COVID-19 is a new disease caused by a novel coronavirus. There is still limited information on the risk factors for severe disease but as COVID-19 thrives around the globe, we see that obese and diabetic corona patients have worse outcomes and a more challenging time in dealing with the infection.
Realizing that the coronavirus will hang around, the best contingency plan is to do whatever we can to lower our risk of complications. Now is the time to make ourselves resilient to pull through, especially for individuals who are above their ideal weight and/or have diabetes (type 2).
Obesity is a critical risk factor for insulin resistance, and insulin resistance increases risk for type 2 diabetes, hyperlipidemia, cardiovascular disease, and some types of cancer. Obesity is a complex disease involving an excessive amount of body fat. Although there are genetic, behavioural, metabolic and hormonal influences on body weight, obesity occurs most commonly due to a combination of excessive food intake and lack of physical activity. When your body receives more calories than it needs and than it is able to burn, your body stores these excess calories as fat.
Below, I briefly touch upon inflammation and oxidative stress in relation to obesity and diabetes. Inflammation at physiological levels plays a protective role and is needed (for fighting infections and wound healing for example), however CHRONIC SYSTEMIC INFLAMMATION IS HARMFUL. Obesity and diabetes promote systemic inflammation and systemic inflammation in the light of COVID-19 complicates matters because the immune system, trying to fight the virus, goes into overwork. This can create a brutal cycle driven by cytokine molecules promoting a cytokine storm, an overwhelming inflammatory body state.
Why that happens? It’s a multifactorial and complex process but one aspect is known, a baseline inflammation and oxidative stress level is high.
OBESITY ADDS THE EXTRA INFLAMMATORY LOAD GENERATED BY ADIPOSE TISSUE
Excess fat cells results in excess pro-inflammatory cytokines, and it results in excess inflammation.
Fat tissue cells (adipocytes) secrete adipokines, aka cytokine molecules, to communicate with the body regarding long-term energy storage, reproductive function, blood pressure regulation, energy homeostasis, the immune response, and many other physiologic processes. The adipokines possess pro- and anti-inflammatory properties and play a critical role in integrating systemic metabolism with immune function. As adipose tissue expands during the development of obesity, this balance shifts to favor proinflammatory mediators. The pro-inflammatory adipokines are increased whereas the anti-inflammatory adipokines are decreased. Consequently, it creates and perpetuates a vicious cycle of low-grade inflammation in white adipose tissue (WAT), and metabolic disorders associated with obesity. The higher concentration of pro-inflammatory cytokines in the bloodstream, the higher chance of the body going into the cytokine/inflammatory storm in an event of an inflammatory insult, such as infection.
What’s more, obesity and production of inflammatory adipokines suppress insulin signaling resulting in insulin resistance. Simply put, obesity increases insulin resistance and it’s called obesity-mediated insulin resistance. The mechanism of it is not completely understood but it’s likely related to adipose tissue dysfunction/lipotoxicity, inflammation, mitochondrial dysfunction, and hyperinsulinemia. What’s worth knowing is that insulin resistance precedes diabetes.
INSULIN RESISTANCE IF NOT MANAGED CAN PROCEED TO DIABETES (type 2)
Taking the right measures on time can prevent diabetes, yet many people are unaware of having insulin resistance. WHY? The tests are not typically done and the symptoms are not always recognized, especially if you are not aware of what you should pay attention to. People are often diagnosed when already being (pre)diabetic, this is when their fasting blood sugar is abnormally elevated. If you want to learn more on the topic of insulin resistance, do check my other blog.
Type 2 Diabetes is a complex chronic inflammatory condition characterized by multiple metabolic and vascular abnormalities that can affect the response to pathogens. One of diabetic hallmarks is low-grade systemic INFLAMMATION. The body produces excessively pro-inflammatory cytokines (like TNF-α) and proinflammatory monocytes whereas there is decreased activity of anti-inflammatory cytokines such as interleukin- (IL-) 10. As a result, there is an imbalance between pro- and anti-inflammatory activities. Diabetes and uncontrolled glycemia are found to be significant predictors of severity and deaths in patients infected with different viruses.
