Health Effects of Liposuction in Overweight Women With Elevated Insulin Levels, Impaired Glucose Tolerance and/or Type 2 Diabetes

Obesity is a major predisposing factor for future Type 2 diabetes because it is often associated with insulin resistance and impaired glucose tolerance. Insulin resistance has been suggested as the common link for other aspects of the cardiac dysmetabolic syndrome that includes hypertension, dyslipidemia, obesity, and macrovascular arterial disease. There are racial disparities in the prevalence of both obesity and Type 2 diabetes: Compared with non-Hispanic Caucasians, African American women have almost twice the prevalence of overweight, obesity, and Type 2 diabetes. Because data from predominantly Caucasian populations suggest that the quantity of truncal (sometimes called upper body) adipose tissue, which includes the adipose tissue surrounding the abdominal viscera, is far more important for risk stratification than that found in the limbs or buttocks, which contain subcutaneous adipose tissue, it has been presumed that attempts at treatment of obesity should concentrate on reducing visceral fat. However, despite their greater risks for the complications of obesity, African Americans have less visceral abdominal adipose tissue than Caucasians matched for body weight. Further, recent metabolic studies suggest that upper body subcutaneous adipose tissue may play a significant role, particularly for African Americans, in the comorbid metabolic conditions associated with obesity. With the advent of the large volume liposuction technique, selective removal of substantial quantities of subcutaneous adipose tissue has become possible. It is unknown whether the complications of obesity can be ameliorated by removal of subcutaneous adipose tissue, but one preliminary study suggests that fasting hyperinsulinism can be improved by this approach. We propose to conduct a pilot study of 10 patients (five Caucasians and five African-Americans) who plan to undergo liposuction. We will investigate how large volume liposuction affects the metabolic complications of obesity in overweight patients who have hyperinsulinemia, impaired glucose tolerance, or type 2 diabetes. We will investigate the effects of liposuction on various indices of the cardiac dysmetabolic syndrome by performing studies of insulin sensitivity and lipid metabolism at four time points: before large volume liposuction, 1 month after liposuction, 4 months after liposuction, and 1 year after liposuction. At each visit we will study body composition, blood pressure, cardiac function, dietary habits, insulin insensitivity, free fatty acids, and lipid profiles.