Cardiovascular–Kidney–Metabolic Syndrome in Children and Adolescents: A Life-Course Continuum from Obesity and Insulin Resistance to Cardiovascular and Renal Disease

Background: Cardiovascular, kidney, and metabolic disorders are increasingly recognised as interconnected across the life course. In children and adolescents, obesity and insulin resistance may coexist with hypertension, dyslipidaemia, dysglycaemia, kidney abnormalities, and early cardiovascular injury. This review evaluates the applicability of the cardiovascular–kidney–metabolic (CKM) framework to paediatric practice. Methods: Structured narrative review synthesised PubMed/MEDLINE-indexed evidence spanning paediatric obesity, insulin resistance, type 2 diabetes mellitus, hypertension, dyslipidaemia, kidney dysfunction, and cardiovascular phenotypes. Systematic reviews, evidence-based guidelines, randomised trials, and longitudinal cohorts were prioritised. Results: The reviewed evidence indicates that excess adiposity can promote insulin resistance, inflammation, dyslipidaemia, hypertension, endothelial dysfunction, and renal hyperfiltration, thereby linking metabolic, cardiovascular, and renal pathways. Increased arterial stiffness, greater carotid intima-media thickness, and adverse ventricular remodelling have been identified in high-risk young people. Longitudinal findings show that childhood cardiometabolic risk factors are associated with later cardiovascular and metabolic outcomes, while youth-onset type 2 diabetes represents a particularly severe phenotype with early multiorgan complications. Newer anti-obesity and antihyperglycaemic therapies may modify several components of the CKM pathway, although long-term paediatric cardiovascular and renal outcome data remain limited. Conclusion: CKM syndrome is best viewed as a life-course continuum whose biological trajectory may begin in childhood. Developmentally adapted paediatric staging, validated longitudinal biomarkers, and long-term intervention studies remain important research priorities.