Guide series
Type 1 diabetes from diagnosis to adulthood, a parent’s guide
You came home from the hospital with a child, a sharps bin, an emergency contact card, and a quiet certainty that the next twenty years had just changed shape. The first night, you stood in the doorway of the bedroom and listened to the breathing. The CGM line was where it was. The team said you would learn. They were right; nobody told you that the learning never ends, only what it is about. This guide is the long arc, from the cot to the adult clinic, written for the family doing the work.
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What this guide is, and what it is not
From the conversations I have in clinic, the families who arrive most steady are not the ones who already know the answers. They are the ones who have a sense of the road. They know that what is hard at 2am with a toddler is not what will be hard with a fifteen year old at a party, and they know that the team they have now is not the team they will have at twenty. They know roughly when the work changes hands, and they know that the handover is gradual, not a switch. This guide is written to give the parent that sense of the road.
It is not a substitute for the diabetes team. It is not a personalised plan. The numbers in here are population averages drawn from clinical trials and consensus guidelines (ISPAD 2024 is the spine, with the trial chain laid over the top). Approximately 500,000 patient-days from approximately 1,300 people living with diabetes over more than ten years sit behind the GNL view; none of that touches the specifics of your child. Your child’s correction factor, basal rates, exercise plan, and clinic letter are conversations with the team. What this guide can do is give you the vocabulary, the trial names, and the recognition you need to walk into those conversations as an equal.
Population-average evidence, individual conversations with the care team. The trials tell us what tends to happen across hundreds or thousands of children; your child lives in the variation around the average. Both layers are true at the same time.
One body, four rhythms
The body talks back through the glucose, honestly, in every age band. What shifts is what the family is doing, and what the child can do for themselves. The international paediatric guidelines (ISPAD 2024) route care through four bands: infant under 2, preschool 2 to 6, paediatric 7 to 14, and adolescent 15 to 17. Each band has its own rhythm, its own evidence layer, and its own moments the family already knows by heart. The picture below holds the four bands together so the structure reads once, before the parts.
The four parts, mapped to four life stages
The work changes shape four times between diagnosis and adulthood, and the change is not driven by birthdays alone. It is driven by what the child can sense, what they can do, where they are, and who is in the room. This guide follows that arc.
Part 1. Infants and preschoolers (under 6)
You stand at the cot at 2am and look at the line on the phone. The child has slept through. You have not. The dose at this age is small enough that a 0.1 unit error matters, and the child cannot yet tell you that they feel low. About 60% of the children diagnosed under their first birthday arrive in DKA, in the largest international study we have (Cherubini 2020, Diabetologia); the textbook signs were written for older children. Modern hybrid closed-loop has shifted what is possible in this band: KidsAP02 (NEJM 2022) added around two extra hours a day in target on CamAPS FX, with nighttime time-in-range reaching 82%. The systems do not remove the work; they shift where it goes. Part 1 also carries the Dusk-Then-Drop pattern, the midday hypo trap, pre-bolusing the unpredictable eater, and what to ask the team about when doses run below five units.
Part 2. School-age children (7 to 14)
Your child is bolusing at the school lunch table now, mostly without prompting. You are half a step back, and you can feel the half-step. The school nurse calls less. The PE teacher knows the rough shape. This is the band where the technology evidence is strongest: severe hypoglycaemia is around a third lower on pump than MDI in children and young people, in the DPV propensity-matched cohort (Karges et al 2017, JAMA, n=30,579), and DKA is lower too. The 780G and Omnipod 5 paediatric pivotals (Pihoker 2023, Brown 2021) sit in this age band. Part 2 covers the school day, AID choice, ISPAD’s tiered glycaemic targets, and the conversations that are increasingly between the child and the team with you alongside.
Part 3. Adolescents (15 to 17)
The CGM is in the drawer this weekend, not on the arm. The teenager came home from the party fine, but you saw the line for the hour they were out. The conversation in the morning will not be about the number. The canonical adolescent glycaemic dip is well known to ISPAD (2024, Ch21); the part less spoken about is what runs underneath it. Hilliard et al 2013 (Patient Education and Counseling, n=150) showed that lower quality of life early in an adolescent’s care year tracked into higher HbA1c twelve months later, mediated by reduced engagement with monitoring in the middle. Quality of life acted as the leading indicator. Part 3 covers diabetes distress, screening, AID at higher HbA1c (the Karges 2024 DKA signal lives here too), eating-disorder-risk screening, and what the team can do that you may not have asked for yet.
Part 4. Transition to adult care (17 to 21)
The last paediatric clinic appointment will be quieter than you expect, and the first adult one will be stranger. The corridor smells different. The team is new. The eighteen-month conversation about transition should have started long before this. Wentzell et al 2022 (Canadian Journal of Diabetes, n=287) validated the first diabetes-distress measure designed specifically for the 18 to 30 emerging-adult window; the instrument exists because the gap is real and measurable. Part 4 covers what the family role becomes when consent moves to the young adult, what to ask the paediatric team to put in the transfer letter, and what good adult diabetes care should look like.
The evidence in one picture
Across the four bands, the closed-loop trials run in the same direction. The chart below puts them next to each other so the family lens reads cleanly: the gain is real, the magnitude is similar, the populations and durations differ, and a head-to-head between systems is not what these trials were built to be.
