Effect of hypo- and hyperthyroidism on gastric myoelectrical activity.

Altered fibrinolytic parameters and serum lipid profile are strongly related to thyroid dysfunction. To investigate the patterns of the fibrinolytic abnormalities and serum lipid profile in the hypo- and hyperthyroid patients. We also took an aim at studying the relationships between free T4 levels (FT4) and these parameters. Hyperthyroid (n = 30), hypothyroid (n = 20) patients and euthyroid control subjects (n = 30) were evaluated for several fibrinolytic parameters including plasma plasminogen activator inhibitor-1 (PAI-1) and D-dimer (D-D). Serum lipid profile and lipoprotein(a) (Lp(a)) were also measured. We found different patterns of fibrinolytic abnormalities and lipid profile in hypo- and hyperthyroid patients. The hypothyroid patients had low plasma PAI-1 levels and high D-D values as compared to hyperthyroid patients (p < 0.001) and euthyroid control subjects (p < 0.05 and 0.001, respectively). In sharp contrast, the hyperthyroid patients had high plasma PAI-1 levels (p < 0.001) but without concomitant change in plasma D-D values, as compared to the euthyroid control subjects. Hypothyroidism was associated with high total cholesterol, triglycerides, LDL-C and Lp(a) levels and low HDL-C levels as compared to both hyperthyroid and euthyroid states (p < 0.001). FT4 levels were correlated positively with HDL-C but negatively with total cholesterol, triglycerides, LDL-C and Lp(a) levels in both hypo- and hyperthyroid patients. Also FT4 levels were correlated positively with PAI-1 but negatively with D-D in both hypo- and hyperthyroid patients (p < 0.02, 0.01, 0.001 and 0.03 respectively). We found hyperfibrinolytic, and hypofibrinolytic patterns in hypothyroid, hyperthyroid patients, respectively. The hypothyroid patients had atherogenic lipid profile. These variations indicate possible pathophysiologic roles for thyroid hormones in the regulation of the fibrinolytic system and lipid profile. Mechanisms of these variations are open for future investigations.

Background: Hypothyroidism is a common hormonal disorder affecting various organs including lungs and pulmonary dysfunction in hypothyroid patients has been noted.&#x0D; Objective: To observe maximum voluntary ventilation (MVV) in hypothyroid female patients.&#x0D; Materials and method: This cross-sectional study was carried out in the Department of Physiology, BSMMU, Dhaka, Bangladesh, from 1st July 2008 to 30th June 2009 on 60 hypothyroid female patients of 30-50 years old. Based on treatment, hypothyroid patients were divided into B1 (untreated patients on their 1st day of diagnosis) and B2 (patients treated for at least 12-18 months). For comparison, 30 age and BMI matched apparently healthy subjects (Group A) were also studied. The study group was selected from the Out Patient Department of Endocrinology, BSMMU, Dhaka, Bangladesh, and the control group was selected by personal contact. Serum TSH and serum FT4 levels were measured by Microparticle Enzyme Immunoassay (MEIA) principle in AxSYM system. Maximum voluntary ventilation (MVV), which is a lung function parameter, was measured by a digital MicroDL spirometer. Data were analyzed by one way ANOVA test, independent sample t-test and Pearson’s correlation coefficient test.&#x0D; Results: The mean percentage of predicted values of lung function parameter of MVV in control subjects and treated hypothyroids were within normal ranges. However, this value was significantly lower in untreated hypothyroid subjects in comparison to those of control and treated hypothyroid subjects. In addition, MVV showed negative correlation with serum TSH level and positive correlation with serum FT4 level and these relationships were statistically significant in control group and treated hypothyroid subjects.&#x0D; Conclusion: This study reveals that MVV may be lower in untreated hypothyroid female patients compared to control and treated hypothyroids and the deterioration may be positively correlated with serum FT4 level and negatively correlated with serum TSH level. Treatment of hypothyroids may reverse these changes.&#x0D; Delta Med Col J. Jul 2020;8(2): 55-60

