Link Between Obesity and Thyroid - The Insider Look
Posted By Rupa Jaiswal
Posted on Jan 12, 2022
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
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.
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
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.