Blood lipid concentrations and risk of myocardial infarction

In western countries, individuals with plasma lipid concentrations above a set threshold value are judged to be at risk of coronary heart disease. However, in Algeria, people tend to have lower lipid concentrations than those in the developed world, and might, therefore, be excluded from preventive strategies and denied treatment. We did a study in Algeria in which we investigated the plasma lipid profiles of 67 individuals who had had a myocardial infarction, and 70 controls. We compared our results with those of two other similar studies done in France and Ireland. An increase in concentration of total cholesterol and LDL cholesterol, and a decrease in HDL cholesterol, was associated with raised risk of myocardial infarction in our study, but lipid concentrations rarely reached the recommended threshold values. However, cholesterol ratios (total/HDL, LDL/HDL) provided consistent and comparable estimates of cardiovascular risk across the three populations. Our results raise the question of whether threshold recommendations for cardiovascular risk prevention, in populations with low concentration of plasma lipids, should be made.