Hyperthyroidism

Efren Alvarez Jr.
Joy Nidar



<sorry sir for the late posting>

1. You do not need to put a background on the function of the thyroid gland and the thyroid hormones.

2. Please put citation on this definition:
"Hyperthyroidism is a condition wherein the thyroid gland becomes overactive producing too much thyroid hormone which then circulates around the body."

3. With this statement,

"Hyperthyroidism is a relatively common disorder (Volkov, Merkin, Press, & Peleg, 2009). It is most frequent in women age 20 to 40, although men can develop this condition as well (Cooper, McDermott, & Wartofsky, 2006).

It has been stated by Reid and Wheeler (2005) that the prevalence of hyperthyroidism in community-based studies has been estimated at 2 percent for women and 0.2 percent for men. As many as 15 percent of cases of hyperthyroidism occur in patients older than 60 years."

What can you conclude on which age group is the disease most prevalent?
Does Cooper, McDermott, & Wartofsky, 2006 rationalize why is this common in women?

4. With this statement,

"While Cooper (2003) noted, in a more recent survey done in the USA, investigators noted hyperthyroidism in0•5% of randomly selected individuals. An additional 0•8% had subclinical or mild hyperthyroidism, in which serum thyrotropin is low or undetectable, but circulating thyroid hormone is within the normal range. In this investigation, the percentage of individuals with values of thyrotropin less than 0•4 mU/L (lower limit of the normal range), was 1–2%, except in individuals older than 80 years, in whom it was roughly 3%. The development of the various forms of hyperthyroidism depends to a great extent on the iodine intake of the population."

What can you conclude about which type is most common in occurence? And why?

University of the East
Ramon Magsaysay Memorial Medical Center, Inc.
GRADUATE SCHOOL
Aurora Boulevard, Quezon City

Efren Alvarez Jr.
Joy Nidar

Introduction

Hyperthyroidism

Hyperthyroidism is a condition wherein the thyroid gland becomes overactive producing too much thyroid hormone which then circulates around the body. (Cooper, 2003)

Some experts limit the word hyperthyroidism to the diseases in which the thyroid gland synthesizes and secretes excessive hormone. Then use the word thyrotoxicosis to refer to any condition in which there is an excessive amount of circulating thyroid hormone. But many in the health field as well as patients use the two terms interchangeably. (Cooper, 2003)

Hyperthyroidism is a relatively common disorder (Volkov, Merkin, Press, & Peleg, 2009). It is most frequent in women age 20 to 40, although men can develop this condition as well (Cooper, McDermott, & Wartofsky, 2006).

It has been stated by Reid and Wheeler (2005) that the prevalence of hyperthyroidism in community-based studies has been estimated at 2 percent for women and 0.2 percent for men. As many as 15 percent of cases of hyperthyroidism occur in patients older than 60 years.

CONCLUSION

When a woman is pregnant, serum human chorionic gonadotropin (hCG) increases especially on the first trimester, including the menopausal stage. The hCG is a weak thyroid stimulator. Therefore, hCG acts as a thyroid stimulator that replaces TSH. When TSH level decreases, the serum free T4 increases. Which may contribute to production of excess T4 or hyperthyroidism. The age group of 20 to 40 is a child bearing age group. (Hershman, 2008)


While Cooper (2003) noted, in a more recent survey done in the USA, investigators noted hyperthyroidism in0•5% of randomly selected individuals. An additional 0•8% had subclinical or mild hyperthyroidism, in which serum thyrotropin is low or undetectable, but circulating thyroid hormone is within the normal range. In this investigation, the percentage of individuals with values of thyrotropin less than 0•4 mU/L (lower limit of the normal range), was 1–2%, except in individuals older than 80 years, in whom it was roughly 3%. The development of the various forms of hyperthyroidism depends to a great extent on the iodine intake of the population.

CONCLUSION

One of the possibility of developing hyperthyroidism is the amount of iodine intake. The higher the amount of iodine intake, (normal - 300mg per day) the more chance of developing hyperthyroidism. (Cooper, 2003)
Iodine helps to fix thyroid function which in turn helps to set growth and body weight. (Nuble, 2005.)

Cause

Graves’ disease, an autoimmune condition, is the most common cause of hyperthyroidism. It accounts for 60 to 80 percent of all cases of hyperthyroidism (Reid & Wheeler, 2005). It happens when the immune system attacks the thyroid gland causing it to enlarge and produce too much thyroid hormone. It is a chronic condition and hereditary. Distinctive among those with this condition is the bulging of the eyes caused by the swelling behind the eyes, occurring in about 50% (Cooper, McDermott, & Wartofsky, 2006) to 90% (Volkov, Merkin, Press, & Peleg, 2009) of the patients.

