methimazole and Weight-Loss

A 22-year-old woman presented to the emergency department (ED) with a 24-hour history of nausea, vomiting, diarrhea, generalized abdominal pain, and mild headache. She denied shortness of breath, chest pain, or anxiety, and didn't have a history of cardiac problems. The physical examination revealed tachycardia (heart rate, 135 beats/min) and a respiratory rate of 24 breaths per minute.

Topics: Adult; Antithyroid Agents; Atenolol; Female; Humans; Hyperthyroidism; Methimazole; Nausea; Pulmonary Edema; Tachycardia; Treatment Outcome; Vomiting; Weight Loss; Young Adult

Thyroid hormone and leptin are essential regulators of energy homeostasis. Both hormones stimulate energy expenditure but have opposite effects on appetite. The mechanisms behind food intake regulation in thyroid dysfunctions are poorly understood. It has been shown that hypothyroid rats exhibited impaired leptin anorexigenic effect and signaling in total hypothalamus, even though they were hypophagic. It was hypothesized that hypothyroidism modulates the expression of neuropeptides: orexigenic neuropeptide Y (NPY) and anorexigenic proopiomelanocortin (POMC), independently of inducing nuclei-specific changes in hypothalamic leptin signaling.. Adult male rats were rendered hypothyroid by administration of 0.03% methimazole in the drinking water for 21 days. Protein content of NPY, POMC, and leptin signaling (the signal transducer and activator of transcription 3 [STAT3] pathway) were evaluated by Western blot, and mRNA levels by real time reverse transcription polymerase chain reaction in arcuate (ARC), ventromedial (VMN), and paraventricular (PVN) hypothalamic nuclei isolated from euthyroid (eu) and hypothyroid (hypo) rats. Leptin anorexigenic effect was tested by recording food intake for two hours after intracerebroventricular (i.c.v.) administration of leptin. Statistical differences were considered significant at p ≤ 0.05.. Hypothyroidism was confirmed by decreased serum triiodothyronine, thyroxine, and increased thyrotropin, in addition to increased levels of pro-TRH mRNA in PVN and Dio2 mRNA in the ARC of hypo rats. Hypothyroidism decreased body weight and food intake associated with decreased protein content of NPY and increased content of POMC in the ARC. Conversely, hypothyroidism induced central resistance to the acute anorexigenic effect of leptin, since while euthyroid rats displayed reduced food intake after leptin i.c.v. injection, hypothyroid rats showed no response. Hypothyroid rats exhibited decreased leptin receptor (ObRb) protein content in ARC and VMN but not in PVN nucleus. ObRb protein changes were concomitant with decreased phosphorylated STAT3 in the ARC, and decreased total STAT3 in VMN and PVN. However, hypothyroidism did not affect mRNA levels of Lepr or Stat3 in the hypothalamic nuclei.. Experimental hypothyroidism induced a negative energy balance accompanied by decreased NPY and increased POMC protein content in the ARC, resulting in predominance of anorexigenic pathways, despite central leptin resistance and impairment of the leptin signaling cascade in a nuclei-specific manner.

Topics: Animals; Appetite Regulation; Arcuate Nucleus of Hypothalamus; Disease Models, Animal; Eating; Energy Metabolism; Feeding Behavior; Hypothyroidism; Iodide Peroxidase; Iodothyronine Deiodinase Type II; Leptin; Male; Methimazole; Neuropeptide Y; Paraventricular Hypothalamic Nucleus; Phosphorylation; Pro-Opiomelanocortin; Rats, Wistar; Receptors, Leptin; Signal Transduction; STAT3 Transcription Factor; Thyrotropin-Releasing Hormone; Ventromedial Hypothalamic Nucleus; Weight Loss

Thyrotoxicosis after total thyroidectomy is mostly iatrogenic. Rarely, a hyperfunctional thyroid remnant or ectopic tissue may be the cause. There are few cases of Graves' disease arising from thyroid tissue located in the mediastinum and none in which Graves' disease was diagnosed only after surgery. We report the case of a patient with Graves's disease in a mediastinal thyroid mass presenting 7 years after total thyroidectomy for nontoxic goiter.. A 67-year-old Caucasian woman presented with palpitations, fatigue and weight loss. She had a history of total thyroidectomy for nontoxic multinodular goiter at the age of 60 without any signs of malignancy on microscopic examination. She had been medicated with levothyroxine 100 μg/day since the surgery without follow-up. She was tachycardic, had no cervical mass or eye involvement. Her thyroid-stimulating hormone levels were suppressed (0.000 μU/mL) and her free thyroxine (3.22 ng/dL) and free triiodothyronine (8.46 pg/mL) levels increased. Neither mediastinal enlargement nor trachea deviation was found on chest roentgenogram. Levothyroxine treatment was stopped but our patient showed no improvement on free thyroxine or free triiodothyronine 10 days later. Thyroglobulin was increased to 294 mg/mL. A cervical ultrasound scan revealed no thyroid remnant. Her anti-thyroid-stimulating hormone receptor antibodies were high (19.7 U/L). Corporal scintigraphy demonstrated increased intrathoracic radioiodine uptake. A computed tomography scan confirmed a 60 × 40 mm mediastinal mass. Methimazole 10 mg/day was started. Three months later, her thyroid function was normal and she underwent surgical resection. Microscopic examination showed thyroid tissue with no signs of malignancy.. Although thyrotoxicosis after total thyroidectomy is mostly due to excessive supplementation, true hyperthyroidism may rarely be the cause, which should be kept in mind. The presence of thyroid tissue after total thyroidectomy in our patient may correspond to a remnant or ectopic thyroid tissue that became hyperfunctional in the presence of anti- thyroid-stimulating hormone receptor antibodies.

