Stress and lipoprotein metabolism: Modulators and mechanisms

Elevated concentrations of triglycerides and low-density lipoprotein (LDL) cholesterol,¹ especially in combination with low concentrations of high-density lipoprotein (HDL) cholesterol,² are associated with an increased risk of atherosclerosis, coronary heart disease, and stroke. While several dietary and genetic factors contribute to atherogenic lipoprotein profiles,^3,4 stress also contributes to unfavorable concentrations of lipoproteins that may predispose to cardiovascular disease.^5,6 This report reviews the data supporting a link between stress and lipid metabolism, with particular focus on the mechanisms whereby stress could be related to increased lipid concentrations, and several factors which could modulate a relationship between stress and lipid levels. Following a brief discussion of stress, this report is divided into three main sections. First, data that support a relationship between stress and lipoprotein metabolism are considered. Data from laboratory studies, studies of episodic and chronic stress, studies on personality, and experiments from the animal literature are reviewed. The second major section discusses mechanisms that could account for stress effects on lipoprotein metabolism. This section considers the metabolic effects of stress, the effects of stress on hemoconcentration, and behavioral responses to stress that could affect lipid concentrations. The final major section reviews various modulators of the stress-lipid relationship, including intervening personality variables, gender, diet, seasonal variations in lipoprotein concentrations, and genetics and polymorphism. The concluding comments in this review address several promising areas for further research.