What's The Connection Between High Blood Cholesterol and High Blood Pressure

Studies showed that one in five Singaporeans has one or more cardiovascular disease (CVD) risk factors, such as high blood cholesterol, high blood pressure, diabetes, smoking, and physical inactivity. Among them, high blood cholesterol and high blood pressure are the two fastest-growing risk factors in the last ten years. Jointly, they can increase the risk of CVD by more than three times. Dr Brian Khoo, a cardiologist at the Farrer Park Hospital, tells us more.

Cholesterol is not inherently bad
“Cholesterol is essential lipids (fats) needed for your body to function, However, too much cholesterol is harmful to your body, as it causes cholesterol plaque build-up in your arteries and leads to various diseases,” Dr Khoo explained.

Your body needs cholesterol to build cells and make vitamins and other hormones. The liver also uses it to produce bile, which helps you digest fats into smaller fatty acids for absorption into your body. At the same time, the liver also makes the cholesterol that your body needs, The other source of cholesterol is the foods you consume, also known as dietary cholesterol. Commonly, these include meat, eggs, poultry, and dairy products.

Too much bad cholesterol is the problem
While cholesterol is not naturally bad, excess cholesterol could lead to an increased risk of cardiovascular disease. As the disease advances, blood clot formation may occur within the arteries and block blood flow to the heart and brain, resulting in a heart attack or stroke.

“There are two main types of cholesterol: low-density lipoprotein (LDL), or bad cholesterol, and high-density lipoprotein (HDL), or good cholesterol,” Dr Khoo said.

What gives LDL its bad name lies in what it does. It accumulates on the walls of the arteries, making them narrower. The fatty deposits form cholesterol plaques that line your artery walls, reducing blood supply to vital organs.

The HDL, on the other hand, carries cholesterol (including the LDL) away from the arteries to your liver. The liver then removes the cholesterol from the body. So high levels of HDL can lower your risk for heart disease and stroke.

“High blood cholesterol occurs when your total cholesterol or LDL cholesterol levels are too high, while HDL cholesterol is abnormally low. If you are diagnosed with high blood cholesterol, it means that your LDL cholesterol level is equal or above 4.1 millimoles per litre (mmol/L) or equal or above l60mg/dL.”

The National Population Health Survey 2019-2020 conducted by the Ministry of Health (MOH) showed that the prevalence of high blood cholesterol among Singaporeans has increased from 26.2% in 2010 to 39.1% in 2019-2020.

High blood cholesterol and high blood pressure are linked
“High blood cholesterol is mainly caused by eating fatty food, lack of physical activity, being overweight, smoking, and drinking alcohol. While lifestyle factors may affect your blood cholesterol levels, other risk factors may have elevated cholesterol regardless of their lifestyle choices as high blood cholesterol tends to run in families,” Dr Khoo said.

High blood cholesterol causes inflammation and the release of certain hormones that make blood vessels tighten or “constrict,” causing the arteries to become stiff and narrow. The heart then has to pump extra hard to pump blood and maintain a good blood flow to other body parts, resulting in higher blood pressure.

“When your blood vessels have persistently raised pressure, it means you have hypertension or high blood pressure. Blood pressure levels are defined as systolic blood pressure equal to or above l40mmHg and/or diastolic blood pressure equal to or above 90mmHg,” he added.

According to the National Population Health Survey, over one in three (35.5%) Singapore residents aged 18 to 74 had hypertension (or high blood pressure) during 2019-2020, up from 19.8% in 2010.

“Individuals with high blood cholesterol tend to have high blood pressure as both conditions are usually diagnosed together. Research showed that high blood cholesterol can lead to high blood pressure, presumably due to plaque build-up causing artery blockage.”

Health risks
Dr Khoo said that despite being different conditions, they share the same risk factors: overweight, unhealthy diet, lack of physical activities, smoking, stress, and even genetics.

Both conditions affect your health by damaging your arteries, which may lead to cardiovascular diseases such as heart attack, stroke, heart failure, kidney failure, and peripheral arterial disease. The term “silent killer” applies to both conditions, as individuals tend not to be aware until it is too late. While high blood cholesterol raises the risk of heart disease and stroke by 2.3 times, high blood pressure on top of high blood cholesterol multiplies the risks by 3.5 times.

Baseline risk:
A 40-year-old male non-smoker with Total Cholesterol of l85mgldl, Systolic Blood Pressure of l20mmHG, no glucose intolerance, ECG-LVH negative and a probability of developing Cardiovascular Disease of 15/1000 (or 1.5%) in eight years.

Managing both high blood pressure and high blood cholesterol level
While you cannot change factors like age, gender, and genetics, a healthy lifestyle can help to lower blood pressure and blood cholesterol levels, and brings in amazing health benefits.

“Implementing lifestyle changes, for example, eating a healthy diet and exercising, can help lower total cholesterol and blood pressure,” Dr Khoo advised.

Having a healthy diet rich in fruit, vegetables, whole grains, fish, lean proteins, nuts, seeds, and vegetable oils have been shown to reduce LDL cholesterol levels.

Limiting intake of saturated fat and trans fats, for example, fatty meats, processed meats, and other high-salt foods, as well as sugary foods and drinks.

Following the Singapore Heart Foundation’s Heart Smart Eating Plate to get a balanced diet, maximise nutrient intake and practice portion control to prevent excessive weight gain and reap benefits for your heart.

Staying active and exercising need not be a punishing high-intensity workout at the gym. Instead, any enjoyable exercise like sporting games and brisk walks in a park nearby would do just fine. Aim for 150 – 300 minutes of moderate-intensity aerobic physical activity and 2 times of muscle and bone strengthening activities per week. Regular physical activity may increase good cholesterol (HDL) levels modestly and contribute to the reduction of LDL cholesterol and triglycerides.

Maintaining a healthy weight with an ideal body mass index of 18.5 – 22.9kg/m2.

Avoid having too much alcohol by having no more than one standard drink a day for women and two drinks a day for men. A standard drink refers to:

• 2/3 can (220ml) of beer
• One small glass (100ml) of wine
• One glass (30ml) of spirit

When lifestyle changes are not helping you to achieve good control of your blood cholesterol or blood pressure, you may need to consult your doctor for medications to treat each condition specifically.

“Individuals with both high blood pressure and high blood cholesterol will need medications for disease control. To help minimise the number of tablets consumed each day, various 2-in-1 blood pressure and cholesterol-lowering medications are now available in the market,” he added.

Going for a routine health screening like a simple blood test is recommended for men and women aged 40 years and older.

Monitoring your blood pressure regularly with a home blood pressure monitor can help with the early detection of high blood pressure.

Dr Khoo advised that cardiovascular risk factors should not be treated independently. Have a fruitful discussion with your doctor on the risks and benefits of initiating medical treatment. Remember to adhere to the treatment plan your doctor has prescribed for you. Finally, bear in mind that even though you have started medication, healthy lifestyle changes remain a must in your daily life.