Possible Scenario: existing systemic inflammation + infection
Now imagine: when virus infects you, the body responds by making pro-inflammatory cytokines (which is good) but if you already have high baseline inflammation, generating even more INFLAMMATION - on the top of existing low-grade inflammation - will be overwhelming for the body and more difficult to regulate, as a result can cause complications. The mechanism of the coronavirus pathogenicity hasn’t been completely deciphered yet but one of possible reasons why people with underlying health conditions (chronic inflammation) do not survive, is related to the cytokine storm (cytokine release syndrome), where excess inflammation and poor regulation of inflammation is devastating.
Cytokine storm refers to excessive and uncontrolled release of pro-inflammatory cytokines. Cytokine storm syndrome can be caused by a variety of diseases, including infectious diseases, rheumatic diseases and tumor immunotherapy. It is commonly manifested as systemic inflammation, multiple organ failure, and high inflammatory parameters.
Next to excess inflammation it’s also common to have excess oxidative stress in a disease state.
Both, oxidative stress and chronic inflammation are known to play a role in metabolic diseases, including diabetes. Just as with chronic inflammation, oxidative stress is triggered by the imbalance between oxidative and antioxidative systems in the body. Imbalance results from overproduction of oxidative-free radicals and associated reactive oxygen species (ROS), and reduced anti-oxidant activities to clear ROS. In relation to coronavirus, it’s good to know that infections also increase oxidative stress.
To counteract the effect of free radicals, antioxidants can scavenge and neutralize ROS. For example, many foods like vegetables and fruits contain naturally occurring antioxidants including vitamins, minerals and phytonutrients. Another good reason to eat your veggies.
ROS are chemically reactive molecules containing oxygen, they are formed as metabolic byproducts. Examples include hydrogen peroxide, superoxide radicals, singlet oxygen, hydroxyl radicals and peroxynitrite anion. Excessive levels of ROS can be harmful because ROS can alter the structure and function of proteins and lipids. These altered proteins and lipids can impair the function of our cells leading to dysfunctional metabolism, and overall poorer biological activity, immune activation and inflammation.
HERE IS WHAT YOU CAN DO
Reduce unnecessary inflammation and support antioxidative defenses.
Unnecessary inflammation is inflammation resulting from poor diet, poor lifestyle, lack of physical activity, stress, lack of sleep, various metabolic and hormonal imbalances, and disease. Necessary inflammation helps us to deal with certain stressors such as infections, wounds, allergies, or toxins by creating an inflammatory response to protect us.
Knowing that obesity is a risk factor for COVID-19 complications and that proper management of obesity will first of all help you prevent developing type 2 diabetes, and second of all will help you reduce unnecessary inflammation and oxidative stress: you should take this opportunity now and use effective lifestyle interventions to reclaim your health. Don’t wait. The earlier you act the better.
Dietary changes, increased physical activity and behaviour changes can help you lose weight. And weight loss can improve or prevent the health problems associated with obesity.
If you feel overwhelmed, take it step by step and work with a professional who can guide you in the process.
Don’t make excuses, just take the first step. For example, if your diet is low in vegetables – start increasing portions of vegetables with your lunch and dinner, and have more diversity of it. Adding veggies will provide anti-inflammatory and anti-oxidant molecules that your body can utilize to counteract inflammation and oxidative stress. If your diet is already healthy and balanced and you can’t lose weight or stabilize blood sugar, contact a professional for tailored made recommendations.
Want to learn more about healthy and nutritious meal composition? Check my blog about creating a healthy plate.
Information provided below is meant for educational purposes only, and does not constitute medical or nutritional advice or act as a substitute for seeking such advice from a qualified health professional.
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