Diabetes Of The Brain: An Unrecognized Complication Of Small Vessel Disease

Small vessel disease of the brain is a condition that rarely comes to mind when evaluating a foot wound in a patient with diabetes. However, make no mistake about it; the brain is a target organ at risk for microvascular complications that can affect cognition and related wound healing in the patient with diabetes.

Over the past several weeks, I have had conversations with a few colleagues about interesting cases in their practices. In a strange coincidence, each related a similar experience where a patient with diabetes failed to follow instructions concerning home treatment of a wound. Each of my colleagues reported discussing the wound care with the patient and felt the patient understood their instructions.

So, the question arises, “Could vascular dementia be a contributing factor when patients forget to take their medications or fail to perform appropriate wound dressing changes?” Could it be that the inability to think clearly, combined with changes in motor function (gait), are unrecognized factors in the development of DFUs and contribute to the challenge of healing those wounds?

The medical literature clearly documents the relationship between small vessel disease (SVD) and foot wounds along with the effect of small vessel disease on the eyes, kidneys, and cardiovascular system. Small vessel disease of the brain is associated with vascular risk factors, such as hypertension, atherosclerosis, diabetes mellitus, and atrial fibrillation. There is evidence of increased risk of cognitive decline, dementia, gait and balance disturbances, and Parkinsonism among individuals with SVD, although prospective studies are scarce.¹

In cerebral small vessel disease (CSVD), symptoms are due to either complete (lacunar syndromes) or incomplete infarction white matter lesion (WML) of subcortical structures leading to accompanying complaints, including the lacunar syndromes, where blood flow to one of the small arteries in the brain is blocked, along with cognitive, motor (gait) and/or mood disturbances.²

“With diabetes, you have an increased risk of damage to blood vessels over time, including damage to the small blood vessels in the brain. This damage affects the brain’s white matter,” says Joseph C. Masdeu, MD, PhD, of the Houston Methodist Neurological Institute. “White matter is the part of the brain where nerves talk to one another. When the nerves in the brain are damaged, you can have changes in thinking called vascular cognitive impairment or vascular dementia.”³

People with type 2 diabetes may face a double whammy because they tend to have other problems such as low HDL, high triglycerides, and high blood pressure that may combine to promote inflammation that also can cause blood vessel damage.³

In a 2016 article in Diabetes Care, the authors found that those with type 2 diabetes and diabetic retinopathy have more cerebral small vessel disease than with those without retinopathy. This suggests that the brain is a target organ for microangiopathy, similar to the retina.⁴

Hyperglycemia, Hypoglycemia Or Both?

Increased blood sugar levels have a harmful impact on the whole body, and the brain is no exception. Both hyperglycemia and hypoglycemia can negatively impact the brain. High levels of blood glucose entering the brain cause damage to blood vessels over time. Low blood sugar levels can impact thinking, mood, cause dizziness, result in poor coordination, and cause nausea, hunger, shakiness, cold or clammy skin, or a pounding heart. Brain impairment is a recognized consequence of hypoglycemia.⁵

Many patients with Type 2 diabetes develop cognitive impairment because they are less fit and lead a sedentary, unhealthy lifestyle, which also leads to obesity, heart disease, high cholesterol levels, and high blood pressure. All of these issues can result in inflammation that also damages the blood vessels of the brain.⁵

A 2019 article concluded that that cerebral small vessel disease, cerebral microbleeds (CMBs) in particular, is more common in young people with type 1 diabetes compared with healthy control subjects.⁶

Investigators at the Nanjing University Medical School in China recently published the results of a study in which they compared and evaluated cognitive function in subjects with type 2 diabetes and peripheral neuropathy versus subjects with diabetes and no neuropathy. The investigators found that patients with diabetic peripheral neuropathy had decreased cognitive abilities compared to patients without.⁷

Helping Patients Protect Brain Health

The best way to treat brain damage from diabetes is to prevent it from developing. Working to keep blood sugars in control by observing a healthy lifestyle and diet may help prevent cognitive decline. Other steps to maintain brain health include:

• Intermittent fasting, which can help to control blood sugar;

• Exercise;

• Meditation;

• Increased omega-3 intake;

• High-quality sleep nightly;

• Probiotics to help optimize gut health;

• Losing weight if needed;

• Maintaining your weight once you have reached a healthy level;

• Eating nutritiously;

• Avoiding processed foods and sugar;

• Keeping alcohol consumption to a minimum;

• Stopping smoking if you smoke; and

• Increasing physical activity and regular exercise.

These actions are all important choices for a healthy brain and body. Controlling diabetes can minimize the damage nicknamed, "diabetes of the brain" and keep patients mentally sharp.⁸

Dr. Hinkes is President and Chief Medical Officer of ePrevenir, Inc. He is board certified by the American Board of Foot and Ankle Surgery and is a Fellow of the American College of Foot and Ankle Surgeons and the American Professional Wound Care Association. He is the author of “Healthy Feet for People With Diabetes” and “Keep the Legs You Stand On,” available at www.amazon.com.

References

1. van Norden A, de Laat K, Gons RAR, et al. Causes and consequences of cerebral small vessel disease. The RUN DMC study: a prospective cohort study. Study rationale and protocol. BMC Neurol. 2011;11:29.

2. Roman GC, Erkinjuntti T, Wallin A, Pantoni L, Chui HC. Subcortical ischaemic vascular dementia. Lancet Neurol. 2002;1(7): 426-436.

3. D’Arrigo T. Diabetes and your brain. Available at: https://www.webmd.com/diabetes/features/diabetes-brain . Reviewed February 17, 2015. Accessed August 10, 2021.

4. Sanahuja J, Alonso N, Diez J, et al. Increased burden of cerebral small vessel disease in patients with type 2 diabetes and retinopathy. Diabetes Care. 2016;39(9):1614-1620.

5. Sepalika Women’s Hormonal Health Clinic. Diabetes and your brain: understand the connection and safeguard your brain. Available at: https://www.sepalika.com/type-2-diabetes/diabetes-and-the-brain/ . Published August 4, 2017. Accessed August 10, 2021.

6. Thorn LM, Shams S, Gordin D, et al. Clinical and MRI features of cerebral small-vessel disease in type 1 diabetes. Diabetes Care. 2019;42(2):327-330.

7. Mann RH. PN in type 2 diabetes more pernicious than previously thought. PM News. Available at: https://podiatrym.com/search3.cfm?id=140222 . Published July 29, 2021. Accessed August 10, 2021.

8. Peterson TJ. Diabetes of the brain: how diabetes affects the brain. HealthyPlace. Available at: https://www.healthyplace.com/diabetes/complications/diabetes-of-the-brain-how-diabetes-affects-the-brain . Updated May 10, 2019. Accessed August 10, 2021.