High LDL Cholesterol in Youth Poses Mid-life Peril Most young adults look upon heart disease as an "old person's" problem, and many therefore assume they do not need to be concerned with their diet, or with their cholesterol profile, just yet. However, a new study in the Annals of Internal Medicine should cause younger people to reconsider the relevance of these two very important health-related factors at this stage in their lives. Story continues below . . . The research tracks 3,258 men and women between the ages of 18 and 30 enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study between 1985 and 1986. The participants underwent blood tests for LDL ("bad") cholesterol, HDL ("good") cholesterol, and triglycerides (fat in the blood, which is also linked to cardiovascular disease risk). The blood lipid tests were repeated through the 20-year course of the CARDIA study. Two decades later, these now middle-aged adults underwent special scans of their hearts to detect and quantify calcium deposits in their coronary arteries. (The "coronary calcium score" is used to predict a patient's risk of experiencing future cardiac events like angina or heart attack.) The findings are cause for considerable concern. First of all, at the time they entered into this clinical study, fully 87 percent of these volunteers were found to already have one or more abnormalities in their HDL, LDL, and/or triglyceride levels, which are associated with an increased risk of cardiovascular disease. The coronary calcium scores provided even more worrisome news at the study's end. When average LDL levels were compared with calcium scores, it quickly became apparent that elevated LDL during young adulthood is associated with a rising and significant risk of coronary artery disease during middle age. Among the volunteers who maintained normal LDL levels (less than 70 mg/dL, or less than 1.81 mmol/L) during their young adult years, there was an 8 percent incidence of coronary artery calcification (coronary artery atherosclerosis) 20 years later. However, among those with elevated LDL levels (160 mg/dL or higher, or 4.14 mmol/L or higher), the incidence of coronary artery disease was 44 percent. Even relatively mild increases in LDL levels during young adulthood were associated with an increased risk of coronary artery disease in mid-life. When compared to patients with LDL levels less than 70 mg/dL (less than 1.81 mmol/L), here's how the risk levels stacked up: • Patients with LDL levels of 70 to 99 mg/dL (1.81 to 2.56 mmol/L) were 50 percent more likely to have detectable coronary artery disease. • Patients with LDL levels between 100 and 129 mg/dL (2.59 to 3.34 mmol/L) were found have a 140 percent increased risk of coronary artery calcifications. • Patients with LDL levels between 130 and 159 mg/dL (3.37 to 4.12 mmol/L) experienced a 230 percent increased risk of developing coronary artery disease. • Finally, patients with LDL levels of 160 mg/dl or higher (4.14 mmol/L or higher) had a whopping 460 percent increase in the risk of developing coronary artery disease by the time they reached middle age. While the diagnosis of coronary artery calcifications does not mean that every one of these volunteers will go on to experience heart attacks, coronary artery calcium deposits (due to atherosclerosis) have been proven to significantly increase the risk of angina and heart attack, as well as other complications of cardiovascular disease. This is a powerful public health study because of its long-term follow-up of a relatively large group, telling us unequivocally at least two very important things that we all should know regarding the risk of developing cardiovascular disease during middle age. The first is that a strikingly large majority of young adults in the United States are already overweight, and already have abnormal blood lipid levels (which are known to be associated with an increased lifetime risk of cardiovascular disease). Secondly, even relatively mild increases in the level of LDL cholesterol in the blood during early adulthood are associated with a significant increase in the likelihood of having heart disease by middle age. With significantly elevated LDL levels, over time, that likelihood skyrockets. Based upon these findings, it may be necessary to revisit the recommended age for initiating routine annual testing of LDL cholesterol levels, particularly for young adults who are obese, or who have a family history of cardiovascular disease. I also cannot stress enough the direct linkages that exist between diet and weight, on the one hand, and LDL levels on the other hand. We are facing a true epidemic of obesity in this country, with two-thirds of the population already categorized as overweight or obese. And the proportion of the American population that is overweight or obese continues to rise every year. The results of this study add to prior research data regarding the lifetime health effects of poor lifestyle and diet choices – even when these poor choices are made during the very early years of our adult lives. See more of Dr. Robert Wascher's health advice here. Editor's Notes: |