Age-Related Differences in Glycemic Control, Management Practices, and Complications Among Adolescents and Young Adults with Type 1 Diabetes Mellitus

Background: Adolescence and young adulthood are high-risk phases in type 1 diabetes mellitus (T1DM). Age-related differences in glycemic control, insulin practices, complications, and comorbidities remain insufficiently characterized. This study compared glycemic control, management practices, complications, and comorbidities between adolescents and young adults with T1DM in Hail, Saudi Arabia. Subjects & Methods:  In this cross-sectional study, we recruited 302 participants with T1DM from endocrinology outpatient clinics in the Hail region: 152 adolescents aged 10–18 years and 150 young adults aged 19–35 years. Data was collected through interviews and medical record review. Clinical, behavioral, and metabolic variables were compared between groups. Results: Adolescents had poorer glycemic control, with HbA1c ≥9.1% more common than in young adults (28.9% vs 15.3%, p<0.001), despite their higher use of continuous glucose monitoring (89.5% vs 76.0%, p=0.001). Young adults had higher BMI (26.38±4.79 vs. 21.45±5.62, p<0.001), higher rates of overweight/obesity, greater insulin omission (28% vs. 16.4%, p=0.043), and higher rates of recurrent hypoglycemia (>3 episodes: 52.0% vs. 27.6%, p<0.001). Chronic complications and psychological comorbidities were also more frequent in young adults. Conclusions: Distinct age-related risk profiles were identified among individuals with T1DM. Adolescents were particularly vulnerable to poor glycemic control despite greater use of modern monitoring devices, whereas young adults carried a greater burden of insulin omission, obesity, recurrent hypoglycemia, chronic complications, and psychological comorbidities. These findings support age-specific multidisciplinary interventions and structured transition care to improve long-term outcomes.