A 52-year-old man with obesity, hypertension, and type 2 diabetes mellitus
presents for routine evaluation. Laboratory investigations reveal total
cholesterol of 290 mg/dL, LDL cholesterol of 195 mg/dL, triglycerides of 240
mg/dL, and HDL cholesterol of 34 mg/dL. Physical examination demonstrates
tendon xanthomas over the Achilles tendon. Family history is significant for
premature myocardial infarction in his father at age 45 years. Diagnosis?
Diagnosis is Severe Hypercholesterolemia with Familial
Hypercholesterolemia (FH), most consistent with Heterozygous FH.
This patient has:
1. LDL-C
195 mg/dL
2. Achilles
tendon xanthomas
3. Premature
coronary disease in a first-degree relative
4. Additional
ASCVD risk factors, including type 2 diabetes, hypertension, and
obesity
He also has moderate hypertriglyceridemia with
triglycerides of 240 mg/dL.
If the LDL-C of 195 mg/dL represents his untreated baseline,
he meets criteria for definite clinical FH by the Dutch Lipid
Clinic Network score.
1. Definition
Dyslipidemia refers to abnormal concentrations of
circulating lipids or atherogenic lipoproteins, including:
1. Elevated
LDL cholesterol
2. Elevated
triglycerides
3. Elevated
non-HDL cholesterol
4. Elevated
apolipoprotein B
5. Elevated
lipoprotein(a)
6. Low
HDL cholesterol
Familial hypercholesterolemia is an inherited disorder
characterized by lifelong elevation of LDL-C and markedly increased risk of premature
atherosclerotic cardiovascular disease.
Severe hypercholesterolemia is defined by LDL-C
≥190 mg/dL.
2. Familial Hypercholesterolemia
FH is most commonly caused by pathogenic variants affecting LDL clearance,
including:
1. LDLR
2. APOB
3. PCSK9
Other rarer genetic causes and phenocopies exist.
The major consequences are:
1. Lifelong
exposure to elevated LDL-C
2. Accelerated
atherosclerosis
3. Premature
coronary artery disease
4. Increased
lifetime ASCVD risk
3. Clinical Features
Most dyslipidemia is asymptomatic until ASCVD develops.
Features suggesting FH include:
1. Markedly
elevated LDL-C
2. Tendon
xanthomas
3. Premature
coronary artery disease
4. Strong
family history of premature ASCVD
5. Corneal
arcus at a young age
Tendon xanthomas, particularly involving the Achilles or
extensor tendons, are highly suggestive of FH.
Low HDL-C is associated with increased ASCVD risk, but raising HDL-C
pharmacologically is not a treatment target.
4. Diagnosis of FH
FH can be diagnosed clinically using validated criteria such as the Dutch
Lipid Clinic Network score.
The LDL-C component of this score should use the untreated LDL-C
level.
4.1 Dutch Lipid Clinic Network Score in This Patient
If LDL-C 195 mg/dL is the untreated baseline:
1. First-degree
male relative with premature coronary disease before age 55:
1 point
2. Tendon
xanthomas:
6 points
3. Untreated
LDL-C 191 to 250 mg/dL:
3 points
Total score = 10 points
Interpretation:
1. >8
points: definite FH
2. 6
to 8 points: probable FH
3. 3
to 5 points: possible FH
4. 0
to 2 points: unlikely FH
Therefore:
If LDL-C 195 mg/dL is the untreated baseline, DLCN score = 10,
meeting criteria for definite clinical FH.
If the patient is already receiving lipid-lowering therapy, use the documented
pretreatment LDL-C for formal DLCN scoring.
5. Laboratory Evaluation
5.1 Standard Lipid Profile
Assess:
1. Total
cholesterol
2. LDL-C
3. HDL-C
4. Triglycerides
5. Non-HDL-C
In this patient:
Non-HDL-C = 290 - 34 = 256 mg/dL
This confirms a very high burden of atherogenic lipoproteins.
Modern LDL-C estimation methods such as the Martin-Hopkins or
Sampson equations are generally more accurate than the traditional
Friedewald equation, particularly when triglycerides are elevated.
5.2 Non-HDL-C and Apolipoprotein B
Because this patient's triglycerides are 240 mg/dL,
assessment of atherogenic burden should not rely on LDL-C alone.
In adults with triglycerides ≥150 mg/dL, measurement of non-HDL-C or
ApoB is preferred over LDL-C alone to guide clinical decision-making.
