Diabetes - long-term effects

Diabetes is a condition in which there is too much glucose (a type of sugar) in the blood. Over time, high blood glucose levels can damage the body’s organs. Possible long-term effects include damage to large (macrovascular) and small (microvascular) blood vessels, which can lead to heart attack and stroke, and problems with the kidneys, eyes, gums, feet and nerves.

The good news is that you can reduce these risks by keeping your blood pressure, blood glucose and cholesterol within the recommended range. Being a healthy weight, eating well, limiting alcohol, and not smoking all help. Regular check-ups and screening are important to pick up any problems early.

Healthy eating#

If you have diabetes, include a wide variety of nutritious foods in your diet and avoid snacking on sugary foods. Enjoy a range of foods from each food group, choosing foods high in fiber and low in fat, and reduce your salt intake. It can help to consult a dietitian, who can review your current eating plan and guide you on food choices and portion sizes.

Limit alcohol#

If you drink alcohol, follow the recommended low-risk guidelines and keep your intake modest. If you are pregnant, considering pregnancy or breastfeeding, no alcohol is recommended.

Healthy weight#

If you are overweight, even losing a small amount of weight, especially around the abdomen, helps lower your blood pressure, blood glucose and cholesterol. Losing weight can be difficult, so to get started set yourself a short-term, achievable goal. Think about the food you eat: whether you really need it, whether it is a healthy choice, and what the portion size is. An accredited dietitian can help you set a realistic meal plan and answer your food-related questions.

Be as active as possible#

General physical activity guidelines recommend at least 30 minutes of moderate-intensity activity a day, gradually building up the duration and intensity. For weight loss, a minimum of 60 minutes a day is recommended.

If you are unable to do activities such as walking, swimming or gym work, consider water aerobics, chair exercises or strength training with light weights. Check with your doctor if you are not sure whether an activity is suitable for you, as some medical conditions can limit certain types of exercise. An exercise physiologist can help set up a plan that suits your needs and ability.

Don’t smoke#

Smoking is the single greatest lifestyle risk factor for developing diabetes complications. It can undo all the benefits gained from weight loss, healthy eating, and good blood glucose and blood pressure control.

Smoking affects circulation by raising the heart rate and blood pressure and narrowing small blood vessels. It also makes blood cells and blood vessel walls sticky and allows dangerous fatty material to build up, which can lead to heart attack, stroke and other blood vessel disease. People with diabetes who smoke have higher blood glucose levels and less control over their diabetes than non-smokers with diabetes.

Regular checks#

You can help pick up problems early by having regular checks of your blood pressure, blood glucose, cholesterol, kidney function, eyes, feet, and teeth and gums.

Blood pressure#

Have your blood pressure checked every time you visit your doctor, or at least twice a year. A common target is under 130/80, but ask your doctor what is right for you. Blood pressure control is just as important as blood glucose control in reducing the risk of diabetes complications.

Blood glucose#

Keeping your blood glucose within the recommended range helps reduce your risk of long-term problems. Speak to your doctor or diabetes educator if you are unsure of your target range. Depending on your management plan, you may be advised to check your levels at home. Regular monitoring shows how medicine, food, exercise, illness and stress affect your diabetes.

HbA1c measures how much glucose has attached to your red blood cells over about a three-month period, and it is a direct measure of your risk of long-term problems. It is recommended at least once a year, but may need checking every three to six months. For most people with diabetes the goal is no more than 53 mmol/mol (7%), though recommended ranges vary depending on the person, for example with children, frail elderly people, pregnant women, or the type of diabetes and how it is managed.

Cholesterol and triglycerides#

Have a cholesterol and triglyceride test at least once a year. Aim for total cholesterol less than 4.0 mmol/L and triglycerides less than 2.0 mmol/L. There are several causes of high cholesterol, including family history and diet. Too much saturated fat can raise the LDL (“bad”) cholesterol in your blood and lead to plaque building up in your blood vessels. Foods high in saturated fat include full-fat dairy, fatty meats, pastries, biscuits, cakes, coconut cream or milk, palm oil and fatty take-away foods.

Long-term complications#

The most common long-term, diabetes-related problems involve damage to the small blood vessels, causing problems in the eyes, kidneys, feet and nerves (microvascular complications), and damage to the large blood vessels of the heart and legs (macrovascular complications). Other parts of the body can also be affected, including the digestive system, skin, sexual organs, teeth and gums, and the immune system.

Cardiovascular disease#

Cardiovascular disease includes blood vessel disease, heart attack and stroke, and is a leading cause of death. The risk is greater for people with diabetes, who often have raised cholesterol and blood pressure. Smoking, a family history of cardiovascular disease and being inactive also increase the risk. To reduce your risk and catch problems early:

• Have your blood pressure checked at least every six months, or more often if it is high or you take medication for it.
• Have your HbA1c checked at least every year, or every three to six months if recommended.
• Have your cholesterol checked at least every year.

Further tests, such as an electrocardiogram (ECG) or exercise stress test, may also be recommended.

Eyes#

Diabetes-related eye problems include:

• Retinopathy – blood vessels in the retina become damaged, which eventually affects vision. It has several stages and usually causes no symptoms early on, so a full diabetes eye check is essential to detect it early and allow treatment before further damage occurs.
• Macular edema – the macula, part of the retina that helps you see clearly, can swell when retinal blood vessels are damaged and fluid builds up, making vision blurry. Treatment is available and early detection is important.
• Cataracts – the lens becomes cloudy, making vision cloudy, distorted or sensitive to glare. People with diabetes can develop cataracts at an earlier age than usual.
• Glaucoma – the fluid pressure inside the eye rises to an unhealthy level and can damage the eye over time. It occurs in people with and without diabetes, but is more common in people with diabetes.

