Lipid Panel Interpretation Flashcards

A direct (beta-quantification) LDL-C measurement differs from the Friedewald-calculated LDL-C primarily in which clinical scenario?

Answer: When triglycerides exceed 400 mg/dL or in type III hyperlipoproteinemia

Direct LDL-C measurement by ultracentrifugation or homogeneous assay is essential when TG exceed 400 mg/dL or when type III dyslipidemia is present, conditions that invalidate the Friedewald equation.

In a patient with metabolic syndrome, which lipid panel pattern is the classic triad?

Answer: High TG, low HDL-C, and small dense LDL particles (often normal or mildly elevated LDL-C)

Metabolic syndrome dyslipidemia is characterized by hypertriglyceridemia, low HDL-C, and predominance of small dense LDL particles, with total LDL-C often only mildly elevated despite high particle number.

Which calculation correctly determines the total cholesterol to HDL-C ratio for a patient with TC 210 mg/dL and HDL-C 42 mg/dL?

Answer: 5.0

TC/HDL-C ratio = 210 ÷ 42 = 5.0; a ratio below 5 is generally desirable, and this patient is at the borderline threshold for cardiovascular risk.

A CLS is reviewing a lipid panel in a patient taking niacin. Which expected lipid change is most characteristic of niacin therapy?

Answer: Marked increase in HDL-C and reduction in both TG and LDL-C

Niacin has the broadest lipid effect profile: it raises HDL-C most significantly (15–35%), reduces TG (20–50%), and modestly reduces LDL-C (5–25%), making it unique among lipid-modifying agents.

A patient with hypothyroidism presents with TC 320 mg/dL and LDL-C 240 mg/dL. What is the most appropriate first step in management?

Answer: Treat the underlying hypothyroidism and recheck the lipid panel

Hypothyroidism is a reversible secondary cause of hypercholesterolemia; thyroid hormone replacement often normalizes lipids and should precede any lipid-specific pharmacotherapy.

When interpreting a lipid panel in a pregnant woman at 28 weeks gestation, what physiologic change is expected?

Answer: LDL-C and TG increase due to estrogen-mediated changes in lipoprotein metabolism

Pregnancy is associated with physiologic hyperlipidemia: LDL-C increases ~50%, TG may double or triple (especially in the third trimester), and HDL-C initially rises then plateaus due to estrogen and progesterone effects.

A patient's lipid panel shows LDL-C 95 mg/dL but apolipoprotein B is 130 mg/dL (above goal). This discordance suggests what?

Answer: The patient has a high number of small, dense LDL particles carrying relatively less cholesterol per particle

LDL-C/apoB discordance indicates small dense LDL particle predominance, where each particle carries less cholesterol but the total particle count (and atherogenic risk) is higher than LDL-C alone suggests.