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.

ObjectiveHepatocyte deletion of estrogen receptor alpha (LKO-ERα) worsens fatty liver, dyslipidemia, and insulin resistance in high-fat diet fed female mice. However, whether or not hepatocyte ERα regulates reverse cholesterol transport (RCT) in mice has not yet been reported.Methods and resultsUsing LKO-ERα mice and wild-type (WT) littermates fed a Western-type diet, we found that deletion of hepatocyte ERα impaired in vivo RCT measured by the removal of 3H-cholesterol from macrophages to the liver, and subsequently to feces, in female mice but not in male mice. Deletion of hepatocyte ERα decreased the capacity of isolated HDL to efflux cholesterol from macrophages and reduced the ability of isolated hepatocytes to accept cholesterol from HDL ex vivo in both sexes. However, only in female mice, LKO-ERα increased serum cholesterol levels and increased HDL particle sizes. Deletion of hepatocyte ERα increased adiposity and worsened insulin resistance to a greater degree in female than male mice. All of the changes lead to a 5.6-fold increase in the size of early atherosclerotic lesions in female LKO-ERα mice compared to WT controls.ConclusionsEstrogen signaling through hepatocyte ERα plays an important role in RCT and is protective against lipid retention in the artery wall during early stages of atherosclerosis in female mice fed a Western-type diet.

Food insecurity is defined as limited or uncertain ability to acquire nutritionally adequate and safe foods in socially acceptable ways. The United States Department of Agriculture (USDA) has divided food insecurity into two categories: low food security and very low food security. Low food security is characterized by irregular access to food, binge eating when food is available, overconsumption of energy-dense foods, obesity, and even type 2 diabetes. This type of food insecurity occurs in impoverished urban areas of high-income countries such as the United States. In contrast, very low food security is distinctly different from low food security and can lead to undernutrition and frank starvation. Very low food security is found in developing countries in both rural areas and urban slums. In these countries, food insecurity is often exacerbated by natural disasters and climate changes that compromise food availability. With a focus on the social, economic, and behavioral factors that promote obesity and cardiometabolic disease in food insecure households in the United States, this review will first define the key terms and concepts associated with food insecurity. Then, the characteristics of food insecure households and the relationship to cardiometabolic disease will be discussed. Finally, the cardiac consequences of food insecurity in developing countries will be briefly described.