Topics: Aged; Antithyroid Agents; Fatigue; Female; Goiter; Graves Disease; Humans; Mediastinal Diseases; Methimazole; Thyroidectomy; Thyrotoxicosis; Thyroxine; Tomography, Emission-Computed; Treatment Outcome; Weight Loss

To evaluate the effect of idiopathic orthostatic edema and the effect of thyrotoxicosis on weight fluctuation and fluid retention in the presence of surgically induced panhypopituitarism and diabetes insipidus controlled with hormone replacement.. Dextroamphetamine sulfate was used for weight gain when no other etiologic factor was found. Methimazole was used when weight loss occurred when serum T4 and free T4 indicated thyrotoxicosis.. Sympathomimetic amine therapy very effectively controlled the weight gain and methimazole controlled the weight loss.. Hypopituitarism and diabetes insipidus controlled with hormone replacement do not protect against fluid retention from idiopathic edema.

Topics: Antidiuretic Agents; Antithyroid Agents; Deamino Arginine Vasopressin; Dextroamphetamine; Diabetes Insipidus; Edema; Female; Humans; Hypopituitarism; Methimazole; Middle Aged; Posture; Sympathomimetics; Thyrotoxicosis; Weight Gain; Weight Loss

Topics: Adult; Apgar Score; Eyelids; Female; Fetal Growth Retardation; Graves Disease; Heart Rate, Fetal; Humans; Infant, Newborn; Male; Methimazole; Potassium Iodide; Pregnancy; Propranolol; Thyrotoxicosis; Thyroxine; Ultrasonography; Weight Loss

Hyperthyroidism was diagnosed in four guinea pigs by demonstration of an increased serum total thyroxine concentration. The main clinical signs were comparable with those observed in feline hyperthyroidism and included weight loss despite maintenance of appetite and a palpable mass in the ventral cervical region. Three animals were treated successfully with methimazole for between 13 and 28 months. Clinical signs and regular measurement of circulating total thyroxine concentrations appear to be convenient parameters for monitoring response to medical therapy.

Topics: Animals; Antithyroid Agents; Female; Guinea Pigs; Hyperthyroidism; Male; Methimazole; Rodent Diseases; Thyroxine; Weight Loss

Topics: Adult; Anti-Arrhythmia Agents; Antithyroid Agents; Anxiety; Arrhythmias, Cardiac; Dyspnea; Graves Disease; Humans; Hypokalemic Periodic Paralysis; Malaysia; Male; Methimazole; Muscle Weakness; Neurologic Examination; Potassium; Propranolol; Propylthiouracil; Sleep Initiation and Maintenance Disorders; Tremor; Weight Loss

Topics: Adrenergic beta-Antagonists; Antithyroid Agents; Anxiety; Body Temperature Regulation; Diagnosis, Differential; Graves Disease; Humans; Hyperthyroidism; Male; Methimazole; Middle Aged; Muscle Weakness; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Tachycardia; Thyroid Function Tests; Tremor; Weight Loss

Topics: Adrenergic beta-Antagonists; Anorexia Nervosa; Antithyroid Agents; Body Image; Female; Humans; Hyperthyroidism; Methimazole; Sweating; Tachycardia; Weight Loss

To determine whether age-related differences in body weight loss in hyperthyroidism could be related to caloric intake, the body weight and food consumption of Fischer 344 male rats were monitored every other day for four weeks. Six-month-old (young) rats were compared to 16-month-old rats (intermediate age) and 25-month-old (aged) rats. Hypothyroidism was induced with 0.025% methimazole in the drinking water for four weeks. Hyperthyroidism was induced with triiodothyronine (T3) injections (15 micrograms/100 g body weight i.p.) for the last 10 days of observation. A group of young rats pair fed with aged rats was included as a control group. The body weight changes of aged rats were similar to hypothyroid young rats. An index of T3 catabolic effect was calculated based on the net weight loss and food intake. This index was not different in aged rats compared to young rats. The apparent hypersensitivity of aged rats to T3 as evidenced by excessive weight loss could totally be attributed to decreased caloric intake. It is concluded that aged rats compared to the young are not more sensitive to the overall catabolic effects of thyroid hormones.

Topics: Aging; Animals; Energy Intake; Hyperthyroidism; Hypothyroidism; Male; Methimazole; Rats; Rats, Inbred F344; Thyroid Hormones; Triiodothyronine; Weight Loss