Fact Sheets: Heart Disease & CKD * Blood Pressure & Chronic Kidney Disease
Amazing Kidneys - protect your kidneys to save your heart!
If you have a chronic condition such as Chronic Kidney Disease it is important to learn all you can about the condition and its complications. You can then work with your health team to stay healthier. By acting early, you can help prevent some of the long‐term complications of chronic kidney disease such as cardiovascular or heart disease.
Many people are unaware that kidney dysfunction greatly increases the risk of developing cardiovascular disease, which can lead to an event such as a heart attack. The kidneys play a central role in regulating blood pressure and balancing important electrolytes which maintain the heart’s rhythm.
You are considered at 'increased risk' of developing CKD if you are:
- are 60 years or older
- are of Aboriginal or Torres Strait Islander descent
- have diabetes
- have a family history of kidney disease
- have established heart problems (heart failure or past heart attack) and/or have had a stroke
- have high blood pressure
- are obese (BMI of 30 or more)
- are a smoker
Cardiovascular disease (CVD) or heart disease, includes all diseases and conditions of the heart and blood vessels, such as arteries and veins. The most common diseases and conditions include heart attack, heart failure, stroke, blockages in the blood vessels and vascular kidney disease.
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What are the risk factors for CVD?
Age - your risk increases with age
Women are more at risk after menopause as their cholesterol levels increase
Gender - men are at more risk
Family history of CVD can put you at increased risk
Hereditary factors such as race - people of Aboriginal and Torres Strait Islander descent are at higher risk
Depression - may also be a risk factor
Chronic health conditions - e.g. kidney disease, high blood pressure, high cholesterol, obesity, metabolic disorders e.g. diabetes
Why does kidney disease increase your risk of heart disease?
Our kidneys help to control and maintain your body’s chemical balance. For example, our kidneys make hormones that regulate the electrolytes and fluid balance. Hormones such as renin and angiotensin control how well the blood vessels expand and contract, so our kidneys play an important role in maintaining good blood pressure levels.
If your kidneys aren’t working properly your blood pressure can rise.
If high blood pressure is left unchecked it tends to thicken the blood vessel walls causing blood vessels to narrow. High blood pressure can also damage small blood vessels taking blood to the kidney filters and the filters themselves. Severe, uncontrolled blood pressure weakens the heart muscle, enlarges the heart and can cause kidney failure.
Your kidneys control the acid level in your body
As well as acid levels, they also control the level of minerals and salts in our body, such as potassium, chloride, bicarbonate, phosphate, sulphates, magnesium, sodium (salt), calcium and potassium. These minerals and salts are called electrolytes. Electrolytes are found in the food and fluids we consume. Electrolytes are important as they keep you healthy, but too much or too little can make you sick.
If you have too much sodium, your body retains water
Repeated fluid overload can damage your heart. Too much potassium may cause an abnormal heart rhythm and not enough magnesium can affect heartbeat and change mental state. One of the jobs that healthy kidneys do is balance fluids. But when kidneys are diseased, they can’t effectively get rid of wastes in the body including fluid and sodium. When that happens, high blood pressure and heart problems can occur. For a person with chronic kidney disease (CKD), reducing the amount of sodium in their diet can help protect heart health.
Australian World Action on Salt & Health Drop the Salt Campaign for some helpful tips. To find an extensive brand list of low sodium foods - www.lowsodiumfoods.com.au
The balance of calcium and phosphate levels in blood is also upset by CKD
This eventually causes calcium deposits to build up in your blood vessels and heart and is known as atherosclerosis. Poor control of calcium and phosphate levels increases the risk of cardiovascular disease over time. Refer to our Fact Sheet - Calcium and Phosphate on this topic.
CKD often causes anaemia
Anaemia is a serious disease leading to other health conditions, if left untreated. For example when the numbers of red blood cells drop, your heart works harder to maintain oxygen levels. If the heart works too hard, the heart muscle becomes larger and can lead to heart failure.
If your kidney damage is caused by diabetes you are at a much higher risk of CVD
You are more at risk because diabetes also affects the heart and blood vessels. Good control of blood glucose and blood pressure levels is essential.
HOW CAN YOU REDUCE YOUR RISK OF CVD?
The best way to reduce the risk of CVD is to control and maintain a healthy blood pressure, cholesterol level and blood glucose level if you have diabetes.
If you have chronic kidney disease, this usually means using medication as well as having a healthy lifestyle. Identifying chronic kidney disease early and slowing the progression to end‐stage kidney failure, as well as reducing other risk factors, is important in reducing your risk of CVD.
What is normal blood pressure?
Since blood pressure varies from person to person and for each person during the day, there are no fixed rules about what blood pressure reading is ‘normal’.
