Lesser known fats in the blood known as triglycerides are even more strongly associated than cholesterol with stroke risk, according to a new study published recently.
People have traditionally been advised to lower their cholesterol levels in order to prevent stroke (ischaemic strokes are caused by a blockage to blood supply to part of the brain). Triglycerides and cholesterol are both types of fat that circulate in your bloodstream. But there are as yet no such recommendations regarding triglyceride levels.
New research from Copenhagen Hospital University in Denmark calls this into question, highlighting the importance of also looking at a person’s triglyceride level, and for individuals to better understand their risk of stroke, including knowing their triglyceride and cholesterol levels, and understanding what they can do to lower their risk. Fortunately, lowering that risk can also help prevent heart attack, other blood vessel problems and some types of cancer.
The researchers looked at the health of almost 14,000 men and women who had taken part in a study in Denmark investigating heart disease and stroke. All those involved had their cholesterol and triglyceride levels measured at the start and were followed for up to 33 years — an extremely lengthy study so its findings are very important. During the study, 1,674 of the participants had an ischaemic stroke — almost 1 in 8 of the study participants.
The researchers found women with the highest triglyceride levels (5mmol/L or more) were almost four times more likely to have an ischaemic stroke than women with the lowest triglyceride levels (less than 1mmol/L). Men with the highest triglyceride levels were twice as likely to have an ischaemic stroke as those with the lowest levels.
Conversely, the researchers found that cholesterol level did not have as great an effect on stroke risk in women while in men, only those with the highest levels of cholesterol (more than 9mmol/L or twice the recommended level) had a greater risk of ischaemic stroke. This risk was calculated to be four times higher compared with those men with the lowest level (less than 5mmol/L).
All these results took into account other factors that can affect risk of stroke — such as blood pressure, age, whether or not the participants smoked or drank alcohol.
Commenting on the study, Dr Christine Bennett, Chief Medical Officer of Bupa Australia said: “Both cholesterol and triglycerides are important measures of your cardiovascular disease risk — risk that increases your chance of stroke, heart attack and other conditions. This study outlines the importance of looking at levels of all the different types of fat in a person’s blood — your ‘lipid profile’ — along with other risk factors to manage the health of their blood vessels and circulation system.
“It’s a risk that you can do something about, and so it’s unnecessary to live with that. Checking both your cholesterol and triglyceride levels as part of your lipid profile, as well as testing for other risk factors, such as blood pressure, diabetes risk, weight and family history, can give you an overall picture of your heart disease and stroke risk.”
“Together you and your doctor can use this information to make a realistic and workable plan to help you reduce your chances of ill health in the future. It’s never too early to start to reduce your chances of having a stroke.”
| Healthy adults | Adults with or at high-risk of coronary artery disease | |
| Total cholesterol | Below 5.5 mmol/L | Below 4.0 mmol/L |
|---|---|---|
| LDL cholesterol | Below 2.5 mmol/L | Below 2.0 mmol/L |
| HDL cholesterol | Above 1.0 mmol/L | Above 1.0 mmol/L |
| Triglycerides | Below 1.5 mmol/L | Below 1.5 mmol/L |
Varbo A, Nordestgaard BG, Tybjærg-Hansen A, et al. Nonfasting triglycerides, cholesterol, and ischemic stroke in the general population. Ann Neurol. 2011; published online doi: 10.1002/ana.22384. Available:http://onlinelibrary.wiley.com/doi/10.1002/ana.22384/abstract.