What carries across all four bands
If you are reading this with a child on a CGM in the next room, the thread that joins the four bands is something you already know. The family is the constant. Not in a sentimental way; in a clinical and structural way. The CGM share goes to the parent, then to the parent and the partner, then to the parent and the school, then to the young person and a slowly-receding parent. The sibling without T1D absorbs the family rhythm anyway. The partner of a parent with a child with T1D learns the night-time language even before they learn the daytime one. The diabetes team is the second constant; they hold the longitudinal record across the bands, they know what your family does well and where it tends to struggle, and they are the people best placed to spot the moments where the routing changes.
Population averages are most of the story. They are not all of it. The trials we lean on describe what happens to the typical child and the typical family; the technology, the structured education, and the team-and-family partnership get most families most of the way to the gain. The remaining piece is your child, and it is where life actually happens. Every figure on this guide is a starting point for a conversation with your diabetes team, not a target to hit alone.
Where this guide cannot go, and how it came together
This guide does not replace your paediatric diabetes team. If your child is unwell, ketones are climbing, hypoglycaemia is recurring, or the pattern on the CGM is somewhere you cannot bring it back, the team is the first conversation. Ask early. Ask in writing if you need to. Ask again if the first answer is “not yet”. The guide was built out of clinic, from over 300 children with T1D and their families at Birmingham Women’s and Children’s NHS Foundation Trust, from the families whose 2am, whose school-lunch table, whose teenager-in-the-doorway told the story. The science is ours to bring; the work is yours.
Particular thanks to Louise Collins, RN and Dr Ruth Krone at Birmingham Children’s Hospital, whose clinical practice shaped the under-5s sections of Part 1, the four-band routing across the cluster, and the team-and-family voice that runs through every paragraph.
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References
Cherubini V, Grimsmann JM, Akesson K, et al. Temporal trends in diabetic ketoacidosis at diagnosis of paediatric type 1 diabetes between 2006 and 2016: results from 13 countries in three continents. Diabetologia. 2020;63(8):1530-1541. Elding Larsson H, Vehik K, Bell R, et al. Reduced prevalence of diabetic ketoacidosis at diagnosis of type 1 diabetes in young children participating in longitudinal follow-up (TEDDY). Diabetes Care. 2011;34(11):2347-2352. Ware J, Allen JM, Boughton CK, et al. Randomised trial of closed-loop control in very young children with type 1 diabetes (KidsAP02). New England Journal of Medicine. 2022;386(3):209-219. Sherr JL, Bode BW, Forlenza GP, et al. Safety and glycaemic outcomes with a tubeless automated insulin delivery system in very young children with type 1 diabetes. Diabetes Care. 2022;45(8):1907-1910. Karges B, Schwandt A, Heidtmann B, et al. Association of insulin pump therapy vs insulin injection therapy with severe hypoglycaemia, ketoacidosis, and glycaemic control among children, adolescents, and young adults with type 1 diabetes. JAMA. 2017;318(14):1358-1366. Pihoker C, Forlenza GP, Buckingham BA, et al. MiniMed 780G paediatric pivotal trial. Diabetes Technology and Therapeutics. 2023. Brown SA, Forlenza GP, Bode BW, et al. Multicentre trial of a tubeless automated insulin delivery system in children and adults with type 1 diabetes. Diabetes Care. 2021;44(7):1630-1640. Bassi M, Franzese A, Iafusco D, et al. Comparison of glycaemic outcomes between Tandem Control-IQ and MiniMed 780G hybrid closed-loop systems in paediatric type 1 diabetes. Frontiers in Endocrinology. 2023. Karges B, Rosenbauer J, Stahl-Pehe A, et al. Hybrid closed-loop insulin therapy and risk of severe hypoglycaemia and diabetic ketoacidosis in young people (aged 2 to 20 years) with type 1 diabetes (DPV). Lancet Diabetes and Endocrinology. 2024. Hilliard ME, Wessendorf KA, Peugh JL, Hood KK. How poorer quality of life in adolescence predicts subsequent type 1 diabetes management and control. Patient Education and Counseling. 2013;91(1):120-125. Wentzell K, Strout TD, Laffel LMB, Vessey JA. Assessing diabetes distress in emerging adults with type 1 diabetes: development and validation of the PAID-EA. Canadian Journal of Diabetes. 2022;46(5):503-509. Sundberg F, Smart CE, Samuelsson J, Akesson K, Krogvold L. Using time in tight glucose range as a health-promoting strategy in preschoolers with type 1 diabetes. Diabetes Care. 2025;48(1):6-14. Bergford S, Riddell MC, Gal RL, et al. Predicting hypoglycaemia and hyperglycaemia risk during and after activity for adolescents with type 1 diabetes (T1DEXIP). Diabetes Technology and Therapeutics. 2024. ISPAD Clinical Practice Consensus Guidelines 2024, chapters 11 (DKA), 12 (hypoglycaemia and insulin), 13 (sick day), 15 (psychological care), 16 and 17 (technology), 21 (adolescence), 22 (school), 23 (managing preschoolers). Pediatric Diabetes. 2024. DPV registry under-6 insulin-requirement variability (Tauschmann and the DPV group), Pediatric Diabetes. 2023.