Combined pre-hypertension, pre-diabetes, and pre-hyperlipidaemia and long-term cardiovascular risk in young adults: a nationwide cohort study

BACKGROUND AND AIMS: Young adults with pre-hypertension, pre-diabetes, and pre-hyperlipidemia are often classified as "low risk" by conventional 10-year cardiovascular prediction tools, resulting in limited preventive attention. This study evaluated the long-term cardiovascular consequences of concurrently having all three premorbid metabolic conditions in a nationwide cohort of young adults. METHODS: We analyzed 1,743,696 Korean adults aged 30-39 years who underwent national health screening in 2009. Individuals with established hypertension, diabetes, or dyslipidemia were excluded. Participants were categorized into those with combined pre-hypertension (systolic blood pressure 120-139 mmHg or diastolic blood pressure 80-89 mmHg), pre-diabetes (fasting plasma glucose 100-125 mg/dL), and borderline dyslipidemia (LDL-C 130-159 mg/dL) versus those with none of the three conditions. The primary outcome was a composite of myocardial infarction, stroke, and cardiovascular death during long-term follow-up. Risks were estimated using multivariable Cox proportional hazards models. RESULTS: Among 497,316 eligible participants, 44,553 (9.0%) had all three premorbid conditions. During a mean 14.2-year follow-up, the incidence of the composite outcome was nearly twofold higher in the combined pre-disease group. After full adjustment, the combined pre-disease group was significantly associated with higher composite risk (adjusted HR 1.23, 95% CI 1.11-1.36), driven primarily by increased risks of myocardial infarction (aHR 1.18) and stroke (aHR 1.35). No significant differences were observed for all-cause mortality. Subgroup findings were consistent across BMI, lifestyle behaviors, and lipid patterns. CONCLUSIONS: The simultaneous presence of pre-hypertension, pre-diabetes, and pre-hyperlipidemia in young adults confers a measurable and clinically relevant elevation in long-term cardiovascular risk, despite the absence of overt cardiometabolic disease. These findings highlight a metabolic "gray zone" that is underestimated by current guidelines and underscore the need for earlier identification and preventive attention in young adults with clustered borderline abnormalities.