Heart; Kidneys

CKM syndrome: The intersection of obesity, diabetes, heart and kidney diseases

Heart; Kidneys

Illustration of a doctor with a stethoscope holding out his hand to underscore internal organ icons.
Obesity, heart disease, diabetes, and kidney disease are all connected, and that has been formalized in a new condition called cardiovascular-kidney-metabolic syndrome (CKM).

For decades, doctors, and scientists have gathered evidence that four cardiometabolic conditions are intertwined: obesity, heart disease, diabetes, and chronic kidney disease.

Providers have historically had to approach this web of conditions by separating the sum into its parts – spotting and treating the individual diseases separately, often after damage had been done to the patient’s heart and kidneys.

This fragmented approach has brought to a halt the previously declining U.S. cardiovascular death rate and let slip through the cracks thousands of heart attacks, strokes, and cases of kidney failure each year – cases that could have been prevented with guardrails to identify and address the four conditions collectively.

Fast-forward to 2023, and that need is finally being fulfilled.

The American Heart Association (AHA) has given the four-pronged disease the official name cardiovascular-kidney-metabolic syndrome (CKM), and its Presidential Advisory is the first to formally acknowledge CKM as a disorder that can be prevented, staged, and treated to reduce the risk of severe cardio-kidney events.

I served on the writing group for the advisory with Sonali S. Patel, M.D., Ph.D., Associate Professor of Cardiology in UT Southwestern’s Department of Pediatrics, and a team of cardiologists and researchers from around the country.

With an emphasis on healthy lifestyle patterns, the advisory establishes screening criteria and intervals for children and adults, and it highlights new, advanced treatments that can help reshape cardiovascular-kidney-metabolic health care and prevention.

How does CKM start?

CKM is a progressive syndrome that develops over time, often starting in childhood with family habits and social-environmental pressures that lead to excess fat accumulation, such as relying heavily on takeout meals or living in a food desert where fresh produce wasn’t readily available but processed and fast foods were. Lack of physical activity exacerbates the problem, leading to an unhealthy course.

Excess fat causes inflammation and insulin resistance, which can lead to metabolic risk factors such as high blood pressure, Type 2 diabetes, chronic kidney disease, high cholesterol, and metabolic syndrome – a combination of conditions characterized by a large waistline that affects nearly a third of U.S. adults. From there, severe problems are more likely to develop, such as:

How is CKM detected and diagnosed?

The AHA’s advisory establishes stages for CKM, much like we have for cancer. But in this case, the stages pinpoint windows for prevention, intervention, and management:

  • Stage 0: The patient has no risk factors.
  • Stage 1: The patient is overweight or obese, with excess fat deposits under the skin and/or inside the organs, along with early problems such as prediabetes. Stage 1 is often overlooked as “not bad enough” for treatment, but it is the sweet spot for health education and disease prevention.
CT image of calcium around the heart.
A cardiac CT shows calcium around the heart.
  • Stage 2: CKM risk factors are developing, such as high cholesterol, hypertension, diabetes, metabolic syndrome, or kidney disease.
  • Stage 3: Screenings identify damage to the heart or blood vessels. For example, a cardiac CT used for coronary artery calcium scoring might show deposits on the heart, or coronary angiography could show cholesterol buildup, a weakened or stiff heart muscle, or signs of heart failure, with or without symptoms.
  • Stage 4: These patients already have cardiovascular disease and complications such as heart attacks, strokes, atrial fibrillation, and peripheral artery disease or have advanced kidney disease.

Early identification of CKM is key to reducing heart- and kidney-related mortality. However, there is no singular test for CKM – screening and diagnosis still rely on evaluation of the separate conditions. The advisory outlines recommendations for lifelong screening criteria and intervals based on a patient’s age, lifestyle, and personal risk factors.

For most adults, general target number ranges to work toward are as follows:

  • Blood pressure: Healthy blood pressure reads consistently less than 120/80 mg/dL. The elevated blood pressure range is 120-129/80 mg/dL, and hypertension begins at 130-139/80-89 mg/dL .
  • Blood sugar: A healthy fasting blood glucose range is less than 100 mg/dL. Prediabetes is 100-125 mg/dL, and 126 mg/dL or higher is Type 2 diabetes.
  • Body mass index: BMI is a height/weight ratio that helps to estimate a patient’s level of body fat. A healthy BMI for most adults is 18.5 to 25, but for those of Asian ancestry, the range is 18-23. BMI of 25-29 is overweight and 30 or higher is considered obese. Calculate your BMI.
Man getting his waist measured.
Your waist circumference is directly tied to metabolic health.
  • Waist circumference: Less than 34.6 inches, or 31 inches if of Asian ancestry. Waist circumference is directly tied to metabolic health, independent of weight and BMI.
  • Cardiovascular disease risk: Starting at age 30 or earlier, adults should get a 10-year risk estimation for atherosclerotic cardiovascular disease (heart attacks or strokes). The AHA has unveiled a novel risk assessment tool, PREVENT, for doctors to help patients understand their 10-year and 30-year risk for heart disease.
  • Albuminuria: This protein in urine can be an early indicator of kidney dysfunction and heart disease. It should be less than 30 mg/g or less than 3 mg/mmol.

