The information in a cholesterol panel, including the levels of HDL ("good" choleserol) and LDL ("bad" cholesterol) are only part of the evaluation for a person's risk of heart disease. Other factors may be more important, such as heavy smoking or a very bad family history of early heart attack. High levels of triglycerides and LDL have been associated with increased risk of death from coronary artery disease in those under 50. One of the most influential studies, which is ongoing and cited immediately below, is the
Framingham study. This is a collaboration of Boston University and the
National Heart, Lung, and Blood Institute. The National Heart, Lung, and Blood Institute is part of the National Institutes of Health and receives federal funding. I know of no margarine manufacturers underwriting this study. Some studies have shown that there is no connection between cholesterol levels and heart attacks in younger patients, but other studies dispute this.
From JAMA:
Cholesterol and mortality. 30 years of follow-up from the Framingham study.
From 1951 to 1955 serum cholesterol levels were measured in 1959 men and 2415 women aged between 31 and 65 years who were free of cardiovascular disease (CVD) and cancer. Under age 50 years, cholesterol levels are directly related with 30-year overall and CVD mortality; overall death increases 5% and CVD death 9% for each 10 mg/dL. After age 50 years there is no increased overall mortality with either high or low serum cholesterol levels....
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From JAMA:
Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III)
...Research from experimental animals, laboratory investigations, epidemiology, and genetic forms of hypercholesterolemia indicate that elevated LDL cholesterol is a major cause of CHD [coronary heart disease]. In addition, recent clinical trials robustly show that LDL-lowering therapy reduces risk for CHD....For persons with CHD and CHD risk equivalents, LDL-lowering therapy greatly reduces risk for major coronary events and stroke and yields highly favorable cost-effectiveness ratios....
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From Academic Emergency Medicine:
Risk Factors for Acute Myocardial Infarction in Young Women
OBJECTIVES: Young women presenting to the ED with acute myocardial infarction (AMI) are often difficult to identify. The objective of this study was to determine the cardiac risk factors and ECG findings for young women presenting to the ED with AMI....The AMI group had more smokers (77% vs. 22.6%, OR = 11.5), hypertension (46.3% vs. 12.6%, OR = 6.6), diabetes (26.8% vs. 4.7%, OR = 7.4), elevated cholesterol (28% vs. 19.6%, OR = 2.5), and obesity (BMI > 30) (48.8% vs. 27%, OR = 2.6), with p < 0.05 for all categories. All AMI patients had at least one cardiac risk factor....CONCLUSIONS: Young women with AMI displayed all the usual risk factors, with smoking being the greatest risk, and approximately 92% had an initial ECG suggestive or diagnostic of AMI. All AMI cases had at least one risk factor for coronary artery disease. Young women without a cardiac risk factor and a normal EKG would be very unlikely to have AMI.
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From the Journal of Internal Medicine:
Cholesterol and triglyceride concentration as risk factors for myocardial infarction and death in women, with special reference to influence of age
...Objective. To evaluate the importance of serum cholesterol and triglyceride concentrations as predictors of myocardial infarction and death in women of different ages....Results. In the total population only serum triglyceride concentration was a strong independent risk factor for both end-points studied. Serum triglyceride concentration measured in 38- and 46-year-old women had no predictive value with respect to 24-year incidence of myocardial infarction or death. In 50-, 54- and 60-year-old women, high serum triglyceride concentration consistently predicted myocardial infarction and total mortality. Serum cholesterol concentration, on the other hand, showed evidence of direct association for 24-year all-cause mortality in the younger premenopausal group. Serum cholesterol had no predictive value for myocardial infarction or mortality in the peri- and postmenopausal ages....Conclusions. There appears to be age-specificity in association between serum lipids and these end-points in women, serum cholesterol concentration being more important for younger women and serum triglyceride concentration more important for postmenopausal women as risk factors, observations which need further attention.
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From the New England Journal of Medicine:
A prospective study of cholesterol, apolipoproteins, and the risk of myocardial infarction
BACKGROUND. The independent contributions of subfractions of high-density lipoprotein (HDL) cholesterol (HDL2 and HDL3) and apolipoproteins in predicting the risk of myocardial infarction are unclear....RESULTS. The levels of total cholesterol and apolipoprotein B-100 were significantly associated with an increased risk of myocardial infarction (data on levels of low-density lipoprotein cholesterol were unavailable). Both HDL cholesterol and HDL2 levels were associated with a substantially decreased risk of myocardial infarction, but the HDL3 level was the strongest predictor....CONCLUSIONS. This study underscores the importance of HDL cholesterol in predicting the risk of myocardial infarction and demonstrates protective effects of both the HDL3 and HDL2 subfractions of HDL cholesterol.
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From the British Heart Journal:
Serum cholesterol and acute myocardial infarction: a case-control study from the GISSI-2 trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto-Epidemiologia dei Fattori di Rischio dell'Infarto Miocardico Investigators
OBJECTIVE--To examine the role of serum cholesterol in acute myocardial infarction in a population of patients with no history of coronary heart disease and to establish the nature of this association, the degree of risk, and the possible interaction between serum cholesterol and other major risk factors for acute myocardial infarction....CONCLUSIONS-- This study indicates that serum cholesterol was an independent risk factor for acute myocardial infarction. This association was linear, with no threshold level. Moreover, there was a multiplicative effect between cholesterol and other major risk factors on the relative risk of acute myocardial infarction.
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If you HDL continues to be high, it will be viewed as a protective factor in deciding your risk for heart disease. There's still a lot to be discovered about cholesterol, heart disease, and atherosclerosis, but taking some commonsense measures to protect yourself is prudent. This includes monitoring your cholesterol, not smoking, maintaining a healful weight, eating a lower-fat diet with no trans fats and little saturated fats, and exercising often.
