Инсулинова резистентност и отслабване

(за съжаление не знам как да копирам всички схеми, а те са много и подробни)

Richards, Byron J.; Mary Guignon Richards. Mastering Leptin: Your Guide to Permanent Weight Loss and Optimum Health (S.40). Wellness Resources Books. Kindle-Version.

The primary hormone made by white fat cells is leptin. Leptin talks directly to the hypothalamus gland of the brain. When leptin levels are high in the properly functioning person, this tells the brain to decrease food intake and increase sympathetic nerve activity, thus increasing metabolic rate and stimulating white adipose tissue to break down stored fat. 26 As sympathetic nerve activity increases and metabolic rate increases, leptin is lowered, signaling the need to accumulate more stored energy. This completes a circle of communication between fat cells and the brain. This is how metabolism works when a person’s body is in a state of natural balance. It is an example of a homeostatic system in the human body relating to the natural balance of energy. It has its own built-in checks and balances. The ebb and flow of these communication signals are fundamental to having an appropriate appetite.

A BREAKDOWN IN COMMUNICATION
 When there are problems with leptin, there is a breakdown of proper communication. Low leptin levels cause a person to have no appetite, resulting in too much weight loss and the loss of bone density. High leptin levels cause a person to eat frequently or to rapidly gain weight from whatever is eaten. This is the opposite of how the hormone behaves when it is working properly. There is a disruption of the normal communication between the brain and fat cells. Not only does this cause confusion about eating, but there are major consequences for the rest of the body as well. It is not a desirable state of affairs for white adipose tissue, a primary endocrine organ, to be in a state of poor communication. In addition to the daily eating patterns, this circle of communication can be viewed in the context of how a person does on a month-to-month basis. If not enough food is consumed, then leptin tends to stay low, decreasing sympathetic nerve stimulation and metabolic rate and increasing appetite. This results in the hibernation effect that enables humans to survive prolonged periods of reduced food availability. Metabolism consequently slows down to conserve body fat for survival. When enough food is consumed, the leptin level rises, telling the brain to quit eating and increase metabolic rate. This enables the body to have an energetic metabolic drive. There is a higher level of leptin, meaning there is adequate fuel on hand so that the body can work at an optimum rate and does not need to be in starvation mode. This is how the leptin hormone behaves when it works correctly, as opposed to how it functions during times of leptin resistance. When there is leptin resistance, the brain does not hear the phone call from fat cells telling it there is enough fuel in storage. Consequently, the fat cells keep accumulating weight because neither the brain nor the fat-cell troops have a sense of what is actually happening (figure 4). In an effort to stimulate metabolism, the brain releases adrenaline. This is magnified by too much stress. Such adrenaline should stimulate fat cells to release energy which in turn should cause weight loss. However, when adrenaline is too high too often, fat cells develop adrenaline resistance. From a fat cell’s point of view, it is like being yelled at too often. After a while, the fat cells go numb to the adrenaline, and adrenaline resistance develops. This causes metabolism of fat cells to stay locked in a “hibernation metabolic rate.” It also causes weight gain around the middle, high blood pressure, and sleep problems (figure 5).

TIMING AND LEPTIN
In addition to communication between the brain and fat cells, leptin levels follow a daily pattern. Leptin levels are highest during the first few hours of sleep and fall to their lowest level in the morning. 27 They peak before the adrenal steroid cortisol which is highest at 6 a.m., and they are not tied to cortisol production. 28 A person who is in a good rhythm and pattern will not be hungry before bed because the brain correctly senses the higher level of leptin; thus the appetite signal is turned off and food cravings are absent. A person who craves food before bed has leptin resistance, meaning that the brain does not sense the leptin signal to not eat even though leptin is naturally highest at this time. A major clue that a person is heading down a pattern of leptin resistance is out-of-control eating after dinner. Eating after dinner seriously disturbs healthy leptin function. Furthermore, a meal that has too many carbohydrates or sweets can cause the normal night pattern of rising leptin to occur seven to nine hours earlier than it should, completely throwing the body out of proper rhythm. 29 In other words, eating too many sweets will cause leptin levels to rise at the wrong time. Once a person has leptin resistance, this leads to overeating, especially at night. For example, if a person has a sweet roll, muffin, or orange juice for breakfast or too many cookies at lunch, there will commonly be a leptin-resistant urge to eat after dinner that evening.