ApoB reflects the total number of circulating atherogenic
lipoprotein particles.
Measurement is particularly useful in:
1. Hypertriglyceridemia
2. Diabetes
mellitus
3. Metabolic
dysfunction
4. Discordance
between LDL-C and non-HDL-C
5. Assessment
of residual ASCVD risk
LDL-C nevertheless remains a central treatment target in FH.
5.3 Lipoprotein(a)
Lp(a) should be measured at least once in all adults.
An Lp(a):
1. ≥50
mg/dL
2. ≥125
nmol/L
is considered an important ASCVD risk-enhancing level.
Because FH and premature family ASCVD are present, Lp(a) measurement is
particularly relevant in this patient.
6. Evaluation for Secondary Causes
Before attributing severe hypercholesterolemia entirely to FH, evaluate for
secondary contributors.
Important causes include:
1. Hypothyroidism
2. Nephrotic
syndrome
3. Chronic
kidney disease
4. Cholestatic
liver disease
5. Poorly
controlled diabetes
6. Obesity
and dietary factors
7. Selected
medications
Evaluation may include:
1. TSH
2. HbA1c
or glucose
3. Serum
creatinine and eGFR
4. Urinalysis
or urine albumin assessment
5. Liver
biochemical tests
6. Medication
and alcohol review
Secondary contributors do not exclude coexisting FH.
7. Genetic Testing and Family Screening
In adults with severe hypercholesterolemia and suspected FH, panel-based
genetic testing can be useful and should be considered.
Important points:
1. Genetic
testing can confirm a pathogenic FH variant
2. It
may improve risk stratification
3. It
facilitates cascade screening
4. A
negative genetic test does not exclude clinically diagnosed FH
5. Genetic
confirmation is not required before starting treatment
Cascade screening:
1. Screen
first-degree relatives
2. Extend
cascade screening to additional relatives, including second-degree
relatives when appropriate
3. Use
lipid testing and, when a familial pathogenic variant is identified, targeted
genetic testing
4. Children
in affected families should be screened early
8. Pathophysiology
Atherosclerosis is driven primarily by retention of ApoB-containing
lipoproteins within the arterial wall.
1. LDL
and other ApoB-containing particles enter and become retained in the arterial
intima
2. Inflammatory
responses and macrophage uptake develop
3. Foam
cells and atherosclerotic plaques form
4. Progressive
plaque burden increases the risk of myocardial infarction, ischemic stroke, and
peripheral arterial disease
In FH, lifelong LDL-C exposure substantially accelerates this process.
9. Management
9.1 Lifestyle
Lifestyle therapy is essential but is usually insufficient by itself
in FH.
Recommend:
1. Heart-healthy
dietary pattern
2. Reduce
saturated fat
3. Avoid
trans fats
4. Increase
soluble fiber
5. Weight
reduction when appropriate
6. Regular
physical activity
7. Tobacco
cessation
8. Optimize
diabetes and blood pressure control
9. Minimize
alcohol, particularly with elevated triglycerides
9.2 Statin Therapy
For LDL-C ≥190 mg/dL, treatment should begin with maximally
tolerated statin therapy regardless of calculated 10-year ASCVD risk.
High-intensity options include:
1. Atorvastatin
40 to 80 mg daily
2. Rosuvastatin
20 to 40 mg daily
A high-intensity statin generally aims for an LDL-C reduction of ≥50%.
Standard population risk calculators should not be used to decide
whether to treat a patient with FH.
9.3 Lipid Goals in This Patient
This patient has:
1. Severe
hypercholesterolemia
2. Definite
clinical FH if LDL-C 195 mg/dL is untreated
3. Type
2 diabetes
4. Hypertension
5. Obesity
He has no documented clinical ASCVD in the vignette.
Appropriate treatment goals are:
1. LDL-C
<70 mg/dL
2. Non-HDL-C
<100 mg/dL
3. ApoB
<70 mg/dL, when measured
4. ≥50%
reduction in LDL-C from untreated baseline
His current LDL-C of 195 mg/dL and non-HDL-C of 256
mg/dL are therefore markedly above goal.
9.4 Additional LDL-Lowering Therapy
If maximally tolerated statin therapy does not achieve the treatment goal,
add nonstatin therapy.
