Hunger satiety hormone leptin has been found to cause cardiovascular disease in obese individuals. Leptin is produced by body fat and is also known as the satiety hormone or the starvation hormone. Leptin plays a role in functions related to fertility, immunity and brain function, and it’s intended to tell the brain that we are full so calorie burning can take place. Leptin’s main goal is energy balance – calories expelled and calories taken in.
Leptin resistance is thought to be the reason why many of us overeat. Being obese leads to having more body fat. Leptin is produced by body fat, so in theory, if someone is fat the additional leptin should tell the body that it is full and does no require more food. Unfortunately, there is something broken in the cycle; even though obese people have more leptin, the signals are not being sent to tell the brain it is full and to stop eating.
New research found another break in leptin discovery: it may actually be the cause of cardiovascular disease in obese people.
Role of hunger hormone leptin in obesity related cardiovascular disease
The findings come from researchers at the Medical College of Georgia at Georgia Regents University. Dr. Eric Belin de Chantemele from the university said, “With obesity, leptin cannot tell our brain to stop eating, but it can still tell our brain to increase the activity of the cardiovascular system.”
Cell structures in animal models showed leptin activates aldosterone synthase expression in the adrenal glands – this produces steroid aldosterone. Aldosterone is a hormone which aids in the regulation of blood pressure, and when unbalanced aldosterone can contribute to cardiovascular disease and kidney disease. High levels of aldosterone are often seen in obese individuals, but researchers are unsure how aldosterone levels get so high.
Medications are available that could improve aldosterone levels and reduce the risk of cardiovascular disease in obese individuals. Leptin receptor blockers, too, are under study as a potential form of treatment.
It has been observed that obese people become insensitive to leptin on a metabolic level but not on a cardiovascular one. But why this occurs is still very much unknown. Some theories suggest dysfunction in signaling.
The researchers put increasing dosages of leptin in the adrenal cells and saw levels of aldosterone increase as well. When the leptin receptors were inhibited, the increase in aldosterone did not happen. Similar research was conducted in the fat of mice and the association remained present.
Researchers then looked at 40 overweight men and women to determine if the leptin-aldosterone association was still present. Both in animal and human studies, not only was the association present, but it was stronger in females compared to males.
“We want to see if we can confirm what we are seeing in mice in the human population. If we see that, that probably tells us a blocker of aldosterone action, such as spironolactone, would be a good treatment particularly for obese females,” Belin de Chantemele added.
The findings were published in Circulation.
What causes leptin resistance?
As mentioned, leptin resistance is when the normal signals of feeling full are not properly transmitted, which contributes to overeating. There are a few different reasons why leptin resistance can occur, such as:
Inflammation: Inflammation signals the hypothalamus, which can cause leptin resistance.
Free fatty acids: Elevated free fatty acids in the bloodstream increases fat metabolites in the brain, which interfere with leptin signaling.
Having high leptin: More fat means more leptin is produced. Although more should indicate fullness, it seems when too much leptin is available the signals don’t work.
Along with contributing to leptin resistance, these factors all contribute to obesity as well.
Other factors include:
- High stress levels
- Consuming fructose
- Lack of sleep
- High insulin levels
- Exercising too much
- Grain and lectin consumption
Managing leptin resistance
A leptin resistance can be complicating and difficult to manage as it cannot be reversed. The worse part is that unlike blood sugar, you can’t simply monitor it by checking your blood for levels. You simply have to become aware and take conscious steps towards better management. Tips for managing a leptin resistance include:
- Minimizing or eliminating simple starches, refined foods, sugars and fructose from your diet
- Consuming more protein and healthy fats in the morning for breakfast – you will feel fuller for longer
- Getting adequate and quality sleep
- Going outside and getting some sun
- Not snacking and not eating a meal prior to bed
- Cutting back on exercising initially as it can add additional stress – when you get back into exercise avoid long hours of cardio and stick with sprinting or weight lifting
- Increasing your intake of omega fatty acids
Leptin’s role in weight loss
When leptin is unbalanced weight loss can become quite difficult. In a case study of a nine-year-old obese girl doctors found her leptin was quite low. After treatment to restore leptin she was better able to lose weight. The results were confirmed when similar treatment was conducted on her cousin.
Weight loss occurs when the body is able to expel more calories than are taken in. If a person overeats and does not rid themselves of those extra calories, it contributes to weight gain. When leptin signals are lacking and not understood by the brain it can result in a person overeating, thus leading to weight gain.
A study is being conducted about whether obese people with low leptin levels could potentially benefit from leptin therapy – similar to how diabetics require insulin. As far as we know low leptin levels make weight loss difficult, but screening would need to be required to truly determine low leptin levels in obese individuals.
Leptin resistance and diabetes
Insulin resistance is when the body does not use insulin correctly – this is a known factor for diabetes. Similarly, a resistance to other hormones can lead to diabetes – case in point: leptin resistance.
Both leptin and insulin resistance contribute to obesity and both resistances can be found in obese people. In one study researchers found that by lowering insulin levels cravings stopped, thus contributing to individuals limiting their eating habits. This is also a sign that leptin may be functioning better.
Stress and sleep deprivation, too, have been found to play a role in both insulin and leptin resistance. When we are stressed out our body send signals telling the brain we are not okay and that we should consume more food. Prolonged stress can contribute to overeating that adds to weight gain, which ultimately can result in a leptin and insulin resistance.
Therefore, if you want to improve both leptin and insulin resistance, you need to pay close attention to your diet and physical activity routine. What makes it easier is that the same style of eating can benefit both resistances.
The goal is to reduce our junk food intake, eliminate added sugars and stick with more wholesome foods. Refined carbohydrates are definitely not on the list, instead whole grains, fruits and vegetables and lean proteins are a must.
Not only will eating in this way help you better control your diabetes, but it can help curb your overeating due to leptin resistance as well. You should stick with foods that keep you fuller for longer. Alongside a healthy eating plan, exercise, too, is still important for both conditions. A healthy lifestyle can get you back on the right track for success.
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