Stress and Glucose levels: an intimate relationship

Michael Sapko
Michael Sapko
May 24, 2021

Blood glucose levels normally move up and down throughout the day. After a meal, for example, blood glucose levels rise until insulin can shuttle the sugar molecules into muscle and other tissues of the body. But eating food is not the only reason blood sugar levels rise. Fear and stress are potent causes of blood sugar spikes. In fact, this is one of the ways in which chronic stress is harmful to the body.

To our bodies, modern-day stress = ancient fear.

Throughout much of human history, we have had to struggle just to stay alive. We had the stresses of finding enough food to eat and water to drink while trying to avoid predators or other humans from killing us. We used to have it pretty rough, actually. We are all descendants of the most successful humans—the ones who made it to reproductive age. Our predecessors passed down to us a very useful thing indeed: the sympathetic nervous system.

The sympathetic nervous system is what controls our “fight or flight” response. When we sense danger, the sympathetic nervous system jolts into action by releasing epinephrine (aka adrenaline) and cortisol into the bloodstream. These chemical messengers increase heart rate, send blood to muscles, and release glucose into the blood—all to prepare the body to either fight to the death or run like mad.

Fortunately, most of us encounter very few things in modern life that require instantaneous life-or-death responses. Unfortunately, the sympathetic nervous system still reacts as if we do. Instead of a lion hiding in the bushes, we may be stressed by an upcoming deadline at work. What is worse, modern stress lasts much longer than ancient fear cues. Our ancestors killed or outran the lion and that was the end of it. Our work deadline may be days away, plus we have to pick up the kids, and make dinner, and pay the mortgage, and…we feel like we are constantly being chased by lions.

Cortisol, epinephrine, and blood glucose levels

Cortisol and epinephrine both raise blood glucose levels, in some cases, to very high levels. For instance, high-stress situations such as severe medical illness can cause blood sugar levels to rise so high that doctors mistakenly think patients who do not have diabetes actually have diabetes.1 High levels of cortisol in the blood cause gluconeogenesis (the formation of new glucose) and glycogenolysis (the breakdown of a glucose storage molecule to produce free sugar).2 So when people who have normal blood sugar levels undergo severe stress, they may temporarily have blood sugar levels that rise so high they need to be treated with insulin.1

The stress effect for people with diabetes (or even prediabetes) can make blood sugar levels go even higher.1 People with type 2 diabetes mellitus have a certain degree of insulin resistance. When cells are resistant to insulin, glucose in the blood cannot move as readily into the cells. Consequently, that glucose stays in the bloodstream for a longer time. That is why, after a meal, blood glucose levels go higher and stay elevated longer in people with diabetes than in people without the disease. Add stress hormones to the situation, and blood glucose levels can reach very high levels. Stress is even one of the factors that causes blood glucose levels to stay elevated apart from food (i.e., elevated fasting blood glucose).

The damage caused by high blood glucose levels

By now, people with diabetes know the major risks of poorly controlled blood sugar levels. Chronically high blood glucose levels lead to a number of irreversible, serious, even deadly conditions including blindness, kidney failure, nerve problems, heart attack, stroke and sudden death.3 However, even blood sugar levels that are modestly higher than normal (e.g., hemoglobin A1c above 7%) can increase the risk for a number of subtle but potentially serious problems. Modestly elevated blood glucose levels impair the body’s immune system, which means people are more susceptible to infections and wounds heal more slowly. People may experience chronic inflammation and increased levels of reactive oxygen species; the blood is more likely to clot, and the blood vessels react abnormally.4 Diabetes is not just a disease that can kill you later in life—persistently elevated blood sugars can harm the body today.

Modern sources of stress (and stress hormones)

While we are not literally being chased by lions, our bodies experience stressors every day in countless ways. A little bit of stress is actually helpful in the modern world. A small squirt of cortisol into the bloodstream helps us learn and remember.5 So, feeling a little stressed while studying for an upcoming examination can enhance performance on the test. Excessive stress, on the other hand, actually impairs performance and interferes with long-term memory formation.6 Simply put, a little stress is helpful, a lot of stress is harmful.

The key seems to be how we perceive stress. A normal amount of stress for one person can be an intolerable amount to another. Likewise, an event that is seemingly minor to someone can have a major impact on someone else. This process is complex; it involves the brain, hormones, even the immune system.7 The bottom line is that we all process stressors differently. If someone cannot find a way to process stress in a healthy way, it can result in high blood glucose levels. Moreover, a 12-year longitudinal study of almost 13,000 people showed that perceived stress is a strong risk factor for type 2 diabetes, independent from high blood pressure, physical inactivity, smoking, poor diet, or obesity.8 In other words, excessive amounts of perceived stress may be a primary cause of diabetes.8

Stress (and blood sugar) reduction for your health

Fighting against the sympathetic nervous system is no easy feat. If we could change the way we perceive stress, we could reduce the negative effects of stress on our blood glucose levels and our bodies. Sometimes this perception of stress is taking place on a level we do not fully realize. So, keeping track of blood sugar is the best way to know how food and life’s stressors are affecting you. Exercise is a great way to reduce stress and blood sugar levels. Try to put life’s stressors in the proper perspective. What things can you change and what things are outside of your control. Mindfulness meditation is a stress-reliever and can reduce fasting blood glucose levels.9 Lastly, do not worry too much about worry. Certainly, managing diabetes and other healthcare-related matters is critical to good health, but managing them should not be their own causes of stress.

