How Insulin Resistance Works

What is insulin resistance?

Insulin resistance (IR) is the reduced capacity of tissues like those in the liver, muscle, and fat (adipose) tissue, to properly respond to insulin. Insulin is a hormone that is secreted by specialized endocrine cells in the pancreas. Insulin is responsible for shuttling sugar (glucose) into cells so that the glucose may be converted into energy to carry out normal, cellular processes. This shuttling of glucose into cells also keeps blood glucose levels moderated. If the cells become resistant to insulin, it results in further stimulation and secretion of insulin (hyperinsulinemia) from the pancreas and into the blood. This chronic response of insulin resistance and resulting hyperglycemia or high blood sugar can cause adverse metabolic disease outcomes to be discussed below.

What makes someone insulin resistant?

Insulin resistance can be caused in some cases by genetic factors and conditions such as PCOS (polycystic ovarian syndrome), lipodystrophy, type A and B insulin resistance, and hormonal issues, to name a few. There are also predisposing lifestyle factors that are implicated in IR development. These factors include:

• Obesity, especially deep, visceral fat that surrounds the organs that can cause inflammation and the pancreas to malfunction.
• Aging
• Physical inactivity
• Certain medications
• Glucose toxicity
• History of gestational diabetes
• Ethnicity: People of African, Hawaiian, first nation indigenous, Asian, Hispanic, or Pacific Islander descent are at increased risk
• History of high blood pressure, heart disease, or stroke
• Elevated cholesterol (dyslipidemia and hyperlipidemia)

Potential health implications for insulin resistance.

Chronically elevated insulin in the blood can predispose people to develop type 2 diabetes. Type 2 diabetes is characterized by worsened resistance of cellular capacity to respond to insulin, impaired secretion of insulin, and high blood sugar/glucose levels. This also puts people at a higher risk of developing blood clots (thrombosis), heart disease, hypertension, non-alcoholic fatty liver disease, atherosclerosis (hardened arteries), and kidney disease.

Can insulin resistance be reversed?

Insulin resistance is one of the conditions that constitute metabolic syndrome, which puts people at an increased risk of developing the chronic diseases previously discussed. However, they are not inevitable, and there are treatment options to slow or halt this cascade. Dietary intervention and engaging in daily activity and planned physical exercises are important for weight loss and improved blood glucose and lipid (fat) levels. Once diagnosed, treatment may include consultations with physicians and a registered dietitian to help one lower blood sugar and attain a healthy weight. Routine medical checkups will also be necessary to check blood lipids, HbA1c (to assess 3 months of glucose control), and weight for example. Drug interventions may also be indicated by a physician as well.

Tips for healthy habits in insulin-resistant people

Health interventions that help those diagnosed with insulin resistance include the following interventions:

• Limiting the consumption of sugary junk foods, white flour, and starchy vegetables.
• Incorporating fiber-rich legumes, whole grains, fruit, and vegetables.
• Home preparing foods and limiting pre-prepared, convenience foods.
• Choosing a low glycemic index diet- includes foods with a limited potential for raising blood glucose.
• Including lean meats, skim dairy or non-dairy alternatives, and healthy fats from nuts, seeds, and fish as opposed to saturated fats. This is especially important if your doctor has informed you that your blood lipids like cholesterol, are abnormally high.
• Increased physical activity such as gardening, walking, dancing, swimming, aerobics weight-lifting, or other enjoyable activities into daily living.
• Take the stairs instead of an elevator or do laps around your house to increase physical activity.
• Check blood sugar daily.