Cholesterol guidelines were updated in 2018 by the American College of Cardiology and the AHA to move away from target numbers and focus on aggressive prevention and management based on a patient’s age, ethnicity, diabetes status, atherosclerotic heart disease status, and whether they have very high cholesterol. Studies suggest having a “bad” (LDL) cholesterol at or below 100 mg/dL and ideally less than 70 results in a lower risk of stroke and heart disease.

Related reading: Sleep disorders and obesity: A vicious cycle

What are the best ways to prevent CKM?

A key point in the AHA advisory is that starting early in life with diet, exercise, and weight management can help patients avoid CKM – we cannot wait until adulthood to start addressing patients' risk factors.

None of these lifestyle recommendations is new, but they bear repeating because they continue to play an important role in disease prevention and management:

  • Avoid smoking, tobacco use, and vaping. If you already have these habits, UT Southwestern offers free help to quit.
  • Limit added sugars. Current AHA recommendations are no more than 6 teaspoons daily for women and children 2 and older; 9 teaspoons or less for men. Children younger than 2 should not consume added sugar.
  • Exercise daily. The AHA recommends getting at least 150 minutes of moderate activity (walking, pickleball) or 75 minutes of vigorous physical activity (running, basketball, tennis) each week. Include strength training such as resistance bands or weightlifting at least twice weekly.
  • Follow a heart-healthy eating plan. The Mediterranean diet is proven to reduce risk factors that lead to heart attack. The DASH (low-sodium) diet is beneficial for patients with hypertension or heart failure.
  • Take medications and therapies as prescribed. Blood pressure and cholesterol medications like statins work behind the scenes to improve your heart health. Patients with chronic inflammatory conditions such as psoriasis, lupus, or rheumatoid arthritis and mental health conditions or sleep disorders such as obstructive sleep apnea are also at increased risk.

Patients with a family history of the individual conditions of CKM are at high risk of developing the syndrome. High-risk demographic groups such as those with South Asian ancestry or socioeconomic challenges are also at increased risk of CKM.

The advisory recommends increasing the number of care navigators whose role it is to connect patients facing transportation, health coverage, and health education challenges with resources and help collate a patient’s health data from primary care through various specialists. Navigators can also set screening and follow-up visits and streamline access to health services.

Related reading: Eat well for less: 5 building blocks for a nourishing, affordable pantry

Are there any advanced treatments for CKM?

The past decade has brought an explosion of sophisticated treatments to prevent and treat CKM. New medications combined with proper nutrition, heart-healthy lifestyle habits, and exercise allow patients to double down on their metabolic health:

  • SGLT2 inhibitors: Originally developed to treat diabetes, this class of medications is shown to prevent kidney failure and reduce heart failure-related hospitalization and heart disease-related death.
  • GLP-1RAs: Also rooted in diabetes care, the GLP-1RA drug semaglutide (e.g., Wegovy or Ozempic) is shown to improve insulin resistance and glycemia, reduce weight, and significantly reduce heart disease-related deaths regardless of diabetes status.
  • PCSK9-inhibitors: This potent cholesterol-lowering medication is for patients with very high cholesterol that cannot be controlled with lifestyle changes and statins.
  • RAAS inhibitors: These medications turn down the function of the renin-angiotensin-aldosterone system, reducing the risk of kidney and heart disease by improving blood protein filtration and reducing cell growth and inflammation.
  • Nonsteroidal mineralocorticoid receptor antagonist: nsMRAs maintain function of the tiny filters in the kidneys and reduce albumin-creatinine ratio levels. They’re also shown to reduce the risk of heart disease in patients with kidney problems.
  • ARNI: These aggressive blood pressure medications block the hormone angiotensin and increase levels of natriuretic peptides to improve heart and kidney function in patients with heart failure with reduced ejection fraction and kidney disease.

Related reading: It’s time to get heart failure patients the medications they need

The AHA’s Presidential Advisory provides a starting point for tying individual CKM conditions together to address the full scope of a patient’s cardiovascular-kidney-metabolic health. Almost all of us are born with good health, but too many of us give it away, often without realizing it, over our lifetime.

We must preserve wellness for ourselves, model healthy behaviors for our children, and take advantage of this groundswell of cardiometabolic knowledge to enjoy longer, healthier lives.

To talk with a cardiologist about CKM risk factors, call 214-645-8300 or request an appointment online.