Living with early-onset type 2 diabetes in young adulthood: a narrative review of lived experience and implications for developmentally appropriate care.

Introduction: Early-onset Type 2 Diabetes Mellitus (T2DM), defined as diabetes diagnosis before 40 years old, is associated with substantial lifetime cardiometabolic risk. Although many challenges of living with T2DM are shared across adulthood, diagnosis during young adulthood may shape how this condition is perceived, prioritised and managed during a formative stage of life. This narrative review aimed to synthesize how adults diagnosed with T2DM between 18 and 39 years of age experience, understand and manage their condition, and the implications for developmentally appropriate clinical care. Methods: We conducted a structured narrative review of English-language qualitative, mixed-methods and observational quantitative studies identified in PubMed, MEDLINE (via Ovid) and EMBASE (via Ovid) from database inception to 31 August 2025. Direct evidence from adults diagnosed at 18 to 39 years was prioritised. Studies of adults aged ≥18 years with youth-onset T2DM were used as closely related supporting evidence, and broader adult T2DM studies as contextual evidence. Study selection, extraction and appraisal followed predefined procedures, with reporting informed by SANRA. Results: Recurring themes included difficulty integrating diabetes into identity, stigma, competing work and family demands, material hardships, family and sociocultural influences and healthcare services perceived as not aligned with young adults' priorities. Young adults valued practical and age-appropriate communication, flexible appointment scheduling, credible digital education and peer support. However, much of this evidence was cross-sectional or derived from small, single-site qualitative studies and intervention evidence was limited. Conclusion: Although many challenges overlap with the broader T2DM population, they may have particular significance when diabetes develops during young adulthood. Developmentally appropriate care should combine cardiometabolic risk management with flexible, collaborative and non-stigmatizing support. Prospective studies are needed to test whether such models improve patient-reported, clinical and health-service outcomes.