vs 132 mg/dL]; P<.001). The LDL diameter had a high inverse correlation with triglyceride level (r=-0.71), and a high direct correlation with high-density lipoprotein cholesterol (HDL-C) level (r=0.60). We observed a significant multiplicative interaction between triglyceride and total cholesterol (TC) levels (P=.01). After simultaneous adjustment for lipids and a variety of coronary risk factors, LDL particle diameter was no longer a statistically significant risk indicator, with a relative risk (RR) of 1.09 (95% confidence interval [CI], 0.85-1.40) per 0.8-nm decrease. However, triglyceride level remained significant with an RR of 1.40 (95% CI, 1.10-1.77) per 1.13 mmol/L (100-mg/dL) increase. The association between triglyceride level and MI risk appeared linear across the distribution; men in the highest quintile had a risk about 2.5 times that of those in the lowest quintile. The TC level, but not HDL-C level, also remained significant, with an RR of 1.80 (95% CI, 1.44-2.26) per 1.03-mmol/L (40-mg/dL) increase.
CONCLUSIONS: These findings indicate that nonfasting triglyceride levels appear to be a strong and independent predictor of future risk of MI, particularly when the total cholesterol level is also elevated. In contrast, LDL particle diameter is associated with risk of MI, but not after adjustment for triglyceride level. Increased triglyceride level, small LDL particle diameter, and decreased HDL-C levels appear to reflect underlying metabolic perturbations with adverse consequences for risk of MI; elevated triglyceride levels may help identify high-risk individuals.
18 Evidence type: prospective study
The emergence of triglycerides as a significant independent risk factor in coronary artery disease. Assmann G, Schulte H, Funke H, von Eckardstein A. Eur Heart J. 1998 Oct;19 Suppl M:M8-14.
The Prospective Cardiovascular Münster (PROCAM) study involved 4849 middle-aged men who were followed up for 8 years to record the incidence of coronary heart disease (CHD) events according to the risk factors present at study entry. The study showed that fasting levels of triglycerides were an independent risk factor for CHD events, irrespective of serum levels of high density lipoprotein cholesterol (HDL-C) or low density lipoprotein cholesterol (LDL-C). Other independent predictors of CHD included serum levels of LDL-C and HDL-C, age, systolic blood pressure, cigarette smoking, diabetes mellitus, a family history of myocardial infarction and angina pectoris, but did not include total serum cholesterol levels. Individuals with an LDL-C/HDL-C ratio > 5 had a 19.2% chance of experiencing a CHD event in the next 8 years. Furthermore, if an LDL-C/HDL-C ratio > 5 was combined with hypertriglyceridaemia (> or = 2.3 mmol. l-1), the risk of CHD increased to 26.9%. The association between hypertriglyceridaemia and CHD events may be related to the presence of atherogenic, triglyceride-rich particles in plasma, such as LDL and very low density lipoproteins. High triglyceride levels may also predispose to thrombosis.
Triglycerides' role in coronary heart disease (CHD) risk assessment has long been debated. Although meta-analyses have suggested that triglycerides are an independent risk factor for CHD, a consensus has emerged that triglycerides more appropriately represent a biomarker of CHD risk rather than an independent risk factor. Ongoing studies will determine whether triglyceride lowering confers additional CHD benefit beyond that attained via low-density lipoprotein (LDL) cholesterol reduction. The American Diabetes Association presently recommends lowering elevated triglycerides as a secondary therapeutic target after LDL cholesterol, whereas other organizations, such as the National Cholesterol Education Program, recommend non-high-density lipoprotein cholesterol as the second priority after attaining the LDL cholesterol goal. However, reducing very high triglycerides (ie, > 500 mg/dL) remains a sufficiently high priority in affected individuals.
20 Evidence type: analysis of observational results from a randomized controlled t