These figures can be a useful guide:
*High normal 120-139 / 80-89
A single high reading is not enough to make a diagnosis of ‘high blood pressure’
You need to have a series of high readings taken on several different days, at different times, before high blood pressure can be confirmed. Your blood pressure does not stay the same, it changes to meet the demands of your body. It is usually at its highest when we exercise and lowest when we sleep. It can also rise due to anxiety, excitement, activity or nervousness.
Is high blood pressure related to kidney disease?
Yes, high blood pressure is closely related to kidney disease in a couple of different ways. High blood pressure can cause kidney damage and kidney damage can cause high blood pressure. The kidneys produce a hormone called renin; this helps to control blood pressure in the body. If your kidneys aren’t functioning properly, renin release can be increased, raising the blood pressure.
Although some people with high blood pressure can get headaches, dizziness or nosebleeds, high blood pressure does not always give warning signs. Often high blood pressure is found accidentally. You may have high blood pressure and feel perfectly well. The only way to know if your blood pressure is high is to have it checked regularly by your doctor.
High blood pressure can occasionally be caused by a problem in an endocrine gland, such as the adrenal gland. These cases are fairly rare and can be cured by treatment. Certain drugs such as birth control pills, decongestants and diet pills can also raise blood pressure. Your doctor can advise on these issues.
If high blood pressure is left unchecked it can cause blood vessels in your kidneys to become thickened and narrowed. This can affect your blood supply to the kidneys and, as a result, your kidney function. Uncontrolled blood pressure may cause severe or total kidney failure. High blood pressure can develop as a result of almost all kidney diseases. A narrowing of the main artery to one or both kidneys can also cause high blood pressure; this is called renal artery stenosis.
Why does cholesterol increase the risk?
Cholesterol is a type of fat or lipid, which the body needs to stay healthy. It is not necessary to eat foods that are high in cholesterol as your body is very good at producing its own. There are two types of cholesterol, which is a white and waxy substance:
Low‐density lipoprotein (LDL) cholesterol
You need a small amount of LDL but sometimes it is called the 'bad' cholesterol because the excess goes into the bloodstream and clogs up your arteries.
High‐density lipoprotein (HDL) cholesterol
Called the 'good' cholesterol because it helps to take the LDL cholesterol out of the bloodstream.
The most common form of stored fat in your body. Usually only a small amount is found in your blood. Triglycerides may not cause fatty deposits in your arteries but are often linked to low HDL or a tendency towards diabetes. Both increase your risk of CVD. In most cases, regular overeating causes a person to have raised triglycerides, which are linked with an increased risk of health conditions including diabetes and heart disease.
The liver is the main processing centre for cholesterol. When we eat animal fats, the liver makes cholesterol and returns any it can't use to our bloodstream. When there is too much cholesterol circulating in our bloodstream, it can build up into fatty deposits. These deposits cause the arteries to narrow and can eventually block the arteries completely, leading to heart disease and stroke.
If you have diabetes your LDL particles are unusually small and dense, which can be more harmful to blood vessels. Your triglycerides and HDL levels are often too low so people with diabetes are at higher risk of CVD.
MANAGING YOUR MEDICATION IS AN IMPORTANT PART OF TREATMENT
Your doctor may prescribe a variety of medications to treat chronic kidney disease, most are designed to control blood pressure and help regulate the body’s chemistry. Prescribed medications can include:
Cholesterol or lipid (fat) lowering medications
For the general population, the recommended level of cholesterol is no higher than 5.5mmol/litre. However for people with chronic kidney disease, diabetes and in other high‐risk groups for CVD, the recommended level is less than 4. This lower target is often difficult to achieve without medication. Various medications can lower cholesterol levels. Not everyone takes the same type of blood lipid medication and often a combination of drugs is used. One common drug is called a statin - statins lower LDL cholesterol and triglyceride levels and boost the HDL levels.
Blood pressure medication
Good blood pressure control can slow the progression of chronic kidney disease, delay the need for dialysis, maintain your heart health and increase the life of a transplant. If you have chronic kidney disease, your blood pressure target is 130/80. Different types of blood pressure tablets work in different ways, so it is not unusual for more than one type to be prescribed. The dose may alter according to your needs.
Angio-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB)
Used to keep your blood vessels opened and relaxed. ACE inhibitors prevent a hormone called angiotensin from forming and narrowing your blood vessels. Both these medications also help protect your kidney function. Other medication called beta‐blockers helps to lower blood pressure by allowing it to beat slower and less forcefully. Calcium‐channel blockers help the blood vessels to relax by keeping calcium out of your blood vessels and heart.
A diuretic or water pill
Often prescribed as well as it helps rid your body of extra fluid and sodium through your urine.
Your doctor may prescribe a medication called a phosphate binder you take with your meals and snacks containing phosphate. This is given to lower the amount of phosphate absorbed from the food you eat. Phosphate binders are taken with food and act by trapping the phosphate in the gut before it has a chance to move into the blood. There are several types of phosphate binders.
