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Insulin Sensitivity

Information and Tips

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Updated February 22, 2012

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Insulin sensitivity refers to how sensitive certain bodily tissues are to insulin and how effective insulin is in carrying out functions, such as helping to transport blood sugar (glucose) into cells.

Diabetes is a complicated disease that involves many conditions and interactions. Insulin is an important player to learn about in this intricate disease. It is helpful to know how insulin is supposed to function normally and how it functions when you have diabetes. When you have type 2 diabetes, insulin resistance occurs because of lowered insulin sensitivity. One of your management goals should be to increase your insulin sensitivity.

Normal Function of Insulin

Insulin is a hormone secreted by the pancreas. While it has several functions, its most well-known in regards to diabetes is how insulin aids in the metabolism of carbohydrates. When you consume carbohydrates, the digestive system extracts glucose from the food you eat and releases it into the bloodstream. When glucose levels rise, the pancreas secretes insulin to help get glucose into your cells to be used or stored as energy. Insulin acts like a key, attaching to receptors on cell walls, causing the cell to become receptive to glucose and allowing it to enter the cell. Glucose gets quickly cleared from the bloodstream, and both glucose levels and insulin levels are reduced.

Insulin Resistance and Insulin Sensitivity in Diabetes

Insulin resistance may occur when insulin cannot attach to the receptors properly, there are not enough receptors, or the internal mechanism that allows glucose into the cell is not working correctly. Whatever the case, the body's tissues are not able to receive the glucose they need, and these tissues are considered to have lowered insulin sensitivity.

Glucose builds up in the bloodstream because it cannot get into cells. The body releases more insulin in an effort to lower glucose levels. As a result, lowered insulin sensitivity causes both high glucose levels and high insulin levels.

Health Risks

Insulin resistance due to decreased insulin sensitivity causes hyperinsulinemia (high insulin levels) and hyperglycemia (high glucose levels). Hyperinsulinemia increases your risk of many health problems, including high blood pressure, heart disease, weight gain, stoke, anxiety, depression, blood fat abnormalities, and insomnia. Hyperglycemia can increase your risk for conditions and diseases such as ketoacidosis, type 2 diabetes, cognitive problems, blood clots, vascular damage, nerve damage, eye disease, kidney disease, and cardiovascular disease.

Tips to Improve Insulin Sensitivity

Diabetes lifestyle changes have proven to be very powerful in increasing insulin sensitivity, and can include:

  • Diet: Some studies have shown that insulin sensitivity may be improved with a high-fiber, low-glycemic index diet.
  • Exercise: A very effective way to increase insulin sensitivity is with regular exercise. One moderate-intensity exercise session can cause a 40% improvement in glucose uptake, and the effects can last from 48-72 hours. The U.S. Centers for Disease Control and Prevention recommend 30-60 minutes of regular physical activity on most days of the week. For maximum benefit, perform both cardiovascular exercise and resistance or weight training. Building up muscle mass helps burn more calories at rest and produces a longer duration in improvement of insulin sensitivity.
  • Weight loss: While exercise has short-term, temporary effects, weight loss could help increase insulin sensitivity in the long term.
  • Adequate sleep: About 7-8 hours of sleep is recommended for most adults.
  • Reducing stress: Chronic high stress has been found in some studies to be a predictor of insulin resistance.
  • Medications: Lifestyle changes may be enough to improve insulin sensitivity. However, medications such as Metformin might also be needed. Talk to your doctor about what might work best for you.

Sources:

Horowitz, Jeffrey F. "Exercise-Induced Alterations in Muscle Lipid Metabolism Improve Insulin Sensitivity." Exercise and Sport Sciences Reviews Oct 2007 35(4):192-196

Hostility and Stress Predict Insulin Resistance. Anti-Aging Medicine and Advanced Preventative Health. Accessed February 9, 2012. http://www.worldhealth.net/news/hostility_and_stress_predict_insulin_res/#

Newsom, Sean A; Everett, Allison C; Horowitz, Jeffrey F FACSM. "A Single Session of Exercise Improves Insulin Sensitivity in Obese Adults." Medicine & Science in Sports & Exercise May 2011 43(5):59

Pathophysiology of the Endocrine System, Physiologic Effects of Insulin. Colorado State University. Accessed: February 9, 2012. http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/pancreas/insulin_phys.html

Ross, Robert PHD. "Does Exercise Without Weight Loss Improve Insulin Sensitivity?" Diabetes Care March 2003 26(3):944-945

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