Low triglycerides-high high-density lipoprotein cholesterol and risk of ischemic heart disease

Background: A high triglyceride (TG)-low high-density lipoprotein cholester ol (HDL-C) level (TG greater than or equal to1.60 mmol/L [greater than or e qual to 142 mg/dL] and HDL-C less than or equal to1.18 mmol/L [less than or equal to 46 mg/dL]) is associated with a high risk of ischemic heart disea se (IHD), whereas a low TG-high HDL-C level (TG less than or equal to1.09 [ less than or equal to 97 mg/dL] and HDL-C greater than or equal to1.48 mmol /L [greater than or equal to 57 mg/dL]) is associated with a low risk. Conv entional risk factors tend to coexist with high TG-low HDL-C levels. We tes ted the hypothesis that subjects with conventional risk factors would still have a low risk of II-ID if they had low TG-high HDL-C levels. Methods: Observational cohort study of 2906 men aged 53 to 74 years free of IHD at baseline. Results: During 8 years, 229 subjects developed IHD. Stratified by conventi onal risk factors-low-density lipoprotein cholesterol level (less than or e qual to4.40 mmol/L or >4.40 mmol/L [less than or equal to 70 mg/dL or >170 mg/dL] [median value]), hypertensive status (blood pressure >150/100 mm Hg or taking medication), level of physical activity (>4 h/wk or less than or equal to4 h/wk), and smoking status (nonsmokers vs smokers)-the incidence i n men with high TG-low HDL-C levels was 9.8%;1 to 12.2% in the low-risk and 12.2% to 16.4% in the high-risk strata; the corresponding values in men wi th low TG-high HDL-C concentrations were 4.0% to 5.1% and 3.7% to 5.3%, res pectively. Based on an estimate of attributable risk, 35% of IHD might have been prevented if all subjects had had low TG-high HDL-C levels. Conclusion: Men with conventional risk factors for IHD have a low risk of I HD if they have low TG-high HDL-C levels.