NEW YORK (Reuters Health) – Coronary heart disease that continues to progress to serious events in patients whose LDL levels have been brought down adequately — called “residual risk.” — is strongly and perhaps synergistically associated with high triglyceride levels and low HDL cholesterol, researchers report.
Dr. Vincent J. Carey and colleagues at Harvard Medical School and Harvard School of Public Health, Boston, Massachusetts came to that conclusion after comparing lipid profiles in 170 patients who had been admitted for incident coronary heart disease events (cases) with those of 175 control patients who had non-CHD conditions and were matched to the case subjects by age, gender, ethnicity and LDL strata.
As reported in the American Journal of Cardiology online August 2, mean LDL levels in the two groups were 73 mg/dL and 87 mg/dL, respectively — well below guideline-recommended levels. Corresponding levels for HDL were 37 vs 47 mg/dL, and for triglycerides, 147 vs 136 mg/dL.
The investigators found that a 23-mg/dL increment in triglycerides conferred a 20% increased risk of CHD, while a 7.5-mg/dL decrease in HDL raised the risk by about 40%.
“High triglycerides and low HDL cholesterol interacted synergistically to increase the odds ratio to 10 for the combined greatest triglycerides (>190 mg/dL) and lowest HDL cholesterol quintiles (<30 mg/dL),” Dr. Carey and colleagues report.
Even in the CHD patients with LDL levels of 70 mg/dL or less, triglycerides and HDL conferred a similar or greater risk as in the whole cohort.
The authors conclude, “These findings contribute to the rationale for considering low HDL and high triglycerides levels, especially when they occur together, in quantifying the risk level to select the type and intensity of treatment.”
Contribution of High Plasma Triglycerides and Low High-Density Lipoprotein Cholesterol to Residual Risk of Coronary Heart Disease After Establishment of Low-Density Lipoprotein Cholesterol Control
Am J Cardiol 2010.