Serum low-density lipoprotein to high-density lipoprotein ratio as a predictor of future acute myocardial infarction among men in a 2.7-year cohort study of a Japanese northern rural population

Aim: To examine and compare the predictive value of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), TC/HDL-C and LDL-C/HDL-C ratios for future cardiovascular outcomes in the general Japanese population.Methods: A total of 24,566 eligible participants aged 18 years or older, without cardiovascular disease, were enrolled through multiphase health screening and divided into quartile groups based on lipoprotein levels or ratios. Primary endpoints of the study were definitive acute myocardial infarction (AMI) and ischemic stroke, and cases of sudden death with unknown causes were not included. We used Cox proportional hazard models to examine the relationships between the quartiles and incidences of AMI or ischemic stroke, adjusting for traditional risk factors.Results: Mean age was 63.7 years for males and 60.7 years for females. Mean follow-up period was 2.7 years, and 40 cases of AMI and 182 cases of ischemic stroke were recorded. The hazard ratio (HR) for AMI was significantly higher in the top quartile of the LDL-C/HDL-C ratio and LDL-C levels, and third quartile of TC among male participants. The HR of male participants with a LDL-C/HDL-C ratio of 2.6 or higher was significantly higher than other quartiles. No association between lipoprotein levels or their ratio quartiles and ischemic stroke was seen for either sex after adjusting for risk factors.Conclusions: Our results indicated that the LDL-C/HDL-C ratio is an independent predictor for AMI, and the importance of better management of cardiovascular risks among people with high LDLC/HDLC ratios for the prevention of future cardiovascular disease.