Health Conditions Linked to Parkinson’s
Parkinson’s disease (PD) has been linked to several other health conditions. PD seems to put people at a higher risk of developing some diseases, like cardiovascular disease and melanoma. Other conditions, like Crohn’s disease and diabetes, put people at a higher risk of developing PD.
People living with PD are twice as likely as the general population to develop cardiovascular disease, and they have a 50% greater chance of dying from it. Cardiovascular disease, also called heart disease, includes conditions that involve narrowed or blocked blood vessels that can lead to conditions like heart attack or stroke.1,2
While PD is thought of as a condition that affects the brain, research has shown that PD may actually begin in the enteric nervous system, the part of the autonomic nervous system that controls the gastrointestinal organs. Constipation may be one of the earliest symptoms of PD, prior to a person being diagnosed with the condition.
Dysregulation of the gut microbiota (the normal bacteria that live in the intestines) is also an early symptom of PD, and an area of active research is how the microbiome influences the development of the disease. Another link with the gastrointestinal system and PD is people with inflammatory bowel disease.
Inflammatory bowel disease involves chronic inflammation of all or part of the digestive tract. Research has found that there seems to be an increased risk of developing PD among people with IBD, especially among those with Crohn’s disease.3-5
Increased risk of skin cancer
People with PD have an overall decreased risk of cancer diagnoses, but they have an increased risk of developing malignant melanoma, a type of skin cancer.
Melanoma accounts for just 4-5% of all skin cancers, but it is more likely to grow and spread. It accounts for nearly 75% of the cancer-related deaths from skin cancer. The risk of developing melanoma is increased among people with PD who have a first-degree relative with melanoma. Researchers have found that the genetic mutation in Parkin may play a common role between the two conditions.6,7
Many people with PD have genitourinary dysfunctions, conditions related to the sex organs or urinary system. Common genitourinary dysfunctions in people with PD include urinary incontinence and sexual dysfunction.
Genitourinary dysfunctions can greatly impact the quality of life of people living with PD, and urinary dysfunctions are associated with higher levels of being placed in nursing care.8
Musculoskeletal conditions, those relating to the muscles and the bones of the skeleton, are common among people with PD, although they are frequently unnoticed and undertreated. Common musculoskeletal conditions in people with PD include frozen shoulder, low back pain, arthritis, and osteoporosis.9
Link between diabetes and PD
Studies have shown that people with type 2 diabetes have an increased risk of developing PD. Due to the increased risk of developing PD among people with diabetes, it is not a surprise that the prevalence of diabetes is higher among people with PD than in non-PD people.
It is estimated that between 8-30% of people with PD have diabetes. In addition, 50-80% of people with PD have abnormal glucose tolerance tests. Glucose tolerance tests measure the body’s ability to use glucose (sugar). Abnormal results may indicate diabetes or pre-diabetes, a condition that indicates a person is at risk of progressing to type 2 diabetes. Diabetes seems to accelerate the progression of both motor and non-motor symptoms of PD.10-12
Vitamin D deficiency
Vitamin D deficiency is common among people living with PD. It is not clear whether people living with PD have more vitamin D deficiency because they get out less and have less sun exposure, or if there is some disease mechanism that causes less vitamin D in the body. A deficiency in vitamin D can lead to complications, such as weakened bones. People with PD who have a deficiency in vitamin D may be at increased risk of bone fracture.13,14
PseudoBulbar affect (PBA) is a condition that can occur in people with a variety of neurological conditions, including PD. PBA is characterized by sudden, uncontrollable outbursts of crying or laughing, and it is believed to develop when the underlying neurological disease affects areas of the brain related to emotion.
In people with PBA, the involuntary emotional responses do not match the person’s feelings, and the outbursts can be intense, can happen multiple times throughout the day, and they may occur during inappropriate times. PBA can have a significant impact on a person's social life. While it may be confused with depression or bipolar disorder, PBA is a separate condition, and there is treatment available that can help reduce the emotional outbursts.15