When Dave, age 40, came into my office for his physical exam, he was aware that he had gained a significant amount of weight and gotten out of his exercise routine in recent years. But, since he was basically healthy and taking no medications, he was surprised that his lab tests indicated an increased risk for coronary heart disease due to high cholesterol.
Like Dave, an estimated 105 million Americans have high or borderline high cholesterol. Although some people have genetic risk factors for this condition, the most common causes are unhealthy diets, not exercising, and being overweight.
Cholesterol is a yellow waxy substance that is transported through the blood by protein carriers. It serves as an essential building block of hormones, cell membranes and bile acids for fat digestion. While about 75 percent of our cholesterol is manufactured in the liver, the remaining 25 percent comes from foods of animal origin (plants have no cholesterol).
Because of the different types of protein carriers, high blood levels of cholesterol can be both good and bad. While HDL (high-density lipoprotein) cholesterol protects the arteries, LDL (low-density lipoprotein) cholesterol can damage the delicate inner lining of the arteries and contribute to atherosclerosis, a process of plaque formation that narrows arteries to vital organs such as the heart, brain and legs. Small dense LDL is another harmful form of cholesterol that is often found in people with diabetes.
The U.S. Preventive Services Task Force recommends routine screening for cholesterol with a fasting blood test. The goal is to establish a lipid (fat) profile for every patient. This profile shows your total, LDL and HDL cholesterol values. It also measures your triglycerides (blood fats), which in high amounts are considered harmful to arteries.
According to the National Cholesterol Education Program’s ATP III classification scale, desirable values are less than 200 mg/dL (milligrams per deciliter of blood) for total cholesterol; less than 130 mg/dL for LDL (or lower if you have other risk factors for heart disease); and less than 150 mg/dL for triglycerides. In contrast, HDL is most beneficial at 60 mg/dL or higher.
Typically, screening begins for men at 35 and for women at 45. For men and women with other heart-disease risk factors, screening should start at 20.
Therapeutic Lifestyle Changes: If warranted by your lipid profile and risk analysis, a range of treatment options will be considered. I encourage my patients to start with three months of “therapeutic lifestyle changes.” The goal is to reduce their LDL cholesterol (think “L” for “lousy”) and increase their HDL cholesterol (“H” for “healthy”) through diet, regular exercise, maintaining a normal weight and not smoking.
Dietary goals are to reduce consumption of saturated fats (which are solid at room temperature) and increase consumption of fish, soluble fibers, and plant stanols and sterols (found in vegetable oil, nuts, legumes, whole grains, fruits and vegetables, and added to some products such as juices and margarines available from your grocery store). Fish oil supplements are also beneficial due to their rich omega-3 content and potential at some dosages to lower triglycerides.
Because diets are complex, I refer many patients to a registered dietitian in our clinic for additional guidance regarding food choices and daily limits, especially if we are not seeing progress in cholesterol levels at their six-week follow-up visit.
The importance of lifestyle changes cannot be overstated. In addition to reducing the risk for many other chronic health problems, diet and exercise are essential as the foundation for cholesterol management and heart health. In fact, evidence from 40 years of clinical trials shows that for every 1 percent reduction in cholesterol levels, the risk of coronary heart disease drops by 2 to 3 percent.
Drug Therapy: While television ads tout the benefits of cholesterol-lowering drugs, these medications have risks and should not be prescribed without careful consideration. However, if cholesterol problems remain after three months of lifestyle changes, or if other risk factors are present, they may be recommended. Previous guidelines recommended starting and adjusting the dose of medication to reach a target level of LDL (i.e. 130, 100 or even 70 mg/dL) based upon whether a patient had coronary heart disease or was at high risk.
However, in 2013, new guidelines from the American College of Cardiology and American Heart Association recommended going from a specific target LDL strategy to identifying whether a patient fell into one of four “statin benefit groups,” and then using low, medium or high doses of medication according to the patient’s risk. The new risk calculator to identify these benefit groups has proven somewhat controversial as it only applies to those over age 40 and seems to identify a disproportionately large number of older adults who would qualify for statin therapy. You can try it yourself at http://tools.cardiosource.org/ASCVD-Risk-Estimator/.
The most potent and recommended cholesterol-lowering drugs are the “statin” class. The other cholesterol drugs including niacin, fibrates, bile acid blockers, and cholesterol absorption blockers have been de-emphasized in favor of statins due to their lack of outcomes data. Statin drugs must be monitored closely with your provider due to liver and muscle side effects, and they are not prescribed for women who are pregnant or breastfeeding or for anyone with severe liver problems.
Christopher Pamp is a board-certified nurse practitioner at the UW Neighborhood Shoreline Clinic. For more information or to make a clinic appointment, call 206.520.5050 or visit www.uwmedicine.org/uwnc.