Very high values of serum high-density lipoprotein cholesterol

Area of Science:

• Cardiology
• Clinical Biochemistry
• Endocrinology

Background:

• Limited knowledge exists regarding individuals with very high serum high-density lipoprotein cholesterol (HDL-C) levels.
• Existing knowledge primarily focuses on rare genetic conditions like familial hyperalphalipoproteinemia.

Purpose of the Study:

• To investigate the prevalence and potential causes of very high HDL-C levels in a general population.
• To determine if elevated HDL-C is always associated with genetic factors or absence of coronary heart disease.

Main Methods:

• Analysis of HDL-C testing data over a 60-month period.
• Identification of individuals with HDL-C levels ≥2.58 mmol/L (≥100 mg/dL).
• Review of medical histories for medications (estrogens, ranitidine), alcohol consumption, and presence of coronary heart disease.

Main Results:

• 46 individuals (43 women) identified with very high HDL-C (range: 2.58–6.15 mmol/L).
• Sixteen individuals were using estrogens, ranitidine, or had alcohol consumption.
• Several individuals with elevated HDL-C showed evidence of coronary heart disease.

Conclusions:

• Very high HDL-C levels are found in the general population, particularly in women.
• Environmental factors, including H2-blockers, estrogens, and alcohol, frequently contribute to elevated HDL-C.
• Elevated HDL-C is not always genetic and does not guarantee protection against coronary heart disease or increased longevity.