Normal triglyceride levels in people of African descent may hinder diagnosis of metabolic syndrome

In most people, high blood levels of the fat known as triglycerides are an early warning sign of type 2 diabetes and metabolic syndrome, but in people of African descent these dangerous health conditions may go undiagnosed because triglyceride levels are not at the level used to diagnose metabolic syndrome (>150 mg/dL). This is known as the "TG (or lipid) paradox." Understanding how African Americans are at increased risk for cardiovascular disease (CVD) despite a normal TG level is unclear and is the focus of a review article in Metabolic Syndrome and Related Disorders.

Early detection of the disorders that are part of the metabolic syndrome—including insulin resistance and inflammation—is based on identification of at least three of the following five following features: increased waist circumference; elevated blood pressure; triglycerides level >150 mg/dL; low levels of HDL-cholesterol; blood glucose >100 mg/dL. Metabolic syndrome confers an increased risk for CVD and diabetes and is accompanied by sleep apnea, fatty liver disease, and polycystic ovarian disease. While triglyceride screening is considered worldwide to be a reliable indicator of these life-threatening conditions, researchers are just beginning to study and understand the TG paradox, the differences in people of African descent that allows their triglyceride levels to remain unaffected, and other risk factors that might be used instead as an early warning sign of insulin resistance.

"This paradox of lower triglyceride levels and higher levels of HDL-cholesterol in African Americans compared to whites in spite of increased insulin resistance in the former needs to be researched further," says Ishwarlal (Kenny) Jialal, MD, PhD, Editor-in-Chief of the Journal and Robert E. Stowell Endowed Chair in Experimental Pathology, Director of the Laboratory for Atherosclerosis and Metabolic Research, and Professor of Internal Medicine at the University of California, Davis Medical Center (Sacramento). "Also, a new lower cut-off for triglycerides needs to be developed by policy makers of guidelines to better appreciate the metabolic syndrome and its sequelae in African Americans."

Sophia Yu, Darleen Castillo, Amber Courville, PhD, RD, and Anne Sumner, MD, National Institutes of Health, Bethesda, MD, emphasize the importance of identifying strategies for early detection, intervention, prevention of diabetes and cardiovascular disease in blacks in the article "The Triglyceride Paradox in People of African Descent."