Introduction
There have been different concerns on the relationship between hypothyroidism which is the underactiveness of the thyroid gland which cause an insufficient thyroid hormone production and weight gain/ obesity. This is due to the fact that hypothyroidism affects the metabolism calories and is frequently irreversible and progressive
Main Discussion
There are two types of hypothyroidism; the subclinical or mild hypothyroidism and overt hypothyroidism. The subclinical hypothyroidism state is where the concentration of TSH (Thyroid Stimulating Hormone) is elevated above the reference or normal range and the thyroxine is standard. The overt condition is where the thyroid stimulating hormone is above normal range and the thyroxine is below the range Nilsson (2007).
Research shows that 2 to 5 percent of those people with subclinical or mild hypothyroidism condition do not necessary lead to overt hypothyroidism. This is because of the treatment of the condition at early stages. Hypothyroidism was first identified in the nineteenth century after an operation being done on the thyroid gland was performed; there were swellings of the face, hands and other eyes. After much analysis by the doctors, they realized that this was caused by the lack of thyroid hormones that are produced by the thyroid glands.
A number of research studies have been done to try and ascertain if really this relationship should be a concern or is just a myth. Experiments have been done to patients with hypothyroidism to determine the cause of the condition. A person with hypothyroidism produces less thyroid hormone making the body functions and metabolism to be slow. This can have an effect to the normal metabolic function of the body.
Hypothyroidism is a common type of thyroid dysfunction in the United Sates of America with up to five percent of the population having the problem. According to “the survey by National Health and Nutrition Examination of 1999 to 2002, 4,392 individuals are reported to have hypothyroidism (Centers for Disease Control and Prevention). Out of this population, women are the more affected population and more likely to be affected compared to men. Among women, older women are more likely to suffer from hypothyroidism with about twenty percent of those above 60 years have hypothyroidism. For the cases of hypothyroidism which are caused by iodine deficiency, the prevalence is about 2 to 5 percent and it increases to 15 percent for those who are more than 60 years. Research done by Verma, et all (2008) showed that those people with overt hypothyroidism are more overweight considered to those with subclinical hypothyroidism.
The survey by “the National Health and Nutrition Examination” also shows that in those who have hypothyroidism both overt and subclinical hypothyroidism, whites are the ones with the higher percentage of 5.1 percent then Mexican Americans. The prevalence was lower in African American with a percentage of about 1.7 percent.
Hypothyroidism which affects the thyroid glands is caused by a number of factors. One of the causes is the thyroid gland swelling leading to the damage of cells in the thyroid gland thus incapable of producing the require amount of thyroid hormone. Also thyroid surgery can causes hypothyroidism. These occurs because during the surgery, a section of the thyroid gland is removed thus leading to small number of cells that produces hormone that cannot produce the required amount of hormone for the normal body function.
Also in some rare conditions, a malfunction of the pituitary gland leading to less production of Thyroid Stimulating Hormone that is responsible for the coordination of the production of thyroid hormone from the thyroid glands. This will therefore leads to a reduced amount thyroid hormone produced. Iodine deficiency can also lead to hypothyroidism in most parts of the world (Galofre, et al. 2008)
A person who has hypothyroidism has a number of signs and symptoms depending on the intensity of the condition and the deficiency of the thyroid hormone. Of this signs and symptoms, one of the unwanted and frustrating symptoms is the gaining of weight which is generally slow but steady. During the first instances, one cannot correlate the gaining of weight and hypothyroidism. But after some time, the gaining of weight is much more noticeable and the fear of obesity is common. This therefore me him or her to conclude that the obese condition that he or she has is as a result of hypothyroidism. Other signs and symptoms associated with hypothyroidism are muscle weakness, menstrual periods that are heavy, pale and dry skin, muscle aches, increased blood cholesterol levels and hoarse voice among others Burman, et al., (2009).
Different studies relate weight gain with the thyroid gland. Although the relationship between different thyroid diseases like hypothyroidism, metabolism and weight gain which leads to obesity is still complex, studies done recently shows there is a possibility of the relationship. Thyroid glands secretes hormone known as thyroid hormone which is necessary for metabolic regulation. The metabolic activity uses energy present in calories present in the body for its activity and is measured by the quantity of oxygen used by the body at a definite time. The measurement of metabolic rate is most of the time done when one is resting making it to be known as BMR (basal metabolic rate) which according to (SirGan, 2006) was used as a test to evaluate the status of the thyroid gland. Hypothyroidism which is caused by low thyroid hormone can be measured using basal metabolic rate and is associated with low basal metabolic rate (low BMR).
