Cholesterol Archive

Timing may improve potency and help you cope with side effects.

We all want our medicines to be as effective as possible, and that requires effort on our part. It may be necessary to avoid taking pills with certain foods or drinks, and to check that medications won't interfere with each other.

And in some cases, it may be important to take a drug at a particular time of day. This approach, known as chronotherapy, is gaining attention as research suggests a relationship between when we take medications and how well they work.

People monitor their cholesterol levels, but they should also watch their triglycerides.

Most people have heard of the two main kinds of cholesterol: the "good" HDL and the "bad" LDL. Doctors focus on controlling LDL, as high levels can lead to a buildup of fatty deposits in the arteries and block blood flow, which can trigger a heart attack or stroke.

A blood test called a lipid profile measures your HDL, LDL, and total cholesterol levels. But within that test is another number you should not ignore: your triglyceride levels.

In the journals

High levels of low-density lipoprotein (LDL), or "bad" cholesterol, have long been associated with a greater risk of heart disease. Yet, research has shown that about 75% of heart attack sufferers do not have dangerously high LDL levels.

A study published Nov. 18, 2019, in the International Journal of Nanomedicine looked closer at this issue. Researchers found that high amounts of a subclass of LDL may be a stronger predictor of potential heart problems than overall LDL levels.

Triglycerides are the most common form of fat both in food and in the bloodstream. Growing evidence suggests that above-normal triglyceride levels can raise the risk of cardiovascular disease.

When it comes to understanding this link, the devil is in the details.

When we talk about LDL cholesterol, it's always described as bad or harmful — and with good reason. High blood levels of this artery-clogging substance boost the risk of heart disease, the nation's leading cause of death. The more you can lower your LDL cholesterol (through diet, exercise, or medications), the lower your risk of a heart attack. For heart attack survivors, national guidelines recommend aiming for an LDL cholesterol level of less than 70 milligrams per deciliter to prevent a second heart attack.

In the past year, however, two studies in the journal Neurology reported a higher risk of hemorrhagic (bleeding) stroke in people with LDL levels of 70 and lower. While that sounds worrisome, a closer look at the findings can put these results into perspective.

Chronic stress is associated with an increased risk of heart disease, heart attacks, and strokes. These strategies can help you manage it.

People often complain about stress, but it's actually a natural reaction with an essential purpose.

When the body senses danger, it starts its fight-or-flight response. Your nervous system releases hormones like adrenaline and cortisol, which jolt the body into a protective mode. Your heart pounds faster, muscles tighten, blood pressure rises, breathing quickens, and your senses sharpen.

Several new technologies and medications that may benefit the heart are moving into cardiology care.

As regular readers of the Heart Letter know, our features tend to focus on lifestyle advice and currently available therapies for heart disease. As the new decade begins, we're also looking to the future. Editor in Chief Dr. Deepak L. Bhatt selected five promising new developments in cardiovascular research that you may be hearing more about in the coming years.

1. Digital stethoscopes

First developed more than 200 years ago, the instrument doctors use to listen to the heart and lungs has undergone some high-tech improvements in recent years. The latest digital stethoscopes feature specialized microphones and sensors that filter, buffer, and amplify sounds from the heart. The sounds are then converted to a digital signal and sent wirelessly to a smartphone, where the patterns can be visualized and further analyzed. Some models are so sensitive they can detect turbulent blood flow in the arteries of the heart, possibly enabling doctors to detect coronary artery disease. Studies assessing that potential use are currently under way.

What is the test?

People who have leg pain when exercising may need an evaluation to make sure they have normal blood flow through their leg arteries. Normally blood pressure is similar whether it is measured in the legs or in the arms. If blood pressure is lower in the legs, it usually means that cholesterol buildup inside the leg arteries is interfering with circulation. By taking accurate blood pressure measurements at different locations along your legs, your doctors can determine if you have any arterial narrowing and, if so, where.

In order to get accurate blood pressure measurements, your doctor uses a technique called Doppler ultrasound. Doppler ultrasound is a painless way to detect blood flowing through a small artery. It uses sound waves and a type of sonar detection system to make noise when blood flow is detected. For arterial studies of the legs (called segmental Doppler pressures), Doppler ultrasound is used in place of the stethoscope that doctors usually use when taking blood pressures.

In the summer of 2015, the FDA approved two new cholesterol- lowering drugs, alirocumab (Praluent) and evolocumab (Repatha). They belong to a novel category of medications called PCSK9 inhibitors.

To understand what these drugs are and how they work, it's helpful to know a little bit about PCSK9 and why you might want to inhibit it. PCSK9 is a protein that targets and breaks down a certain class of receptors in the liver. Those receptors remove LDL from the blood as it passes through the liver. By reducing the number of these receptors, PCSK9 effectively increases the level of LDL in the blood. Studies have shown that people with excess PCSK9 have higher LDL and tend to suffer early heart disease, while those who are lacking PCSK9 (either entirely or partially) have low LDL and less heart disease.

Ongoing efforts seek to better identify and treat familial hypercholesterolemia, a leading cause of early heart attacks.

Some 35 million Americans have cholesterol values that put them at high risk for heart disease. The vast majority likely have dozens of different genetic mutations, each of which raises cholesterol by a little bit. Coupled with an unhealthy diet and not enough exercise, cholesterol creeps up slowly over time in these people.

But a small minority — about one of every 250 adults — have a genetic condition called familial hypercholesterolemia (FH). Most have a mutation in one of three key genes that provide instructions that help remove excess "bad" LDL cholesterol from the bloodstream. When one of these genes doesn't operate properly, LDL cholesterol levels can skyrocket as high as 350 milligrams per deciliter (mg/dL) — more than three times higher than the desirable level of less than 100 mg/dL. Their total cholesterol levels (which includes LDL cholesterol plus other lipids) may reach 500 mg/dL or higher.