Introduction

Most people are aware of the need to check their blood cholesterol from time to time, and, if necessary, to do something about it. For some time, we have been informed of the epidemic of overweight and type 2 diabetes in developed countries like the USA. Now the US National Heart, Lung, and Blood Institute has issued guidelines for managing high cholesterol levels that set new, more aggressive targets for treatment. If they are followed, the number of US adults who should be taking lipid-lowering drugs will almost triple.

Here is a summary of the new guidelines, somewhat simplified.

Your cholesterol numbers

Everyone age 20 and older should have their cholesterol measured at least once every 5 years. It is best to have a fasting blood test called a "lipoprotein profile" to measure your:

• Total cholesterol
• LDL (bad) cholesterol - low-density lipoprotein cholesterol, the main source of cholesterol buildup and blockage in the arteries
• HDL (good) cholesterol - high-density lipoprotein cholesterol, helps keep cholesterol from building up in the arteries
• Triglycerides - another form of fat in your blood

The focus initially is on the LDL cholesterol level. Its value is categorized this way:

LDL mg/dL	LDL mmol/L
Below 100	Below 2.6	Optimal
100-129	2.6 - 3.3	Near optimal/above optimal
130-159	3.4 - 4.1	Borderline high
160-189	4.2 - 4.9	High
Above190	Above 5.0	Very high

HDL (good) cholesterol protects against heart disease, so for HDL, higher numbers are better. A level less than 40 mg/dL (1.0 mmol/L) is low and increases your risk for developing heart disease, while levels above 60 mg/dL (1.5 mmol/L) lower your risk. Triglycerides can also increase the risk of heart disease; they may require treatment if they continue to be raised (i.e. above 150 mg/dL, or 1.7 mmol/L) after your LDL cholesterol has been controlled.

Do you need active treatment?

Apart from your LDL level, the major risk factors for coronary heart disease (and stroke) are:

• Cigarette smoking
• High blood pressure (BP above140/90 mmHg, or you are taking medication for high blood pressure)
• Low HDL cholesterol - i.e. below 40 mg/dL.
• Family history of early heart disease (i.e. heart disease in your father or a brother before 55, in your mother or a sister before 65)
• Age: men 45 or older, women 55 or older

Here's your target LDL level, depending on how many risk factors you have:

• None, or just one, risk factor: below 160 mg/dL (4.2 mmol/L)
• More than one risk factor: below 130 mg/dL (3.4 mmol/L)
• If you have diabetes or some sort of heart disease: below 100 mg/dL (2.6 mmol/L)

So, what's the plan?

Before deciding this, your physician should make sure there isn't another reason for your having raised lipid levels. Tests can show if you have diabetes, an underactive thyroid gland, liver disease, chronic kidney failure, or are taking any suspect medications (progestins, anabolic steroids, or corticosteroids).

About half those who have to lower their LDL cholesterol levels can reach their target by changes in their lifestyle, without the need for medication. This approach is called Therapeutic Lifestyle Changes (TLC) - see link to another article below. The main changes are:

1. Diet The TLC diet is a low-saturated-fat, low-cholesterol eating plan that calls for less than 7% of calories from saturated fat and less than 200 mg of dietary cholesterol per day. You should take only enough calories to maintain a desirable weight and avoid weight gain. If your LDL is not lowered enough by this, you can increase the amount of soluble fiber in your diet, and add food products that contain plant stanols or plant sterols (for example, cholesterol-lowering margarines).
2. Weight Management If you are overweight, losing some can help lower your LDL and is especially important if you have high triglyceride and/or low HDL levels, and/or have a large waist measurement (more than 40 inches for men and more than 35 inches for women).
3. Physical Activity Apart from helping in weight loss efforts, regular physical activity can itself actually improve your cholesterol numbers (30 minutes on at least 5 days a week, if possible!).

You should have a check-up after 6 weeks on the TLC regime. If your LDL cholesterol level hasn't improved, intensify your efforts in all three areas, and return in 6 weeks for another blood test. At this point, your physician may advise you to start a lipid-lowering medication.

Drug treatment

When you start medication you should continue your TLC - this will help keep your drug dose down (and thus help avoid side effects), and lower your risk of heart disease in other ways, too.

The likely first choice of drugs will be one of the statins (HMG CoA reductase inhibitors). These drugs are very effective in lowering LDL cholesterol, and are generally extremely safe. Recently one statin, cerivastatin (Baycol), has been withdrawn because of a number of cases of a severe side effect involving degeneration in the muscles, leading to kidney failure. The other statins available (e.g. lovastatin, pravastatin, simvastatin, fluvastatin, and atorvastatin) do not cause this adverse effect, or only extremely rarely in a very mild form. Statins can have other good effects, in addition to their lipid-lowering action - they appear to delay or prevent heart attacks and strokes.

Other first-line drugs include bile acid sequestrants, nicotinic acid, and fibric acids. Bile acid sequestrants lower LDL and can be used alone or in combination with statins. Nicotinic acid lowers both LDL and triglycerides, and raises HDL. Fibric acids lower LDL to some extent, but are used mainly for high triglyceride and low HDL levels. Your physician will advise you on the need to use one or other of these drugs, all of which can produce occasional noticeable side effects.

The prime purpose of treatment is to lower your LDL to its target level. You should have a check about 6 weeks after starting medication, so that the dose can be adjusted and, if necessary, another drug added. Once your LDL target is reached, other lipid risk factors (high triglyceride, low HDL cholesterol) and your non-lipid risk factors (if any) must be addressed.

One important target for therapy is the so-called metabolic syndrome, or syndrome-X, which represents a mixture of lipid and nonlipid risk factors. The syndrome is diagnosed if there any 3 of the following: waist measurement over 40 inches (men) or 35 inches (women), raised triglyceride with low HDL, high blood pressure, and a fasting blood glucose over 110 mg/dL. If you think you may qualify, check the separate article on TLC - see the link below.

Conclusions

It's clear that our knowledge of the risk factors for coronary heart disease has increased to the point where we can, and should, take more aggressive preventative steps. Adapting lifestyle changes can, in many cases, help avert both coronary disease and type 2 diabetes. These new recommendations provide the course of action for you to take charge of one of the major factors associated with early cardiac death - your cholesterol numbers. You have to provide the necessary discipline to follow the recommendations.