Association of Triglyceride–to–HDL Cholesterol Ratio With Heart Rate Recovery

Abstract

OBJECTIVE—Insulin resistance is associated with autonomic dysfunction. An attenuated decrease in heart rate after exercise (or heart rate recovery [HRR]) predicts all-cause mortality and is believed to reflect decreased parasympathetic activity. Utilizing triglyceride/HDL cholesterol concentration as a marker of insulin resistance, we sought to assess the association between insulin resistance and HRR. RESEARCH DESIGN AND METHODS—Our study population included 4,963 healthy adults who participated in the Lipid Research Clinics Prevalence Study and underwent exercise testing. HRR was considered abnormal if it did not drop ≥42 bpm 2 min after completion of exercise. Fasting blood specimens were drawn. RESULTS—Individuals in the highest quartile of triglyceride/HDL cholesterol had a significantly higher prevalence of abnormal HRR (40 vs. 30%, multivariable-adjusted prevalence ratio 1.18, 95% CI 1.01–1.39; P = 0.04). As a continuous variable, an increase in 1 SD of triglyceride–to–HDL cholesterol ratio was associated with a greater likelihood of an abnormal HRR, even after adjusting for >20 covariates (adjusted OR 1.16, 95% CI 1.07–1.25; P < 0.001). During 12 years of follow-up, there were 284 deaths. In age- and sex-adjusted analysis, participants with an abnormal HRR and high triglyceride–to–HDL cholesterol ratio had significantly higher mortality than those with a normal HRR and high triglyceride–to–HDL cholesterol ratio (hazard ratio = 1.49, 95% CI 1.08–2.04; P = 0.015). CONCLUSIONS—HRR is associated with triglyceride–to–HDL cholesterol ratio and identifies patients with insulin resistance who are at increased risk of death.