Used to treat anaemia It can be given as an injection on a weekly, fortnightly or even monthly basis depending on your blood results. The dose varies from person to person. Your doctor uses the level of haemoglobin in your blood and your body weight to decide on the dose. EPO can cause high blood pressure but it is better to treat blood pressure than to stop taking this medication.
Folic Acid with vitamins B12 and B6 - Used to lower amino acid levels.
Bicarbonate supplement - Used to treat acidosis.
Low doses of aspirin may be given to improve blood circulation. Caution should be taken if used by people on dialysis or post transplant.
Medication should only be taken as advised by your health team
Each medication is given for a particular reason and should be taken as directed. Never change a dose or stop taking a medication without your doctor’s approval. To prevent unwanted side effects, it is important to tell your doctor about all of your medications including those sold over-the-counter such as vitamins and herbal supplements.
If you are concerned that your medication may be affecting your health, refer to the ABC Health Consumer Guides or check with Medicines Line 1300 MEDICINE (1300 633 424) for more information.
DO HEALTHY LIFESTYLE CHOICES HELP REDUCE CVD?
Healthy lifestyle choices can help to improve your overall health so lower your risk of CVD. They can also reduce the amount of medication you need or make your medication work better. Healthy lifestyle choices include:
being a non‐smoker
eating a healthy diet with plenty of fruit and vegetables, plus low in salt
and saturated fat, unless otherwise directed by your doctor
staying fit by doing at least 30 minutes of physical activity on most days of the week
be aware of your blood pressure
maintaining a healthy weight
drinking alcohol only in moderation
doing things that help you to relax and reduce stress
- drink water instead of high sugar drinks of any kind
avoid certain medications
Can diet help control cholesterol?
You can reduce your cholesterol level using a combination of medication and dietary changes.
It is very important to talk to your doctor or a dietitian experienced in kidney disease before making any changes to your diet.
Your eating plan has to be designed with your special needs in mind. If you are on dialysis, you could be asked to limit your salt, phosphate, potassium or fluid intake but only if these are causing problems. People with kidney transplants have a much less restricted diet.
Dietary cholesterol often comes from saturated fats found mostly in animal products
These are some dietary tips:
limit the amount of cholesterol‐rich foods you eat.
eat plenty of fresh fruit, vegetables and wholegrain foods as these are high in fibre and may improve your blood lipid levels.
choose low or reduced fat milk, yoghurt and other dairy products or have 'added calcium' soy drinks.
choose lean meat (meat trimmed of fat or 'heart smart').
limit fatty meats, e.g. sausages and salami - choose leaner sandwich meats like turkey breast or cooked lean chicken.
have fish (fresh or canned) at least twice a week.
replace butter and dairy blends with polyunsaturated margarines.
minimise salt use in cooking, consider 'low salt' or 'no added salt' products
use unsaturated cooking oils labelled as 'polyunsaturated' or consisting of canola or olive oils.
include foods in your diet that are rich in soluble fibre and healthy fats
limit dairy foods - and only use low fat varieties
Less 'medical' outline - National Institute for Health USA In Brief: Your guide to lowering your blood pressure with DASH
New England Journal of Medicine publication (Volume 344:3-10 January 4 2001 No 1) Effects on Blood Pressure of Reduced Dietary Sodium & Dietary Approaches to Stop Hypertension (DASH) Diet proven to help lower blood pressure
Why is exercise important?
The key is to start slowly and gradually increase the time and intensity of your activities. Physical activity leads to increased strength, stamina and more energy. If you are only starting out, aim to do some physical activity for at least 30 minutes, 3-4 times weekly. These 30 minutes can be broken down into smaller blocks, e.g. 3 x 10 minutes, which can be increased as you become fitter.
It is important to STOP exercising and tell your health care team if you get any chest pain or pressure, dizziness or feeling faint, irregular or fast heart rate!
Quick links website
Kidney Health Resources- Patient Recommended weblinks
Chapter 7 - Heart Health from KHA's Living with Kidney Failure
Measure up and CKD and Measure Up with healthy eating Tips on how to become healthier
Useful external links
Heart Foundation of Australia Information on cardiovascular health
Heart Health & Kidney Disease Renal Resource Centre NSW
Online risk calculator at www.cvdcheck.org.au your risk of developing CVD over the next 5 years * Manage your heart and stroke risk * Know your heart and stroke risk (consumer booklet) * Know your heart and stroke risk (consumer summary sheet)
Updated 16 August 2013
Disclaimer: This is intended as a general introduction to this topic and is not meant to substitute for your doctor's or health professional's advice. All care is taken to ensure the information is relevant and applicable to each Australian state. It should be noted Kidney Health Australia recognises each person's experience is individual and variations do occur in treatment and management due to personal circumstances. Should you require further info always consult your doctor or health professional.