Insulin resistance occurs when the hormone, produced by the pancreas, cannot be used by the body. Insulin facilitates the breakdown of glucose for energy. With insulin resistance, the pancreas continue to secrete insulin until the demand is too great. The result is high levels of glucose in the body that upsets balance. Insulin resistance is the precursor to type 2 diabetes, also described as pre-diabetes and associated with glucose intolerance.
Obesity
Obesity is one of the major causes of insulin resistance. The correlation between high-calorie fatty foods, over-secretion of insulin (hyperinsulinemia), hormone disruption in the central nervous system and increased hunger appears in the study "Fast Food, Central Nervous System Insulin Resistance, and Obesity," September 2005 in the journal "Arteriosclerosis, Thrombosis, and Vascular Biology." Increased waist size increases the chances of insulin resistance and pre-diabetes. In children and adults, belly fat poses the greatest obesity-related risk for diabetes from insulin resistance.
Fatty Liver Disease
There is a link between insulin resistance and fatty liver disease--a condition that results in fat accumulation in the liver. The disease interferes with metabolism of cholesterol (lipid metabolism) and is more commonly diagnosed in individuals who are obese. The study, "Fatty liver--an additional and treatable feature of the insulin resistance syndrome" is published in the "Oxford Journals." Seventeen percent of individuals studied who had fatty liver disease also had hyperinsulinemia.
Genes
Heredity is also associated with insulin resistance and pre-diabetes. Specific genes have been studied and found to be a cause of insulin resistance. Obesity and inactivity increase the risk that insulin resistance will develop in individuals whose family members have diabetes.
Inactivity
Inactivity can lead to insulin resistance even in otherwise healthy individuals. Researchers studied 20 healthy volunteers placed on bed rest for five days. The study, "Physical inactivity rapidly induces insulin resistance and microvascular dysfunction in healthy volunteers," published at PubMed, concluded that physical inactivity leads to impaired metabolism and is a cause of insulin resistance.
References
- National Diabetes Information Clearinghouse: Insulin Resistance
- Arteriosclerosis, Thrombosis, and Vascular Biology: Fast food, Insulin Resistance and Obesity
- The Children's Hospital: Belly Fat and Insulin Resistance in Kids
- BMJ: Waist circumference and insulin resistance
- Oxford Journals: Fatty Liver Disease and Insulin Resistance