THE BRAIN SETS LEPTIN RHYTHM
It is interesting to note that the control of the daily pattern of leptin secretion comes from the biological clock in the brain. 30 Even though the hormone itself is produced in fat cells, it responds to a rhythmic signal coming from the brain. Previously, we have described how the sympathetic nerves are involved in communication to fat cells and how fat cells talk back to the brain. Now there is an additional feature of this communication system: there is a daily timing pattern essential for proper leptin function. This daily timing pattern is under control of the brain, which functions like the conductor of an orchestra. Malfunctioning leptin patterns opens the door to understanding why leptin isthe cause of so many health problems. Leptin levels are crucial to survival instinct, the fundamental core level of energy. Without fuel, nothing in the human body works. Leptin is the most important hormone signal gauging fuel supply. Just as we alter our driving patterns to go to a gas station when the car’s fuel gauge says empty, so it is that leptin levels command powerful urges relating to food consumption. When the rhythmic pattern of leptin secretion is disrupted, the brain has trouble with energy regulation in general, and other timing patterns in the body are thrown out of natural rhythm. There are numerous examples in this book that show that major health problems involve the loss of proper leptin timing, not necessarily related to the amount of leptin. Leptin levels in the blood could be at a “normal” amount; they are simply not doing what they are supposed to be doing at the right time. This is a very important point. A lab test for leptin in the blood does not reflect these problems.

LEPTIN TONE AND ACTIVE METABOLISM
In addition to the normal nighttime rise in leptin, there also occurs a pulsing regulation. In a twenty-four-hour period, there are as many as thirty-two pulses of leptin activity. These relate to circulating adrenaline levels. 31 This is believed to act as a sort of tension in the regulatory system, providing the ability of the hormone to fluctuate on a gradual basis, rather than in blatant on-and-off patterns. This leptin and adrenaline tension is essential for fast-action response to stress, as more fuel is needed to produce energy in the case of an emergency demand. In essence, this leptin and adrenaline tension provides an “energy tone,” much like the muscle tone we feel when we are in good physical shape. The opposite of this “energy tone” is a fatigued or washed-out feeling. The dominant factor that influences leptin production is the sympathetic nervous system. There is a cycle of communication between fat cells and the brain. They talk to each other in an effort to figure out the fat storage needs on a long-term basis. This long-term plan can also be put on hold for short-term energy needs to deal with stress.

REVIEWING PRIMARY LEPTIN REGULATION
The brain determines other hormone activity in the body based on the perception of leptin. The brain controls the leptin rhythm. Leptin is the most important hormone in helping the brain determine energy use in the body. Leptin is under short-term regulation, daily regulation, and long-term regulation. It is central to body rhythms, because timing is fundamental to your brain’s calculation of how much energy it can spend for any particular situation. There is a tremendous amount of complexity in this system, which enables your body to elegantly distribute energy so that it can survive. These points alone explain why drug therapy will not work to solve leptin resistance. Drugs will simply block transmission and cause a blatant off-or-on function. They will interfere with the natural trend of the twenty-four-hour pattern and will interfere with the proper leptin tone in circulation. Drugs will also handicap the stress response and depress immune function. Only in the case of a true genetic inability to make leptin will leptin drugs have any value, which at this time affects only a handful of people in the world. 32 The great majority of overweight and fatigued Americans do not suffer from such a genetic problem; they suffer from serious leptin mismanagement.

LEPTIN AND INSULIN
Leptin from fat cells and insulin from the pancreas also communicate with each other. This is similar to two department heads in a company talking to each other. Insulin production stimulates leptin production. 33 Leptin receptors are present on the insulin-producing B-cells of the pancreas, demonstrating the ability to turn off insulin production. 34 In normal physical function, leptin and insulin have a balancing effect on food intake, energy storage, and a stable energy level. Once leptin resistance sets in and leptin levels are high, then the pancreatic B-cells do not respond to the signal from leptin to stop making insulin. 35 However, insulin keeps stimulating leptin production at the same time that insulin promotes calories to store as fat. Furthermore, the high circulating insulin causes cells throughout the body to be resistant to insulin. Thus, we see that leptin resistance sets the stage for insulin resistance, and the two problems continue to play off each other and make each other worse (figure 6).

THE KEY TRIAD OF PROBLEMS
Hence, we see the triad of leptin resistance, insulin resistance, and adrenaline resistance as the main cause of any problem of excess weight (figure 7). For example, when the fat cells in the abdominal area become resistant to adrenaline, then the individual begins to gain weight around the middle. This is a common area for weight gain in men; it also happens to women who struggle with menstrual irregularities and women at menopause. This type of weight gain around the middle is the worst kind of weight gain, the type most associated with cardiovascular disease. More is explained about insulin resistance in chapter 16. We mention it here to emphasize the issue of efficiency and metabolism. Individuals struggling with body weight have a key triad of efficiency problems. The common denominator is that the hormonal signals cannot get through to their targets; there is resistance. It is like trying to call someone on the phone and they do not answer. The messages in the phone calls contain adrenaline, leptin, and insulin. There are various reasons why the phone calls are not answered, all of which fall under the general category of the body being out of natural balance. Expensive lab tests are not needed to prove there is a problem. A person just has to look in the mirror and then take note of his or her level of energy. The problem slowly and progressively gets worse as a person gets older.