· heart disease
· Alzheimer’s Disease
If you said: heart disease and diabetes or fibromyalgia and migraine, you’re right. Medical science confirms that people who get one of those conditions are statistically more likely to have the other.
Now go back to that list. What two conditions have an inverse relationship, that is, which two diseases rarely go together?
The answer is Alzheimer’s Disease and cancer.
This does not mean they can never occur in the same person, but it has been recently confirmed that Alzheimer’s Disease seems to have some sort of effect that protects people from cancer. So does Down’s Syndrome and Parkinson’s Disease (although Parkinson’s patients have a higher rate of prostate cancer and melanoma, they overall have lower-than-average rates of cancer).
Medical scientists call these comorbidities—diseases that for some reason or other go together. Sometimes the association seems like one causes the other, such as knee arthritis and obesity or severe chronic pain and clinical depression. Other times, the diseases seem completely random, such as heart valve disease and psoriasis or chronic obstructive pulmonary disorder (COPD) and heart burn. Comorbidities and inverse relationships are of interest to scientists because they may help guide us to the underlying processes of the disease. Psoriasis and psoriatic arthritis are comorbid (even related) conditions that have very different effects—so what’s going on? The speculation is that the genetic conditions that predispose a person to psoriasis (a skin disorder) can also affect the joints.
Sometimes comorbidities may seem related but aren’t, such as the link between atrial fibrillation and heart failure. Both are cardiac conditions, but atrial fibrillation is an electrical problem of the heart resulting in a too-fast rhythm while heart failure is a plumbing problem—the heart cannot pump effectively. They aren’t really related yet they are comorbid.
Sometimes, a disease is considered particularly devastating because of the company it keeps. Diabetes, for example, is comorbid with heart disease, coronary artery disease, neuropathy (nerve pain), and Alzheimer’s Disease. Arthritis—which can often be managed—is comorbid with hypertension and stroke. Kidney disorders can be comorbid with coronary heart disease, the cause of heart attacks.
Some diseases are comorbid with mental health conditions, such as the link between fibromyalgia and panic attacks or epilepsy and depression. Mental health disorders can also be comorbid with each other, for example, people with post-traumatic stress disorder are at high risk to have another psychiatric diagnosis in their lifetime.
Comorbidities can complicate healthcare but the real intrigue in these associations is where they can lead us in our understanding of disease. Two comorbid but dissimilar diseases may have some underlying mechanism that can help us better understand both. Knowing, for instance, that Alzheimer’s Disease patients have some sort of built-in cancer protection may help us unlock the secrets of cancer.
Jo Ann LeQuang is a professional writer specializing in medical topics and a Christ-follower whoblogs at AWretchLike.Me.