The difference in basal metabolic rate whether high or is associated with the changes in the balance of energy in the body. For the body to produce energy one must have eaten food that has calories and its balance (energy balance) is determined by the amount of calories that the body uses and the one that one consumes. If there is a significant change in the hormone like for instance inadequate thyroid hormone which leads to hypothyroidism, there is a change in ‘Basal Metabolic Rate’ which in turn leads to low Basal Metabolic Rate and change in energy balance in the body. A low BMR due to change in energy reaction affects the body weight. The body weight will increase in situations of low BMR because the amount of calories used is less compared to the amount of calories consumed (Arenz, et al.2008).
A person with hypothyroidism has a decreased basal metabolic rate due to the change in the energy balance in the body. As earlier stated the change in energy balance is due to the different in the amount of calories the body use and the amount consumed. In a decreased basal metabolic rate, there is less energy produced as there is les thyroid hormone produced. This means that the amount of calories eaten by the person is more than that being used. The extra calories are therefore stored in the body leading to weight gain. In a circumstance that the condition (hypothyroidism) persists, there is much weight gain that leads to obesity. Those people with a severe case of hypothyroidism tend to gain more weight that those with less severe case.
Obesity or weight gain in hypothyroidism is much more intricate than one can think. The weight gained in hypothyroidism is not only due to the accumulation of calories and fats in the body caused by low metabolism but also it is caused by the accumulation of excess water and salt in the person (Lubell, et al 2009). Although there is weight gain in a person with hypothyroidism, it does not lead to an enormous weight gain. One can gain about five to ten pounds due to hypothyroidism depending on the level of hypothyroidism severity. The lack of thyroid hormones due to hypothyroidism affects the metabolism of starch as there is no enough energy for its metabolism. The starch therefore accumulate therefore accumulates in the body leading to weight gain.
The endocrine system; which the thyroid glands falls can also be said to be associated with obesity/ weight gain. The fats that are in the body are stored in the adipose layer which undergoes lipid metabolism to produce energy used in the body. This metabolism depends on the assimilation of signals that include hormone (thyroid hormone), nutrients and neuronal pathways. The adipose layer which is associated with obesity can be synthesized with help of hormones to produce “adipocytokines” such as the leptin hormones released by adipocytes. The leptin hormone has several functions, for instance, it works as anti obesity hormone. In fact, a research has shown that cases of obesity are associated with the reducing levels of leptin.
Therefore if a person is suffering from hypothyroidism there is a decrease in the production of the thyroid hormone which is essential for the lipid metabolism. This in turn will lead to less fat being metabolized in the adipose layer leading to an increase in weight/ obesity. Also lack of thyroid hormone will lead to the less production of the leptin hormone which according to studies can act as anti obesity hormone (Amati, 2007).
Due to the consideration that hypothyroidism is associated with obesity; obesity has been used to diagnose the condition. This has also lead to programs being put in place to reduce weight to those who are obese and has hypothyroidism by first going for treatment of hypothyroidism Tozzo (2007). Research shows that the treatment of subclinical hypothyroidism does not have much influence on the total body weight. But in the case of a more severe case of hypothyroidism, there is about a 10 percent weight loss after treatment. This is because when a person has hypothyroidism, there is accumulation of water, fat and salt (accumulation of calories) leading to weight gain or obesity. Thus upon treatment of hypothyroidism these components are lost and the body reduces in weight. The treatment which is done by addition of the thyroid hormone also returns the metabolism of starch to normal thus the excess starch that was stored is metabolized resulting to weight loss Rotondi (2009).
Conclusion
Hypothyroidism which causes production of insufficient thyroid hormone by the thyroid gland can be associated with weight gain and after sometimes obesity. Weight gain, which is one of the signs and symptoms of hypothyroidism, is associated with the relationship between the amount of food eaten and the one used during metabolism to form a change in energy balance. This weight gain is caused by the low basal metabolic rate that is caused by low metabolic rate. Therefore the body accumulates much calories found in starch, fat, water and salt in food eaten which in the long run lads to weight gain.
“The National Health and Nutrition Examination” survey showed that hypothyroidism is more common in women than males. Among women, the older women are at more risk to the condition. This is due to the fact that at older age the thyroid gland is easily infected with diseases like goiter that affects the production of the thyroid hormone leading to hypothyroidism.
As shown in different research, the weight gain is more in the overt or severe hypothyroidism compared to the subclinical hydrothyroidism. This shows that incase one is diagnosed with these condition, he or she should visit a doctor before it becomes severe as it can cause much gain in body weight leading to obesity. One should also see a nutritionist to know the kinds of food that can be eaten to avoid increase in weight while suffering from hypothyroidism because in some extreme conditions it can lead to obesity.
References
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