There is the recognition of a pattern of elevations of serum enzymes in hyperthyroid and hypothyroid patients. The aims of this study were to determine the activities of serum creatine kinase (CK) and lactate deydrogenase (LDH) in thyroid disorders, and to evaluate the relationship between CK, LDH and FT4, and TSH levels. In this retrospective study, thyroid function tests, serum CK and LDH activities were obtained from the medical records of newly diagnosed hyperthyroid and hypothyroid patients attending the Endocrinology Clinic at the University Hospital of the West Indies from 2005- 2009. Elevation of CK activity was found in 5 patients (28%, 5/18) with overt hypothyroidism and in 12 patients (24.0%, 12/50) with subclinical hypothyroidism. The mean CK activity in subclinical hypothyroid patients was 179.80 ± 125.68 U/L compared with 389.901 ± 381.20 U/L in overt hypothyroid patients. The elevation of LDH activity was found in 6 patients (33.3%, 6/18) with overt hypothyroidism and in 37 patients (74.0%, 37/50) with subclinical hypothyroidism. In the hypothyroid patients, a positive correlation was found between CK activity and TSH (r = 0.292, P = 0.015), and a negative correlation between CK activity and FT4 (r = - 0.325, P = 0.007); and between FT4 and TSH (r = - 0.371, P = 0.002). The significant elevation in serum CK and LDH activities indicates that these can be used as parameters for screening hypothyroid patients but not hyperthyroid patients.

The aims of this study were to investigate the effects of H. pylori eradication on gastric myoelectrical activity and dyspeptic symptoms. Sixty-two subjects with H. pylori infection and no active peptic ulcer participated in this study, which involved three sessions. Anti-H. pylori therapy consisting of clarithromycin and omeprazole was given for two weeks. Gastric myoelectrical activity was measured using surface electrogastrography and dyspeptic symptoms were scored at each session. A [14C] urea breath test was performed at baseline and one month after treatment. In comparison with baseline, the percentage of normal slow waves was significantly increased and the mean total symptom score was significantly reduced one and three months after therapy (P < 0.05). Approximately 40% of patients with nonulcer dyspepsia' symptoms and H. pylori infection have abnormal gastric myoelectrical activity, which may be normalized following the eradication of H. pylori infection. The normalization of gastric myoelectrical activity may be one explanation for the significant symptom improvement in this subset of the dyspepsia population after H. pylori eradication.

Background The deficiency of vitamin D3 (VD) is a universal health issue, its role in different kind of diseases is being studied recently. However, its role in thyroid diseases is not well established yet. This study aims to determine the impact of VD in the pathogenesis of hypothyroidism and hyperthyroidism. Method. Three hundred Iraqi females with age ranged between 30 and 55 years participate in this research, 100 of them were hypothyroid patients, 100 females were hyperthyroid patients and the other 100 females were healthy volunteers served as controls. Thyroid hormones, VD, liver function parameters, and kidney function parameters were determined using different analysis techniques. Results. The levels of VD were significantly decreased in both hypothyroid and hyperthyroid patients (19.644 ± 10.524 for hypothyroid patients and 22.712 ± 11.249 for hyperthyroid patients vs. 30.880 ± 2.587 for controls, p <0.0001). Liver function parameters were within the normal ranges in all the patients. Creatinine and uric acid were within the normal ranges, while urea was significantly increased and out of the normal clinical range in both hypothyroid and hyperthyroid patients (39.560 ± 9.912 for hypothyroidism patients and 42.460 ±7.171 for hyperthyroid patients vs. 26.920 ± 5.033 for controls, p <0.0001). Conclusion. Vitamin D3 and kidney function tests must be included in the differential detection of thyroid diseases. Still, further investigations are needed to understand the underlying mechanism by which VD affects thyroid hormone regulation.

To investigate the thyroid hormone metabolism in altered states of thyroid function, serum concentrations of 3, 3'-diiodothyronine (3, 3'-T2), 3', 5'-T2 and 3, 5-T2 as well as T4, T3 and rT3 were determined by specific radioimmunoassays in 17 hyperthyroid and 10 hypothyroid patients, before and during the treatment. Serum T4, T3, rT3, 3, 3'-T2 and 3', 5'-T2 concentrations were all higher in the hyperthyroid patients than in age-matched controls and decreased to the normal ranges within 3 to 4 months following treatment with antithyroid drugs. In the hypothyroid patients, these iodothyronine concentrations were lower than in age-matched controls and returned to the normal ranges after 2 to 3 months treatment with T4. In contrast, serum 3, 5-T2 concentrations in hyperthyroid patients (mean +/- SE : 4.0 +/- 0.5 ng/dl) were not significantly different from those in controls (3.9 +/ 0.4 ng/dl), although they tended to decrease in 3 of 6 patients after the antithyroid drug therapy. Serum 3, 5-T2 levels in the hypothyroid patients (3.8 +/- 0.6 ng/dl) were also within the normal range and showed no significant change following the T4 replacement therapy. However, serum 3, 5-T2 as well as 3, 3'T2 concentrations rose significantly with a marked rise in serum T3 following T3 administration, 75 micrograms/day for 7 days, in Graves' patients in euthyroid state.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma total homocysteine levels in hyperthyroid and hypothyroid patients

