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Hyperthyroidism And Hypothyroidism

The “Butterfly” in Me

Often describe as butterfly-shaped gland, the thyroid gland is  situated at the base of the  neck and  releases  hormones  — triiodothyronine (T3) and thyroxine (T4) — that controls  the bodys metabolism and regulate  vital functions, such as body temperature and heart rate, muscle and digestive function, brain development and bone maintenance.  It is important that T3 and T4 levels are neither too high nor too low and a balance is achieved with the help of the hypothalamus and the pituitary.

Over the years MEMS ( MALAYSIAN ENDOCRINE AND METABOLIC SOCIETY ) has developed into a professional body, the objectives of which are to advance the interest and practice of endocrinology among the Malaysian medical fraternity and the general public. MEMs has continued to update and train healthcare providers in thyroid disease management with reference to international clinical guidelines.

The country’s first-ever clinical practice guidelines on the management of thyroid disorders has been published by the Malaysian Endocrine and Metabolic Society (MEMS) and was launched on the 3rd October 2020. MEMS then president Datuk Dr Zanariah Hussein said while there had been a consensus statement on thyroid disorder management, there was a great need for standardised and updated guidelines for clinical practice. As such, she described the publication of the guidelines as an “important milestone” on managing thyroid disorders, which commonly go undiagnosed.

The prevalence of  hyperthyroidism  in Malaysia is 3.4%:  hypothyroidism is  2.1% and 3.6% for  thyroid nodules. 9.3% of the population had goitre (thyroid gland enlargement).   Females were found to have a higher prevalence of thyroid dysfunction, 5 to 8 times more likely than  their male counterparts. About 1 in 8 women would develop thyroid problems during her lifetime. Its not understood why  women are more prone but it is suspected that the development of thyroidism and its variants is  linked to autoimmunity which is more commonly found in women.

 Hyperthyroidism: overworked and stressed out

Hyperthyroidism occurs  when the gland  produces too much T-4 causing one to experience irritability, nervousness, shaking, muscle weakness, sudden weight loss and sleeping problems amongst others but it is  a treatable condition. The most common cause is Graves disease which is a genetic autoimmune condition that can cause the tissue and swelling of muscle behind the eyes commonly known as Graves opthalmopathy.

Other causes  include toxic adenoma and toxic multinodular goitre. Endogenous sources of thyroid hormones which are rare could be due to the presence of  teratoma of the ovaries  composed mainly of thyroid tissue and metastatic thyroid carcinoma secreting thyroid hormones. Over-the–counter supplements containing various amounts of T3 and/or T4 contribute to the exogenous sources of thyroid hormones which are generally commoner nowadays.
It’s diagnosed through a physical examination, blood test – Serum thyroid-stimulating hormone (TSH), free T4 (fT4) and  free T3 (fT3)    –   and TSH Receptor Antibodies (TRAbs) TRAbs which is a specific biomarker for the diagnosis of Graves’ disease. The main of therapy is to achieve a euthyroid state  as quickly and safely as possible with antithyroid medications (methimazole and propylthiouracil), radioactive iodine ablation of the thyroid gland, or surgery which is generally rare. These medications do not cure Graves’ hyperthyroidism; however, when given in adequate doses, they are very effective in controlling hyperthyroidism. Nonadherence  is one of the main cause for failure to achieve euthyroidism.  A patient is considered to be in remission if they have a normal serum TSH, free T4, and free T3 for a year after discontinuation of anti thyroid drug (ATD) therapy. The choice of treatment depends on the underlying diagnosis, the presence of contraindications to a particular treatment modality, the severity of hyperthyroidism, and the patient’s preference. A low-iodine diet is usually advised for patients with hyperthyroidism such as cruciferous vegetables vitamins and minerals which contain iron, zinc and selenium.

Thyroid storm  is an endocrine  emergency and is marked by the extreme overproduction of the two hormones ( T4 and T3). Not all people with hyperthyroidism will develop thyroid storm but particularly in those who aren’t receiving appropriate treatment or infection associated with hyperthyroidism. Symptoms  are similar to those of hyperthyroidism, but  are more sudden, severe, and extreme. Individuals with  thyroid storm are typically admitted to an intensive care unit and can be fatal without prompt, aggressive treatment.

Hypothyroidism: underactive and tired out

This occurs when the  gland doesn’t produce sufficient amount of  T-3 and T-4 hormones, or enough thyroid-stimulating hormone (TSH ). The most common cause is  Hashimoto’s thyroiditis  which is an autoimmune condition whereby the  body attacks its own immune system causing  the thyroid to stop producing hormones and is  more frequently seen  in women.

