Thyroid Disorders Towards a Healthy Endocrine System

Thyroid Disorders Towards a Healthy Endocrine System

What are Thyroid Disorders? The thyroid is a butterfly-shaped gland in the middle of the lower neck. Through the release of hormones, the thyroid regulates metabolism, influences the way energy is utilised, and impacts almost every organ in the body. Thyroid disorders refer to the conditions due to the malfunctioning of the thyroid. Hypothyroidism Hyperthyroidism Definition Risk Factors When the thyroid produces insufficient thyroid hormone, resulting in the body using energy, slower than it should Female and > 60 years old Family history of thyroid disorders Previous thyroid problem Prior thyroid surgery Radiation treatment of the thyroid, neck, or chest When the thyroid produces too much thyroid hormone, making the body use energy faster than it should Female and > 60 years old Family history of thyroid disorders Pernicious anaemia Type 1 diabetes Major Causes Common Symptoms Hashimoto s thyroiditis and other forms of thyroidal inflammation Congenital hypothyroidism Surgical removal of part or all of the thyroid Radiation treatment of the thyroid Excess/insufficient iodine intake Pituitary disease Fatigue Gain in weight Puffiness in the face Low tolerance of cold Pain in the joints and muscles Constipation Dry skin Thinning hair Heavy or irregular menstrual periods Goiter Graves disease Thyroiditis Overactive thyroid nodules Non-cancerous tumour of the pituitary gland Excess iodine intake Fatigue Loss of weight Low threshold for heat Trembling hands Frequent bowel movement or diarrhoea Irritability Nervousness Sleeping difficulties Rapid and irregular heartbeat Goiter

Laboratory Tests fo Free Thyroxine (FT4) Playing an important role in regulating metabolism, FT4 is a hormone synthesised and secreted by the thyroid. FT4 circulates freely and is metabolically active. Measurements of FT4 are often used to help diagnose hypothyroidism and hyperthyroidism. Free Triiodothyronine (FT3) FT3 is a hormone synthesised and secreted by the thyroid. Unbound and metabolically active, FT3 is usually measured to help diagnose hyperthyroidism as well as to monitor patients with thyroid disorder. Thyroid-Stimulating Hormone (TSH) TSH stimulates the thyroid to synthesise and secrete FT4 and FT3. TSH measurements are used to detect primary hypothyroidism and hyperthyroidism. Anti-Thyroid Peroxidase (Anti-TPO) Antibody Measurements of anti-tpo antibody can aid in the diagnosis of various autoimmune thyroid diseases such as Hashimoto s thyroiditis and Graves disease. A higher level of anti-tpo antibody is also a risk factor for postpartum thyroiditis.

r Thyroid Disorder Thyroglobulin (Tg) Produced mainly by the thyroid, Tg is a glycoprotein homodimer that acts as a substrate for FT4 and FT3 synthesis. The Tg test is often used to assess the effectiveness of thyroid cancer treatment and it is also ordered to help diagnose hyperthyroidism. Thyroglobulin Antibody (TgAb) The TgAb test measures antibodies to Tg. For most healthy individuals, Tg is usually undetectable in the blood stream. While TgAb may be tested as part of an evaluation after thyroid cancer treatment, it can also help diagnose hypothyroidism. Thyroid-Stimulating Hormone Receptor Antibody (TRAb) The TRAb test is often used for the differential diagnosis of hyperthyroidism and as part of treatment management. Measurement of TRAb can also be taken in the last trimester of pregnancy for the diagnosis of neonatal thyroid disease. Thyroid-Stimulating Immunoglobulin (TSI) TSI measurements are used to monitor the response to Graves disease therapy and to predict remission or relapse, confirm Graves' ophthalmopathy, and predict neonatal hyperthyroidism. TSI is specific to the stimulatory kind of antibody, versus that of TRAb which detects both, leading to a better diagnosis of Graves disease.

Assessment Stratification for Thyroid Dysfunction a If laboratories are unable to identify those specimens that specifically require the measurement of both serum TSH and FT4, then it would be prudent to measure serum TSH and FT4 on all specimens rather than embark on a firstline serum TSH strategy. 2.2 Screening for Thyroid Dysfunction, UK Guidelines for the Use of Thyroid Function Tests 2006. b TSH-secreting pituitary adenomas and selective pituitary resistance to thyroid hormone, that will be overlooked by serum TSH measurement alone; serum FT4 and FT3 concentrations should also be measured when these conditions are suspected. Laboratory Testing Strategies, ATA Guidelines. c To confirm or rule out thyrotoxicosis. NACB Guideline: Laboratory Support for the Diagnosis and Monitoring of Thyroid Disease, Laurence M. Demers, PhD, FACB and Carole A. Spencer, PhD, FACB. Thyroid Tests at Quest Quest Laboratories offers a full suite of tests for the diagnosis of thyroid disorder. TEST Free T4 (FT4) Free T3 (FT3) Thyroid-Stimulating Hormone (TSH) Anti-Thyroid Peroxidase (Anti-TPO) Antibody Thyroglobulin (Tg) Thyroglobulin Antibody (TgAb) Thyroid-Stimulating Hormone Receptor Antibody (TRAb) Thyroid-Stimulating Immunoglobulin (TSI) QTP1 QTP2 QTP3 QTP4 QTP5 QTP6 QTP7 QTP8 Published: August 2017

About Quest Laboratories Quest Laboratories is the largest independent private medical laboratory in Singapore with two international accreditations. Accredited by the Singapore Accreditation Council (SAC-SINGLAS ISO 15189) and the College of American Pathologists (CAP), Quest is part of Healthscope, one of Australia's leading providers of integrated healthcare, operating over 40 private hospitals and more than 50 medical centres, with leading pathology facilities in New Zealand, Singapore, Vietnam, and Malaysia. Main Laboratory 67 Ubi Avenue 1, StarHub Green, North Wing, #07-01 to 07, 09 & 10 Singapore 408942 T: (65) 6275-5501 F: (65) 6277-0236 Satellite Laboratory 290 Orchard Road, Paragon Medical, #17-07 to 09 Singapore 238859 T: (65) 6737-2788 F: (65) 6887-3249 E: sales@questlabs.com.sg W: www.questlabs.com.sg