What is Insulin Resistance?

Insulin resistance is a looming threat to our overall health and wellness as a society. A recent analysis from the National Health and Nutrition Examination Survey (NHANES) in 2021 found that 40% of adults in the US age 18-44 are insulin resistant (Freeman & Pennings, 2023). This is up from 22% in 2003 - i.e. over the past 20 years, the number of us with insulin resistance has almost doubled 😲.

Insulin resistance is a central component to the development of multiple metabolic diseases, including:

• type 2 diabetes
• weight gain/ obesity
• hypertension
• dyslipidemia
• cardiovascular disease
• Non-alcoholic fatty liver disease
• memory issues- dementia/ brain fog

In this post, you'll learn what insulin resistance is. You'll learn the causes of insulin resistance and simple lifestyle hacks we can work on to reverse insulin resistance... ultimately mitigating our chances of developing these disease states. While it may sound daunting, understanding insulin resistance can empower us to take control of our metabolic health and pave the way for a vibrant and fulfilling life.

What is Insulin Resistance? 

Insulin resistance occurs when the cells in our body become less responsive to insulin, a hormone produced by the pancreas. Insulin plays a crucial role in regulating blood sugar levels by facilitating the uptake of glucose from the bloodstream into cells, where it is used for energy. When cells become resistant to insulin, glucose remains in the bloodstream, leading to elevated blood sugar levels.

My favorite way to think about this is as a lock and key. Insulin is a key and opens up cell doors so that they can get glucose. With insulin resistance, the key doesn't fit in the lock so well. The doors don't open and glucose (sugar) stays in the blood stream rather than going into the cells. 

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To counter act the elevated blood sugar levels, your body releases more insulin. This is a compensatory mechanism and it's important to note that a higher fasting insulin level can precede a diagnosis of diabetes by 10-15 years.

In most current primary care practices, only a Hemoglobin A1c is measured. This tells you an average of your blood sugars over 3 months. If your body is still able to compensate your blood sugar levels will be normal. If you looked at your fasting insulin, you could see something brewing way before you actually get to the prediabetic or diabetic range. You could take action sooner! 

Causes of Insulin Resistance

Several factors can contribute to the development of insulin resistance, including:

1. Sedentary Lifestyle: Lack of physical activity can impair insulin sensitivity and lead to insulin resistance. Skeletal muscle makes up about 40% of your total body mass and is the primary source of insulin-mediated glucose uptake (Myers, Kokkinos, & Nyelin, 2019). If you aren't moving your body, your main blood sugar uptake system isn't going to be doing its job. 
2. Poor Diet: Consuming a diet high in refined carbohydrates, sugary foods, and unhealthy fats can contribute to insulin resistance. This is mainly through inflammatory processes and activation of inflammation related cytokines, such as tumor necrosis factor- alpha (Lee, Park & Choi, 2022). Additionally with ingestion of unhealthy fats, increased amounts of free fatty acids leads to ectopic fat accumulation and excess weight. 
3. Excess Weight: Being overweight or obese increases the risk of insulin resistance, as excess fat can interfere with insulin signaling. Excess accumulation of lipids (fats) in the liver and muscle can induce insulin resistance (Lee, Park & Choi, 2022). 
4. Genetics: Family history and genetic predisposition can also play a role in insulin resistance. Fortunately genetics have only been shown to influence insulin resistance 10-30% of the time (Myers, Kokkinos, & Nyelin, 2019). This means that your lifestyle choices can reverse or prevent insulin resistance!  
5. Hormonal Changes: Women may experience insulin resistance during periods of hormonal fluctuations, such as pregnancy or menopause. This is due to the intricate link between all of our hormones and the importance of balance with them. Through practice, I have found that when you address blood sugar and insulin issues first, the rest of the hormones seem to fall in line. 

Effects of Insulin Resistance 

Insulin resistance can have far-reaching effects on your health and well-being. Some common consequences include:

1. Type 2 Diabetes: Insulin resistance is a precursor to type 2 diabetes, a chronic condition characterized by high blood sugar levels. If the lock and key is broken, the sugars stay in the blood. 
2. Weight Gain: Insulin resistance can make it difficult to lose weight and may lead to further weight gain (Wondmkun, 2020). Fatty tissue is inflammatory and this inflammation leads to insulin resistance. Insulin resistance also contributes to weight gain because excess sugars gets stored as fat.... it's a viscous cycle that can be challenging to get out of. 
3. Cardiovascular Disease: Insulin resistance is associated with an increased risk of heart disease, stroke, and other cardiovascular complications. This is due to higher triglyceride levels, higher blood pressure and hardening of the arteries associated with hyperinsulinemia. 
4. Polycystic Ovary Syndrome (PCOS): Insulin resistance is a common feature of PCOS, a hormonal disorder that can affect women's reproductive health.
5. Fatigue and Low Energy: Fluctuations in blood sugar levels can result in fatigue, low energy levels, and difficulty concentrating. 

Managing Insulin Resistance

The good news is that insulin resistance can often be managed and even reversed with lifestyle modifications. Here are some strategies to improve your insulin sensitivity and promote metabolic health:

1. Adopt a Balanced Diet: Focus on whole, nutrient-dense foods such as fruits, vegetables, lean proteins, and healthy fats. Limit processed foods, sugary snacks, and refined carbohydrates.
2. Stay Active: Incorporate regular physical activity into your routine, aiming for a combination of aerobic exercise, strength training, and flexibility exercises. One of the most obvious effects of regular exercise is its impact on insulin resistance (Myers, Kokkinos, & Nyelin, 2019). 
3. Maintain a Healthy Weight: Aim for a healthy weight through a combination of diet, exercise, and stress management. Even modest weight loss can improve insulin sensitivity.
4. Manage Stress: Chronic stress can contribute to insulin resistance (🙋‍♀️ This happened to me). Practice stress-reducing techniques such as mindfulness, yoga, or deep breathing exercises. Check out this video for a mindfulness technique.
5. Prioritize Sleep: Aim for 7-8 hours of quality sleep each night, as inadequate sleep can disrupt hormone levels and exacerbate insulin resistance.

Conclusion

Navigating metabolic health issues like insulin resistance can leave you feeling overwhelmed at times, but it's important to remember that small changes can make a big difference. By taking proactive steps to improve insulin sensitivity and prioritize your well-being, you can unlock a world of possibilities. Let's embrace this journey with optimism and determination, knowing that we have the power to shape our health and create a vibrant future filled with vitality and joy.

References

Freeman AM, Acevedo LA, Pennings N. Insulin Resistance. [Updated 2023 Aug 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507839/

Lee SH, Park SY, Choi CS. Insulin Resistance: From Mechanisms to Therapeutic Strategies. Diabetes Metab J. 2022 Jan;46(1):15-37. doi: 10.4093/dmj.2021.0280. Epub 2021 Dec 30. PMID: 34965646; PMCID: PMC8831809.

Myers J, Kokkinos P, Nyelin E. Physical Activity, Cardiorespiratory Fitness, and the Metabolic Syndrome. Nutrients. 2019 Jul 19;11(7):1652. doi: 10.3390/nu11071652. PMID: 31331009; PMCID: PMC6683051.

Wondmkun YT. Obesity, Insulin Resistance, and Type 2 Diabetes: Associations and Therapeutic Implications. Diabetes Metab Syndr Obes. 2020 Oct 9;13:3611-3616. doi: 10.2147/DMSO.S275898. PMID: 33116712; PMCID: PMC7553667.