Severe acquired (secondary) high-density lipoprotein deficiency

Area of Science:

• Lipidology
• Cardiovascular Medicine
• Biochemistry

Background:

• Decreased high-density lipoprotein cholesterol (HDL-C) is a significant cardiovascular disease risk factor.
• While genetic factors play a role, approximately 50% of low HDL-C cases are secondary to other conditions or treatments.
• Very low HDL-C (<20 mg/dL) is uncommon and often linked to genetic mutations in HDL metabolism.

Purpose of the Study:

• To identify and review the causes of severe acquired HDL-C deficiency.
• To differentiate secondary HDL-C deficiency from primary genetic causes.
• To provide clinical context for practitioners regarding severe acquired HDL-C deficiencies.

Main Methods:

• Literature review of identified causes of severe acquired HDL-C deficiency.
• Extensive review of these identified causes.
• Inclusion of case discussions from clinical experience.

Main Results:

• Severe acquired HDL-C deficiency can result from hypertriglyceridemia, critical illness, androgenic anabolic steroids, and acquired lecithin cholesteryl acyl transferase deficiency or liver disease.
• The "disappearing HDL syndrome" describes rapid severe HDL-C decline in ambulatory patients.
• This syndrome can be associated with peroxisome proliferation-activated receptor agonist treatment or paraproteinemias.

Conclusions:

• Severe acquired HDL-C deficiency requires careful distinction from primary genetic causes.
• Understanding secondary causes is crucial for appropriate patient management.
• Clinical awareness and case discussions aid in recognizing these conditions.