Reduced levels of testosterone induce LDL oxidation and atherosclerotic lesions involving inflammatory imbalance and reduced macrophage apoptosis

Abstract

Atherosclerosis is among the major cardiovascular diseases that cause death in the world. Men who are deficient in androgen hormones are more susceptible to this disease. The aim of this study was to evaluate the influence of reduced levels of testosterone on the lipid profile, pro and anti-inflammatory cytokines, apoptosis of peritoneal macrophages and the development of atherosclerosis in LDLr-/-mice, as well as on the levels of OxLDL in healthy male humans. Tissues and organs of the experimental animals were used to evaluate lipid deposition in aorta and apoptosis of peritoneal macrophages. In humans the levels of testosterone and OxLDL were analyzed in blood samples from healthy male subjects, who were divided into two groups: low level and high level of testosterone. Animals with decreased testosterone did not present changes in the lipid profile or the levels of IL-6 and TNF-α. However, a decrease in IL-10 and an increase in the IL-6/IL-10 and TNF-α/IL-10 ratios were observed. An increase in the aorta lipid deposition was observed and a decrease in macrophage apoptosis was also demonstrated. In humans, there was an increase of OxLDL in the group with lower levels of testosterone. The findings suggest that decreasing endogenous testosterone levels may induce the development of atherosclerosis, with participation of inflammatory response and macrophage apoptosis. This is reinforced by our human studies, where individuals with low testosterone levels had higher LDL oxidation, which may predict a high atherosclerotic risk for these men.