting that slightly higher serum TSH levels might be better for elderlies.


1994 ◽  
Vol 130 (3) ◽  
pp. 276-280 ◽  
Author(s):  
Stig Valdemarsson ◽  
Mario Monti

Valdemarsson S, Monti M. Increased ratio between anaerobic and aerobic metabolism in lymphocytes from hyperthyroid patients. Eur J Endocrinol 1994;130:276–80. ISSN 0804–4643 While an increased oxygen consumption is accepted as one consequence of hyperthyroidism, only few data are available on the role of anaerobic processes for the increased metabolic activity in this disease. In this study we evaluated the relative importance of anaerobic and aerobic metabolism for the metabolic activity in lymphocytes from patients before and after treatment for hyperthyroidism. Total lymphocyte heat production rate (P), reflecting total cell metabolic activity, was determined in a plasma lymphocyte suspension using direct microcalorimetry. The contribution from aerobic metabolism (O2 – P) was calculated from the product of the lymphocyte oxygen consumption rate and the enthalpy change for glucose combustion, and the anaerobic contribution as the difference between P and O2 – P. The total lymphocyte heat production rate P was 3.37 ± 0.25 (sem) pW/cell (N = 11) before and 2.50 ± 0.11 pW/cell (N = 10) after treatment for hyperthyroidism (p < 0.01) as compared to 2.32 ± 0.10 pW/cell in a control group (N = 18). The aerobic component O2 – P amounted to 1.83 ± 0.11 pW/cell in the patient group before and 1.83 ± 0.08 pW/cell after treatment and to 1.71 ± 0.16 pW/cell in 10 controls. Out of P, the O2 – P component corresponded to 56.8 ± 4.4% in the hyperthyroid state and to 73.7 ± 3.2% after treatment (p < 0.01) as compared to 73.4 ± 4.4% in the 10 euthyroid controls. It was concluded that the increased metabolic activity demonstrated in lymphocytes from hyperthyroid patients cannot be explained by an increased oxygen-dependent consumption. This suggests that cell function may be comparatively more dependent on anaerobic metabolism during thyroid hormone excess and that adenosine triphosphate generation thereby has to be supplied through an increased metabolism of energy-rich substrates along anaerobic metabolic pathways. Stig Valdemarsson, Department of Internal Medicine, Lund University Hospital, S-221 85 Lund, Sweden


2017 ◽  
Vol 50 (01) ◽  
pp. 37-43 ◽  
Author(s):  
Maryam Tohidi ◽  
Arash Derakhshan ◽  
Samaneh Akbarpour ◽  
Atieh Amouzegar ◽  
Ladan Mehran ◽  
...  

AbstractThe objective of the study was to investigate the relation of different thyroid function states with the incidence of cardiovascular disease (CVD)/coronary heart disease (CHD) among a Middle-Eastern population with a high incidence of CVD/CHD. A total of 3975 participants entered the study (43.6% men). According to their thyroid stimulating hormone (TSH) and free thyroxin (FT4) levels, the participants were categorized into 5 groups: euthyroid, subclinical hypothyroidism, overt hypothyroidism, subclinical hyperthyroidism, and overt hyperthyroidism. Multivariable Cox proportional hazard models were used to assess the relation of different thyroid function states with incident CVD/CHD, with euthyroid state as reference. The mean age (SD) of the participants was 46.5 (12.0) years. At baseline, no significant difference was observed in the frequency of prevalent CVD cases (n=201) between all groups. No significant interaction was found between prevalent CVD and different thyroid function states with outcomes, hence, we did not exclude participants with prevalent CVD from data analysis. A total of 400 CVD events (358 CHD cases) during a median follow-up of 11.2 years (inter-quartile range: 1.96) occurred. During the follow-up, even in the age and sex adjusted model, no association was observed between different states of thyroid dysfunction and incidence of CVD/CHD. The multivariable hazard ratios (95% CI) of subclinical hypothyroidism, hypothyroidism, subclinical hyperthyroidism, and hyperthyroidism for CVD events were 1.21 (0.77–1.88), 0.76 (0.33–1.69), 0.81 (0.46–1.41) and 1.48 (0.70–3.16), respectively. Both at baseline and during follow-up, no relation was observed between different states of thyroid function with prevalence and incidence of CVD/CHD.


