The monster in your family
KOCHI: There are 750 million persons who are affected with thyroid globally. In India, it is estimated to be 42 million. Hypothyroidism is more common than hyperthyroidism and affects 10 per cent of women and three per cent men while hyperthryoidism affects two per cent women and 0.2 per cent men.
In India, around 73 per cent of diabetic females and 25 per cent of persons with cholesterol problems have hypothyroidism. Since many patients are asymptomatic, they do not know they have thyroid.
The largest gland
The 15-25 gram thryoid gland situated in front of the neck is the largest endocrine gland in the body, compared to the one gram pituitary gland or the 4.5 gram adrenal gland. Thyroid gland secretes 100 mcg of T4 and 30 mcg of T3 hormones daily and these minute quantities control the metabolic activities of each cell in the 60 kg body.
These hormones are necessary for the growth, energy and development of every organ especially the brain. Fatigue, forgetfulness and depression are the common symptoms in hypothyroidism, while irritability, nervousness and loss of weight are in favor of hyperthyroidism. Hypothyroidism is one of the most common causes of infertility.
60 per cent of thyroid diseases are autoimmune leading to hypothyroidism or rarely hyperthyroidism. In autoimmune thyroid diseases, the body produces antibodies against your own thyroid and these antibodies destroy the thyroid cells resulting in hypothyroidism or stimulates the thyroid cells resulting in hyperthyroidism. Auto immune hypothyroidism is 10 times more common than hyperthyroidism.
Genes have an important role in the production of auto-antibodies (CLT4 gene, PTPN 22 gene). 30 per cent pregnant women have hypothyroidism and almost all of them have positive thyroid antibodies.
In pregnancy, the disease can produce antenatal complications like abortion, miscarriage, fetal death and in children low IQ and neonatal hypothyroidism (cretinism). Hence, it is mandatory to test the thyroid function and thyroid antibodies in pregnancy.
Familial hypothyroidism
Seventy five percent babies born to women with positive thyroid antibodies had thyroid antibodies in their blood and five per cent had neonatal hypothyroidism. It is not surprising to observe all the members of the family (children and parents) suffering from hypothyroidism (familial). Hypothyroid children may have obesity, a low IQ and are poor in their studies.
They are often tortured with special tuitions and scoldings. These kids should be subjected to thyroid function studies including antibodies. Even if asymptomatic, a child or adult with a hypothyroid family member should undergo the above tests. Children with positive antibodies but normal thyroid function should undergo periodic evaluation since they are prone to the development of hypothyroidism in future.
To prove the familial nature of the disease recently, we evaluated 142 (57 males and 85 females) immediate relatives of 74 hypothyroid patients with positive thyroid antibodies seen in our clinic (eight males, 66 females). Thyroid function tests including thyroid antibodies were done in relatives.
Surprisingly, 133 relatives (94 per cent) had positive thyroid antibodies. 65 persons (45.7) had hypothyroidism out of which 55 were already taking treatment for hypothyroidism and 10 (15.4%) were newly detected at the time of this evaluation.
This study thus shows that hypothyroidism is often familial, and detection of the same at an early stage is beneficial. Testing immediate relatives of a thyroid patient with positive antibodies should be made mandatory and compulsory.