Endemic simple goitre and its prevention and control

Introduction

It is an expansion of a simple thyroid gland with out toxic display is called simple endemic goitre or in other words,a morbid enlargement of the thyroid gland.A normal thyroid gland takes up a space of about 5 cm square across the front of the wind pipe( trachea) rings below the cricoid cartilage.It is a few mm in thickness at its central part. Normally the gland is not visible nor palpable. It becomes palpable only when it is enlarged 5 times all round. So goitre can not be diagnosed before the gland is 5 times expanded.It regulates body growth, metabolic rate, the development of brain, sexual development at adolescence, maintain normal pregnancy and milk lactation. These are carried by its internal secretions(hormone) called thyroxine. This gland has a chemical attraction for iodine. Iodine is necessary for the reduction of thyroxine.

Prevelance(Epidemiological distribution)

Local inhabitants in the foot hills of Himalayas up to the height of 6000 to 7000 ft,suffer from endemic goitre. Simple goitre becomes endemic if the soil in an area is lack of iodine and hence results in low iodine content in water and vegetables and products grown there upon. Such goitre areas are found in Swiss, french,Austrian and Italian Alps and rocky mountains in United states and also found in Himalayan regions.The distribution of endemicity in these areas is, however belonging to focus, sometimes the goitre pockets adjourns the non goitre areas, separated by only a water shed or supply of salt.

Causes of the simple goitre

Simple goitre develops if enough iodine is not made available to the thyroid gland or if the demand increases as in puberty for growing tissues or if the thyroid can not utilise the available iodine. Thyroid may go deficient of iodine if it is deficient in food, water, milk if it is not properly absorbed. It may less in food and water if it is less in soil or bacterial pollution of water or cyanates in vegetables. The deficiency in hill areas may also be low consumption of common salt due to non availability or low bodily requirement due to the cold atmosphere. In mountainous areas the soil is also poor in sodium or potassium salts. If the soil is salt free due to ancient deposition of ice on it which has left silt-free salt dry, for example, in North America, St.Lawrence and lake city area and Oregon.

Stages of goitre.

Simple goitre starts in childhood due to lack of iodine and fully develops by the age of 30 years after that it becomes nodule or swelling.The cells increases in size and numbers in the attempt to produce enough thyroxine out of diminished iodine contents,when it is enlarged more than about 5 times.It is palpable and called first stage. according to expansion it has 4 stages and further enlargement of swelling becomes irregular and nodular,then terned as nodular goitre,and this stage may be reached after 30 years of age.hence there are 2 groups,first group is called non nodular and second is called nodular stage.

Effects of goitre

Simple goitre may not cause any ill effects,but has a potential of becoming nodular and then its big size it may cause disturbances in breathing due to pressure on the nerve.When it may become a toxic goitre and rise to the signs and symptoms of Graves disease.Congenital or infancy defects are more common in goitrogenic tracts. Nodular goitre may turn to malignancy in advanced ages.

Causes of iodine deficiency in regional areas

Genetic character of the local population, deficient iodine in vegetable products due to presence of cyanates, bacteriological pollution of water supplies causing iodine deviation,high magnesium and calcium hardness of water and lack of iodine in the soil and tracts.

Prevention,control and remedy

Administration of a minute quantity of iodine from childhood prevents goitre in endemic areas. Iodized salt supply to population in goitrogenous areas prevents endemic goitre from developing the community. It is proposed by mixing and and then grinding common salt with 0.02 percent of potassium iodide or 0.002 percent of iodate. It is noted that even proprtions of lower than this will prevent endemic goitre. Eltraxin(sodium levo-thyroxine)is used with results for rapid reduction of enlarged goitre. Uncomplicated cases may be treated with Eltroxin with out admission to hospitals,but those cases showing toxicity or other complications should be admitted to hospitals.All treatments should be given under the supervision of registered medical practitioners. Monthly or periodical check up for the detection of the early goitre in endemic areas also be carried out as preventive and control measures.

PM Kutty