Depending on the severity of  hormone deficiency , the signs and symptoms  vary and  tend  to develop slowly, often over a number of years. These include  dry skin ,extreme fatigue, depression, forgetfulness, and weight gain which are  neither sensitive nor specific and overlap significantly between patients with and without thyroid disease.
A physical examination and a blood test to check TSH  ,T4 and T3 levels will be carried out. There’s no cure for hypothyroidism but  the standard  gold treatment is daily use of the synthetic thyroid hormone levothyroxine to achieve a state of euthyroidism and normalisation of circulating levels of TSH and thyroid hormones. Levothyroxine  if taken with various medications or  and milk based beverage  can impair the absorption of levothyroxine. Hence its advisable to take levothyroxine first thing in the morning on an empty stomach , 1-2 hours before breakfast, and 4 hours before consuming any milk based products or any supplements. The dosage may change over time, so regular   visits with your doctor is recommended. Five foods to add to your diet If you have hypothyroidism are roasted seaweed
which is naturally rich in iodine , salted nuts which  are an excellent sources of selenium, baked fish known to be  rich in Omega-3 fatty acids and selenium , frozen yogurt and dairy products are said to contain iodine and fresh eggs contain healthy amounts of both selenium and iodine.

Myxedema coma is an extreme complication of hypothyroidism and is life threatening in which patients exhibit multiple organ abnormalities and progressive mental deterioration. This occurs when the body’s compensatory responses to hypothyroidism are overwhelmed by a precipitating factor such as infection. Patients with myxedema coma usually have longstanding hypothyroidism, although it may not have been previously diagnosed. The patient with myxedema coma should be admitted to the intensive care unit as it  carries a significant mortality rate even with appropriate testing and treatment.

 THYROID AND MY BABY

Thyroid disease is the second most common endocrine disorder affecting women of reproductive age, and when untreated during pregnancy can lead to  increase risk of miscarriage, placental abruption, hypertensive disorders and growth restriction.

The prevalence of hyperthyroidism in pregnancy ranges from 0.1% to 1.6% worldwide. In Malaysia, the incidence of hyperthyroidism in pregnancy is 0.9 per 1000 deliveries. The onset of the disease in pregnancy is  rare . Grave’s disease is  the most common cause.

The prevalence of hypothyroidism in pregnancy ranges from 0.3% to 4.8%. The onset of the disease in pregnancy is rare  and the most common cause of hypothyroidism in pregnancy is chronic autoimmune thyroiditis (Hashimoto’s thyroiditis)  apart from surgery, radioiodine ablation, congenital hypothyroidism and rarely, lymphocytic hypophysitis.

Thyroid cancer: the prognosis is good

Thyroid cancer is a rare type of cancer and can present as a painless lump or swelling in the neck. It can also be associated  with unexplained hoarseness of voice  that lasts for weeks , a sore throat or difficulty swallowing that doesn’t get better or may present without any symptom whatsoever.  However , not all thyroid nodules indicate thyroid cancer. About 1 in 20 thyroid lumps are cancerous. The exact cause of thyroid cancer is unknown, but it can be linked to some inherited conditions. Women are 2 to 3 times more prone  to develop thyroid cancer than men.

There are 4 main types of thyroid cancer:  papillary carcinoma – the most common type, accounting for about 6 out of 10 (60%) cases; it usually affects people under the age of 40. Follicular carcinoma – accounts for around 3 out of 20 (15%) cases of thyroid cancer and tends to affect older adults. Medullary thyroid carcinoma – accounts for between 5 and 8 out of every 100 diagnosed cases (5-8%); can run in families and anaplastic thyroid carcinoma –  the rarest and most aggressive type of thyroid cancer and it usually affects older people over the age of 60 .

Tests and procedures used to diagnose thyroid cancer include: physical examination, blood test, ultrasound imaging fine needle aspiration biopsy and other imaging test and genetic testing in particular for medullary thyroid carcinoma.

Treatment  depends on the type and grade of the cancer, and whether a complete cure is realistically achievable. Modalities of treatment include a combination of surgery to remove  most or all of  the thyroid gland (thyroidectomy) and  radiotherapy that destroys any remaining cancer cells and prevents the thyroid cancer returning. This is  followed by  lifelong treatment with levothyroxine. Recurrence is seen in 5-20% of people with a history of thyroid cancer and can also present in other parts of their body such as the bones.

Although women are at greater risk of developing thyroid problems,  it can happen to anyone. ​ With a proper diagnosis, thyroid dysfunction can be successfully treated so you can enjoy a healthy lifestyle.