Heart disease, diabetes and kidney disease are among the most common chronic illnesses in the United States — and they’re all closely connected.
Adults with diabetes are twice as likely to have heart disease or a stroke compared with those who don’t have diabetes. People with diabetes — Type 1 and Type 2 — are also at risk of developing kidney disease. And when the kidneys don’t work well, a person’s heart has to work even harder to pump blood to them, which can then lead to heart disease.
The three illnesses overlap so much that last year the American Heart Association coined the term cardiovascular-kidney-metabolic syndrome to describe patients who have two or more of these diseases, or are at risk of developing them. A new study suggests that nearly 90 percent of American adults already show some early signs of these connected conditions.
While only 15 percent of Americans meet the criteria for advanced stages of C.K.M. syndrome, meaning they have been diagnosed with diabetes, heart disease or kidney disease or are at high risk of developing them, the numbers are still “astronomically higher than expected,” said Dr. Rahul Aggarwal, a cardiology fellow at Brigham and Women’s Hospital in Boston and co-author of the study.
The research suggests that people should pay attention to shared risk factors for these diseases early on — including excess body fat, uncontrolled blood sugar, high blood pressure and high cholesterol or triglyceride levels.
A Dangerous Cycle
Your kidneys, heart and metabolic system (which helps process the food you eat into energy and maintains your blood sugar levels) work closely together. If something goes awry with one, it can lead to problems with the others.
One of the most important early changes in people who go on to develop Type 2 diabetes is insulin resistance, which happens when your body doesn’t respond to insulin after meals like it should. This causes blood sugar levels to go up.
Over time, elevated blood sugar narrows and stiffens blood vessels. This means the heart has to work harder: Blood pressure increases to help blood cells and nutrients squeeze through tight, inflexible vessels. (People with Type 1 diabetes, whose bodies don’t produce enough insulin, can also experience this if their blood sugar is poorly controlled.)
That high blood pressure is like kerosene on fire. It triggers inflammation in the body, said Dr. Chiti Parikh, the executive director of Integrative Health and Wellbeing at Weill Cornell Medicine in New York. This inflammation, combined with insulin resistance, drives up the levels of triglycerides and LDL cholesterol, which contribute to a buildup of plaque in blood vessels. Eventually, the plaque can rupture and cause a heart attack or a stroke.
All these factors — high blood pressure, uncontrolled blood sugar, and high triglycerides and LDL cholesterol — also take a toll on the kidneys. They can reduce blood flow to the kidneys and cause scarring to the cells that filter our blood. And when the kidneys stop filtering blood as well as they should, it causes imbalances in the amount of fluid, hormones, acids and salt in the body, said Dr. Kumar Sharma, director of the Center for Precision Medicine and chief of the Nephrology Division at University of Texas Health at San Antonio. This drives more inflammation and cardiovascular problems and makes it more difficult to keep blood sugar in check.
While blood sugar issues often start this dangerous cycle, Dr. Parikh said, excess body fat, inflammation, high cholesterol and other risk factors can also drive changes that can lead to heart or kidney disease or diabetes downstream.
Prevent the Progression
Preventing or managing any of these risk factors can help treat or lower the risk for diabetes, kidney disease or heart problems.
During annual wellness visits, your health care provider should check your blood pressure and may order blood tests that measure your glucose, cholesterol and triglyceride levels. A doctor might also assess your kidney health by measuring protein in urine or creatinine in the blood. Another blood test can measure C-reactive protein, which can hint at the presence of inflammation, Dr. Parikh said.
Once you have an idea of your overall health, look for areas where you can start to make meaningful changes. Adding more fiber, fruit and vegetables to your diet can help regulate blood sugar and reduce blood pressure. Increasing muscle mass through strength training has been shown to help with insulin resistance. And any kind of movement can be beneficial in managing your blood sugar and blood pressure. Experts recommend aiming for 150 minutes of exercise every week.
“Don’t think in terms of all or nothing,” said Dr. Estrelita Dixon, an internal medicine specialist at UC Health in Cincinnati.
In some cases, you may need medication to help manage high blood sugar, blood pressure or high cholesterol. There is mounting evidence that certain diabetes drugs, including newer medications like Ozempic and older SGLT2 inhibitors, can also help across kidney disease and cardiovascular disease.
They might be different conditions, doctors said, but approaching diabetes, heart disease and kidney disease holistically could help prevent serious complications down the road.