Numerous factors can cause your high-density lipoprotein, or HDL cholesterol, to be low. According to the American Heart Association (AHA), high levels of HDL, also known as good cholesterol, may protect you against heart attack. Medical experts believe that HDL cholesterol may carry cholesterol away from your arteries and back to your liver, where it is processed and excreted from the body. Some factors -- including certain medical conditions and lifestyle factors -- can cause low HDL cholesterol.
Metabolic Syndrome
Metabolic syndrome, also known as syndrome X, may cause low HDL cholesterol. According to the National Heart Lung and Blood Institute (NHLBI), metabolic syndrome is the name for a group of factors -- including abdominal obesity, elevated triglyceride levels, decreased HDL cholesterol, high blood pressure and higher than normal fasting blood sugar --associated with being overweight or obese. These factors increase a person's likelihood of heart disease, diabetes and stroke. Common signs and symptoms associated with metabolic syndrome include increased abdominal fat, a blood pressure greater than 120/80 and insulin resistance. MayoClinic.com states that possessing one component of metabolic syndrome means that you are likely to have others. The more components of the condition you have, the greater your health risks.
Tangier Disease
Tangier disease may cause low HDL cholesterol. The Genetics Home Reference website -- a service of the U.S. National Library of Medicine -- states that Tangier disease is an inherited disorder in which HDL cholesterol levels are significantly reduced. Because low levels of HDL are associated with vascular problems, a person with Tangier disease has a moderately increased risk of cardiovascular disease. Along with decreased levels of HDL cholesterol, common signs and symptoms associated with this disease include moderate increases in the amount of fat in the blood, disruptions in nerve function and enlarged tonsils that are orange in color. In some cases, a person with Tangier disease may develop atherosclerosis -- an accumulation of fatty and fibrous deposits in the lining of the arteries. Possible complications associated with Tangier disease include an enlarged spleen and liver, clouding of the eyes and type 2 diabetes.
Sedentary Lifestyle
A sedentary lifestyle -- a lifestyle in which you perform little physical activity -- may cause low levels of HDL cholesterol. According to Aetna Women's Health, a physically active lifestyle confers numerous health benefits, including improved heart strength and capacity, improved weight regulation, decreased likelihood of high blood pressure and diabetes, decreased triglyceride levels and up-regulation of HDL cholesterol. A sedentary lifestyle does not provide your heart with sufficient exercise, causing it to lose strength, flexibility and endurance. You are leading a sedentary lifestyle if you are physically inactive at home and at work and if you fail to engage in exercise for at least 20 consecutive minutes, three times per week. Aetna Women's Health states that, to improve cardiovascular fitness and boost HDL levels, you need to perform aerobic exercise, or activities that require continuous, rhythmic contractions of your body's large muscle groups.
