Cholesterol and Lipid Disorders

Frederick R. Jelovsek MD

Everyone tells us to watch our fat and cholesterol intake but it is apparent that some women are more genetically predisposed to have higher serum cholesterol values than others. Arteriosclerosis is caused by deposition of cholesterol in the wall of arteries but it is a combination of several lipoproteins (lipids) involved in the process including very low density lipoprotein (VLDL), remnant lipoprotein, and low density lipoprotein (LDL). There probably needs to be some injury to the blood vessel wall to facilitate this lipid deposition but basically the more lipid floating around in the blood stream, the more that gets deposited in blood vessels. High density lipoprotein (HDL) carries away cholesterol from the arterial walls so it is called a "good" cholesterol. This is the cholesterol that is increased by postmenopausal estrogen replacement and that is naturally higher in women during their reproductive years before menopause.

Most of the time lipid levels can be kept in normal range by a reasonable diet, but some women will continue to have high cholesterol levels even when they stick to a low fat diet because they have a familial tendency to lipid disorders. One article, Knopp RH: Drug treatment of lipid disorders. N Engl J Med. 1999;341 (7):498-511, (1) reviewed when high lipid levels should be treated with medical therapy in addition to diet. Since then, there has been a new update of LDL goals, Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) , JAMA 2001. 285;(19):2486-2497. 

What are the causes of hyperlipidemia?

There are several familial (genetic) conditions that lead to primary lipoprotein disorders.

Primary Lipoprotein Disorders

Disorder	Complications
Familial hypertriglyceridemia	pancreatitis
Familial combined hyperlipidemia	coronary artery disease,peripheral vascular disease, stroke
Remnant removal disease (familial dysbetalipoproteinemia)	coronary artery disease,peripheral vascular disease, stroke
Familial or polygenic hypercholesterolemia	coronary artery disease, occasionally peripheral vascular disease, stroke
Familial hypoalphalipoproteinemia (low HDL syndrome)	coronary artery disease, peripheral vascular disease, (may be associated with hypertriglyceridemia

There are also many secondary causes for elevated cholesterol and if you have a high serum cholesterol value, these conditions should be treated or changed, if they can, prior to taking any lipid lowering medication.

• obesity
• diabetes or insulin resistance
• hypothyroidism
• nephrotic syndrome (kidney disease)
• alcohol ingestion
• antihypertensives (beta adrenergic antagonists)
• thiazide diuretics
• steroid medications
• acne treatment (isotretinoin)
• sertraline (Zoloft®) therapy

How do cholesterol levels and other factors make you at risk for cardiovascular disease?

When hyperlipidemia and low serum HDL concentrations occur in combination with other cardiovascular risk factors, early (young age) cardiovascular disease is quite common.

Risk factors for heart disease are:

• Age, postmenopausal or over 55
• hypertension 140/90 or over or treatment for it
• smoking
• diabetes mellitus
• history of cardiovascular disease in first degree relatives (less than 65 years for women, male relatives less than 55 years of age)
• serum HDL cholesterol concentration less than 40 mg/dl

When do cholesterol levels become serious enough so that I need to be on a strict medical diet or prescription drug therapy?

Most of the therapy criteria depend upon whether a woman already has risk factors or even existing cardiovascular disease and what the total cholesterol and LDL cholesterol levels are.

Threshold Cholesterol Values for Therapy

Category	Dietary Therapy Threshold		Drug Therapy Threshold
Total cholesterol	LDL cholesterol	Total cholesterol	LDL cholesterol
0 or 1 risk factor for cardiovascular disease	240 mg/dl	160 mg/dl	275 mg/dl	190 mg/dl optional 160-189 mg/dl
2 or more risk factors for cardiovascular disease	200 mg/dl	130 mg/dl	240 mg/dl	10 year risk < 10%*, 160 mg/dl 10 year risk 10-20%*, 130 mg/dl
existing cardiovascular disease	160 mg/dl	100 mg/dl	200 mg/dl	130 mg/dl

From Knopp RF 1999
* - From the Framingham Heart Study Point Scores for women, a score of 20 or over.

What kind of diet is recommended as treatment for hyperlipidemia?

Low cholesterol diets have been divided into low (Step I diet) and lower (Step II diet). They can be begun sequentially or if conditions are bad enough to warrant drug therapy, you can go directly to Step II when treatment is begun. Step I diet contains no more than 30 percent of calories from fat, less than 10% of calories from fatty acids, and less than 300 mg of cholesterol per day. A Step II diet restricts further by limiting the calories from saturated fatty acids to less than 7% a day and the cholesterol to less than 200 mg per day. This diet decreases LDL cholesterol concentrations 8-15%.

Why not just take medication to lower my cholesterol in case my diet plan is less than perfect?

Different drugs are used as treatment for hyperlipidemia but the most common ones are in a class called "statins". They are similar to building blocks of cholesterol and act as competitors so that real cholesterol is not manufactured. These would include: lovastatin (Mevacor®), pravastatin (Pravachol®), simvastatin (Zocor®), atorvastatin (Lipitor®), fluvastatin (Lescol®), and cerivastatin (Baycol®). When given alone for the prevention of heart disease, these drugs can reduce coronary artery disease by 25-60% and reduce the risk of death from any cause by 30%. They can have serious side effects, however, so they are not routinely given for only slightly elevated cholesterol levels

Adverse side effects of statins

Common

• gastrointestinal upset
• muscle aches
• hepatitis

Rarer

• muscle disease
• rash
• peripheral nerve inflammation
• insomnia
• lupus-like syndrome

It is to your advantage to learn the most about cholesterol that you can. It can play a role in heart disease which is a frequent cause of death and disability in women. You can have a home Cholesterol/Lipid Profile Test done at home which will help tell you if you have a serious problem.