SpectraCell Blog

Leptin Resistance: Everything You Need to Know

Posted by SpectraCell Laboratories, Inc. on Wed, Aug 09, 2017 @ 02:26 PM

Overeating.jpgLeptin, often called the “satiety hormone,” is an adipokine (signaling molecule produced by fat cells) whose main function is to regulate energy and fat stores. In a metabolically healthy person, a temporary increase in caloric intake (such as after a big meal) corresponds to an increase in leptin production. This prompts the hypothalamus to send signals that promote satiety, which cues one to stop eating.

Leptin was the first adipokine to be discovered (in 1994) and changed how scientists view fat tissue. Fat stores were previously thought to be inert tissue that did not cause any direct harm. Upon the discovery of leptin and its related genes, scientists learned that excess adipose tissue is actually metabolically active, releasing several hormones (adipokines) and inflammatory enzymes. Consequently, it is now considered an endocrine organ.

Although leptin suppresses appetite, one can become leptin resistant, feeling hungry even when one consuming enough calories to maintain metabolic requirements. In a way that is analogous to insulin resistance, leptin resistance occurs in obesity: the higher the fat stores, the more leptin produced. In fact, leptin varies exponentially (as opposed to linearly) with adipose tissue. This means that changes in fat mass profoundly affect leptin levels. Over time, as leptin increasingly circulates in blood, the brain eventually becomes resistant to its effects. As a result, one becomes inclined to overeat, unable to experience satiety and therefore feeling hungry even when leptin levels are high! This is referred to as leptin resistance. 

An increase in leptin (in the short term) follows an increase in caloric intake. This promotes satiety and signals one to stop eating. However, in the long term, a chronic increase in leptin can be attributed to excess body fat, estrogen (endogenous and exogenous), insulin (leptin is released dose-dependently in response to insulin), stress, and some steroid medications such as dexamethasone.

Loss of fat tissue, reduction in caloric intake via dieting and fasting, testosterone (which is anabolic – this increases appetite), and ghrelin (the hunger hormone) are all factors that lower leptin. Sleep deprivation, which upregulates appetite, is a reason why sleep loss is linked to cravings, and also impacts levels.

Factors that impact leptin sensitivity include:

  • Excess body weight
  • High Fructose Corn Syrup (this blocks leptin receptors)
  • High Triglyceride levels block leptin’s ability to reach the hypothalamus
  • Estrogen deficiency: the leptin-estrogen link may cause menstrual cravings
  • Lectins in grains bind to leptin receptors, inducing leptin resistance 

Leptin receptors are found in several tissues besides the hypothalamus, including endothelial, muscle, placental, and liver cells. Although its appetite-regulating effects are well established, it is known to play a role in fertility and puberty; however, its other functions are not fully understood.

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Whether you are at high risk of heart disease or managing an existing metabolic condition, SpectraCell’s CardioMetabolic test is appropriate and recommended.

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Topics: cardiometabolic, Weight Management, Leptin, Leptin Resistance

Why is high blood sugar so bad?

Posted by Elissa Rodriguez on Mon, Nov 07, 2016 @ 02:06 PM

sugar.jpgDid you know that November is National Diabetes Month? This is extremely appropriate after Halloween and the sugar binging that usually accompanies it. While feasting on leftover candy, you might want to keep the following information in mind. After ingestion, sugar is not simply “burned off.” Even if you are fit and lean, sugar is harmful because it accelerates cellular aging. Sugar in the bloodstream attaches to proteins, creating something called advanced glycation end products (AGEs). These end products render those proteins inactive, and are commonly used as a marker for aging. In fact, one of the hallmark diagnostic tests for chronically elevated blood sugar/ diabetes is HbA1C, which is an AGE of a hemoglobin molecule. Sugar profoundly alters hormone balance, especially over time, which can set off a cascade of metabolic dysfunction that further accelerates aging systemically, from the arteries to the liver and skin. The dangers of sugar extend beyond a few extra pounds – this ubiquitous substance (found in everything from salad dressings to condiments to your favorite desserts) – actually ages the body from the inside out. 

 

 

Topics: diabetes, sugar, cardiometabolic, advanced glycation end products, cellular aging, high blood sugar, sugar binge