Gastric myoelectrical activity modulates gastric motor activity. Abnormalities in gastric myoelectrical activity may be associated with gastric motility disorders. The aim of this study was to investigate the correlation of gastric myoelectrical activity with gastric emptying in symptomatic patients with and without gastroparesis. Ninety-seven patients with symptoms suggestive of gastroparesis participated in the study. Gastric myoelectrical activity was recorded using surface electrogastrography. The electrogastrogram (EGG) was recorded for 30 min in the fasting state and for 120 min after a solid test meal. Gastric emptying of the solid meal was simultaneously monitored for 120 min. Patients with delayed gastric emptying showed a significantly lower percentage of normal gastric slow waves (P < 0.03) and a significantly reduced increase of the dominant power in the postprandial EGG (P < 0.02). Postprandial EGG parameters were found to be able to predict delayed emptying of the stomach. Postprandial gastric dysrhythmia predicts delayed gastric emptying with an accuracy of 78%, while the abnormality in postprandial EGG power predicts delayed gastric emptying with an accuracy of 75%. All patients with abnormalities in both the rhythmicity and the power had delayed gastric emptying. Patients with delayed gastric emptying have a lower percentage of normal gastric slow waves in the EGG and a lower postprandial increase in the dominant power. Abnormalities in the postprandial EGG seem to be able to predict delayed emptying of the stomach. However, a normal EGG does not seem to guarantee normal emptying of the stomach.

It is known that NT-proBNP levels increase in cardiac failure. However, NT-proBNP levels in different thyroid states are still unclear. We aimed to evaluate serum NT-proBNP levels in both hyperthyroid and hypothyroid patients without cardiac insufficiency. Thirty-six patients with hyperthyroidism (42.9 +/- 16.7 years), 25 patients with hypothyroidism (35.4 +/- 13.9 years) and 34 age-matched euthyroid subjects (41.4 +/- 13.8 years) were included in the study. After anthropometric evaluations, body fat analyses were determined by bioelectrical impedance. Electrocardiography and echocardiography were used in cardiac evaluations. Serum NT-proBNP was measured by immunoassay. Mean serum NT-proBNP levels in hyperthyroid patients were higher than in both control subjects (13.65 +/- 13.02 vs. 6.50 +/- 4.83 pmol/l, P = 0.002) and hypothyroid patients (13.65 +/- 13.02 vs. 5.98 +/- 5.08 pmol/l, P = 0.003). However, mean serum NT-proBNP levels in hypothyroid patients were not different from those in control subjects. There was a positive correlation between serum NT-proBNP and thyroid hormones (NT-proBNP and FT3: r = 0.324, P = 0.001; NT-proBNP and FT4: r = 0.269, P = 0.009, respectively). Serum NT-proBNP levels were positively correlated with left ventricle end-diastolic diameters (r = 0.232, P = 0.04), interventricular septum thickness (r = 0.315, P = 0.006), and negatively correlated with left ventricular ejection fraction (r = -0.238, P = 0.04). Serum NT-proBNP levels may increase in hyperthyroidism independently of cardiac insufficiency. Therefore, hyperthyroidism may lead to cardiac ultrastructural changes undetermined by conventional echocardiography and these changes may be responsible for elevation of NT-proBNP levels. In contrast to decreased thyroid hormones, excess thyroid hormones may have a more pronounced effect on serum NT-proBNP levels.