2020 ◽  
Vol 9 (1) ◽  
pp. 55-62
Author(s):  
L E Zijlstra ◽  
D M van Velzen ◽  
S Simsek ◽  
S P Mooijaart ◽  
M van Buren ◽  
...  

Objective Thyroid hormones have been implicated to play a role in cardiovascular disease, along with studies linking thyroid hormone to kidney function. The aim of this study is to investigate whether kidney function modifies the association of subclinical thyroid dysfunction and the risk of cardiovascular outcomes. Methods In total, 5804 patients were included in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). For the current analysis, 426 were excluded because of overt thyroid disease at baseline or 6 months, 266 because of inconsistent thyroid function at baseline and 6 months, 294 because of medication use that could influence thyroid function, and 16 because of missing kidney or thyroid values. Participants with normal fT4 were classified, based on TSH both at inclusion and 6 months, into three groups: subclinical hypothyroidism (TSH >4.5 mIU/L); euthyroidism (TSH = 0.45–4.5 mIU/L); and subclinical hyperthyroidism (TSH <0.45 mIU/L). Strata of kidney function were made based on estimated glomerular filtration rate into three clinically relevant groups: <45, 45–60, and >60 mL/min/1.73 m2. The primary endpoint consists of death from coronary heart disease, non-fatal myocardial infarction and (non)fatal stroke. Results Mean age was 75.3 years, and 49.0% patients were male. Mean follow-up was 3.2 years. Of all participants, 109 subjects (2.2%) had subclinical hypothyroidism, 4573 (94.0%) had euthyroidism, and 182 (3.7%) subclinical hyperthyroidism. For patients with subclinical hypothyroidism, euthyroidism, and subclinical hyperthyroidism, primary outcome occurred in 9 (8.3%), 712 (15.6%), and 23 (12.6%) patients, respectively. No statistically significant relationship was found between subclinical thyroid dysfunction and primary endpoint with adjusted hazard ratios of 0.51 (0.24–1.07) comparing subclinical hyperthyroidism and 0.90 (0.58–1.39) comparing subclinical hypothyroidism with euthyroidism. Neither was this relationship present in any of the strata of kidney function, nor did kidney function interact with subclinical thyroid dysfunction in the association with primary endpoint (P interaction = 0.602 for subclinical hyperthyroidism and 0.388 for subclinical hypothyroidism). Conclusions In this secondary analysis from PROSPER, we found no evidence that the potential association between thyroid hormones and cardiovascular disease is modified by kidney function in older patients with subclinical thyroid dysfunction.


1992 ◽  
Vol 126 (4) ◽  
pp. 291-295 ◽  
Author(s):  
Stig Valdemarsson ◽  
Julie Ikomi-Kumm ◽  
Mario Monti

The role of the Na/K pump for the increased cell energy expenditure in hyperthyroidism was studied by measuring total lymphocyte heat production rate in samples with and without ouabain inhibition of Na/K ATP-ase. In addition, the relative contribution of aerobic processes to lymphocyte thermogenesis was calculated from oxygen consumption measurements. In 12 patients with clinical and laboratory hyperthyroidism total lymphocyte heat production rate was 3.19±0.21 pW/cell, significantly higher than in 7 patients with subclinical hyperthyroidism (2.14±0.11 pW/cell) and in 15 euthyroid subjects (2.26±0.11 pW/cell) (p<0.001). The relative decrease in lymphocyte heat production rate after ouabain, giving a quantitative measure of the activity of the Na/K ATP-ase and reflecting the importance of Na/K pump function for the overall rate of lymphocyte metabolism, was not significantly different between the groups: 19.5±3.6% in hyperthyroid patients, 14.2±2.3% in subclinical hyperthyroid patients and 17.8±3.1% in euthyroid subjects. According to the rate of lymphocyte oxygen consumption, aerobic processes represented 58.4±6.7% of total lymphocyte energy expenditure in hyperthyroid patients, not significantly different from subclinical hyperthyroidism (62.6±8.4%) or from euthyroidism (66.6±2.7%). These data do not support the hypothesis of a specific role of the Na/K pump function for the increased cell thermogenesis in hyperthyroidism and indicate a parallel stimulation of aerobic and anaerobic processes by thyroid hormone excess.