Cooper (2003) furthermore explains that pregnancy is complicated by Graves’ disease in aboutone in 500 women. It is important that Graves’ disease is detected in pregnancy, since untreated hyperthyroidism is associated with miscarriage, premature labour, lowbirthweight, and eclampsia.

Toxic multinodular goiter, the development of one or more autonomously functioning thyroid nodules that produce excessive quantities of thyroid hormone (Cooper, 2003), causes 5 percent of the cases of hyperthyroidism in the United States and can be 10 times more common in iodine-deficient areas. It typically occurs in patients older than 40 years with a long-standing goiter, and has a more subtle onset than Graves’ disease. (Reid & Wheeler, 2005)

Various forms of thyroiditis, in which thyroidal inflammation damages thyroid follicles, resulting in unregulated release of thyroid hormone into the circulation, are less common. (Cooper, 2003)

Subacute thyroiditis, usually following a viral illness, produces an abrupt onset of thyrotoxic symptoms as hormone leaks from an inflamed gland. Symptoms disappear by the 8th month but it can be recurrent for some people. (Reid & Wheeler, 2005)

Lymphocytic thyroiditis is caused by lymphocytes, producing a painless inflammation in the thyroid. (Cooper, McDermott, & Wartofsky, 2006)

Postpartum thyroiditis is lymphocytic thyroiditis that develops shortly after pregnancy (Cooper, McDermott, & Wartofsky, 2006). It can occur in up to 5 to 10 percent of women in the first three to six months after delivery. (Reid & Wheeler, 2005)

Treatment-induced hyperthyroidism

Iodine-induced hyperthyroidism can be due to excessive intake of iodine, exposure to radiographic contrast media, or medications. The synthesis and release of thyroid hormone is increased with excess iodine in iodine-deficient patients and in older patients with preexisting multinodular goiters. (Reid & Wheeler, 2005)

Thyroid hormone-induced hyperthyroidism (factitial) can be due to excessive intake of thyroid hormone either by intentional or accidental ingestion. Some patients may take thyroid preparations to achieve weight loss. (Reid & Wheeler, 2005)


Signs and Symptoms

Major symptoms
• Palpitations
• Hyperactivity
• Anxiety and nervousness
• Heat intolerance
• Tremor
• weight loss
• diarrhea
• disturbances of menstruation
• sweating

Common signs
• weight loss despite increased appetite
• tachycardia or atrial fibrillation
• systolic hypertension
• warm and smooth skin
• fine tremor
• muscle weakness

Sympathetic symptoms, such as anxiety, hyperactivity and tremor, are often exhibited by the younger patients. Cardiovascular symptoms, such as dyspnea and atrial fibrillation, are more common with older patients.

As mentioned before, hyperthyroidism is associated with thyroid ophtalmopathy in up to 90% of patients. It is manifested by periorbital edema, conjunctival edema (chemosis), injection, poor lid closure, extraocular muscle dysfunction (diplopia), and proptosis. Only 5% develop severe ophthalmopathy characterized by diplopia, visual-field deficits, and blurred vision. It is a medical emergency when there is optic nerve compression caused by orbital edema which leads to early loss of color vision and orbit pain. Pressure of the optic nerve can cause permanent vision loss if not treated.

(Volkov, Merkin, Press & Peleg, 2009)





COMPLICATIONS

According to Walker S. et al. Iodine is a constituent of thyroid hormones, which affects our central nervous system development and regulate many physiological processes.

Thomsen et al. (2007), in a clinical study of the increased risk of affective disorder following hospitalization with hyperthyroidism showed that patients with hyperthyroidism who was discharged from the hospital has a greater chance of readmission with affective disorder other than patients who have non toxic goiter and osteoarthritis. They also indicated that the risk was similar whether or not patients with Graves’ disease were included in the hyperthyroidism cohort, indicating that the increased risk of hospitalisation with affective disorder was not specifically associated with Graves’ disease or with Graves’ ophthalmopathy, and that patients hospitalized with hyperthyroidism caused by Graves’ disease are at a similar risk of subsequent affective disorder as patients hospitalised with hyperthyroidism from other causes

According to Fadel B. et al. (2000), our heart is sensitive to the action of thyroid hormone, and measurable changes in cardiac performance are detected with small variations in thyroid hormone. They concluded many conditions and cardiac diseases drugs are associated with the serum level of the patient and may resul to thyroid dysfunction.
They also added that many of the genomic and nongenomic actions of thyroid hormone, most patients with hyperthyroidism demonstrate hemodynamic and cardiovascular manifestations. Serious cardiac complications such as congestive heart failure, atrial fibrillation, and angina pectoris may arise in hyperthyroid patients, and their treatment requires the control of the underlying hyperthyroid state.