The c-erbAalpha gene encodes two thyroid hormone receptors, TRalpha1 and TRalpha2, that arise from alternative splicing of the TRalpha pre-mRNA. TRalpha2 is not able to bind triiodothyronine (T(3)) and acts as a weak antagonist of TRs. It has been suggested that the balance of TRalpha1 to TRalpha2 is important in maintaining homeostasis. Here, we study the effect of thyroid hormone on the splicing of TRalpha under various conditions in HepG2 cells. First, T(3) was added to HepG2 cells that endogenously express TRalpha. This resulted in a decrease in the TRalpha1:TRalpha2 mRNA ratio after the addition of 10(-)(8 )M or 10(-)(7 )M T(3). Then, HepG2 cells were incubated with sera from hypothyroid or hyperthyroid patients. Sera from hyperthyroid patients (n=6) decreased the TRalpha1:TRalpha2 ratio compared with HepG2 cells incubated with sera from euthyroid patients (n=8). Sera from hypothyroid patients (n=6) had no effect on the TRalpha1:TRalpha2 ratio but supplementation with T(3) caused a decrease in the ratio. Finally, we tested sera from patients with nonthyroidal illness (NTI; n=17) which showed no effect on TRalpha splicing when compared with controls. Free thyroxine levels in sera from hypo-, eu-, and hyperthyroid patients, but not that of NTI patients, were negatively correlated (P<0.01) to the TRalpha1:TRalpha2 ratio. We next studied the expression of the splicing factors hnRNP A1 and ASF/SF2 (SF2) in relation to the splicing of the TRalpha gene. In HepG2 cells incubated with NTI sera a negative relationship was found between the ratio of hnRNP A1:SF2 and the TRalpha1:TRalpha2 ratio. A high hnRNP A1:SF2 ratio is associated with the use of the distal 5'-splice site. The splicing direction should then change towards TRalpha2, which is indeed the case. Rev-ErbA, which is partly complementary to TRalpha2 and could therefore interfere in the splicing process, did not relate to the TRalpha1:TRalpha2 ratio. In conclusion, high T(3) levels induce a low TRalpha1:TRalpha2 ratio which could protect the cell from excessive T(3)-induced gene expression. In vivo, this might be a mechanism to keep tIssues relatively euthyroid during high serum T(3) levels.

Objective. Stress impairs gastrointestinal motility, causing, for example, delayed gastric emptying and altered intestinal transit. However, little is known about the effect of various stress factors on gastric tone and gastric myoelectrical activity (GMA). The aim of this study was to assess the effect of various kinds of stress on gastric tone and GMA in a canine model. Material andmethods. Six dogs, implanted with a gastric cannula and one pair of gastric seromuscular electrodes, were studied. Three kinds of stress (visual, thermal, or audio stimulation) were applied in separate sessions. GMA and gastric tone were recorded for 30 min at baseline and 30 min during stress. Results. Visual stress (blinding) did not alter gastric tone or GMA; cold stress (ice water) and audio stress (loud noise) significantly inhibited gastric tone: gastric volume was increased from 107.2±13.5 ml at baseline to 135.6±23.8 ml with cold stress (p=0.041), and from 106.4±5.7 ml at baseline to 159.2±15.1 ml with audio stress (p=0.007). Although the dominant frequency or power of gastric slow waves was not altered, the percentage of normal gastric slow waves was markedly reduced from 98.3±0.8 to 87.5±3.7 with cold stress and from 90.2±3.3 to 80.6±2.9 with audio stress (p<0.05). Conclusions. Cold- and audio stress inhibit gastric tone and impair gastric slow waves, whereas visual stress does not seem to have such effects. These findings will help to increase our understanding of gastrointestinal motor disorders related to stress.

AimThis study aims to explore and compare the efficacy of radioiodine treatment (RIT) in hyperthyroid and euthyroid patients who have been treated with amiodarone (AM) in the past or are currently undergoing AM treatment. Clinical observation of a group of patients with amiodarone-induced hypothyroidism during a 12-month follow-up period was used for comparison.DesignThis was a observational, two-centered study. Patients were assessed at baseline and at 2 months, 6 months, 8 months, and 12 months after RIT.PatientsGroup A: At baseline (61 males [M] and 17 females [F], mean age 50±19 years), there were 78 euthyroid patients with cardiac arrhythmias, who were treated with AM and developed amiodarone-induced thyrotoxicosis, and currently require retreatment with AM. Group B: Hyperthyroid patients (92 M and 26 F, mean age 72±11.8 years) after AM therapy in the past. Group C: Hyperthyroid patients (66 M and 13 F, mean age 63.9±13.2 years) currently treated by AM. Group D: Hypothyroid patients (6 M and 16 F, mean age 61.4±10.4 years) after AM therapy. The patients from Groups A, B, and C were retreated with AM after ~3–6 weeks of RIT.ResultsIn Group A, after 12 months of RIT therapy, recurrent thyrotoxicosis was observed in six (7.7%) cases, and persistent hypothyroidism was diagnosed in 42 (53.8%) cases. In Group B, hyperthyroidism occurring during treatment with AM was found in 40 (33.9%) patients, and permanent hypothyroidism was observed in eleven (12.5%) cases. After annual follow-up in Group C, nine (11.4%) patients were diagnosed with hypothyroidism, while 27 (34.1%) patients were diagnosed with hyperthyroidism. In Group D, all patients had permanent hypothyroidism and when the concentration of serum thyroid-stimulating hormone was >10 µIU/mL, l-thyroxine was applied.ConclusionOur study showed that radioiodine administration is advisable in certain circumstances, even in euthyroid patients. It allows for continuation of further long-term AM treatment. Additionally, RIT allows for the reintroduction of AM therapy that was previously terminated. Hence, it can help control life-threatening tachyarrhythmias and decrease episodes of thyrotoxicosis.

