Short presentation on Leptin

by

Tripty Bansal & Shiny Williams

LEPTIN

What is Leptin?Leptin is a hormone produced primarily by fat cells and to a lesser degree by other tissues. It is the gatekeeper of fat metabolism, because it monitors how much energy a person takes in and it acts to maintain energy balance in the body by regulating metabolism and hunger.

Functions Of Leptin: It controls energy balance It regulates appetite It also helps in many other physiological responses such as female reproduction, immune function etc.

Mechanism Of Action:The level of leptin circulating in the body is directly proportional to the total amount of fat in the body. That means the more fat we have, the greaterthe amount of leptin we have. When present in high levels, it signals our brainthat we’re full and can stop eating. When low, we feel hungry and crave for food.The amount of Leptin Gene that is expressed from fat is strongly regulated. This suggest that the fat cell knows how much fat it has & adjust leptin accordingly. But the underlying mechanism responsible for this regulation is still unknown.

Research Studies:

Howard Medical Institute is conducting an Experimental Research Study to find out this Mechanism. But their recent study

revealed that Leptin reduces food intake by reducing hedonic value of nutrient (pleasure associated with food). So it

shows the pleasure we derive from eating is not fixed but rather reflects the status of metabolic signals such as leptin.

Research is ongoing to evaluate leptin's roles in the body and the links between leptin and obesity and between leptin and

successful weight loss. There is also continued interest in determining whether a leptin-based treatment might be useful

for those who are obese and leptin-deficient.

Diagnostic Test to measure the leptin level in the blood:

Leptin serum test

Leptin testing is not routinely performed and is not indicated for most people. If someone is obese and has persistent

hunger or as a young child who is severely obese, then leptin testing may be considered. Leptin testing is not offered by

most laboratories. The test will probably need to be sent to laboratories where special tests are performed.

Blood test for C-reactive protein

It is generally best to also measure CRP if you are testing leptin since high levels of CRP can bind leptin and prevent it from

getting into the brain effectively. (CRP : Its is a protein which is produced by the liver when there is some inflammation in

the body. In normal conditions there is no CRP detectable in the blood).

The CRP test is a general test to check for inflammation in the body. It is not a specific test. That means it can reveal that

there is inflammation somewhere in the body, but it cannot pinpoint the exact location.

Effects of High Leptin level in the body

Increase blood pressure Obesity Heart disease and stroke Blood sugar related problems Decrease fertility

Lean Women 7.4 3.7-11.1 Lean Men 3.8 2.0-5.6 Leptin values are approximately 2.5 times higher in women than men per unit BMI.

Variations of Leptin level in specific conditions

Leptin level is increase by: Obesity Emotional Stress Obstructive sleep apnea (Intermittently relax and block your airway during sleep) High oestrogen level High insulin level

Leptin level is decrease by: Sleep deprivation Fasting High testosterone level

Leptin Resistance

Most people don't have a leptin deficiency, rather they have lost sensitivity to their leptin. Much like insulin resistance, it's possible to have enough leptin in the blood, but because the body doesn't use it effectively, we still feel hungry. In these cases, the leptin is not getting into the brain effectively and brain is not getting important signals to stop eating. The brain is starved while the body is obese. It is important to take measures to improve body’s leptin sensitivity. This improvement can help to maintain a stable body weight.

Causes of Leptin ResistanceSeveral cellular mechanisms behind leptin resistance have been identified.These include:Inflammation: Inflammatory signaling in the hypothalamus is likely an important cause of leptin resistance in the body. Low-grade inflammation is associated with obesity, type 2 diabetes and the metabolic syndrome. Abdominal obesity is much more strongly associated with inflammation, diabetes, and heart disease than fat accumulation in the lower part of the body. Losing weight will usually reduce low-grade inflammation.

Free Fatty Acids: Having elevated free fatty acids in the bloodstream may increase fat metabolites in the brain and interfere with leptin signaling.

Having high leptin: Having elevated levels of leptin in the first place seems to cause leptin resistance.

Pretty much all of these factors are increased in obesity… so this may form a vicious cycle where people get fatter and increasingly more leptin resistant over time.

Dietary management of inflammation

Types of carbs affect inflammation: Diets with high glycemic index are associated with higher levels of CRP (one of the major markers of inflammation). Fiber consumption is associated with less inflammation. In order to minimize inflammation, choose complex carbohydrates rich in fiber, rather than simple refined sugars. Whole grains are associated with less inflammation than refined grains.

Fruits and vegetables reduce inflammation: Consumption of fruits and vegetables is associated with less inflammation. Vegetarian diets reduce inflammation: Vegetarian diets are associated with lower levels of inflammatory markers (like CRP) compared to non vegetarian diets. This effect may be associated with less risk of heart disease.

Trans fatty acid promote inflammation: Consumption of trans-fats increases systemic inflammation. This relationship is stronger among women who are overweight.

Consumption of omega 3 fatty acid reduce inflammation: Consumption of omega-3 fatty acids is associated with lower levels of inflammatory markers. So the food products rich in omega-3 , such as salmon helps in reducing inflammation.

MUFA reduce inflammation: Consumption of monounsaturated fats, oleic acid in particular may reduce inflammation.

Carotenoids and flavonoids may reduce inflammation: Consumption of carotenoids and flavonoids has been associated with lower inflammation.

Magnesium : Consumption is associated with less inflammation. Whole grain is one of the most important sources of magnesium. Other sources are green leafy vegetables, nuts, and legumes.

Processed food: Highly processed foods may compromise the integrity of the gut and leads to inflammation.

Other Measures To Improve Leptin Resistance

Eat Soluble Fiber: Eating soluble fiber can help improve gut health and may protect against obesity .

Exercise: Physical activity may help to reverse leptin resistance.

Improve Sleep: Poor sleep has been implicated in problems with leptin.

Lower the levels of triglycerides: Having high blood triglycerides can prevent the transport of leptin from blood and into the brain . The best way to lower triglycerides is to reduce carbohydrate intake .

Eat Protein: Eating plenty of protein can cause automatic weight loss. There are many reason for that, one of them may be an improvement in leptin sensitivity .

References:https://www.google.co.in/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=blood+tests+to+measure+the+leptin+level+in+the+blood

http://www.lifeextension.com/vitamins-supplements/itemlc146712/leptin-blood-testhttp://www.docsopinion.com/2013/08/20/top-10-things-you-should-know-about-diet-and-inflammation/https://labtestsonline.org/understanding/analytes/leptin/tab/faq#3http://wellnessmama.com/5356/fix-your-leptin/