Hyperalphalipoproteinemia in hypercholesterolemic adults and children

Area of Science:

• Cardiovascular Health
• Lipid Metabolism
• Public Health Research

Background:

• Hypercholesterolemia is a significant risk factor for cardiovascular disease (CVD).
• Elevated total cholesterol can be due to various lipoprotein profiles, including high levels of high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C).
• Understanding the specific lipid profiles contributing to hypercholesterolemia is crucial for targeted interventions.

Purpose of the Study:

• To characterize the proportion of hypercholesterolemic individuals (children and adults) whose condition is primarily due to elevated HDL-C (predominant hyperalphalipoproteinemia), rather than elevated LDL-C.
• To examine demographic differences (age, race, sex) in the prevalence of this specific type of hypercholesterolemia.
• To provide insights for potential strategies aimed at reducing CVD risk by managing HDL-C levels.

Main Methods:

• Analysis of data from the Lipid Research Clinics collaborative prevalence study.
• Identification of hypercholesterolemic participants (total cholesterol ≥ 95th percentile) based on two examinations.
• Stratification of participants by age (children 6-19 years, adults 20-79 years), race (White, Black), and sex.
• Categorization based on HDL-C and LDL-C levels relative to age-, sex-, and race-specific 95th percentiles.

Main Results:

• In children, 22% of White males, 22% of White females, and 44% of Black males exhibited elevated HDL-C without elevated LDL-C.
• In adults, predominant hyperalphalipoproteinemia was observed in 3% of White males, 10% of White females, 17% of Black males, and 25% of Black females.
• The majority of both children and adults had elevated LDL-C with normal HDL-C.
• Black individuals were more likely than White individuals to have predominant hyperalphalipoproteinemia.
• The mean LDL-C/HDL-C ratio in those with predominant hyperalphalipoproteinemia was significantly lower than the overall mean ratio.

Conclusions:

• Predominant hyperalphalipoproteinemia, characterized by elevated HDL-C, accounts for hypercholesterolemia in a notable proportion of children and adults, especially Black males.
• While elevated LDL-C is the more common cause of hypercholesterolemia, understanding hyper-HDL-C is important for comprehensive CVD risk management.
• These findings suggest that interventions targeting HDL-C elevation may be beneficial for specific populations to reduce cardiovascular risk.