Parkinson's & Diabetes: What's the Connection?

April is designated as Parkinson’s Awareness Month. People with type 2 diabetes may have an increased risk of developing a diagnosis of Parkinson’s disease later in life. Type 2 diabetes and Parkinson’s are both aging-associated diseases as well as chronic diseases that are both turning into epidemics worldwide. Parkinson’s – like diabetes – is considered a whole-body disease. A newly published study found “the group of individuals who had type 2 diabetes had approximately 30-40% higher risk of developing Parkinson’s”.

Diabetes continues to outpace other well-known chronic illnesses and Parkinson’s is now the fastest growing neurological disease in the world, aside from Alzheimer’s. With both type 2 diabetes and Parkinson’s, there are higher rates of depression and worse scores on overall quality of life. People who have both diseases become increasingly dependent on others as their disease progresses. Only in the last 10 years have we understood and acknowledged a relationship between these illnesses.

Insulin resistance, or the lack of ability to utilize your own insulin, is commonly seen in both these diseases. Insulin resistance causes blood sugars to rise, affecting small blood vessels in the eyes, kidneys, nerves, and feet. High levels of insulin in the brain due to insulin resistance can increase the risk of inflammation and stroke in the brain. There are also multiple studies suggesting that “insulin resistance negatively impacts dopamine function in the brain”.

Dopamine is a neurotransmitter. You make dopamine and it is used by your nervous system to send messages between nerve cells. Dopamine plays a role in how we feel pleasure. It affects movement, mood, attention, heart rate, motivation, and learning. Lack of dopamine production is the basis of Parkinson’s disease. Rates of Parkinson’s disease has doubled since 1990 and this unfortunate trend is expected to keep rising for the next 30 years. Due to our aging population, researchers project the number of people with Parkinson’s to double by 2040. Although Parkinson’s is more prevalent in men, the combination of being a woman and having type 2 diabetes leads to an even greater risk of eventually developing Parkinson’s. Still, most people with Parkinson’s do not have diabetes, but the growing numbers of those with both diseases need to be further studied.

What is the link between Diabetes and Parkinson’s?

There are no specific definite reasons noted at this time, but certain factors have been hypothesized:

Possible genetic abnormalities between both diseases.
When both diabetes and Parkinson’s coexist, they may create a more hostile environment in the brain causing brain changes, inflammation, or neurodegeneration.
There could be common “abnormal cellular processes in the brain” in both diseases.
Large and small vessel narrowing from type 2 diabetes may lead to Parkinson’s sooner. Large vessel changes or macrovascular changes affect your heart which may increase risk of heart attack and stroke. Small vessel changes or microvascular changes affect your eyes, kidneys, nerve endings and feet. These complications are commonly seen in type 2 diabetes.
Having type 2 diabetes may lead to a more aggressive form of Parkinson’s.
Oxidative stress and systemic inflammation in the cells may play a role in both diseases.
Excessive intake of sugar impairs our cognition and memory skills in both illnesses.
Type 2 diabetes has been shown to increase the risk of neurodegenerative conditions, including Parkinson’s.
Having type 2 diabetes leads to faster progression of Parkinson’s symptoms.
50-80% of patients with Parkinson’s have abnormal glucose tolerance levels which can eventually lead to type 2 diabetes.

Is sugar intake related to Parkinson’s?

Many patients with Parkinson’s disease report that “eating sugary foods makes their symptoms worse”.
Eating more fast acting carbohydrates may increase dopamine production in the brain.
Higher blood sugar levels can make the brain age and shrink. This causes vascular dementia.
An increase in sugar cravings may be a side effect of the types of microorganisms (bacteria) that live in the gut that can change in those with Parkinson’s.
There is a strong craving for sugar and simple carbohydrates in patients with Parkinson’s. The sugar helps the brain produce high amounts of dopamine – what is lacking in Parkinson’s. It’s like self-medicating.

Tell me about Parkinson’s

Parkinson’s disease is a neurological disease or brain disorder where part of your brain (called the substantia nigra) deteriorates. It generally starts slowly and gradually when 50-60% of these cells are gone, the symptoms begin to appear. It causes uncontrollable movements including shakiness, tremors, rigidness, stiffness, balance issues and coordination difficulties.
In the disease progression there is a change in mental status, changes in behavior, memory problems, sleep issues and fatigue. Nerve cells in the brain area that controls movement become impaired or die. Less dopamine is made which causes the actual movement disorder. Dopamine acts like a messenger between parts of the brain and nervous system that controls body movement.
Norepinephrine, another neurotransmitter, is not readily available which affects your blood pressure. You may feel dizzy, faint and pass out.
There are 90,000 or more cases per year in the US. There are one million Americans presently living with Parkinson’s.
There are 200,000 cases per year worldwide and more than 10 million presently living with it worldwide.
The incidence increases with age. It is more common in males.
The direct and indirect cost of Parkinson’s in the US yearly is $52 billion.
Parkinson’s develops at higher rates in certain parts of the country including Vermont, The Rust Belt – which includes Illinois, Michigan, Missouri, New York, Ohio, West Virginia and Wisconsin (considered the area of industrial manufacturing), parts of Texas, California, Florida and Pennsylvania.

