People with cardiovascular, kidney and metabolic problems (CKM) may face a higher risk of cancer, according to new research from Japan.

The risk appears to rise as these conditions become more advanced, which has led researchers to suggest that cancer prevention should be considered alongside heart and kidney care.

The findings do not prove that the condition causes cancer. But they do add to evidence that the same health problems that raise the risk of heart disease and kidney disease may also be linked to cancer.

What is CKM syndrome?

The “trio” condition is called cardiovascular-kidney-metabolic syndrome, or CKM syndrome. It is a term used by the American Heart Association to describe the overlap between:

• cardiovascular disease, such as coronary artery disease or heart failure
• kidney disease
• metabolic problems, such as excess body fat, high blood sugar and insulin resistance

These conditions often develop together and can make one another worse over time.

In simple terms, CKM syndrome describes a pattern of poor cardiometabolic health that affects several organs at once.

It is increasingly common, and researchers estimate that a large proportion of adults have at least one component of it.

What the new study found

The new study was observational and used insurance claims and health check-up data from nearly 1.4 million people in Japan, collected between April 2014 and August 2023. The result was published in Circulation: Population Health and Outcomes

Researchers followed people for a median of just over three years and compared cancer rates across CKM stages. They reported that cancer risk rose with more severe CKM staging:

• Stage 1: 3% higher risk
• Stage 2: 2% higher risk
• Stage 3: 25% higher risk
• Stage 4: 30% higher risk

The biggest increases were seen in stages 3 and 4, when more serious cardiovascular and kidney disease is present.

In plain language, the study suggests that people with more advanced CKM syndrome were more likely to be diagnosed with cancer during follow-up than those without it.

Why CKM and cancer may be linked

The study cannot say why the link exists, but the researchers and outside experts pointed to several shared biological and lifestyle factors.

These include:

• chronic inflammation
• insulin resistance
• oxidative stress
• excess body fat
• smoking
• alcohol use
• poor diet
• ageing

These factors are known to affect both cancer risk and the development of heart, kidney and metabolic disease.

Inflammation is of particular interest. It can damage tissues over time and may help create conditions in which cancer is more likely to develop. At the same time, inflammation also plays a major role in cardiovascular disease, diabetes and chronic kidney disease.

That means CKM syndrome may not be a single disease with one cause. Instead, it seems to reflect a cluster of conditions that share risk factors and may reinforce each other.

How strong is the evidence?

The findings are based on a large human study, which makes them useful. But it was still an observational study, so it cannot prove that CKM syndrome causes cancer.

There are other important limits too:

• the follow-up period was relatively short
• the study was done in Japan, so results may not apply equally to all populations
• the strongest association was seen only in later CKM stages
• the study does not show which factor, or combination of factors, is driving the risk

That means the research is best seen as a warning sign, not proof of direct causation.

The results fit with what is already known about shared risk factors for cardiovascular disease and cancer, but they also noted that the study does not yet show a clear treatment or prevention strategy specific to CKM syndrome.

What this means for patients and the public

The main message is that protecting heart, kidney and metabolic health may also help lower cancer risk. The same habits that reduce the chances of cardiovascular disease are also linked to lower cancer risk.

These include:

• eating a diet rich in plant foods, lean proteins and healthy fats
• limiting processed meat
• avoiding tobacco and secondhand smoke
• keeping alcohol intake low, or avoiding it
• getting regular physical activity
• managing weight, blood pressure, blood sugar and cholesterol
• attending recommended cancer screenings

This does not mean that everyone with CKM syndrome will develop cancer. It does mean that people with more advanced CKM problems may need closer attention to cancer prevention and routine screening.

Current treatment and prevention approaches

The study does not point to a new cancer treatment. Instead, it supports a more joined-up approach to prevention.

That means clinicians may need to think beyond a single organ system. If someone has diabetes, chronic kidney disease, high blood pressure or established cardiovascular disease, doctors may also want to keep cancer risk in mind when planning long-term care.

At present, the best-supported approach is still to treat the underlying risk factors aggressively and consistently.

Lowering cardiovascular risk is already a priority in CKM syndrome, and that appears likely to bring broader health benefits.

Broader Perspectives

Future studies with longer follow-up will be needed to clarify whether the association is causal and how best to act on it.

The study adds to a growing body of evidence showing that heart, kidney, metabolic and cancer risks are often connected rather than separate. That supports a more holistic approach to prevention, especially for people with multiple long-term conditions.

The most practical lesson is not a new alarm, but a familiar one, measures that protect overall health, such as staying active, eating well, not smoking and keeping chronic conditions under control, may also help reduce cancer risk.