Total cholesterol in dyslipidemia

Is it useful to measure it?

Abstract

Introduction: the relationship between lipid fractions and cardiovascular risk is clear. However, the operational characteristics of total cholesterol (TC) for the diagnosis of dyslipidemias due to elevated LDL cholesterol (LDLC), hypertriglyceridemia and low HDL cholesterol (HDLC) are not clear. s Objective: to establish the sensitivity (Sen) specificity (Spe) and predictive values (PPV and NPV) of TC (>200 mg/dL) for diagnosing various types of dyslipidemias.

Materials and methods: a study of diagnostic tests using all the lipid profiles processed at the Hospital Universitario San Ignacio in Bogotá (Colombia) from January 2006 to January 2017. Sensitivity, Spe, PPV and NPV were calculated for each dyslipidemia and for each LDLC goal.

Results: in 25,754 profiles, the average age was 53.6±18 years. The prevalence of elevated LDLC (based on the goals of 160, 130, 100, 70 or 55 mg/dL) was: 19.9%, 44.5%, 72.7%, 92.1% and 96.8%, respectively; for hypertriglyceridemia (>150 mg/dL) it was 44.7%, and for low HDLC (< 40 mg/dL) it was 33.9%. The sensitivity of TC (>200 mg/dL) for elevated LDLC according to the same goals was: 100%, 95%, 70%, 56% and 53%, with a specificity of: 59%, 81%, 94%, 95% and 92%; PPV=37%, 80%, 97%, 99% and 99%; and NPV=100%, 95%, 54%, 15% and 5.8%. For hypertrygliceridemia: Sen=61%, Spe=61%, PPV=55% and NPV=66%. For low HDLC: Sen=36%, Spe=42%, PPV=26% and NPV=54%.

Conclusions: given the operational characteristics of TC>200 mg/dL, it should not be used as an isolated tool for diagnosing dyslipidemia due to LDLC, HDLC or hypertriglyceridemia