References

  1. Mifsud S, Schembri EL, Gruppetta M. Stress-induced hyperglycaemia. Br J Hosp Med (Lond). 2018;79(11):634-639. 10.12968/hmed.2018.79.11.634
  2. Kajbaf F, Mojtahedzadeh M, Abdollahi M. Mechanisms underlying stress-induced hyperglycemia in critically ill patients. Clinical Practice. 2007;4(1):97.
  3. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Diabetes Study (UKPDS) Group. Lancet. 1998;352(9131):837-853.
  4. Grandl G, Wolfrum C. Hemostasis, endothelial stress, inflammation, and the metabolic syndrome. Semin Immunopathol. 2018;40(2):215-224. 10.1007/s00281-017-0666-5
  5. Smeets T, Giesbrecht T, Jelicic M, Merckelbach H. Context-dependent enhancement of declarative memory performance following acute psychosocial stress. Biol Psychol. 2007;76(1-2):116-123. 10.1016/j.biopsycho.2007.07.001
  6. Vogel S, Schwabe L. Learning and memory under stress: implications for the classroom. NPJ Sci Learn. 2016;1(1):16011. 10.1038/npjscilearn.2016.11
  7. Ray A, Gulati K, Rai N. Chapter One - Stress, Anxiety, and Immunomodulation: A Pharmacological Analysis. In: Litwack G, ed. Vitamins and Hormones. Vol 103. Academic Press; 2017:1-25.
  8. Harris ML, Oldmeadow C, Hure A, Luu J, Loxton D, Attia J. Stress increases the risk of type 2 diabetes onset in women: A 12-year longitudinal study using causal modelling. PLoS One. 2017;12(2):e0172126. 10.1371/journal.pone.0172126
  9. Armani Kian A, Vahdani B, Noorbala AA, et al. The Impact of Mindfulness-Based Stress Reduction on Emotional Wellbeing and Glycemic Control of Patients with Type 2 Diabetes Mellitus. Journal of diabetes research. 2018;2018:1986820-1986820. 10.1155/2018/1986820

Blood glucose levels normally move up and down throughout the day. After a meal, for example, blood glucose levels rise until insulin can shuttle the sugar molecules into muscle and other tissues of the body. But eating food is not the only reason blood sugar levels rise. Fear and stress are potent causes of blood sugar spikes. In fact, this is one of the ways in which chronic stress is harmful to the body.

To our bodies, modern-day stress = ancient fear.

Throughout much of human history, we have had to struggle just to stay alive. We had the stresses of finding enough food to eat and water to drink while trying to avoid predators or other humans from killing us. We used to have it pretty rough, actually. We are all descendants of the most successful humans—the ones who made it to reproductive age. Our predecessors passed down to us a very useful thing indeed: the sympathetic nervous system.

The sympathetic nervous system is what controls our “fight or flight” response. When we sense danger, the sympathetic nervous system jolts into action by releasing epinephrine (aka adrenaline) and cortisol into the bloodstream. These chemical messengers increase heart rate, send blood to muscles, and release glucose into the blood—all to prepare the body to either fight to the death or run like mad.

Fortunately, most of us encounter very few things in modern life that require instantaneous life-or-death responses. Unfortunately, the sympathetic nervous system still reacts as if we do. Instead of a lion hiding in the bushes, we may be stressed by an upcoming deadline at work. What is worse, modern stress lasts much longer than ancient fear cues. Our ancestors killed or outran the lion and that was the end of it. Our work deadline may be days away, plus we have to pick up the kids, and make dinner, and pay the mortgage, and…we feel like we are constantly being chased by lions.

Cortisol, epinephrine, and blood glucose levels

Cortisol and epinephrine both raise blood glucose levels, in some cases, to very high levels. For instance, high-stress situations such as severe medical illness can cause blood sugar levels to rise so high that doctors mistakenly think patients who do not have diabetes actually have diabetes.1 High levels of cortisol in the blood cause gluconeogenesis (the formation of new glucose) and glycogenolysis (the breakdown of a glucose storage molecule to produce free sugar).2 So when people who have normal blood sugar levels undergo severe stress, they may temporarily have blood sugar levels that rise so high they need to be treated with insulin.1

The stress effect for people with diabetes (or even prediabetes) can make blood sugar levels go even higher.1 People with type 2 diabetes mellitus have a certain degree of insulin resistance. When cells are resistant to insulin, glucose in the blood cannot move as readily into the cells. Consequently, that glucose stays in the bloodstream for a longer time. That is why, after a meal, blood glucose levels go higher and stay elevated longer in people with diabetes than in people without the disease. Add stress hormones to the situation, and blood glucose levels can reach very high levels. Stress is even one of the factors that causes blood glucose levels to stay elevated apart from food (i.e., elevated fasting blood glucose).