Possible reasons why you might develop Parkinson’s:

Hereditary. 10-30% of the cases have gene variants.
Higher incidence in Caucasians.
Age. Most cases are seen after age 60. Early onset would be considered before age 50. Parkinson’s developing at a younger age progresses at a slower rate. This is due to the fact that younger people have fewer general health problems.
Environmental factors and toxins seem to have an effect on developing Parkinson’s. Included are being exposed to farm chemicals such as pesticides, fungicides, and herbicides as well as Agent Orange used during the Vietnam war, working with heavy metals, detergents, and solvents. Being exposed to traffic pollution and industrial pollution.
Repeated head trauma and concussions. “Athletes playing contact sports for longer than 8 years are 6 times more likely to develop Lewy body disease – a neurodegenerative disorder causing Parkinson’s like symptoms”. This was seen in boxing, football, rugby, ice hockey and martial arts.
Drug-induced Parkinson’s. Certain psychiatric medications may cause it. Once the medication is stopped, this form reverses.

Parkinson’s symptoms may include:

Slowness of movement, rigidity, balance, and coordination problems
Tremors – resting tremors in the fingers, hands, head, or legs
Sleep difficulties, insomnia, vivid dreams, inability to stay asleep, thrashing movements during sleep
Restlessness, fatigue
Stooped posture
Urinary incontinence
Loss of smell
Excessive perspiration
Constipation
Unintentional weight loss
Drooling
Dementia
Muscle cramping
Reduced eye blinking, dry eyes
Posture changes
Reduced arm swinging while walking
Changes in handwriting, smaller and illegible
Lack of facial expression
Swallowing difficulties, easily choking, aspiration pneumonia
Shuffling stride
Speaking softly in a low pitch
Depression, anxiety, apathy
Restless leg syndrome
Sexual dysfunction

How is Parkinson’s diagnosed?

There are no specific blood tests or lab tests that can diagnose Parkinson’s. There is no cure, but it can be treated. Generally, your physician will perform a full history and physical. A referral to a neurologist is then given. Brain scans may be done including an MRI. A brain MRI is not able to diagnose Parkinson’s. Another type of brain scan called a DAT scan (Dopamine Transporter Scan) may be performed. DAT scans are usually performed at large medical centers. Another way to diagnose is to offer the medication Carbidopa/levodopa. If it improves the symptoms, they can usually confirm the Parkinson’s diagnosis.

How is it treated?

Traditional Measures

Medications are given to raise the amount of dopamine made in the brain. The most common medication is called Carbidopa/levodopa. After taking it for a while, it may become less consistent. Carbidopa/levodopa should be taken on an empty stomach unless it causes nausea. If you do experience nausea or stomach issues take with a dry cracker. Your physician will constantly monitor how it is working. Take as directed and never skip or run out of your medication. Newer medications are always being evaluated. Watch your iron intake which may prevent this medication from being fully absorbed. Avoid iron-fortified cereals and breads. Limit red meat, spinach, lentils and soybeans since they are all rich in iron.
Healthy nutrition. As with diabetes, eating a well-balanced food plan is extremely helpful. There is no specific diet or food plan for Parkinson’s, but eating lean protein, vegetables, fruits, good quality fats like olive oil, fish, nuts with beans, legumes and whole grains in moderation is a good plan. Staying hydrated is important. As with diabetes, avoiding simple sugars, sodium, processed foods, saturated and trans-fats, fried foods, ice cream and sweet drinks is beneficial. Too much protein can interact with medications for Parkinson’s. If swallowing has become a problem, highly seasoned foods and carbonation will help stimulate swallowing. Ask your health care provider about supplements of calcium, vitamin K, magnesium and vitamin D if you do not consume foods high in these. People with Parkinson’s do not absorb calcium well. Bone health is compromised and falling is a big risk. Balance is off.
Physical movement and exercise. Exercise can reduce blood sugars, high levels of circulating insulin, insulin resistance and systemic body inflammation. Balance exercises, stretching and flexibility exercises are crucial. People with Parkinson’s have tight hamstrings, calf muscles and hip flexors. Stretching and flexibility moves keep the body more agile. Look into classes including yoga, tai chi, or dancing; they can be practiced in person or on Zoom. Resistance training with bands or light hand weights should be included for muscle strength. Water resistance work and pool exercises can also strengthen your muscles.
Reciprocal movements. Doing movements from “side to side” or “left to right” can help with Parkinson’s movement disorder. Using an elliptical with 4 limbs working at the same time would be an example. It helps train the brain in more than one movement at a time.
Stress management. Stress can increase Parkinson’s symptoms.
Emotional or mental health help. Since Parkinson’s can cause anxiety, apathy and depression, counseling on a one-on-one session or a group support session may be helpful.
Adequate, high quality sleep. Fatigue is common and proper sleep may be difficult. If you have problems falling or staying asleep, consult your health care provider.
Physical therapy, speech therapy and occupational therapy may be recommended and should be included in your care plan. Day to day living experiences may become difficult due to tremors, balance problems, impulsivity, and muscle weakness. Prescriptions for these services need to be written by your health care provider. A specific program called The Alexander technique is excellent for posture and balance. It allows the mind and body to work together. Using this technique with Parkinson’s allows you to carry out everyday tasks more easily. There are trained instructors who are certified and qualified to teach the Alexander technique. Find one in your area.