2020 ◽  
Author(s):  
Manna Sun ◽  
Xinghe Wang ◽  
Yunyong Fang ◽  
Jiwu Lou ◽  
Chenning Liu ◽  
...  

Abstract Background: Abnormal concentrations of maternal thyroid hormones are risk factors for some obstetrical complications. However, the influence induced by different types of maternal thyroid dysfunction on obstetrical complications and outcomes is still controversial.Methods: A total of 17219 pregnant women were drawn for a thyroid function test, including TSH and fT4. All participants were divided into 7 groups, on the basis of their blood tested results, and their pregnancy outcomes were followed up. The isolated hypothyroxinemia group was further divided into 2 cohorts, according to whether they receive levothyroxine. Pregnant complications and outcomes in two cohorts were observed and analyzed.Results: A total of 2621 (15.22%)were identified to have abnormal thyroid function, including 1150 with subclinical hypothyroidism, 526 with gestational transient thyrotoxicosis (GTT), 419 with subclinical hyperthyroidism, 336 with isolated hypothyroxinemia, 78 with hyperthyroidism and 76 with hypothyroidism. Compare to control group, subclinical hypothyroidism, subclinical hyperthyroidism, isolated hypothyroxinemia and hypothyroidism groups presented higher incidence in one or more complications of pregnancy, while, GTT and drug-controlled hyperthyroidism had little significant effect on pregnancy complications. In isolated hypothyroxinemia group, there were no significant difference outcomes between cohorts using levothyroxine and not treatment.Conclusions: Our results showed a high incidence rate of thyroid dysfunction in pregnant women, and subclinical hypothyroidism is most common, followed by GTT. In general, pregnant women with thyroid dysfunction presented high risk of pregnancy complications. Isolated hypothyroxinemia in pregnant women is a matter of concern and treatment with levothyroxine couldn’t improve pregnancy outcomes and obstetrical complications.


2020 ◽  
Vol 8 (12) ◽  
pp. 744-750
Author(s):  
Peeyush Yadav ◽  
◽  
G.G. Kaushik ◽  

Objective:The present study was aimed to evaluate the levels of resistin and leptin in hypothyroid patients and to find a possible association of thyroid hormones with resistin and leptin. Material and Methods:The present study was conducted on 100 previously diagnosed hypothyroid (PDH) patients (38 Males & 62 Females) and 100 newly diagnosed hypothyroid (NDH) patients (44 Males & 56 Females) attending the outpatient clinics or admitted in wards of J.L.N. Hospitals, Ajmer. 100 healthy control subjects of same age group of either gender were selected for the study. Blood samples were drawn from patients and controls, after overnight fast of at least 8 hours. Estimation of Serum Leptin, Resistin, free T3, free T4, and TSH was done by using Enzyme- Linked Immunosorbant Assay (ELISA) technique. Differences in the parameters among the groups were analyzed by ANOVA test followed by its Tukey HSD post hoc analysis. Correlations between variables were tested using the Pearson rho (r: Correlation coefficient) correlation test. Results:Findings of the present study shows that the levels of serum fT3 (1.79 ± 0.29 pg/mL) and serum fT4 (0.34 ± 0.11 ng/dL) were significantly lower in NDH group compared to PDH group (fT3 = 3.00 ± 0.32 pg/mL & fT4 = 0.81 ± 0.15 ng/dL) and control group (fT3 = 3.12 ± 0.31 pg/mL & fT4 = 0.85 ± 0.11ng/dL) whereas serum TSH levels were significantly higher in NDH group (40.59 ± 13.55 μIU/mL) compared to PDH group (5.34 ± 1.47 μIU/mL) and control group (3.23 ± 1.04 μIU/mL) [Table 1 Figure 1]. Serum leptin levels were significantly higher in NDH group (21.37 ± 6.44 ng/mL) compared to PDH group (16.51 ± 4.47 ng/mL) and control group (11.15 ± 5.29 ng/mL) [Table 2]. A highly significant variation (p<0.0001) in the levels of serum leptin was found between the groups. Serum resistin levels were significantly higher in NDH group (14.50 ± 2.72 ng/mL) compared to PDH group (11.33 ± 1.59 ng/mL) and control group (7.78 ± 1.19 ng/mL) [Table 2]. Highly Significant difference (p<0.0001) in resistin levels was found between the groups. Conclusion: It was suggested that thyroid dysfunction does not affect the leptin levels and also thyroid hormones were not involved in the synthesis and secretion of leptin. Further studies are required to gain more insight into the relationship between leptin and thyroid dysfunction. Resistin shows a significant correlation with thyroid hormones which indicate that serum resistin might be considered as a confirmation extra test for the early detection of atherosclerosis and atherosclerosis induced conditions in hypothyroid patients.