The damage caused by high blood glucose levels

By now, people with diabetes know the major risks of poorly controlled blood sugar levels. Chronically high blood glucose levels lead to a number of irreversible, serious, even deadly conditions including blindness, kidney failure, nerve problems, heart attack, stroke and sudden death.3 However, even blood sugar levels that are modestly higher than normal (e.g., hemoglobin A1c above 7%) can increase the risk for a number of subtle but potentially serious problems. Modestly elevated blood glucose levels impair the body’s immune system, which means people are more susceptible to infections and wounds heal more slowly. People may experience chronic inflammation and increased levels of reactive oxygen species; the blood is more likely to clot, and the blood vessels react abnormally.4 Diabetes is not just a disease that can kill you later in life—persistently elevated blood sugars can harm the body today.

Modern sources of stress (and stress hormones)

While we are not literally being chased by lions, our bodies experience stressors every day in countless ways. A little bit of stress is actually helpful in the modern world. A small squirt of cortisol into the bloodstream helps us learn and remember.5 So, feeling a little stressed while studying for an upcoming examination can enhance performance on the test. Excessive stress, on the other hand, actually impairs performance and interferes with long-term memory formation.6 Simply put, a little stress is helpful, a lot of stress is harmful.

The key seems to be how we perceive stress. A normal amount of stress for one person can be an intolerable amount to another. Likewise, an event that is seemingly minor to someone can have a major impact on someone else. This process is complex; it involves the brain, hormones, even the immune system.7 The bottom line is that we all process stressors differently. If someone cannot find a way to process stress in a healthy way, it can result in high blood glucose levels. Moreover, a 12-year longitudinal study of almost 13,000 people showed that perceived stress is a strong risk factor for type 2 diabetes, independent from high blood pressure, physical inactivity, smoking, poor diet, or obesity.8 In other words, excessive amounts of perceived stress may be a primary cause of diabetes.8

Stress (and blood sugar) reduction for your health

Fighting against the sympathetic nervous system is no easy feat. If we could change the way we perceive stress, we could reduce the negative effects of stress on our blood glucose levels and our bodies. Sometimes this perception of stress is taking place on a level we do not fully realize. So, keeping track of blood sugar is the best way to know how food and life’s stressors are affecting you. Exercise is a great way to reduce stress and blood sugar levels. Try to put life’s stressors in the proper perspective. What things can you change and what things are outside of your control. Mindfulness meditation is a stress-reliever and can reduce fasting blood glucose levels.9 Lastly, do not worry too much about worry. Certainly, managing diabetes and other healthcare-related matters is critical to good health, but managing them should not be their own causes of stress.

References

  1. Mifsud S, Schembri EL, Gruppetta M. Stress-induced hyperglycaemia. Br J Hosp Med (Lond). 2018;79(11):634-639. 10.12968/hmed.2018.79.11.634
  2. Kajbaf F, Mojtahedzadeh M, Abdollahi M. Mechanisms underlying stress-induced hyperglycemia in critically ill patients. Clinical Practice. 2007;4(1):97.
  3. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Diabetes Study (UKPDS) Group. Lancet. 1998;352(9131):837-853.
  4. Grandl G, Wolfrum C. Hemostasis, endothelial stress, inflammation, and the metabolic syndrome. Semin Immunopathol. 2018;40(2):215-224. 10.1007/s00281-017-0666-5
  5. Smeets T, Giesbrecht T, Jelicic M, Merckelbach H. Context-dependent enhancement of declarative memory performance following acute psychosocial stress. Biol Psychol. 2007;76(1-2):116-123. 10.1016/j.biopsycho.2007.07.001
  6. Vogel S, Schwabe L. Learning and memory under stress: implications for the classroom. NPJ Sci Learn. 2016;1(1):16011. 10.1038/npjscilearn.2016.11
  7. Ray A, Gulati K, Rai N. Chapter One - Stress, Anxiety, and Immunomodulation: A Pharmacological Analysis. In: Litwack G, ed. Vitamins and Hormones. Vol 103. Academic Press; 2017:1-25.
  8. Harris ML, Oldmeadow C, Hure A, Luu J, Loxton D, Attia J. Stress increases the risk of type 2 diabetes onset in women: A 12-year longitudinal study using causal modelling. PLoS One. 2017;12(2):e0172126. 10.1371/journal.pone.0172126
  9. Armani Kian A, Vahdani B, Noorbala AA, et al. The Impact of Mindfulness-Based Stress Reduction on Emotional Wellbeing and Glycemic Control of Patients with Type 2 Diabetes Mellitus. Journal of diabetes research. 2018;2018:1986820-1986820. 10.1155/2018/1986820