Link Between Obesity and Thyroid - The Insider Look

Choosing elevator over stairs, excessive consumption of junk food or overconsumption of alcohol, all these factors lead to obesity. Obesity has increased significantly since the 1970s.? Presence of extra body fat or having a body mass index (BMI) more than 30 kg/m is characteristic of obesity. It may be due to consuming more calories than required, genetic makeup of your body, your lifestyle, less sleep, etc.

Apart from obesity, thyroid disorder is another factor that is steadily affecting many individuals across all age groups. One out of three individuals have thyroid-related condition that affects the production of thyroid hormones. The hormone produced by thyroid gland, T4 (thyroxine) and triiodothyronine (T3) is stimulated by Thyroid Stimulating Hormone (TSH). Thyroid conditions may be due to iodine deficiency, autoimmune diseases like Graves' disease or Hashimoto's thyroiditis, toxic nodules, inflammation of thyroid, etc.

Abnormality of thyroid hormones is responsible for weight gain since they control body Metabolic. Several studies have reported a positive correlation between increased BMI and thyroid conditions. Another factor which can be the link between obesity and thyroid disorder is leptin-a starvation hormone (hormone made by adipose cells which also influences TSH release).

Are obese people more prone to Thyroid disorders?
It is clear that hypothyroidism can cause obesity, but the phenomenon of how obese people are more prone to thyroid related condition is still not well understood. According to the study from 2006 based on 6164 adults, higher BMI was linked to higher TSH, especially central obesity (abdominal obesity). Lower Free Thyroxine Ft4 and higher TSH levels are associated with fat accumulation in slightly overweight individuals.

Leptin a hormone which is produced by adipocytes (fat cells), regulates the energy balance by inhibiting hunger and this can be the possible link between BMI and TSH. Leptin hormone is an important neuroendocrine regulator and therefore it plays an important role in the regulation of thyroid homeostasis. There is a negative correlation between the levels of thyroid hormones and leptin. Whereas, the levels of TSH is positively correlated to obesity thereby resulting in a positive correlation with leptin levels. This clearly shows the association between BMI and TSH as reported in clinical studies. With the increase of weight, moderate increase in T3 and TSH levels were noted regardless of insulin sensitivity and metabolic parameter.

Thyroid disorders that cause obesity
Thyroid hormones regulate your body metabolism. Fluctuations in the levels of thyroid hormones are responsible for changes in body weight. Oversecretion of thyroid hormones (Hyperthyroidism) leads to sudden weight loss, whereas under secretion (Hyperthyroidism) leads to sudden weight gain. hypothyroidism leads to low basal metabolic rate (BMR) making individuals more prone to weight gain. Individual's weight gain varies with the severity of hypothyroidism and massive weight gain is rarely seen. In patients suffering from hypothyroidism, excessive fat is not the only reason for weight gain but accumulation of salt & water can also be the cause.

Obesity & Thyroid Cancer
Cases of obesity linked with thyroid cancer have increased significantly in last few decades. Based on the origin, appearance or characteristics, there are mainly 4 types of thyroid cancers
1. Papillary Thyroid Cancer
2. Follicular Thyroid Cancer
3. Medullary Thyroid Cancer
4. Anaplastic Thyroid Cancer
Among all the thyroid cancers, papillary thyroid cancer is the most commonly diagnosed.

One study in US reported obesity to be an independent risk factor for developing thyroid cancer.' Another study demonstrated that risk of developing thyroid cancer in women is greater in overweight and obese (BMI > 25 kg/m) than the normal weight individuals and excess ingestion of calorie, proteins and carbohydrates might be the link between obesity and high risk of papillary and follicular thyroid cancer.

Diagnosis- Prevention is Better than Cure
A set of blood tests should be done regularly for diagnosing obesity-related conditions especially if you are a middle-aged individual and experiencing the symptoms like fatigue, joint pains, concentration problems, weight loss/gain, High blood pressure, frequent urination, nervousness, etc.

Thyroid profile Most of the thyroid hormones produced in the body binds to the protein and some of them are unbound in your blood, hence in free form. T3 & T4 test measures the total T3 & T4 count present in your blood. TSH test can be done in order to measure the TSH levels.
lipid profile This profile measures the level of total cholesterol and triglycerides levels in your blood. LDL-bad cholesterol includes the test for Total Cholesterol, HDL Cholesterol, LDL Cholesterol and Triglycerides.
Blood sugar test This test helps in monitoring your blood glucose level. It is an essential test if you have diabetes.
Cardiac risk markers profile This test assesses your cardiovascular condition and determines the exact condition of your heart. Tests like ApolipoproteinA1, Apolipoprotein-B, Lipoprotein, hs-CRP and Apo B/Apo A1 ratio constitutes the Cardiac Risk Marker.

During obesity, gaining extra weight can affect your body in many ways including your thyroid hormone levels. These alteration leads to various disorder related to thyroid or even cancer in some cases. It is important to take care of your health as it is only you who will be looking after yourself till the very end. Regular health checkup can help you take timely precautionary actions to prevent such conditions.