Adolescent T1D and the Bridge to Adult Care

The canonical glycaemic dip is not a willpower problem

The international paediatric data are unanimous on the shape: time-in-range tends to fall, HbA1c tends to rise, and engagement with diabetes care tends to thin out somewhere between fourteen and seventeen for many young people with T1D. The temptation, especially from outside the family, is to read this as a behavioural failure. The trial evidence reads it differently. Hilliard 2013 (Patient Education and Counseling) followed 150 adolescents over twelve months and found that lower quality of life at the start of a care year predicted reduced blood-glucose monitoring at six months, which then predicted higher HbA1c at twelve. Quality of life was acting as a leading indicator, not a downstream wellbeing endpoint.

The mechanism is recognisable from the inside of an adolescent’s life: identity, peer dynamics, sleep and circadian shifts, exam and first-job pressure, the emerging negotiation between parent and young person about who is doing what. The diabetes does not pause for any of these. The young person who is brilliant at twelve and is now fifteen is not necessarily worse at diabetes; they are now living a life with more competing demands on the same finite cognitive and emotional bandwidth. ISPAD 2024 Chapter 21 (Adolescence) treats this as the canonical window in T1D where care needs to widen in scope, not tighten in instruction.

The DKA signal on AID, and what it actually says

The largest real-world dataset on hybrid closed-loop in young people is the Karges 2024 DPV cohort (Lancet Diabetes Endocrinology, 13,922 young people aged 2 to 20, 2021 to 2023). The headline that has worried families is that DKA risk on closed-loop sat higher than on sensor-augmented pump (1.74 versus 0.96 episodes per 100 patient-years). The piece of the headline that matters more is where the risk concentrated: in young people whose HbA1c was above 7.5 percent, the incidence rate ratio was 2.45; above 8.5 percent, it was 3.43; for young people with HbA1c below 7.0 percent, DKA risk was not significantly elevated. The same cohort showed lower hypoglycaemic coma risk on closed-loop (incidence rate ratio 0.68).

The likely mechanism is plain enough. When the algorithm is doing the day-to-day work, the young person is not doing the manual scanning that used to flag a stuck pump or a failed cannula early. A few hours of undetected insulin under-delivery in an adolescent body that is already making more counter-regulatory hormones than a six-year-old’s tips into ketogenesis sooner. The educational response is not to step away from closed-loop; it is to keep sick-day rules and ketone monitoring active alongside the algorithm, particularly for young people with HbA1c above 7.5 percent. ISPAD 2024 Chapter 11 (DKA) covers the routine; the diabetes team will walk a young person and family through it together.

The mental-health layer the team treats as routine

ISPAD 2024 Chapters 15 (Psychological Care) and 21 (Adolescence) treat routine screening for diabetes distress, depressive symptoms, family functioning, and disordered eating as part of the diabetes visit, not as a referral out. The validated instrument that the field has settled on for the late-teen and emerging-adult window is the Problem Areas in Diabetes, Emerging Adult version (Wentzell 2022, Canadian Journal of Diabetes). It captures the things that distress in this window actually looks like: cost worries, perfectionism, future-children worries, partner-disclosure worries, the feeling of being judged by people who do not have T1D. It is short, it is in plain English, and most paediatric services either use it now or are about to.

Eating-disorder risk in T1D is higher than in the general population, and the early signs are subtle: insulin omission for weight reasons, unexplained weight change, secret meal patterns, food rules that have crept in over months. None of these are the family’s failure to spot; they are usually invisible to the people closest to a young person. What helps is the team being trained to ask, and the family knowing that telling the team early is not over-reacting. Most paediatric diabetes services have direct access to a psychologist or are explicitly working towards integrated psychological care; the conversation is normal and confidential.

The eighteen-month transition conversation

Transition to adult care is rarely the date in the calendar; it is the eighteen-month conversation that ends on that date. Most paediatric services start this conversation around age sixteen, write a transition plan with the young person in the room (not the parent in the room with the young person observing), and join the first adult clinic appointment if the young person asks them to. The plan typically covers self-management skills the young person will need to own (what to do when the pump fails, when to call the team, how to renew prescriptions, how to register with adult services), sick-day routines, mental-health and distress screening, and the human side of saying goodbye to a paediatric team the family has known for a decade.

What sometimes gets missed in transition is that the young person is also losing a relationship. The paediatric team has watched her grow up; the adult team has not. The good handoffs treat that loss with the seriousness it deserves: a joint clinic, a written summary of what has worked and what has not, an explicit invitation back to the paediatric team if the first adult clinic appointment does not land. The family is still part of this conversation, in the role the young person now wants the family to play. Most adolescents want a parent in the background, not in the front seat; the team can help name that out loud so everyone is reading from the same script.

What the family can take to the team

If a young person’s mood, sleep, eating, or engagement with diabetes care has changed over months rather than days, that is the team’s first conversation, not the family’s last resort. Telling the team early is exactly what the team is set up for: brief screening conversations, the option of psychology referral, eating-disorder pathways that work with a young person rather than around them. The PAID-EA is one specific tool the team may already use; if they do not, the conversation can simply name what has changed and let them choose the framework.

If transition is approaching, ask whether the team has a written transition pathway, whether the eighteen-month conversation has begun, and whether a joint adult-paediatric clinic appointment is part of the plan. Ask the young person what they want from the conversation and whether they want a parent there for the first one. Ask the team what to do if the first adult appointment does not land well. The system is designed to absorb this conversation; the families who get the smoothest transitions are the ones who ask for it explicitly.

References for this part