Ansari et al (2004). A huge amount of thyroid hormone circulating in our body system can affect almost all of our organs. Sixty-nine clinically hyperthyroid patients were selected in their study from January 2002 to October 2003. They noted that hyperthyroidism might also present in an atypical fashion. The cardiac complications of long standing hyperthyroidism are serious if the aetiologies are not diagnosed properly earlier. As a non-invasive method, echocardiography can play a vital role in recognizing the cardiac pathology in hyperthyroidism as well as to follow up the response to therapy.


Burman diagnosed patients with thyroid storm as patients who have severe clinical manifestations of hyperthyroidism. According to Ngo et al. (2007) the study of Cardiac abnormalities may be the dominant manifestations of thyroid storm in young men, they concluded that cardiac arrhythmias and contractile dysfunction may be the major manifestations of thyroid storm in young patients.


A study by Conen D, et al (2007), they found out that amiodarone-associated hyperthyroidism usually occurs several years after initiation of the drug. The response to antithyroid drug or prednisone therapy is slow, and the long-term rates of major cardiac events and death are substantial.



REFERENCES:

Ansari S. M., Haider S., Awal M., Khanam N., Siddique A. (2004). Cardiac Complications of Hyperthyroidism: Echocardiographic Evaluation of 69 Hyperthyroid Patients. 17(1), 6-9. Retrieved February 15, 2010 from http://www.banglajol.info

Conen D, Melly L, Kaufmann C, Bilz S, Ammann P, Schaer B, Sticherling C, Muller B, Osswald S. (2007). Major cardiac events are common during follow-up in patients with amiodarone-associated hyperthyroidism. Retrieved February 15, 2010 from http://www.thyroid.org

Cooper, D. (2003). Hyperthyroidism. The Lancet, Volume 362, Issue 9382, Pages 459 – 468. doi:10.1016/S0140-6736(03)14073-1

Cooper, D., McDermott, M., and Wartofsky, L. (2006). Hyperthyroidism. The Journal of Clinical Endocrinology & Metabolism, Vol. 91, No. 7 0. Retrieved on February 15, 2010 from http://jcem.endojournals.org/cgi/content/full/91/7/0

Fadel B., Ellahham S, Ringel M, Lindsay J., Wartofsky L., Burman, K. (2000). Hyperthyroid Heart Disease. Clin. Cardiol, 23. 402-408. Retrieved February 15, 2010 from http://www.uthsc.edu

Ngo SY, Chew HC. (2007) Cardiac abnormalities may be the dominant manifestations of thyroid storm in young men. Retrieved February 15, 2010 from http://www.thyroid.org

Reid, J. and Wheeler, S. (2005). Hyperthyroidism: Diagnosis and Treatment.
Am Fam Physician, 72:623-30, 635-6. Retrieved on February 15, 2010 from EBSCohost.

Thomsen A., Kvist T., Andersen P., and Kessing L. (2007). Increased risk of affective disorder following hospitalization with hyperthyroidism – a register-based study. European Journal of Endocrinology,152, 535–543. Retrieved February 15, 2010 from http://www.eje-online.org

Volkov, I., Merkin, L., Press, Y., and Peleg, R. (2009). Diplopia as the Sole
Manifestation of Hyperthyroidism. The Internet Journal of Family Practice, Volume 4 Number 2. Retrieved on February 15, 2010 from EBSCohost.

Walker S., Wachs T., Gardner J.M., Lozoff B., Wasserman G., Pollit E, Carter J., and the International Child Development Steering Group (2007). Child development in developing countries 2 Child development: risk factors for adverse outcomes in developing countries. 369, 151 Retrieved February 15, 2010 from http://www.ecdgroup.com

Hershman J. (June, 2008). Hyperthyroidism. Retrieved February 19, 2010 from http://www.merck.com

Nuble C (2005). Vitamins and minerals for a Healthy reproductive System. Retrieved February 19, 2010 from http://tl.intelistart.com