People may make an appointment at the private GP clinic because they want some ‘health screening’. But what constitutes health screening?
Should we adopt a one size fits all screening? Or do we need a more realistic pragmatic approach based on the unique individuals we are, the cost of testing, the relevance of the test and what we can do with the results?
Some screening is helpful in that they answer questions such as:
- What are age/gender associated disease conditions?
- What illnesses tend to ‘run in the family’?
- What new signs and symptoms have you become aware of in your body that you want checked out?
Over the coming months, we will take a look at some things we see in the clinic and their possible take home messages.
First Up - Cholesterol
About Cardiovascular Disease
Cardiovascular disease (CVD) is a disease of your heart and blood vessels. It is caused by a process called atherosclerosis. This is thickening or hardening of the arteries due to a build-up of plaque in their inner lining.
CVD is the leading cause of death in England and Wales. It accounts for almost a third of all deaths from heart attack or stroke. And this is where cholesterol comes in.
Cholesterol tends to get a bad press
This goes back to at least the 1970s when it was thought that all fats were bad for us and were the primary cause of heart disease. This concept dramatically changed the American Heart Associaton’s dietetic advice in the USA with the UK following suit. The food industry galvanised into action and flooded the market with low fat foods making a substitution with high sugar to maintain flavour. This changed the nutritional density of foods and was in part a contributing factor in the rise in obesity levels we see today.
Where we get cholesterol and triglycerides and their essential roles
Fats that circulate in your body are called lipids. Cholesterol and triglycerides are two lipids. They each have essential roles in your body. But like most things too much can be harmful.
Some cholesterol is derived from the foods you eat but actually most of it is made in your liver. Cholesterol is essential for providing both rigidity and stability to cell membranes : the building blocks. Also, it is vital in the produc1on of Vitamin D and other hormones. When your body breaks cholesterol down as part of its detoxification processes nothing goes to waste. Bile acids are then made which help digest foods.
By contrast most triglycerides come from your food and only a small amount is manufactured in your liver. Any fat in the food you have eaten is absorbed in your intestines (gut) and then moves around your body in the blood stream. This provides good ‘slow burn’ energy for your muscles and organs and helps keep you warm.
Lipoproteins carry lipids in your blood stream
Lipids can’t just move from A to B of their own accord. They need a transport vehicle and this delivery service comes in the form of lipoproteins. Using lipoproteins made of a special mix of fats and proteins, cholesterol and triglycerides are parcelled up into the right size packages and carried through your bloodstream to your cells.
Types of lipoproteins
We generally refer to four types of lipoproteins based on their size, what they carry and how tightly packed they are. In this article we will just concentrate on three lipoproteins; chylomicron, lowdensity lipoproteins and high-density lipoproteins.
Chylomicron
Triglycerides need a large lipoprotein carrier called chylomicron. Chylomicron carries triglycerides from the food you have just eaten away from your intestine and into your tissues. Your body works beautifully, when healthy. It adjusts to keep everything in balance so chylomicron production is increased after a meal, in anticipation of the extra deliveries needed. Then it slowly decreases.
Low-density and high-density lipoproteins
Cholesterol is parcelled up and carried by either low-density lipoproteins (LDL) or high-density lipoproteins (HDL).
LDL carries most of the cholesterol in your body from your liver to the cells that need it. It is known as ‘bad cholesterol’ as excess LDL cholesterol causes furring up inside your arteries. This is due to excess LDL cholesterol clumping and sticking to your artery wall where an inflammatory reaction and fibrous tissue create ‘plaques’ – a phenomenon known as atherosclerosis. A useful analogy might be the limescale build up inside pipework and pumps in hardwater areas that shorten the lifespan and operational efficiency of domestic appliances!
For your body, LDL cholesterol can ‘clog’ up your system and damage your blood vessels (pipework) leading to injury to vital organs (appliances). Also, the ‘plaque’ of cholesterol can break away from your artery wall causing an inflammatory reaction and the possibility of clot formation. The clot may block your artery completely or travel to other parts of your body. This can result in angina, a heart attack or stroke, transient ischaemic attack (TIA sometimes called mini-stroke) or a compromise in the vital blood circulation to your limbs (peripheral arterial disease).
HDL takes excess cholesterol away from your cells and artery walls back to your liver to be recycled or disposed of. So, HDL reduces the build-up of cholesterol in the artery walls and helps look after your blood vessels by preventing high blood pressure and keeping your heart and other vital organs protected. This is why it has earned its reputation as ‘good cholesterol’.
LDL and HDL levels change very little after a meal unlike triglycerides . When we check a lipid profile blood test it really gives us an insight into an individual’s longer-term diet and lifestyle habits so its is not imperative to have a ‘fasting’ blood lipid sample when we are trying to ascertain your ‘good to bad’ ratio of cholesterol ( This is taken into consideration when analysing triglyceride levels).
Healthy levels of lipids
Triglycerides
Fasting triglyceride: below 1.7mmol/l
Non-fasting triglycerides: below 2.3 mmol/l
Cholesterol
Total cholesterol: below 5mmol/l
Non-HDL cholesterol: below 4mmol/L (this is a summation of ALL of the fats carried on lipoproteins which collectively contribute to damaging or bad cholesterol effects)
HDL cholesterol: >1mmol/L (male) or >1.2mmol/L (female)
Often it will go hand in hand that if you have too high a level of triglycerides you will have too low a level of LDL (good) cholesterol.
What you can do to reduce your cholesterol
Lots of factors can affect your lipid levels.
Some things like age, ethnicity, male gender or family history pose risk factors that you can’t change.
Things you can influence or at least modify:
- Give up smoking (including vaping)
- Improve glycaemic control in diabetes
- Reduce blood pressure
- Keep your waistline in check
- Reduce alcohol intake
- Increase physical activity. Aim for 150 minutes per week in an exercise of your choice. You should be striving for an activity that makes you slightly out of breath! Going for two short but brisk walks per day counts. Do what you enjoy and can reasonably commit to. This is very important especially for those of us in sedentary jobs.
- Make some food swaps
o Reduce fat intake. Swapping ‘solid’ saturated fats such as butter to monosaturated and polyunsaturated fats (generally liquid at room temperature) including olive oil and rapeseed oil
o Eat at least 5 portions of fruit and veg per week
o Eat at least 2 portions of fish per week. Oily fish such as tuna, salmon, trout, mackerel, kipper or sardines are preferable.
o Eat at least 4 portions of high protein/fibre per week (low-fat nuts, seeds, lentals, peas, beans).
o Reduce sugar intake
Despite all of the above some people may need to take a statin. (e.g. Atorvastatin, Simvastatin). This could be for a variety of reasons: they have had a heart attack or a stroke, they have a family history of hyperlipidaemia ( caused by specific genetic abnormalities resulting in abnormally elevated levels of any or all lipids or lipoproteins ) or a lipid screening suggests that they are at a high-risk of an adverse outcome if certain factors are not modified.
Statins are a group or medicines that lower LDL cholesterol production in your liver and assist with its removal from your blood. Therefore, they help to keep your arteries ‘clean’ and your vital organs protected.
There is so much to know about cholesterol. If you wish to have a deeper dive into the subject the following resources are an excellent source of information:
Resources:
https://www.nice.org.uk/guidance/cg181/chapter/Recommendations
Full guidance from the National Institute for Health and Care Excellence.
Cardiovascular disease: risk assessment and reduction, including lipid modification. Last updated 10/02/2023
https://www.heartuk.org.uk/downloads/health-professionals/publications/bloodfats-explained.pdf (a great patient booklet resource looking at lipids, diet etc)