High serum levels of triglycerides have been found associated with increased risk for atherosclerotic cardiovascular disease. Cross cultural comparisons between populations with different cardiovascular mortality do not demonstrate significant differences in serum triglycerides. Lipoprotein analysis however suggests that higher levels of intermediate density lipoproteins might be associated with higher coronary mortality in spite of the same levels in total serum triglycerides. A case-control study in Italy has demonstrated an association between premature development of coronary heart disease (before age 40) and higher concentrations of LDL cholesterol or triglycerides, whereas no difference was detected in LDL apo B. This finding suggested an accumulation of bigger and less dense LDL particles, including also intermediate density lipoproteins. Another case-control study evaluated forty pairs of hypercholesterolemic patient matched for sex and age, but differing for the presence or absence of hypertriglyceridemia. Patients with hypercholesterolemia plus hypertriglyceridemia had a significantly more abnormal condition in the arterial district of the lower limbs in comparison to their normotriglyceridemic counterparts. Studies performed in the Mediterranean area support the idea that high serum levels of triglyceride-rich lipoproteins are associated with an increased occurrence of cardiovascular diseases.