Most people think that hypothyroidism causes obesity. While this can be true, there is another side to the picture. Research is flipping around the binoculars and posing the thyroid-obesity link in a novel manner and it involves the hormone leptin. Over the last few years, growing evidence demonstrates that elevated levels of leptin with other fat cell hormones causes increased susceptibility to autoimmune thyroid disorders like Hashimoto’s and Grave’s disease. Leptin dysfunction, which may or may not be associated with obesity in this focus, actually causes inflammatory challenges to the thyroid causing autoimmune thyroid problems. The unfit fat cells and higher levels of leptin lead to thyroid dysfunction.

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Several years ago, as researchers were starting to learn about leptin, a groundbreaking study identified elevated leptin levels in thyroiditis in women post pregnancy. In this 2004 study, scientists studied women who were one month postpartum who were positive for the thyroid antibodies (TPO - thyroid perioxidase antibodies) versus women who were also one month postpartum but did not have TPO antibodies. TPO levels are most commonly found with Hashimoto’s thyroiditis and to a lesser extent with Grave’s disease, according to the Mayo Clinic.

Leptin levels were elevated in postpartum women who had developed autoimmune thyroid and remained elevated for several months. The study results suggested that elevated leptin levels were involved in the development of the autoimmune thyroid disease. Increased body mass levels occurred with the elevated leptin.

An article published in the journal Thyroid in June 2013 indicated that leptin resistance and obesity enhances the development of autoimmune thyroid problems. The chronic systemic low-grade inflammation from faulty leptin hormone function and unfit fat cells caused immune changes to thyroid. The key link between obesity and the development of autoimmune thyroid problems is leptin.

Excess Leptin Linked with Other Autoimmune Disorders

Adipokines, which are fat cell hormones like leptin, adiponectin, and others, have been linked especially with thyroid autoimmunity, like Hashimoto’s. Leptin elevations are also linked with other TH1, TH2, and TH17 dominant autoimmune disorders like rheumatoid arthritis, lupus, inflammatory bowel disease, multiple sclerosis, type 1 diabetes, psoriasis, and psoriatic arthritis. Research demonstrated that the autoimmune thyroid disorders did not occur when leptin was at normal levels.

Elevated Leptin May Occur Regardless of Body Weight, Age, Etc.

If you are thinking that obesity, leptin resistance, and autoimmune thyroid problems apply only to women that is not the case. A study published last month, demonstrated that men who had normal body weight, but elevated leptin levels correlated with autoimmune thyroid problems. This certainly adds several dimensions, but it reveals that leptin levels play a direct pivotal role in Hashimoto’s autoimmune thyroiditis in men and women in obese and non-obese situations.

Another very recent study again demonstrated that leptin was elevated in autoimmune thyroid patients. In this study, it was found that autoimmune thyroid differences could not be explained by age, body mass index, TSH (thyroid stimulating hormone), FSH (follicle stimulating hormone), estradiol, and free T4 (thyroid). Leptin levels were simply higher in patients with autoimmune thyroid disorders compared to those who didn’t have elevated antibodies.

Leptin elevation leading to autoimmune thyroid concerns extends beyond adults; it affects the young and unborn too. An animal study published just days ago studied unborn rat pups exposed to bisphenol-A (BPA), an endocrine disrupting compound, in very small doses through maternal exposure. BPA is well known common toxin linked with obesity and endocrine disruption. Elevated leptin levels, TSH, TNF, insulin, and adiponectin levels and lowered T4 and T3 were identified in the fetal pups. The authors thought that BPA may penetrate the placental barrier and disturb the fetal thyroid – leptin/adipokine communication links affecting fat metabolism and the endocrine system causing autoimmune thyroid and obesity problems in early life.

There are several ways to understand the layers of interplay between obesity, leptin and autoimmune thyroid. These recent studies provide novel and growing insight into the key viewpoint and link that elevated leptin causes autoimmune thyroid problems. This sequence of events becomes a vicious cycle of autoimmune thyroid inflammation, obesity, and poor function.

Thyroid lab tests like TSH, fT4, and fT3 often won’t identify subclinical autoimmune hypothyroidism. Autoimmune thyroid antibodies or leptin are frequently not measured in the standard medical thyroid work-up. While taking thyroid hormone or using nutrients to help the thyroid gland and hormone do its job is a fundamental approach and the standard of care, it is obvious that leptin must be balanced. These studies provide evidence that elevated leptin is a major instigator of autoimmune thyroid problems. Keep in mind that it has been estimated that nearly all thyroid problems are autoimmune. Leptin is an inflammatory adipokine. When it is out of balance, inflammation rises and autoimmune disorders develop.

Key Focus Points for Leptin Management

Leptin, Thyroid, and Weight Loss. This article was originally published January 14, 2009. It delves into different levels of thyroid and leptin problems. Keep in mind, the studies presented in this current article demonstrate that leptin is elevated in autoimmune thyroid disorders regardless of obesity. Lab changes may or may not be present or even measured. Leptin is “punching the thyroid gland in the nose” showing who is boss.

What Causes Elevated Leptin?

Elevated leptin occurs as a result of several factors. Here are some of them.

Circadian rhythm changes and low level ambient light exposure at night changes the rhythm of metabolism. Emerging research demonstrates this effect occurring around the world. It tells us that having out-of-sync schedules with the natural rhythms of the earth acts as a monkey wrench in the body’s metabolic activities and causes obesity. This directly interferes with leptin function, leading to high levels of inflammation, metabolic syndrome, and obesity.

Research also tells us that eating out-of-sync and the wrong types of food causes elevated leptin. Three meals per day with adequate protein, good quality fats, some complex carbohydrates, unlimited colorful non-starchy vegetables, and low glycemic index fruits like berries and fruits that have a pit are at the mainstay of a healthy diet.

Elevated leptin occurs as result of the high-calorie, nutrient poor intake. 

There are other causes for elevated leptin. Factors include emotional stress, estrogen, insulin, obstructive sleep apnea, and mold toxins and sick building syndrome.

WellnessResources.com contains a vast amount of information about leptin. Here are some great places to learn more.

Top Leptin and Weight Loss Stories of the Past Year

The Leptin Diet Weight Loss Challenge #1 – Overview and Basic Needs

How Digestive Problems Prevent Weight Loss – The Leptin Diet Weight Loss Challenge #2

Why Toxins and Waste Products Impede Weight Loss - The Leptin Diet Weight Loss Challenge #3

Malfunctioning Immunity Causes Weight Gain – The Leptin Diet Weight Loss Challenge #4

Germ Gangs Block Weight Loss – The Leptin Diet Weight Loss Challenge #5

Unclog Your Liver & Lose Abdominal Fat – Leptin Diet Weight Loss Challenge #6

The bottom line: if you have an autoimmune thyroid problem, leptin played a role in causing it. Obesity may or may not be present, but the elevated leptin is. It is imperative to get leptin and the autoimmune inflammation under control. Use this information to help pinpoint why leptin may be elevated. Surgical removal of the thyroid gland and taking thyroid hormone replacement for the rest of your life with an autoimmune thyroid problem is the standard of care in the medical profession. It does nothing to address the leptin-autoimmune inflammatory condition. This approach is likely to leave you feeling miserable with even worsening health. It certainly does not address the deeper issues. Restoration of health is far more complex than a simple hormone replacement. It takes work, but in the long run, your life, health, and those around you will reap the benefits of what you sow with leptin balance.