Impact of Uncontrolled Diabetes on the Heart, Eyes, Kidneys, and Nerves

Diabetes mellitus is a cluster of disorders characterized by high levels of glucose in the blood. It is classified as a “metabolic disorder,” which means it is not restricted to a specific organ but affects the overall health and quality of life of the afflicted person.

According to recent reports, in 2021 about 10.5% of the global population (536.6 million people) was afflicted with this condition, and its prevalence is expected to increase to 12.2% (783.2 million people) by 2045. (1)

Complications Associated With Uncontrolled Diabetes

In uncontrolled diabetes, blood sugar levels remain high over long periods, leading to damage to the organs of the body. The heart, kidneys, eyes, nerves, and brain are all affected by uncontrolled diabetes.

1. How does uncontrolled diabetes affect the heart?

A study published in 2015 in the World Journal of Diabetes attributes cardiovascular disease as a major cause of death in people with diabetes. (2)

The study also outlines the following mechanisms whereby diabetes affects cardiovascular function:

• Obesity: Obesity is common in people with diabetes, especially those with type 2 diabetes, and is associated with an increased risk of cardiovascular disease.
• High LDL: People with diabetes accumulate high levels of low-density lipoprotein (LDL) or “bad cholesterol.” Over time, this type of cholesterol accumulates in the arteries, leading to an increased risk of a heart attack.
• High blood pressure: High blood pressure is common among both type 1 and type 2 diabetics with an incidence of 30% and 60%, respectively. (2)(3) The increased blood pressure causes a greater strain on the blood vessels going through the heart, leading to a higher risk of a heart attack.

2. What is the effect of uncontrolled diabetes on the eyes?

Diabetes can affect the eyes in a number of ways. Five major ocular complications due to diabetes have been listed in a review published in 2015 in the World Journal of Diabetes. (4) These are:

• Diabetic retinopathy (DR): This is the most common ocular complication of diabetes. In DR, the small retinal blood vessels are affected and develop hemorrhages and finally blindness. Diabetic retinopathy is the most common cause of blindness in people over 50 years. (5) In the United States, the prevalence of DR in people with type 1 and type 2 diabetes afflicted with the disease for more than twenty years is 95% and 60%, respectively.
• Diabetic papillopathy (DP): In diabetic papilloppathy, there is swelling of the optical disc. This complication is as common as diabetic retinopathy, but the reason for it is not as clear as in diabetic retinopathy.
• Diabetic macular edema (DME): DME is seen as a consequence of diabetic retinopathy. In this condition, a part of the retina called the macula undergoes swelling due to being filled up with fluid. This leads to difficulty in reading, writing, driving, and recognizing faces and ultimately vision loss. It is a major cause of vision loss in people with type 2 diabetes. (6)
• Glaucoma: In glaucoma, there is a buildup of pressure in the optic nerve, which connects the eye to the brain, causing damage to it, eventually leading to blindness. Diabetes increases the risk of certain types of glaucoma.
• Cataract: In this condition, the eye lens becomes cloudy, leading to blurred vision. People with diabetes have a 2–5 times greater risk of getting a cataract at a younger age than those with no diabetes.

3. How does uncontrolled diabetes affect the kidneys?

Diabetic kidney disease (DKD) or diabetic nephropathy is a complication of type 2 diabetes and affects about one-third of patients. (7)

It could take years for kidney damage to occur in people with diabetes. The early stages of DKD are characterized by an inability of internal organs and tissues, especially the muscle, to respond to insulin. As renal failure progresses, the ability of the kidneys to filter out waste is reduced. (8)

4. Diabetes and nerve damage

The nervous system transmits nerve impulses to and from the brain, making movements and executing different body functions possible. Glucose breakdown to produce energy is the most important process in neurological functioning.

In people with diabetes, the ability to use glucose to produce energy is lost. Hence, they convert the excess glucose to an alcohol, sorbitol. The accumulation of sorbitol in the nerves damages them, leading to diabetic neuropathy. (9)

Nerves are present all over the body. Hence, an impairment in nerve function can have many effects. Symptoms depend on the area of the body and the organs affected by neuropathy.

The two main types of diabetic nerve damage are:

• Peripheral nerve damage: This gives rise to tingling, burning, numbness, cramps, shooting pain, muscle weakening, and loss of coordination and balance. (10)
• Autonomic nerve damage: The symptoms include bladder problems, gastrointestinal problems, erectile dysfunction, vaginal dryness, rapid heart rate, problems with the eyes in adjusting from light to dark, dizziness, and fainting. (11)

5. What is the impact of uncontrolled diabetes on brain function?

Glucose is the sole energy provider for the brain, and anything that interferes with glucose availability to the brain affects its structure and efficient functioning. (12)

A study conducted in 2010 and reported in the journal Diabetes used data from imaging of the brain of children with type 1 diabetes. Results showed that the structure and cognitive function of the brain is affected. (13)

Another study reported in 2015 in the Annals of the New York Academy of Sciences used MRI imaging and found that both type 1 and type 2 diabetics show alterations in brain structure, a decline in understanding, and poor memory. Type 2 diabetes is associated with a 50% increased risk of dementia. (14)

Damage to the blood vessels supplying the brain due to diabetes affects the blood supply to the brain, resulting in a stroke. Sometimes, the damaged blood vessels may rupture, leading to brain hemorrhage.

