A new study published in Circulation: Population Health and Outcomes has delivered an uncomfortable number: 79.2% of young adults, averaging just 23 years old, already show signs of cardiovascular-kidney-metabolic syndrome, or CKM. That means roughly four out of every five people in their early twenties are carrying at least one measurable risk factor for a disease cluster most of us associate with middle age, if we think about it at all before then.

CKM syndrome, formally defined by the American Heart Association in 2023, is built on a simple but consequential insight: obesity, diabetes, kidney disease and heart disease are not separate conditions that happen to occur together. They feed each other. Excess or poorly distributed body fat drives insulin resistance and metabolic dysfunction. That dysfunction strains the kidneys, showing up as declining filtration or rising creatinine. Kidney impairment, in turn, accelerates cardiovascular damage. Each piece amplifies the others, which is why the AHA chose to name and stage them as one interconnected syndrome rather than four unrelated diagnoses.

The staging system runs from 0 to 4. Stage 0 means no risk factors at all. Stage 1 is excess or dysfunctional adiposity, often before any blood test would flag a problem. Stage 2 adds metabolic risk factors such as hypertension or early kidney disease. Stage 3 is subclinical cardiovascular disease or advanced kidney disease, meaning damage is detectable through testing even though the person feels fine. Stage 4 is clinical disease: a heart attack, a stroke, heart failure, or kidney failure that has already happened.

What makes the new study notable is not just the topline percentage but what lies underneath it. Researchers, led by Boston University cardiologist Donald Lloyd-Jones, drew on a cohort of nearly 1,300 young adults and paired CKM staging with carotid ultrasound imaging, a way of directly visualizing arterial injury rather than inferring risk from lab values alone. The staging breakdown was telling: 20.7% of participants sat at stage 0, 40.2% at stage 1, 36.2% at stage 2, and 2.8% had already progressed to stage 3, meaning measurable arterial damage. Not a single participant had reached stage 4. That last detail matters. This is not a story about young people already suffering heart attacks. It is a story about the invisible early architecture of heart disease assembling itself decades before any clinical event, in bodies that otherwise appear perfectly healthy.

That gap between early biological damage and eventual illness is exactly why the twenties deserve more attention than they currently get. Heart attacks and strokes tend to strike in the forties, fifties and sixties, so cardiovascular risk rarely enters a young adult’s thinking. But the underlying atherosclerotic process, researchers now understand, often begins accelerating well before that. A twenty-three-year-old with elevated blood pressure or early insulin resistance is not necessarily years away from consequences. Some already show the vascular fingerprints of a process already underway.

The AHA’s own answer for intervention is a framework called Life’s Essential 8, which scores cardiovascular health from 0 to 100 across eight components: diet, physical activity, nicotine exposure, sleep, body weight, blood lipids, blood glucose and blood pressure. The first five are behavioral and modifiable day to day. The last three are the biological readouts that, in effect, determine where someone falls on the CKM staging scale. A score of 80 or above is considered ideal, 50 to 79 intermediate, and below 50 poor, though because the score is an average, a strong result on one front can mask a serious problem on another.

None of this argues for alarm. It argues for attention. Stages 1 and 2, which capture the overwhelming majority of that 79%, are asymptomatic by definition. There is nothing to feel yet, which is precisely the problem, and precisely the opportunity. Routine screening in a person’s twenties, rather than a habit of waiting until something feels wrong, is what stands between a stage 1 finding and a stage 3 one. The biology, it turns out, does not wait for a diagnosis to begin. DE