Polar T3 syndrome

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Polar Triiodothyronine, also known as Polar T3 syndrome, is a condition found in polar explorers, caused by a decrease in levels of the thyroid hormone T3.[1][2] Its effects include forgetfulness, cognitive impairment and mood disturbances. It can exhibit itself in a fugue state known as the Antarctic stare.[3][4][5]It is regarded as one of the contributory causes of winter-over syndrome.[3]


The exact cause of Polar T3 syndrome is unknown, but there are certain characteristics of this syndrome that are shared with patients that have subclinical hypothyroidism.[6] One common bio-marker that is known is the thyroid-stimulating hormone (TSH), which is a hormone that leads to a cascade of other hormones being released that affect the pituitary gland.[6][7][8] This hormone in particular is found in large quantities in people with Polar T3 syndrome. Additionally, other hormonal changes include a significant decrease in triiodothyronine (T3) and thyroxine (T4).[6][7] All of these biochemical alterations are thought to be due to the extreme cold and dark winter months.[9] Other attributing factors are changes in the circadian rhythm patterns and lack of social interaction.[9]


People diagnosed with Polar T3 syndrome are known to have a variety of symptoms including sleep disruptions, mental impairment, and mood changes. Sleep disruptions include inability to fall asleep or stay asleep and are more prominent in the winter months, according to a study done by Palinkas.[9] Most of these sleep disruptions are characterized by a decrease in short wave sleep and rapid eye movement (REM).[9] The Palinkas survey concluded that on average 64% of people living in the Antarctic polar region are affected by some sort of sleep disruption.[9] In addition to problems with sleep, 51.5% of people suffer from cognitive impairment.[9] This type of deficiency includes a decline in proficient memorization and the inability to concentrate.[9][6] Other areas of mental impairment are mood changes (negative affect).[9] These include depression, anxiety, and irritability throughout the winter months.[9][6][7]

Diagnosis and Treatment[edit]

When determining if a person has Polar T3 syndrome multiple aspects are taken into consideration. Biochemical tests can be carried out which test for differences in serum thyroid and plasma lipid levels.[6] The main purpose of these tests are to gain insight on the thyroid function.[6] Other assessments include analysis of changes in mood and memory function.[9][6] If a person is diagnosed with Polar T3 syndrome using the assessments mentioned above, then hormonal therapy is commonly prescribed including thyroxine supplements.[6]


  1. ^ Reed HL, Silverman ED, Shakir KM, Dons R, Burman KD, O'Brian JT (April 1990). "Changes in serum triiodothyronine (T3) kinetics after prolonged Antarctic residence: the polar T3 syndrome". The Journal of Clinical Endocrinology and Metabolism. 70 (4): 965–74. doi:10.1210/jcem-70-4-965. PMID 2318952.
  2. ^ Palinkas LA, Suedfeld P (January 2008). "Psychological effects of polar expeditions". Lancet. 371 (9607): 153–63. doi:10.1016/S0140-6736(07)61056-3. PMID 17655924.
  3. ^ a b Palinkas LA, Reed HL, Do NV (1997). "Association between the Polar T3 Syndrome and the Winter-Over Syndrome in Antarctica". Antarctic Journal of the United States Review 1997. Retrieved 2011-11-04.
  4. ^ Emily Stone (November 9, 2004). "Treating the Antarctic blues".
  5. ^ "Polar T3 Disorder". Natural History Museum. 17 April 2008.
  6. ^ a b c d e f g h i "Medicine". www.nsf.gov. Retrieved 2018-09-10.
  7. ^ a b c Yamashita, Koh; Suganuma, Kazuki; Funase, Yoshiko; Yamauchi, Keishi; Aizawa, Toru (2012-12). "Elevation of thyrotropin upon accidental hypothermia in an elderly man". Thyroid: Official Journal of the American Thyroid Association. 22 (12): 1291–1293. doi:10.1089/thy.2012.0084. ISSN 1557-9077. PMID 23083443. Check date values in: |date= (help)
  8. ^ "Thyrotropin-releasing hormone | You and Your Hormones from the Society for Endocrinology". www.yourhormones.info. Retrieved 2018-09-20.
  9. ^ a b c d e f g h i j Palinkas LA, Suedfeld P (January 2008). "Psychological effects of polar expeditions". Lancet. 371 (9607): 153–63. doi:10.1016/S0140-6736(07)61056-3. PMID 17655924.