6. What are the oral complications of uncontrolled diabetes?

Oral complications are seen in more than 90% of people with diabetes, according to a recent review published in 2018. The same review lists out the oral manifestations of uncontrolled diabetes, (15) which are:

• Dental caries: Diabetes impairs the ability of the body to fight infections, including infections of the mouth. This leads to bacterial buildup in the mouth. Over time, these bacteria infect the teeth, leading to plaque formation (a yellow coating on the teeth). The plaques erode the enamel of the teeth (the protective layer of the teeth), paving the way for tooth decay or dental caries.
• Periodontal disease: The early stage of periodontal disease is gingivitis, wherein there is irritation of the gums due to hardening of the plaques, leading to swelling and bleeding of the gums. Periodontal disease is advanced gingivitis characterized by damage to the bone and surrounding tissue supporting the teeth, leading to tooth loss.
• Burning mouth disorder: This syndrome affects people with diabetes and gives a feeling of burning or scalding of the tongue and dryness in the mouth with increased thirst.

Understanding Diabetes Better

Glucose is the primary source of energy for all cells in your body and is obtained from the breakdown of the food that you eat. Insulin is a hormone secreted by the pancreas, and it is responsible for helping glucose enter your cells and be broken down to produce energy.

When your body does not produce enough insulin or doesn’t use the insulin well, a buildup of glucose occurs in your blood, leading to diabetes. Over time, this can harm your internal organs and lead to various health complications.

ALSO READ: All About Diabetes: Causes, Myths, Treatment, and Home Remedies

Types of Diabetes

The most common types of diabetes are type 1, type 2, and gestational diabetes.

1. Type 1 diabetes

Type 1 diabetes is also called “juvenile-onset” or “non-insulin-dependent” diabetes mellitus (NIDDM), and it is an autoimmune disorder wherein the body attacks the insulin-producing cells of the pancreas, leading to very little or no insulin. It is usually diagnosed in children, teens, and young adults.

About 5%–10% of people with diabetes have type 1 diabetes, and the afflicted person needs to take insulin shots daily to survive. At present, preventive measures for type 1 diabetes are not known.

2. Type 2 diabetes

Type 2 diabetes is also called “adult-onset” or “insulin-dependent” diabetes mellitus (IDDM), and 90%–95% of people with diabetes fall into this category.

In this condition, the body fails to respond to insulin, and it is usually diagnosed in adults. Thankfully, it can be prevented by implementing healthy lifestyle changes such as losing weight, exercising regularly, and eating healthy food.

3. Gestational diabetes

Gestational diabetes develops in pregnant women who have never had diabetes, and it disappears after the birth of the baby. If you have been diagnosed with gestational diabetes, you or your baby in adulthood have an increased risk of developing type 2 diabetes.

4. Prediabetes

This condition denotes a blood sugar level that is higher than normal but not high enough for a diagnosis of type 2 diabetes. Prediabetes increases your risk of type 2 diabetes, stroke, and cardiovascular disease. The good news is that it can be prevented by adopting lifestyle changes.

Most-Asked Questions About Diabetes

How can I control or reverse uncontrolled diabetes naturally?

You can control or reverse uncontrolled diabetes by adopting a healthy lifestyle.

This includes the following: exercising regularly, restricting your intake of carbohydrates, eating a diet high in fiber, keeping yourself hydrated, avoiding stress, maintaining an ideal weight, and monitoring your blood sugar levels regularly.

What foods help in reversing diabetes?

Foods that are high in fiber help in reversing diabetes. These include dark green leafy vegetables, whole grains, nuts, berries, and bitter vegetables such as fenugreek, bitter gourd, cluster beans, and neem.

Please note that type 1 diabetes cannot be reversed as the body is not producing insulin at all.

How long can I live with uncontrolled diabetes?

The average person diagnosed with type 2 diabetes at 65 years can live up to 80–85 years. In the case of type 1 diabetes, the life expectancy is up to 60–65 years.

Final Word

Diabetes is a metabolic disorder, and if left untreated, it can lead cause damage to your organs and lead to many complications such as cardiovascular disease, stroke, impaired vision, tooth loss, and kidney failure.

However, you can control and reverse your diabetes by making lifestyle changes and leading a good-quality life. This can be achieved by keeping your blood sugar levels under control, eating right, exercising, losing weight, avoiding smoking, and treating high blood pressure and high cholesterol levels.