Of all the health complications associated with obesity, insulin resistance may be the most dangerous of them all, according to Fox News.
The National Diabetes Information Clearninghouse points to obesity and weight-related physical conditions as factors in developing insulin resistance, along with genetics. And once it develops, insulin resistance can result in a number of severe complications, including Type 2 diabetes.
Insulin
According to the National Diabetes Information Clearninghouse, insulin is a hormone created in the pancreas that helps the body cells break down food and take in glucose, a form of sugar that is the main source of energy for the body and is derived from the food we eat.
The NDIC states insulin resistance occurs when the body produces insulin but does not break it down sufficiently. The muscle, liver and fat cells of the body fail to respond to this insufficient insulin supply, and the body interprets as a signal that more insulin is required to help the glucose enter those cells. In the attempt to produce more insulin to meet this apparent demand, the pancreas will eventually fail, and excess glucose will begin to build up in the bloodstream.
This situation, insulin and glucose both existing in the bloodstream at the same time, creates the beginnings of Type 2 diabetes, a condition that can lead to heart disease, heart attacks, stroke, kidney failure, blindness and deafness.
Symptoms
There are no definitive symptoms of insulin resistance, the NDIC states, and a person can have the condition for years without knowing. But those with the severe form of insulin resistance may discover dark patches of skin, primarily on the nape of the neck, but also on the elbows, knuckles, knees and armpits.
While visible symptoms may be rare, the NDIC lists several important factors that can contribute to insulin resistance, many of them associated with an obese condition. They include high blood pressure, a "good" cholesterol level below 35 mg per decaliter of blood or a triglyceride level higher than 250 mg/dL and excessive weight, particularly around the waist. The NDIC also found babies who weigh more than 9 lbs. at birth and/or are diagnosed with gestational diabetes -- diabetes first discovered during the pregnancy -- are also at risk for insulin resistance.
Obesity, Insulin, Cancer
Obesity and insulin resistance have also been explored as possible causes of cancer in some adults. In his report published in the November 2000 issue of "The Journal of Clinical Investigation," Dr. Edward Giovannucci, professor of nutrition and epidemiology at the Harvard School of Public Health, states cancer may be linked to insulin resistance and obesity because of the high levels of insulin in the body.
Insulin, Giovannucci said, is important to the growth of tissue in the body and may also carry with it the ability to signal other growth factors in the body, a process called insulin growth factors, or IGF. He said studies have shown people with high levels of IGFs in their body have a greater risk of developing colon, breast and prostate cancer than those with lower IGF levels.
Controversy
Despite the findings of the CDC and the NDIC, there are some scientists who do not see insulin resistance as a cause of obesity, or vice versa. In their report "Obesity and insulin resistance," Barbara B. Kahn and Jeffrey S. Flier of the Division of Endocrinology and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School state a yet-to-be identified genetic or environmental factor is the silent underlying cause of both obesity and diabetes.
Warnings
While weight loss can improve insulin sensitivity, rapid weight loss diets often don't last and can lead to significant weight gain rebound, reports the American Heart Association. It says the best approach for weight loss is a plant-based diet rich in fruits and vegetables and low in fat.
