Studies based upon valid research show prolonged high dose Anabolic Steroids (AAS) use can have negative effects upon the heart. Eventually non-stop high dosage AAS cycles will lead to a decrease in high-density lipoprotein cholesterol (HDL). HDL protects against cardio vascular disease by shuttling cholesterol out of the blood and back to the liver.
The liver degrades cholesterol into bile and only then can it be excreted from the body. This is the only method the body has to get rid of excess cholesterol. It is not like fat which can be burned or oxidized. A possible explanation for the significant increases in low-density lip-protein (LDL) cholesterol during long AAS protocols is simply a matter of biosynthesis.
Normally the body utilizes cholesterol to synthesize sex hormones endogenously (produced inside the body). Testosterone, estrogen and others all begin as cholesterol. When AAS are introduced exogenously, this process is inhibited.
This in turn allows cholesterol to build-up to dangerous levels until discontinuance of the AAS. An interesting fact is that anything that stimulates HPTA (hypothalamuspituitary- testes-axis) function/activity also decreases bad cholesterol levels. It does so by increasing hormone (like testosterone) production endogenously. Oral AAS have the greatest negative effects upon HDL, while nandrolone have little or no negative effect. In fact there are some studies that support the belief that nandrolones have a positive effect upon HDL levels, though its is not scientifically proven yet.