Total cholesterol in dyslipidemias. Is it a useful measure? / Colesterol total en dislipidemias. ¿Útil medirlo?

ABSTRACT

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. 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. (Acta Med Colomb 2019; 44. DOIhttps//doi.org/10.36104/amc.2019.1320).

RESUMEN

Resumen Introducción: es clara la relation entre las fracciones lipídicas y riesgo cardiovascular, sin embargo, no son claras las características operativas del colesterol total (CT) para el diagnóstico de dislipidemias por colesterol LDL (C-LDL) elevado, hipertrigliceridemia y colesterol HDL (C-HDL) bajo. Objetivo: establecer sensibilidad (S), especificidad (E), y valores predictivos (VPP y VPN) del CT (>200 mg/dL) para diagnóstico de diferentes tipos de dislipidemias. Material y métodos: estudio de pruebas diagnosticas a partir de la totalidad de perfiles lipídicos procesados en el Hospital Universitario San Ignacio de Bogotá (Colombia), desde enero de 2006 hasta enero de 2017. Se calcularon S, E, VPP y VPN para cada dislipidemia y para cada meta de C-LDL. Resultados: en 25 754 perfiles, la edad promedio fue 53.6±18 años. Las prevalencias de C-LDL elevado (según metas de 160, 130, 100, 70 o 55 mg/dL) fueron 19.9%, 44.5%, 72.7%, 92.1% y 96.8% respectivamente; hipertrigliceridemia (>150 mg/dL) 44.7% y C-HDL bajo (< 40 mg/dL) 33.9%. Las sensibilidades del CT (>200 mg/dL) para C-LDL elevado según las mismas metas fueron 100%, 95%, 70%, 56% y 53% y especificidades 59%, 81%, 94%, 95% y 92%. VPP=37%, 80%, 97%, 99% y 99%, y VPN=100%, 95%, 54%, 15% y 5.8%. Para hipertrigliceridemia S=61%, E=61%, VPP=55% y VPN=66%. Para C-HDL bajo S=36%, E=42%, VPP=26% y VPN=54%. Conclusiones: dadas las características operativas del CT>200 mg/dL, éste no debe ser utilizado como herramienta aislada para el diagnóstico de dislipidemia por C-LDL, por C-HDL, ni para hipertrigliceridemia. (Acta Med Colomb 2019; 44. DOIhttps//doi.org/10.36104/amc.2019.1320).