Diagnosis & Classification of Dyslipidemia Flashcards

Which secondary cause of dyslipidemia typically raises HDL-C while also raising LDL-C?

Answer: Chronic alcohol use

Chronic alcohol use increases HDL-C (primarily HDL2) and can raise TG; it may modestly elevate LDL-C through CETP effects, making it the main secondary cause that raises HDL.

The Friedewald equation for LDL-C estimation becomes unreliable when triglycerides exceed:

Answer: 400 mg/dL

The Friedewald formula (LDL = TC − HDL − TG/5) assumes a fixed VLDL:TG ratio and is considered invalid when TG exceed 400 mg/dL.

A patient with homozygous familial hypercholesterolemia (HoFH) typically presents with untreated LDL-C in which range?

Answer: 400–600 mg/dL

HoFH patients typically have LDL-C of 400–600 mg/dL (sometimes >1000 mg/dL with null/null mutations) due to near-absent LDL receptor function.

Which apolipoprotein genotype predisposes to Type III hyperlipoproteinemia (familial dysbetalipoproteinemia)?

Answer: ApoE2/E2

ApoE2 homozygosity impairs clearance of chylomicron and VLDL remnants; ~1% of E2/E2 individuals develop overt Type III dyslipidemia, usually with a second metabolic hit.

Corneal arcus in a patient under age 45 should raise suspicion for:

Answer: Familial hypercholesterolemia

Premature corneal arcus (arcus cornealis) before age 45 is a clinical clue to FH, reflecting chronic severe hypercholesterolemia, and is included in diagnostic scoring tools.

Which of the following best defines 'isolated low HDL' (hypoalphalipoproteinemia) in adults?

Answer: HDL-C <40 mg/dL in men and <50 mg/dL in women with normal TG and LDL-C

Isolated low HDL is defined by sex-specific cutoffs (<40 mg/dL men, <50 mg/dL women) in the context of otherwise near-normal TG and LDL-C levels.

In the Martin-Hopkins equation for LDL-C estimation, the VLDL correction factor varies based on:

Answer: Non-HDL cholesterol and triglyceride strata

The Martin-Hopkins method uses a novel 180-cell table adjusting the TG/VLDL-C ratio based on non-HDL-C and TG strata, improving accuracy at high TG and low LDL-C.