The American Association of Clinical Endocrinologists has come out with a new set of cholesterol guidelines for patients with diabetes. Some of these new target levels are numbers that practicing endocrinologists have been using for years, but others add an extra layer of precision to help clinicians determine the best treatments for patients with diabetes and elevated lipids.
The panel, which included Joslin’s Om Ganda, M.D., published their recommendations in the March/April 2012 issue of Endocrinology Practice. They set a target level of below 70mg/dl for LDL cholesterol for patients with diabetes with one additional risk factor for cardiovascular disease (CAD) whether or not they actually have established CAD. Previously, the goal of 70mg/dl was used only for those who were already diagnosed with heart disease.
LDL cholesterol, (moniker the “bad” cholesterol) stands for low density lipoprotein and is responsible for the build up of dangerous cholesterol plaques in the arteries. High LDL levels raise the risk of heart attack. Other risk factors include:
High blood pressure
High blood cholesterol
Being physically inactive
Having a family history of early heart disease
Age (45 or older for men, 55 or older for women)
Beyond measuring LDL, the panel recommends checking non-HDL cholesterol, which includes LDL and triglyceride levels, as well as measuring apoliproprotein B (apoB) levels in patients who take lipid lowering medications.
ApoB is a major component of LDL It is a protein that allows the LDL particle to bind to the receptors on the target cells and deliver the cholesterol. ApoB is a maker of both LDL particle number and, indirectly, particle size.
The size of LDL cholesterol particles is important since smaller, denser LDL particles are thought have greater oxidative potential (when fat is oxidized substances called free radicals are formed which are damaging to cells). Checking apoB allows physicians to make sure that the medicines they are prescribing are working to reduce the number of LDL particles.
In addition, the guidelines recommend a target of 40mg/dl or greater for HDL cholesterol. High density lipoproteins are responsible for carrying excess cholesterol away form the arteries to be disposed of in the stool. HDL is often called “the good cholesterol.”
Other recommendations focused on the type of medications to use. Statins maintain their place as the primary group of drugs to treat hyperlipidemia but AACE does support the use of fibrates for those with elevated triglycerides and low HDL, after LDL goals are achieved. They also postulate a role for niacin in those patients with low HDL levels who also have elevated LDL.
A previous long-term study, Atherothrombosis Intervention in Metabolic Syndrome with Low HDL Cholesterol/High Triglyceride and Impact on Global Health Outcomes (AIM-HIGH) discounted the benefit of raising HDL levels with niacin in patients with normalized LDL.
Dr. Ganda states, “The role of raising HDL after achieving the LDL goals is still an unsettled question. In AIM-HIGH, the HDL levels achieved with Niacin were relatively modest. A newer class of drugs, currently in development, has the potential to safely raise HDL-cholesterol to a much greater extent than that achieved by niacin.”
The focus of the endocrine community reminds us that diabetes is not just a disease of insulin shortage and glucose control. Diabetes has a fundamental impact on cardiac health. Knowing your lipid numbers (cholesterol, LDL, HDL and TGs) is just as important as knowing your A1C.