We assessed sympathovagal balance in thyrotoxicosis. Fourteen patients with Graves' hyperthyroidism were studied before and after 7 days of treatment with propranolol (40 mg 3 times a day) and in the euthyroid state. Data were compared with those obtained in a group of age-, sex-, and weight-matched controls. Autonomic inputs to the heart were assessed by power spectral analysis of heart rate variability. Systemic exposure to sympathetic neurohormones was estimated on the basis of 24-h urinary catecholamine excretion. The spectral power in the high-frequency domain was considerably reduced in hyperthyroid patients, indicating diminished vagal inputs to the heart. Increased heart rate and mid-frequency/high-frequency power ratio in the presence of reduced total spectral power and increased urinary catecholamine excretion strongly suggest enhanced sympathetic inputs in thyrotoxicosis. All abnormal features of autonomic balance were completely restored to normal in the euthyroid state. beta-Adrenoceptor antagonism reduced heart rate in hyperthyroid patients but did not significantly affect heart rate variability or catecholamine excretion. This is in keeping with the concept of a joint disruption of sympathetic and vagal inputs to the heart underlying changes in heart rate variability. Thus thyrotoxicosis is characterized by profound sympathovagal imbalance, brought about by increased sympathetic activity in the presence of diminished vagal tone.

Thyroid dysfunction encompassing both hypothyroidism and hyperthyroidism, represents a significant global health burden affecting millions of individuals worldwide. Thyroid hormones play a pivotal role in regulating metabolism including glucose homeostasis making their dysregulation a potential contributor to metabolic complications such as hypoglycemia. Despite the well-documented effects of thyroid hormones on glucose metabolism the interplay between thyroid dysfunction and hypoglycemia remains underexplored, particularly in specific populations. This retrospective cohort study investigates the correlation between thyroid dysfunction and hypoglycemia, focusing on differences between hypothyroid and hyperthyroid patients. A total of 200 patients (100 with hypothyroidism and 100 with hyperthyroidism) were analyzed using clinical records, laboratory tests and symptom assessments. Key findings revealed that hypothyroid patients exhibited a higher prevalence of hypoglycemia (45%)compared to hyperthyroid patients(30%).Severe symptoms such as dizziness and sweating were more common in hypothyroid patients, while tremors and palpitations were more frequent in hyperthyroid patients. These findings align with the physiological roles of thyroid hormones in glucose metabolism: hypothyroidism impairs hepatic gluconeogenesis and glycogenolysis, leading to reduced glucose production during fasting, whereas hyperthyroidism accelerates glucose metabolism but may cause reactive hypoglycemia due to rapid glucose utilization or hyperinsulinemia. Logistic regression analysis identified several predictors of hypoglycemia, including age ≥50 years, suboptimal treatment, and hypothyroidism itself. Older patients and those with suboptimal levothyroxine dosing were at heightened risk, underscoring the importance of individualized treatment strategies. This study highlights the critical link between thyroid dysfunction and hypoglycemia, emphasizing the need for early diagnosis, tailored treatment approaches, and regular glucose monitoring in high-risk groups. By integrating clinical evaluation, laboratory tests, and symptom monitoring, healthcare providers can optimize diagnostic accuracy and management strategies for patients with thyroid dysfunction. These findings advocate for multidisciplinary interventions to mitigate the risk of hypoglycemia and improve patient outcomes, particularly in vulnerable populations such as older adults and those with suboptimal treatment adherence.

SUMMARY The urinary excretion of endogenous and exogenous oestrogens was studied in patients with disordered thyroid function, and in obese and non-obese patients without evident thyroid disease. Hypothyroid patients and obese patients converted a larger percentage of administered oestradiol-17β to urinary oestriol and a lower percentage to urinary oestrone than hyperthyroid patients and non-obese patients. The recovery of administered oestradiol as oestriol, oestrone and oestradiol in urine was the same in the hypothyroid, obese and non-obese patients but considerably lower in the hyperthyroid patients. Similar differences were found in the urinary excretion of endogenous oestrogens. The excretion of endogenous oestrogens varies with the weight of the patient; it was greater in the obese than in the non-obese. The findings indicate that the pathways of oestrogen metabolism are influenced by a number of the factors, including thyroid function, associated with the weight of the patient.