Glucagon was long seen as a metabolic villain, insulin’s “bad” counterpart. It raises blood sugar levels and ensures they don’t drop too low. But scientists recently realized that it may, in some cases, also increase satiety and help burn fats. Abnormal glucagon levels can point to issues such as diabetes, disease of the pancreas, and liver disease. Keep reading understand the effects of glucagon and what high or low glucagon levels mean.
What is Glucagon?
Glucagon is a hormone that helps maintain glucose balance in the body. When glucose levels are low, the pancreas releases glucagon, which signals the liver to release glucose. When glucose is high, the pancreases stops glucagon release [1, 2, 3].
Glucagon and insulin are like the yin and yang of the pancreas – one counters and balances the effects of the other. While insulin ensures blood sugar doesn’t spike too high, glucagon ensures it doesn’t drop too low.
Glucagon release is also influenced by the nervous system, amino acids, free fatty acids, and other hormones .
Glucagon has some important functions in the body. For a long time, glucagon was considered insulin’s “bad” counterpart. But aside from increasing blood sugar, glucagon also acts to :
- Burn fats and reduce fat stores
- Increase energy use
- Balance food intake
- Increase satiety
- Reduce the production of bile acids
Glucagon is not a commonly ordered blood test. Doctors will order it if they suspect you have issues with glucagon production. They may order a glucagon test if someone shows symptoms of:
- Low blood sugar (hypoglycemia) 
- Diabetes 
- Liver disease and damage (cirrhosis) [6, 7]
- Pancreas inflammation (pancreatitis) 
- An inherited disorder called multiple endocrine neoplasia type 1, which causes endocrine gland tumors 
- Glucagonoma, a tumor in the pancreas that secretes glucagon 
As the level of blood sugar decreases, the pancreas releases more glucagon. And as blood sugar increases, the pancreas releases less glucagon.
The normal range of glucagon normally ranges from 50 – 150 pg/ml . However, ranges may vary between laboratories.
Low Glucagon Levels
Causes shown here are commonly associated with low glucagon levels. Work with your doctor or another health care professional to get an accurate diagnosis. Your doctor will interpret your levels in conjunction with your symptoms, medical history, and other test results.
Glucagon can be low in both type 1 and advanced type 2 diabetes, where the pancreas fails to produce insulin .
Low glucagon and very low glucose levels (hypoglycemia) can be dangerous. The brain needs glucose to function while having low glucose and low glucagon increases the risk of brain damage or impairment [11, 12].
2) Weight Loss
Weight loss due to diet or gastric bypass surgery decreases glucagon levels. It lowers glucagon and improves insulin resistance, which may help people who were obese restore sugar levels .
3) Pancreas Removal Surgery
Since the pancreas makes glucagon, pancreas removal surgery (pancreatectomy) can cause glucagon deficiency .
Ways to Increase Glucagon
It’s important to work with your doctor to find out what’s causing your low glucagon levels and to treat any underlying conditions.
High Glucagon Levels
Causes shown here are commonly associated with high glucagon levels. Work with your doctor or another health care professional to get an accurate diagnosis. Your doctor will interpret your levels in conjunction with your symptoms, medical history, and other test results.
When your blood sugar is low, it’s normal for glucagon to be high.
Prolonged fasting can increase glucagon. In one study, glucagon blood levels rose twofold on the 3rd day of fasting and then slightly declined over the next 6 weeks. Insulin levels decreased .
2) High-Protein Diets
High-protein and low-carb diets can increase fasting glucagon levels by ~35% .
High protein diets also increase insulin, a rare case when both glucagon and insulin are increased. This is because insulin and glucagon both tell the liver to make more glucose from non-carb sources (such as amino acids), while glucagon also maintains glucose blood levels [15, 16, 17, 18, 19, 20].
High-protein diets are ok in the short run but may contribute insulin resistance in some people in the long-run .
3) Low Insulin
In healthy people, after a meal, high blood sugar will cause the pancreas to release more insulin and less glucagon .
In people with advanced diabetes, the opposite can happen. When glucose levels spike after a meal, glucagon levels increase because the pancreas can’t release enough insulin .
Stress causes the pancreas to release more glucagon (and less insulin), which increases glucose levels. Glucagon may among the main triggers of high glucose levels in people under stress who never had diabetes .
Similarly, insulin resistance and high-stress hormones (including cortisol and epinephrine) also increase glucagon and blood glucose .
In people suffering from serious health problems, high glucagon and glucose levels triggered by stress can cause health complications and increase the risk of disability .
5) Liver Disease and Scarring
People with liver disease and liver scarring (cirrhosis) have high glucagon levels. Glucagon increases even more in people with liver disease who also have brain inflammation and poor mental function [6, 7].
6) Pancreas Inflammation (Pancreatitis)
In an observational study of 30 people, people with inflamed pancreas had increased glucagon levels, especially during the initial inflammatory attack .
Glucagonomas are tumors of the pancreas that secrete glucagon. They can cause very high glucagon blood levels [24, 10].
Multiple endocrine neoplasia type 1 is an inherited disorder that causes tumors to form in the endocrine glands. Patients with this disorder also have high glucagon levels .
Ways to Decrease Glucagon Levels
It’s important to work with your doctor to find out what’s causing your high glucagon levels and to treat any underlying conditions.
Discuss the additional lifestyle changes listed below with your doctor. None of these strategies should ever be done in place of what your doctor recommends or prescribes!
Avoid prolonged fasting. Make sure your diet is well balanced. High protein diets can increase glucagon levels .
Losing weight can help decrease glucagon levels .
Manage stress in your life. Stress can trigger an increase in glucagon levels .
Health Effects of Glucagon
High Glucagon Levels May Increase Diabetes Risk
Some scientists are of the opinion that high glucagon levels may contribute to the development of diabetes. They are working on glucagon-lowering medication.
High glucagon together with low insulin or insulin resistance reduced glucose tolerance, according to an observational study of over 100 people .
This means that glucagon may contribute to long-term increases in blood sugar levels, which can lead to diabetes [4, 26].
High glucagon levels can also contribute to diabetic ketoacidosis, a condition with high levels of acidic ketones in the blood. Too much glucagon and too little insulin cause very high sugar levels and result in the buildup of ketones in the body [27, 28, 3].
Glucagon May Help Fight Obesity
Glucagon and glucagon-like substances are being investigated as weight-loss therapies. That’s because glucagon may increase satiety and may help burn fats. Scientists are designing drugs which would have these beneficial effects of glucagon without raising blood sugar levels. This would potentially help with metabolic syndrome, obesity, or high blood cholesterol .
You may have heard of insulin resistance. But scientists are now realizing that glucagon resistance also exists and it may have many negative health consequences.
Glucagon controls fat-burning. Eating too much unhealthy, saturated fats may impair glucagon signaling. Rats fed a high-fat diet develop glucagon resistance and fatty livers. High-fat diets may damage glucagon receptors and reduce their number. This causes tissues to become insensitive to glucagon and may impair energy and fat balance in the body .