Hormone Produced by Fat Cells Linked to Diabetes, Cardiovascular Disease

Newswise — Adiponectin, a protein hormone produced by the adipocytes (fat cells), could play a pivotal role in the progress of diabetes and cardiovascular disease in African American women.

Researcher Trudy Gaillard, PhD and colleagues today unveiled results of their study that examined the relationships between adiponectin (ADIPO) in the blood and cardiovascular risk factors. ADIPO is known as a hormone that regulates the metabolism of lipids and glucose. It influences how the body responds to insulin and it also has antiinflammatory effects on the cells lining the walls of blood vessels.

While high blood levels of adiponectin have been associated with reduced risk of heart attack and type 2 diabetes, low levels of adiponectin have been found in people who are obese and at increased risk of heart attack. Today's research now also links lower levels of ADIPO with glucose intolerance and high insulin levels.

"In our study group, we found that ADIPO decreased as glucose tolerance and insulin resistance worsened," stated Dr. Gaillard. "As subjects progressed from normal glucose tolerance to impaired glucose tolerance to diabetes, we found increases in fasting glucose, insulin, and c-peptide levels, while ADIPO levels decreased"

The research included 53 obese African American women, ranging in age from 38-58 years, mean body mass index at 34.5±5.8, and with varying degrees of glucose tolerance. Oral glucose tolerance test (OGTT) was performed in each subject. Fasting serum glucose, insulin, c-peptide, and lipids and lipoproteins were also obtained. Insulin resistance was measured using homeostasis model assessment.

Levels of ADIPO in the blood decreased as glucose tolerance deteriorated in this group of high-risk African American women. Factors that increase risk of heart disease, high cholesterol, high levels of low density lipoprotein-cholesterol (LDL-C), and triglycerides, increased as glucose tolerance status worsened and ADIPO levels decreased. At the same time, HDL-C levels, known as the "good" cholesterol, decreased as glucose tolerance worsened and ADIPO levels decreased.

Trudy Gaillard, PhD, program director, Prevention of Diabetes in African Americans Program, conducted this research with colleagues Dara Shuster, MD, and Kwame Osei, MD from the Division of Endocrinology, Diabetes and Metabolism, The Ohio State University, Columbus, Ohio.

Additional conference information and news from the conference can be found at http://www.ishib.org/ISHIB2006.

ISHIB2006 is jointly sponsored by ISHIB and the American Society of Hypertension (ASH). ISHIB (The International Society on Hypertension in Blacks) is a nonprofit, professional medical membership organization devoted to improving the health and life expectancy of ethnic populations. ISHIB was founded in Atlanta, Georgia, in 1986 to respond to the problem of high blood pressure among ethnic populations. Each year, its international interdisciplinary conference presents advancements in the treatment and prevention of cardiovascular diseases to reduce health disparities among ethnic minority populations. In addition to US conference locations, other sites for the conference have included Toronto, London, the US Virgin Island, Kenya, Cameroon, and Brazil.