Coronary Heart Disease Risk Associated with Primary Isolated Hypertriglyceridemia; a Population-Based Study

Background Hypertriglyceridemia is associated with increased risk of coronary heart disease but the association is often attributed to concomitant metabolic abnormalities. We investigated the epidemiology of primary isolated hypertriglyceridemia (PIH) and associated cardiovascular risk in a population-based setting. Methods and Results We identified adults with at least one triglyceride level >= 500 mg/dL between 1998 and 2015 in Olmsted County, Minnesota. We also identified age- and sex-matched controls with triglyceride levels <150 mg/dL. There were 3329 individuals with elevated triglyceride levels; after excluding those with concomitant hypercholesterolemia, a secondary cause of high triglycerides, age <18 years or an incomplete record, 517 patients (49.4 +/- 14.0 years, 72.0% men) had PIH (triglyceride 627.6 +/- 183.6 mg/dL). The age- and sex-adjusted prevalence of PIH in adults was 0.80% (0.72-0.87); the diagnosis was recorded in 60%, 46% were on a lipid-lowering medication for primary prevention and a triglyceride level <150 mg/dL was achieved in 24.1%. The association of PIH with coronary heart disease was attenuated but remained significant after adjustment for demographic, socioeconomic, and conventional cardiovascular risk factors (hazard ratio [HR], 1.53; 95% CI, 1.06-2.20; P= 0.022). There was no statistically significant association between PIH and cerebrovascular disease (HR, 1.06; 95% CI, 0.65-1.73, P= 0.813), peripheral artery disease (HR, 1.27; 95% CI, 0.43-3.75; P= 0.668), or the composite end point of all 3 (HR, 1.28; 95% CI, 0.92-1.80; P=0.148) in adjusted models. Conclusions PIH was associated with incident coronary heart disease events (although there was attenuation after adjustment for conventional risk factors), supporting a causal role for triglycerides in coronary heart disease. The condition is relatively prevalent but awareness and control are low.