Alternative measures

LSVT: Lee Silverman Voice Treatment. Since voice quality changes with Parkinson’s this method may help with voice amplification.
LSVT-BIG. This technique uses overexaggerated physical movements including huge steps and over emphasized arm swings when walking. These patterns get reintroduced to you which can slow the progress of small steps and shuffling, a common problem is Parkinson’s.
Massage can be used to help the muscles relax, be less rigid and reduce joint and muscle pain. It can also stimulate circulation and reduce stress. Massage therapy releases neurotransmitters – feel good hormones in the brain.
Deep brain stimulation. Deep brain stimulation or DBS is a surgical treatment which addresses the movement symptoms. It also may help with sleep issues, pain, and urinary urgency. It does not change the progression of the illness. Electrodes are placed in the brain and a second procedure places an impulse generator battery in the abdomen. The battery delivers electrical stimulation to brain areas that control movement which may help with tremors. It is suggested when medication does not adequately control symptoms. Discuss with your physician to see if you are a candidate.
Acupuncture can be added to reduce pain.
Stem cell therapy. Stem cell therapy is a newer treatment which may decrease neuroinflammation and add brain cells that produce dopamine. “Stem cells are undifferentiated and have the potential to become many types of specialized cells”. It would not cure the disease, but it would be a form of treatment.

What else can I do?

As with diabetes, you need to keep all your medical appointments. Make sure to take medications on time and do not skip a dose. Limit or eliminate alcohol and caffeine. Do not move too quickly which could increase your risk of a fall. Look straight ahead, not down at your feet. Plant your heel first then take a step. Do not walk backwards. Try not to carry things when you are walking. Move small area rugs and other hazards in your walking path. If you are doing all these steps and still falling frequently consider using an aid such as a cane or walker for added balance.

Do not ignore or avoid new or different symptoms. Although uncurable, proper treatment and care can keep Parkinson’s symptoms controlled. Living with Parkinson’s is “unique to every person”. You can’t predict changes in symptoms or life expectancy. You can learn to live with this chronic disease just as you can with diabetes. Learn to navigate your life as best as possible. Live your life more fully and stay involved in your own care plan. Involve your family and friends so they can be a support system for you too!

References

https://www.nhs.uk/conditions/alexander-technique/
https://www.parkinson.org/living-with-parkinsons/treatment/surgical-treatment-options/deep-brain-stimulation
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8820685/
https://www.apdaparkinson.org/article/link-between-diabetes-and-parkinsons
https://www.movementdisorders.org/MDS/Scientific-Issues.htm
https://www.everydayhealth.com/type-2-diabetes/type-2-diabetes-linked-to-increased-risk-of-parkinsons-disease/
https://www.medscape.com/viewarticle/962501
https://www.nia.nih.gov/health/parkinsons-disease
https://my.clevelandclinic.org/health/diseases/22815-parkinsonism
https://www.michaeljfox.org/parkinsons-101
https://www.parkinson.org/library/videos/stages
https://www.aan.com/PressRoom/Home/PressRelease/1654
https://parkinsonsnewstoday.com/news/diabetes-blood-sugar-associated-parkinsons-disease-biomarker-cognitive-impairment/
https://www.webmd.com/mental-health/what-is-dopamine
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9370710/
https://www.dvcstem.com/post/stem-cell-therapy-for-parkinsons
https://www.parkinson.org.uk/information-and-support/types-parkinsonism
https://www.hopkinsmedicine.org/health/conditions-and-diseases/parkinsons-disease/parkinsons-disease-risk-factors-and-causes
https://www.mayoclinic.org/diseases-conditions/parkinsons-disease/diagnosis-treatment/drc-20376062
https://www.hopkinsmedicine.org/health/conditions-and-diseases/parkinsons-disease/6-medication-free-ways-to-feel-better-with-parkinsons-disease