There are other drugs to bring down LDL cholesterol levels, though none is as popular as the statins. Bile acid sequestrants such as cholestyramine, colestipol, and colesevelam modestly lower LDL levels but can have gastrointestinal side effects. Nicotinic acid, or niacin, similarly has a modest effect on LDL levels. Both can be used in combination with statins. In one study, simvastatin and niacin reduced LDL levels by 42%, increased HDL levels by 26%, and reduced coronary events by 90%.
A new target for treatment?
Recent research suggests that the benefits of statins may not be entirely due to their effect on LDL levels. Statin therapy is most effective, it seems, when levels of a particular marker of inflammation are higher. C-reactive protein (CRP) is a sign of inflammation, and it appears to play a role in heart disease. It is thought that statins have anti-inflammatory properties, offering protection particularly to the blood vessel walls that are damaged by inflammation in the development of atherosclerosis.
A research team using data from the PROVE IT–TIMI 22 study found that not only did those who reached LDL levels below 70 mg/dl have fewer cardiovascular events, but that those who had CRP levels below 2 mg/l (milligrams per liter) also had fewer cardiovascular events, and to the same degree of difference. What’s more, the association of lower CRP values and fewer events was detected regardless of the person’s LDL level. Lowering CRP values with statins, therefore, was independently associated with decreased risk.
The authors are careful to point out that these findings should not be generalized from their study population—people who had already been diagnosed with an acute coronary syndrome—to people who have not received such a diagnosis.
However, if diabetes is considered a coronary heart disease equivalent, it might be logical to suggest that, as the earlier studies found, people with diabetes should consider intensive statin therapy.
The question might be answered for all people in a few years. The JUPITER trial will recruit 15,000 people who do not have heart disease but do have elevated CRP levels. The study will determine if rosuvastatin therapy will prevent heart disease in this population.
Lipids are not the only risk factor for heart disease, of course. Care guidelines from the American Diabetes Association also recommend keeping blood pressure under 130 systolic and 80 diastolic (130/80 mm Hg), and starting medication if it exceeds 140 systolic or 90 diastolic. Several classes of drugs used to lower blood pressure have been shown to reduce cardiac events in people with diabetes, including ACE inhibitors, angiotensin receptor blockers (ARB’s), diuretics, and calcium channel blockers.
Antiplatelet therapy, using aspirin or another drug such as clopidogrel, is also recommended for many people with diabetes. These medicines help prevent the blood clots that cause heart attacks, and aspirin is recommended for people with diabetes over the age of 40, or those under 40 who have additional risk factors such as family history and high cholesterol levels.
Finally, the recommendations advise all people with diabetes to not smoke cigarettes. Smoking is associated with a number of health problems, including heart disease.