Based on meta-analysis of prospective studies from the epidemiological literature, TAG is a risk factor for CVD, independent of HDL-cholesterol. The RR values were 1.3 and 1.8 for a 1 mmol/l increase in TAG among men and women respectively. Adjustment for HDL-cholesterol and other risk factors attenuated these estimates, but they remained statistically significant. Recent prospective findings from the Stanford Five City Project (Gardner et al. 1996) and the Physicians' Health Study (Stampfer et al. 1996) further demonstrate that TAG and LDL size are highly inter-related risk factors for CHD. Quantitative genetic analysis from large-scale family studies show that these correlations reflect common genetic influences that may be important for understanding genetic susceptibility to CHD.