Comorbidities and Chronic Kidney Disease

Chronic kidney disease (CKD) is a complex condition that affects every system in the body. It is also a condition with many comorbidities. A comorbidity, also called a comorbid disease, is a health condition that occurs at the same time as another illness.¹

Comorbid diseases tend to act upon each other in ways that make both conditions worse. This is especially true of CKD and the other health conditions that usually occur with it.¹

How do comorbidities affect people with CKD?

A Scottish study found that almost all adults with CKD had at least 1 comorbidity. Only half of people without CKD had a comorbidity. The study also found that having multiple health conditions meant that people with CKD:²

• Had lower quality of life
• Needed more medical care
• Had longer hospital stays
• Had higher rates of death

What are the most common comorbidities with CKD?

Quite a few health conditions can occur with chronic kidney disease. The most common health conditions people with CKD live with are:^1,3

• Diabetes
• High blood pressure
• Heart and blood vessel disease (cardiovascular disease)

These 3 comorbidities have a chicken-and-egg relationship with CKD. Diabetes, high blood pressure, and heart disease can cause CKD or make it worse. But later-stage CKD also makes it hard to control blood sugar and blood pressure, which can lead to diabetes and high blood pressure. CKD also can cause cardiovascular disease.¹

Cardiovascular disease and CKD

Cardiovascular disease plays an outsize role in deaths in people with stage 4 and stage 5 CKD. Studies show that half of all people with stage 4 or 5 CKD die from these heart and blood vessel diseases.²

Cardiovascular disease includes a variety of conditions, including:²

• High blood pressure
• Peripheral vascular disease
• Heart failure
• Stroke
• Atrial fibrillation
• Coronary heart disease

Bone disease and kidney disease

People with kidney disease and kidney failure almost all have a condition called mineral and bone disorder. This occurs when the kidneys are unable to control the blood levels of calcium, phosphorus, and parathyroid hormone (PTH) in the body.¹

Mineral and bone disease affects the bones, heart, and blood vessels. Symptoms include:¹

• Itchy skin
• Bone pain and weak bones
• Blocked blood vessels and heart problems
• Anemia

Inflammation, kidney damage, and CKD

A wide variety of health conditions can cause inflammation or kidney damage. Having 1 or more of these conditions increases your risk of CKD. These conditions include:^2,4-9

• Lupus and other autoimmune conditions
• Glomerulonephritis (inflammation in the kidneys)
• Gout
• Nerve damage (peripheral neuropathy)
• Kidney and bladder stones
• Recurring urinary tract infections
• Chronic obstructive pulmonary disease (COPD)
• Inflammatory bowel disease (IBD)
• Skin disorders such as psoriasis and eczema
• Thyroid disorders
• HIV
• Hepatitis
• Sickle cell disease
• Cystic fibrosis

Mental health issues and CKD

Several mental health issues often coexist with kidney disease, including:²

• Schizophrenia and bipolar disorder
• Depression
• Learning issues
• Anxiety
• Anorexia or bulimia
• Substance and alcohol misuse
• Dementia

CKD and changes in circadian rhythms

Circadian rhythms are natural physical, mental, and behavioral changes that happen in a 24-hour cycle. All animals, including humans, react to daylight and darkness. A common example of a circadian rhythm is to fall asleep at night and wake up during the day. You may hear this called your biological clock or biological rhythms.¹⁰

Circadian rhythms help your organs work properly. But CKD can disrupt these rhythms. For example, circadian rhythms affect how the kidneys manage blood flow and filter waste. CKD disrupts the healthy rhythms of the kidneys, which can lead to:¹¹

• Problems staying asleep and poor sleep quality
• Sleep apnea
• High blood pressure that doesn't go down at night
• Problems peeing
• Faster aging

Balancing CKD with your other health conditions

It is often challenging to manage all the diseases that can occur with CKD. That is because people living with CKD may need many drugs and other treatments, and some of those treatments may make kidney damage worse.^2,3

You can help balance all of your health needs by talking to your doctor about ways to manage your kidney health. You should also make sure all of your doctors are aware of your CKD, especially when they are prescribing treatments. Review all your prescription and over-the-counter drugs and supplements regularly with your doctors.¹²

Your insurance may pay for you to have a case manager or health coordinator. These health workers can make sure your doctors are talking to one another and all of your conditions are treated.¹²

One more thing to know

Some people confuse the words "morbidity" and "mortality." However, these medical terms mean different things. Morbidity means disease or illness. Mortality means death.^13,14