The Triglyceride Paradox in People of African Descent

^{Diabetes, Endocrinology and Obesity Branch, National Institutes of Diabetes, Digestive and Kidney Disease, National Institutes of Health, Bethesda, Maryland.}

^{Department of Nutrition, Clinical Center, National Institutes of Health, Bethesda, Maryland.}

^{Corresponding author.}

Address correspondence to: Anne E. Sumner, M.D., DEOB, NIDDK, NIH, 9000 Rockville Pike, Bethesda, MD 20892-1612. E-mail:vog.hin.kddin.artni@senna

Abstract

Even though insulin resistance, cardiovascular disease (CVD), and type 2 diabetes (T2D) are associated with hypertriglyceridemia, blacks with these conditions usually have normal triglyceride (TG) levels. This is often called a lipid paradox. More precisely, it is a “TG paradox.” The pathways that lead to hypertriglyceridemia have been intensively explored. Yet, the pathways that allow TG levels to be normal in the presence of insulin resistance have received little attention and this is problematic. Tests designed for the early detection of insulin-resistant conditions often use elevated TG levels as a diagnostic criterion. However, insulin resistance, CVD, and T2D are not usually associated with hypertriglyceridemia in people of African descent; therefore, the widespread use of TG levels to predict these conditions needs re-evaluation. This review focuses on black–white differences in: (1) the lipid profile across North America, Europe, and Africa; (2) the efficacy of TG-based screening tests, specifically the metabolic syndrome and its two abbreviated versions, the hypertriglycerdemic waist and TG/high-density lipoprotein cholesterol (HDL-C) ratio; and (3) the mechanisms that allow TG to be normal even in the presence of insulin resistance. Overall, a broader understanding of how TG physiology varies by race could lead to better diagnostic tests and improved health outcomes.

Abstract

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