Abstract
Objective: More than half of patients with acute myocardial infarction (AMI) admitted to Japanese coronary care units reportedly have a serum LDL cholesterol (LDL-C) of less than 120 mg/dl, the target level recommended by the Japanese Society of Atherosclerosis for the primary prevention of AMI in patients with high risk factors. We therefore characterized the lipid profiles of such patients of both genders and compared them with those of control subjects. We also identified the lipid parameters that are significant determinants of AMI.
Methods: We conducted a retrospective community-based case-control study enrolling 955 patients (690 men and 265 women) who had suffered their first AMI and been transferred to 24 hospitals in Hokkaido Prefecture. As controls, 1,892 age-, sex- and residence-matched subjects were randomly selected from the database of a regional health check-up facility. First, lipid parameters were characterized and compared for AMI patients and controls of up to75 years in age with LDL-C<120 mg/dl . We then performed a predictor analysis in which associations between pre-morbid variables and risk factors were investigated by conditional logistic regression analysis.
Results: In 54.8% of the male AMI patients and 36.4% of the male controls, and in 44.9% of the female AMI patients and 30.7% of the female controls, LDL-C was less than 120 mg/dl. In such AMI patients of both genders, HDL-C was significantly lower and the LDL-C/HDL-C ratio was significantly higher than those of the controls. Therefore, among lipid parameters, significant predictors of AMI in both genders were low HDL-C and high LDL-C/HDL-C.
Conclusions: In regular health check-ups, even if subject LDL-C is lower than 120 mg/dl, low HDL-C and a high LDL-C/HDL-C ratio also have to be taken into account to achieve primary prevention of AMI.
