The Effects of Anti-Inflammatory Treatment on Insulin Resistance in Healthy Volunteers

This study, conducted at the Phoenix Indian Medical Center, Phoenix, Arizona, will determine whether reducing subclinical inflammation lessens insulin resistance in healthy, obese volunteers. The study findings may lead to new strategies for preventing type 2 diabetes. In diabetes, blood sugar is higher than normal and can result in serious medical problems, such as blindness and kidney failure. People with subclinical inflammation-inflammation that does not produce symptoms, such as fever, pain, or skin redness-are at increased risk for diabetes. Although the reasons for this are not completely understood, it is known that subclinical inflammation exacerbates insulin resistance, which is a cause of diabetes. Insulin is a hormone that helps control blood sugar, and when it does not work properly, the condition is known as insulin resistance. Normal, healthy volunteers between 18 and 45 years old with a body mass index of at least 30 kg/m2 and who have subclinical inflammation (determined by blood tests) may be eligible for this study. Candidates must be non-smokers and must not have an alcohol or drug problem. Candidates will be screened with a medical history and physical examination, electrocardiogram, and blood and urine tests. Participants will maintain a standard diet and undergo tests and procedures during a 14-day inpatient stay at the Phoenix Indian Medical Center.

In healthy subjects, low-grade inflammation, as measured by serum levels of cytokines or acute phase proteins, is positively associated with adiposity. Recent studies indicate that chronic low-grade inflammation in non-diabetic individuals may cause decline in insulin sensitivity and increases the risk of developing type 2 diabetes. It has been proposed that reduction of low-grade inflammation may reduce the risk of development of type 2 diabetes. In agreement with this hypothesis, the class of anti-inflammatory drugs called salicylates (such as aspirin) that influence a specific anti-inflammatory pathway have been found to decrease plasma glucose levels and increase insulin sensitivity in rodents as well as people with type 2 diabetes. In the present study, we propose testing whether administration of the anti-inflammatory drug Salsalate improves insulin sensitivity in obese non-diabetic individuals and whether this improvement is related with a decrease in serum markers of inflammation. Subjects will be randomly assigned to two treatment groups: placebo or Salsalate (3g/d). An oral glucose tolerance test and a combined euglycemic/hyperglycemic clamp to assess insulin sensitivity and insulin secretion will be performed before and after seven days of treatment. Results of this study may help to identify novel strategies to prevent type 2 diabetes in high-risk groups.