1987 ◽  
Vol 115 (1) ◽  
pp. 87-90 ◽  
Author(s):  
M. Monti ◽  
P. Hedner ◽  
J. Ikomi-Kumm ◽  
S. Valdemarsson

Abstract. Erythrocyte metabolism was studied in vitro by microcalorimetry in 10 hyperthyroid subjects before and after treatment. By inhibiting the enzyme enolase in the Embden-Meyerhof pathway with sodium fluoride (NaF) we have recorded the anaerobic and aerobic contributions in erythrocyte thermogenesis. The decrease in heat production rate in samples with NaF corresponds to the anaerobic contribution, whereas the values from samples with NaF reflect aerobic processes. Before treatment, total heat production rate was 120 ± 2 mW/l erythrocytes which was higher than the post-treatment value of 99 ± 2 (P < 0.001) as well as the value for 14 euthyroid subjects, 108 ± 2 mW/l (P < 0.001). The NaF inhibitable rate was 73 ± ± before and 63 ± 1 mW/l after therapy (P < 0.01). These values correspond to 61 ± 1 and 64 ± 1% (n.s.) of the total heat production rate, and were similar to that of 61 ± 2% for the controls. Heat production rates in the presence of NaF were 47 ± 1 before and 36 ± 1 mW/l after therapy (P < 0.001), representing 39 ± 1 and 36 ± 1% of total values, respectively. The present results show that overall metabolism is increased in erythrocytes from hyperthyroid subjects before treatment and returns to normal after normalization of the thyroid function. Moreover, by using microcalorimetry we found that the metabolic activity along the Embden-Meyerhof anaerobic pathway as well as along the hexose monophosphate aerobic pathway in erythrocytes is stimulated by thyroid hormones.


2007 ◽  
Vol 97 (05) ◽  
pp. 803-806 ◽  
Author(s):  
Erica Romualdi ◽  
Eliana Piantanida ◽  
Victor Gerdes ◽  
Harry Büller ◽  
Maria Tanda ◽  
...  

SummarySeveral in-vivo studies have shown a procoagulant state in both overt and subclinical hyperthyroidism and in subclinical hypothyroidism. Insofar, no clinical studies have ever evaluated the relationship between thyroid dysfunction and clinically deep venous thrombosis (DVT). A pilot cross-sectional study aimed at assessing the frequency of overt and subclinical thyroid dysfunction patients with DVT was carried out. Fifty consecutive adult outpatients with a previous diagnosis of provoked DVT (pDVT), and 50 consecutive adult outpatients with a previous diagnosis unprovoked DVT (unDVT),both of the lower legs,who were followed at the Thrombosis Unit of the University Hospital of Varese, Italy, were enrolled after written informed consent. Fifty subjects, in whom such a diagnosis could be ruled out, served as controls. In each patient serum free thyroxine (FT4), free triiodothyronine (FT3), thyrotropin (TSH), anti-thyroid peroxidase (AbTPO), and anti-thyroglobulin (AbTg) antibodies were assayed. Previously unrecognised subclinical hypothyroidism was diagnosed in seven (14.0%) unDVT patients, one (2%) pDVT patient, and one (2%) control (odds ratio at multivariate analysis, 5.54; 95% confidence interval, 0.6–52.6); one new case of subclinical hyperthyroidism was diagnosed in each group; only one case (in the control group) of clinical overt hyperthyroidism was observed. The prevalence of thyroid autoantibodies, including both euthyroid and subclinical hypothyroid patients, did not differ in the three groups.The results of this pilot study suggest an increased prevalence of subclinical hypothyroidism in patients with unDVT.The clinical relevance of these preliminary findings needs to be addressed in larger prospective studies.


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.


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