Options include:
1. Ezetimibe
2. PCSK9
monoclonal antibody
o Evolocumab
o Alirocumab
3. Bempedoic
acid
Choice depends on:
1. Degree
of additional LDL-C lowering required
2. ASCVD
risk
3. Statin
tolerance
4. Cost
and access
5. Patient
preference
Because FH often requires large absolute LDL-C reductions, combination
therapy is frequently necessary.
9.5 Inclisiran
Inclisiran is a small interfering RNA therapy that reduces
hepatic PCSK9 production.
In adults with severe hypercholesterolemia and LDL-C ≥100 mg/dL
despite maximally tolerated statin therapy with or without ezetimibe,
inclisiran is a reasonable option for additional LDL-C lowering.
Cardiovascular outcomes trials remain pending. Therefore, PCSK9
monoclonal antibodies such as evolocumab or alirocumab are preferred when
therapies with established cardiovascular outcome benefit are available and
appropriate.
10. Hypertriglyceridemia
This patient's triglycerides are 240 mg/dL, representing
moderate hypertriglyceridemia.
Management should focus on:
1. Weight
reduction
2. Improved
glycemic control
3. Exercise
4. Reduction
of refined carbohydrates and added sugars
5. Limiting
alcohol
6. Statin-based
ASCVD risk reduction
7. Evaluation
for secondary causes
At TG 240 mg/dL, fibrate therapy is not routinely indicated solely
to prevent pancreatitis.
Pancreatitis risk becomes clinically important with:
1. TG
≥500 mg/dL
2. Particularly
TG ≥1000 mg/dL
For severe hypertriglyceridemia, fenofibrate or prescription omega-3 fatty
acids may be considered to reduce triglycerides and pancreatitis risk.
10.1 Icosapent Ethyl
Because this patient is:
1. Age
≥50 years
2. Has
type 2 diabetes
3. Has
additional ASCVD risk factors
4. Has
TG 150 to 499 mg/dL
Icosapent ethyl may be considered for additional ASCVD risk
reduction if triglycerides remain elevated after lifestyle optimization and
maximally tolerated statin therapy and LDL-C has been reduced to <100 mg/dL.
The immediate priority in this patient is aggressive LDL-C reduction.
11. Monitoring
1. Repeat
lipid profile after starting or changing lipid-lowering therapy
2. Assess
absolute and percentage LDL-C reduction
3. Assess
adherence and lifestyle measures
4. Escalate
treatment promptly if lipid goals are not achieved
5. Follow
non-HDL-C or ApoB when triglycerides remain elevated
6. Obtain
baseline ALT before initiating statin therapy
7. Routine
serial liver-enzyme monitoring is unnecessary; repeat testing if symptoms or
clinical findings suggest hepatotoxicity
8. Do
not routinely measure CK; check CK when significant or severe muscle symptoms
suggest myopathy
9. Continue
long-term surveillance for ASCVD
12. Key Clinical Insight
LDL-C ≥190 mg/dL + Achilles tendon xanthomas + premature coronary
disease in a first-degree relative strongly suggests familial
hypercholesterolemia.
In this patient:
If LDL-C 195 mg/dL is the untreated baseline, LDL-C 191 to 250 mg/dL
contributes 3 points + tendon xanthomas 6 points + premature coronary disease
in his father 1 point = DLCN score 10 = definite clinical FH.
Because he also has diabetes, hypertension, obesity, and moderate
hypertriglyceridemia, intensive and usually combination lipid-lowering
therapy is indicated.
Treatment goals include:
1. LDL-C
<70 mg/dL
2. Non-HDL-C
<100 mg/dL
3. ApoB
<70 mg/dL when measured
4. ≥50%
LDL-C reduction from untreated baseline
References
1. Blumenthal
RS, Morris PB, Gaudino M, et al. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA
Guideline on the Management of Dyslipidemia: A Report of the American College
of Cardiology/American Heart Association Joint Committee on Clinical Practice
Guidelines. Circulation. 2026;153(17):e1154-e1276.
doi:10.1161/CIR.0000000000001423.
2. Ahmad
Z, Agarwala A, Cuchel M, et al. Update on familial
hypercholesterolemia: An expert clinical consensus from the National Lipid
Association. Journal of Clinical Lipidology.
2026;20(4):708-737. doi:10.1016/j.jacl.2026.01.011.
3. Mach
F, Koskinas KC, Roeters van Lennep JE, et al. 2025 Focused Update of
the 2019 ESC/EAS Guidelines for the management of dyslipidaemias. European
Heart Journal. 2025;46(42):4359-4378. doi:10.1093/eurheartj/ehaf190.