Lipid Panel With LDL:HDL Ratio

Overview:

Abbreviations used are as follows: HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; VLDL-C, very low-density lipoprotein cholesterol. Evaluation of hyperlipidemia as an index to coronary artery disease. Investigation of serum lipids is indicated in those with coronary and other arterial disease, especially when it is premature, and in those with family history of atherosclerosis or of hyperlipidemia. In this sense, the expression “premature” is mostly used to include those with a family history of premature CHD (definite myocardial infarction), or sudden death before 55 years of age in father or other male first-degree relative, or before 65 years of age in mother or other female first-degree relative. Patients with xanthomas should be worked up with lipid panels, but not those with xanthelasmas or xanthofibromas in the sense of dermatofibromas. Those whose fasting serum is lipemic should have a lipid panel, but the serum of a subject with high cholesterol but normal triglyceride is not milky in appearance. The patient with high cholesterol (>240 mg/dL) should have a lipid panel. Patients with cholesterol levels between 200−240 mg/dL plus two other coronary heart disease risk factors should also have a lipid panel.1 In addition to application in programs for evaluation of risk factors for coronary arterial disease, lipid profiling may lead to detection of some cases of hypothyroidism. If a patient has low LDL-C, but very low HDL-C, he/she may still be in jeopardy (Castelli of the Framingham study); therefore, LDL-C:HDL-C ratios are useful. Primary hyperlipoproteinemia includes hypercholesterolemia, a direct risk factor for coronary heart disease. Secondary hyperlipoproteinemias include increases of lipoproteins secondary to hypothyroidism, nephrosis, renal failure, obesity, diabetes mellitus, alcoholism, primary biliary cirrhosis, and other types of cholestasis.

Decreased lipids are found with some cases of malabsorption, malnutrition, advanced liver disease. In abetalipoproteinemia, cholesterol is <70 mg/dL.

Patients with obstructive liver disease may develop lipoprotein abnormalities. Serum lipid factors have not been demonstrated to strongly influence recurrent stenosis following coronary angioplasty, the pathogenesis of which is presently not well understood. LDL-C cannot be calculated if triglyceride is >400 mg/dL.

1. Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. The Expert Panel. Arch Intern Med. 1988 Jan; 148(1):36-69. PubMed 3422148