What is atorvastatin?
Atorvastatin, also known as Lipitor, is a medication from the statin class. It is mainly used to lower bad cholesterol levels, the low-density lipoprotein (LDL) [1, 2, 3].
The medication works by inhibiting an enzyme called HMG-CoA reductase. This enzyme is vital for the production of cholesterol, and blocking it decreases the liver's production of cholesterol. A primary reason for lowering LDL is the prevention of heart attacks and strokes [1, 2, 4].
Typically, atorvastatin is prescribed when one has high LDL levels. It helps manage conditions such as:
- primary hypercholesterolemia,
- familial hypercholesterolemia,
- mixed hyperlipidemia.
An additional effect of atorvastatin is the reduction of triglycerides in the blood [1, 2, 5, 4].
The drug is available as a tablet and is recommended once daily. Often, atorvastatin is part of more complex therapeutic approaches. These strategies, in addition to the pharmacological treatment, commonly include a special diet and regular exercise [2, 3].
What is the mechanism of atorvastatin?
Atorvastatin regulates lipid levels in the blood mainly by inhibiting the enzyme responsible for cholesterol synthesis. The enzyme is called 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) and is found in the liver [1, 6, 7].
Also, atorvastatin increases the number of LDL receptors in liver cell membranes [7]. A higher number of these receptors increases the liver's ability to remove LDL from the blood [1, 7].
In addition to LDL reduction, atorvastatin protects the inner lining of blood vessels (endothelium)[8]. It increases the production of the WWP2 protein, which prevents atherosclerosis development via the PDCD4/HO-1 pathway [9].
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Can atorvastatin cause HDL to go down?
Atorvastatin works primarily on LDL and triglycerides [7]. It has little [11] to no [12] effect on the HDL levels.
However, in some cases of hypercholesterolemia and hypertriglyceridemia, atorvastatin was found even to increase HDL levels [13, 14].
Studies show that atorvastatin does not lower HDL levels. On the contrary, in some cases, it even increases the good cholesterol in the blood.
Can I take atorvastatin with low HDL?
Some studies showed that atorvastatin can cause a slight increase in HDL cholesterol levels [15, 16], while others have found that it has little to no effect [11, 17].
Therefore, taking atorvastatin will not negatively impact the low HDL levels. Thus, low HDL is not a contraindication for this medication. On the contrary, taking atorvastatin can increase the good cholesterol concentration in the blood.
What are normal levels of HDL in blood?
An HDL level of 40 mg/dL or higher is considered normal for men. For women, the normal HDL range is 50 mg/dL or higher [18, 19]. Healthcare professionals usually recommend having HDL above 60 mg/dL [20].
What are the causes of low HDL?
Low levels of HDL can be caused by genetic or secondary causes.
Genetic causes of decreased HDL familial lipid disorders like:
- hypoalphalipoproteinemia [21],
- Tangier disease [22],
- familial lecithin-cholesterol acyltransferase deficiency [22],
- lipoprotein lipase deficiency [22],
- familial combined hypolipidemia [22].
The secondary causes of low HDL are disease and medications. Among the diseases are:
- severe sepsis [22],
- systemic lupus erythematosus [22],
- monoclonal gammopathies [22],
- Crohn's disease [22],
- rheumatoid arthritis [22],
- obesity [23],
- diabetes mellitus [23],
- kidney diseases [23],
- polycystic ovary syndrome [23].
Medications that can lower HDL levels in the blood include:
- benzodiazepines [22],
- beta-blockers [22],
- exogenous testosterone replacement therapy [22],
- some diuretics [23],
- HIV medication [23],
- birth control [23].
Is low HDL dangerous?
Low HDL levels are not beneficial for the body. Small amounts of good cholesterol increase the risk of many diseases.
For instance, low HDL is associated with a risk of cancers, such as breast cancer and lung cancer [24]. Also, having low HDL levels increases the chance of suffering a stroke, heart attack, and death [25, 26].