Background <p>Digital tools are increasingly used in diabetes care, but their long-term effectiveness remains uncertain. A previous randomized controlled trial (RCT) demonstrated promising effects on perceived burden and quality of life after 6 months. The present study extends these findings through a 12-month follow-up, aiming to evaluate the long-term effects of virtual care on glycaemic control, treatment satisfaction, and quality of life among young adults with type 1 diabetes.</p> Methods <p>This single-centre wait-list RCT included 70 young adults aged 18–25 years with type 1 diabetes in Stockholm, Sweden. Participants randomized to the intervention group had access to the virtual platform for 12 months whereas participants in the wait-list control group received access after 6 months. The platform facilitated real-time communication with healthcare providers. Glycated haemoglobin (HbA1c) levels, time in range, time below range, diabetes treatment satisfaction, and quality of life were assessed at baseline and at the 6- and 12-month follow-ups. Comparisons within and between groups were performed using Welch’s paired and independent samples t-test, the Wilcoxon signed rank test, and the Mann-Whitney test.</p> Results <p>At the 12-month follow-up, the intervention group showed a decreased HbA1c level from baseline (62.8 to 58.6 mmol/mol; P = 0.051) and improved time in range (46.6% to 56.9%; P = 0.002). In the wait-list control group, social burden decreased significantly from baseline to 12 months (4.3 to 0.03; P = 0.030). Other measures of quality of life, including social and emotional health, showed no significant differences.</p> Conclusions <p>Virtual diabetes care may enhance engagement and modestly improve glycaemic control in young adults, serving as a practical complement to standard outpatient follow-up.</p> Trial registration <p>ISRCTN (ref: 73435627, registration date: 23/10/2019): https://doi.org/10.1186/ISRCTN73435627.</p>