EP155: Discussion With Dr. Karam Kostner About HDL Cholesterol

Welcome to my podcast. I am Doctor Warrick Bishop, and I want to help you to live as well as possible for as long as possible. I’m a practising cardiologist, best-selling author, keynote speaker, and the creator of The Healthy Heart Network. I have over 20 years as a specialist cardiologist and a private practice of over 10,000 patients. Podcast Summary Introduction Dr. Warrick Bishop, a practicing cardiologist and author dedicated to patient education about heart health, hosts this episode with special guest Dr. Karam Kostner, a cardiologist specializing in cholesterol and lipids. Together, they explore high-density lipoprotein (HDL) cholesterol—what it is, how it works, and what influences its levels in the body. Key Takeaways: HDL is called "good cholesterol" because it transports cholesterol back to the liver for excretion, acting as the body's natural regulator of cholesterol levels. HDL levels are primarily genetically determined, controlled by apolipoproteins like apolipoprotein A1, though lifestyle factors can modify these levels. HDL particle size and composition vary significantly—smaller HDL particles can be more effective at reverse cholesterol transport than larger ones, making HDL assessment more complex than LDL evaluation. Lifestyle factors that reduce HDL include smoking, obesity, and diabetes, while exercise, weight loss, and moderate alcohol consumption increase HDL levels. Hormonal changes such as menopause in women and testosterone use in men can negatively impact HDL levels. Common medications to raise HDL include niacin and fibrates, which are particularly useful for diabetics and those with metabolic syndrome; however, CETP inhibitors that dramatically increase HDL have not been shown to reduce cardiovascular events. Emerging experimental approaches like injecting apolipoproteins to create more effective HDL show promise in early trials but lack large-scale clinical evidence for practical use. HDL testing is minimally affected by fasting status (only about 5% variation), unlike triglyceride testing which requires fasting. While diets rich in monounsaturated fats and omega-3 oils may increase HDL, they often also increase LDL and total cholesterol, potentially negating protective benefits. HDL is protective only to a certain degree; high HDL cannot fully compensate for elevated LDL or other poor lipid profiles in preventing coronary disease.