Most people with early eye damage have no symptoms, but some warning signs need urgent review. If you have flashes of light, floaters, blots and dots, or part of your vision is missing, see your doctor immediately.

Everyone with diabetes should have a professional eye examination by an ophthalmologist or optometrist when first diagnosed, and at least every two years after that (children usually start this screening five years after diagnosis or at puberty). Always tell the person checking your eyes that you have diabetes. If retinopathy or another problem is found, eye tests will be needed every year, or more often if advised.

Kidneys#

Kidney disease (nephropathy) can develop because of changes in the small blood vessels of the kidneys. It is painless and causes no symptoms until it is advanced, so screening is very important. It can be diagnosed early by checking for microalbumin (very small amounts of protein) in the urine at least once a year. Your doctor will also check your kidney function, including the estimated glomerular filtration rate (e-GFR), with a blood test.

If problems are found early, nephropathy can be slowed or prevented with the right treatment. Medicines called ACE inhibitors and angiotensin receptor antagonists help protect the kidneys from further damage and can also be used to treat high blood pressure.

Nerves#

Nerve damage (neuropathy) is usually caused by high blood glucose levels, though similar damage can also result from heavy alcohol use or from vitamin B12 deficiency. Long-term use of the diabetes medication metformin (over three to five years) can increase the risk of vitamin B12 deficiency, and your doctor may test for this.

Damage can affect the sensory (feeling) and motor (movement) nerves of the legs and feet, arms, hands, chest and stomach, and the nerves that control the body’s organs. To help prevent nerve damage, keep your blood glucose in the target range, keep within recommended alcohol guidelines, and do not smoke. Talk to your doctor about any problems with your hands, arms, feet or legs, or your stomach, bowels or bladder.

Feet#

The feet are at risk when the blood supply in both large and small blood vessels is reduced. Nerve damage (peripheral neuropathy) often results, and the structure of the foot can change, for example with clawed toes. Reduced blood supply and nerve function can delay healing, increase the risk of infection, reduce feeling, and lead to ulcers and structural problems. Look after your feet by:

• seeing a podiatrist at least once a year to check the blood supply, nerve function and structure of your feet
• checking your feet every day (ask someone to help if you cannot check them yourself), looking for cuts, blisters, calluses, corns, tinea (especially between the toes) and any changes
• treating any problems early, before they worsen
• using a moisturiser (such as sorbolene), especially on dry, rough or cracked skin on your feet and heels
• wearing comfortable, supportive shoes that fit well
• keeping your feet away from direct heat, such as heaters

Skin#

People with diabetes may have very dry skin because of damage to small blood vessels and nerves, and dry skin on the feet is common. High blood glucose levels over time can affect skin health. The skin acts as a barrier against infection, so keeping it healthy is important; if it becomes dry, it can crack and let in infection. To reduce the risk of skin problems:

• Keep your blood glucose and HbA1c within recommended ranges to lower the risk of skin infections.
• Wear gloves when using household cleaners and solvents.
• Avoid very hot baths and showers, especially if you have peripheral neuropathy, as you may not feel how hot the water is.
• Use a cream or lotion after bathing, preferably unperfumed, and use non-scented soaps or soap alternatives.
• See your doctor if you notice a skin problem.

Teeth and gums#

People with poorly managed diabetes are at greater risk of tooth decay and gum infections, because the small blood vessels that nourish the teeth and gums can become damaged. Dental and gum infections can in turn raise blood glucose levels. Poor oral care can inflame the gums and loosen them around the teeth, and is strongly linked with a higher risk of heart disease. To reduce your risk:

• See your dentist regularly (about every six months) for a check-up.
• Brush at least twice a day (a soft toothbrush is generally recommended) and floss once a day.
• If you have dentures, brush your dentures and gums with a soft toothbrush.

Mental health#

Living with and managing type 1 or type 2 diabetes can lead to stress, anxiety and depression. This can affect your blood glucose and how you manage your diabetes overall, and over time it can affect your health. It is important to talk to your doctor if you are going through times of stress, depression or anxiety. Your doctor can refer you to a counselor or psychologist and help arrange other support.

Infections#

Your immune system helps prevent and fight infection, but high blood glucose levels slow down the white blood cells that do this work, making it harder for the body to fight infection. Support your immune system and reduce your risk by:

• keeping your blood glucose within the recommended range
• getting enough sleep each night
• washing your hands routinely, as needed
• seeing your doctor if you think you have an infection or feel unwell
• having a yearly influenza (flu) immunization
• asking your doctor about the pneumonia vaccine, especially if you are over 65

Thyroid#

People with type 1 or type 2 diabetes are at increased risk of thyroid disease, including both overactive and underactive thyroid. Thyroid disorders can affect general health and may affect blood glucose levels. Thyroid function is assessed with a blood test, so talk to your doctor about whether yours has been checked.

Sexual function#

Reduced blood supply and nerve damage can affect sexual function. In men, erectile dysfunction (the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity) is common at all ages and more common in men with diabetes. It is not a disease but a symptom of another problem, which may be physical, psychological or both; most cases are physical, such as nerve or blood vessel damage. Sexual dysfunction is also reported in women, although there is less research in this area, and it is hard to know whether it relates directly to hormonal changes such as menopause or to diabetes.

Remember, you do not have to manage your diabetes on your own. There are health professionals available to help you.

Key points#

• Being a healthy weight, eating well, reducing alcohol intake and not smoking all help reduce your risk
• Regular check-ups and screening are important to pick up any problems early
• A medical condition may prevent you from doing certain types of physical activity, so check with your doctor
• Smoking is the greatest single lifestyle risk factor for developing diabetes complications
• Blood pressure control is just as important as blood glucose control in reducing the risk of complications

Where to get help#