Cholesterol :: Stress can cause cholesterol levels to climb

Stress can cause cholesterol levels to climb, researchers here have found. A study of 199 men and women here found that “a person’s reaction to stress is one mechanism through which higher lipid levels may develop,” said epidemiologist Andrew Steptoe, D.Sc., of University College London.

He and colleague Lena Brydon, Ph.D., reported in the November issue of Health Psychology that people who showed high levels of stress responses on a test designed to evoke them had more unfavorable lipid profiles three years later than did people who took the same test but managed it without stressful responses.

The participants were 199 men and women who were part of the Whitehall II study. Three years earlier it assessed demographic, psychosocial, and biological risk factors for coronary artery disease in more than 10,000 British civil servants.

The investigators measured cardiovascular, inflammatory, and hemostatic responses as participants performed moderately stressful behavioral tasks involving color and word matching on a computer screen, and tracing an image seen in a mirror.

They were evaluated for stress-induced changes in total cholesterol, LDL cholesterol concentration, HDL cholesterol concentration, and total-to-HDL ratios, and for cardiovascular, cytokine, and hemostatic responses.

In the current study, the investigators “tested the hypothesis that stress-induced acute increases in lipid concentration would predict fasting levels three years later, independent of baseline lipid levels and relevant factors known to influence lipids, including age, body mass index (BMI), smoking status, alcohol consumption, and the use of hormone replacement therapy by women,” Drs. Steptoe and Brydon wrote.

In their analysis, they found that the only significant difference between men and women after three years was the level of HDL, which rose to a greater degree among the 93 women in the study than among the 106 men (P=0.34).

Neither age, hormone-replacement therapy, nor smoking could predict serum lipid concentrations at three years.

Changes in BMI between baseline and follow-up were associated with increases at three years in total cholesterol, LDL, total-to-HDL ratio (all P values <.001), and with a reduction in HDL (P< .001). The authors proposed several mechanisms whereby stress could cause elevations in cholesterol. One possibility is that stress-related release of fatty acids and glucose into the bloodstream could prompt the liver into increased production and secretion of very low-density lipoprotein, which is converted into LDL. Another possibility comes from evidence suggesting impaired lipid clearance after stress, due to reduced activity of lipoprotein lipase. Alternatively, stress could cause down-regulation of hepatic LDL receptors, resulting in impaired clearance of LDL from blood, or there could be stress-related changes in the synthesis and release of inflammatory cytokines that may contribute to changes in lipid profile, they wrote.

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