Objectives: To determine the relationship between glycaemic control trajectory and the long term risk of severe complications in people with type 1 diabetes mellitus, as well as the effects of paediatric and adult HbA1c levels.
Design, setting, participants: Data linkage study of data for adults with childhood-onset type 1 diabetes (diagnosed during 1975–2010) who had transitioned from paediatric diabetes care at the Royal Children’s Hospital (Melbourne) to adult diabetes care at the Royal Melbourne Hospital during 1992–2013.
Main outcome measures: Severe complications were categorised as severe diabetic retinopathy (SDR), chronic kidney disease, ulceration or amputation, and death. Mean HbA1c levels were calculated for the paediatric and adult periods. Four glycaemic control trajectories were defined according to mean paediatric and adult HbA1c levels: stable low (paediatric and adult HbA1c ≤ 66 mmol/mol); improving (paediatric HbA1c > 66 mmol/mol, adult HbA1c ≤ 66 mmol/mol); worsening (paediatric HbA1c ≤ 66 mmol/mol, adult HbA1c > 66 mmol/mol); and stable high (paediatric and adult HbA1c > 66 mmol/mol).
Results: 503 eligible participants (253 men) were identified, 26 (5.2%) of whom had at least one severe complication, including 16 with SDR (3.2%). No-one in the stable low group, but 4% of the improving, 1% of the worsening, and 7% of the stable high groups developed SDR. Higher mean paediatric (per 10.9 mmol/mol increase: odds ratio [OR], 2.9; 95% CI, 1.9–4.3; P < 0.01) or adult HbA1c levels (OR, 2.1; 95% CI, 1.4–3.1; P < 0.01) were associated with increased risk of SDR, as was longer duration of type 1 diabetes (per additional year: OR, 1.3; 95% CI, 1.2–1.5; P < 0.01).
Conclusion: SDR was associated with higher paediatric HbA1c levels, independent of glycaemic control during adulthood; it was not documented in patients with a stable low glycaemic control trajectory.
- 1. DCCT Writing Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. The Diabetes Control and Complications Trial Research Group. N Engl J Med 1993; 329: 977-986.
- 2. DCCT Research Group. Effect of intensive diabetes treatment on the development and progression of long-term complications in adolescents with insulin-dependent diabetes mellitus: Diabetes Control and Complications Trial. J Pediatr 1994; 125: 177-188.
- 3. Pambianco G, Costacou T, Ellis D, et al. The 30-year natural history of type 1 diabetes complications: the Pittsburgh Epidemiology of Diabetes Complications study experience. Diabetes 2006; 55: 1463-1469.
- 4. DCCT Writing Group. Effect of intensive therapy on the microvascular complications of type 1 diabetes mellitus. JAMA 2002; 287: 2563-2569.
- 5. Svensson M, Eriksson JW, Dahlquist G. Early glycemic control, age at onset, and development of microvascular complications in childhood-onset type 1 diabetes: a population-based study in northern Sweden. Diabetes Care 2004; 27: 955-962.
- 6. Miller RG, Secrest AM, Sharma RK, et al. Improvements in the life expectancy of type 1 diabetes: the Pittsburgh Epidemiology of Diabetes Complications study cohort. Diabetes 2012; 61: 2987-2992.
- 7. Hirose A, Furushima D, Yamaguchi N, et al. Prediction of retinopathy at 20 years after onset in younger-onset type 1 diabetes using mean metabolic memory-free HbA1c values: the importance of using HbA1c data of total, not partial, diabetes duration. Diabetes Care 2013; 36: 3812-3814.
- 8. American Diabetes Association. Standards of medical care in diabetes — 2014. Diabetes Care 2014; 37 Suppl 1: S14-S80.
- 9. National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis 2002; 39 Suppl 1: S1-S266.
- 10. Levey AS, Stevens LA, Schmid CH, et al; CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). A new equation to estimate glomerular filtration rate. Ann Intern Med 2009; 150: 604-612.
- 11. Rewers MJ, Pillay K, de Beaufort C, et al. Assessment and monitoring of glycemic control in children and adolescents with diabetes. Pediatr Diabetes 2014; 15 Suppl 20: 102-114.
- 12. Australian Institute of Health and Welfare. Diabetes among young Australians (AIHW Cat. No. CVD 59; Diabetes Series No. 18). Canberra: AIHW, 2012.
- 13. White M, O’Connell MA, Cameron FJ. Transition in type 1 diabetes mellitus from a tertiary pediatric center: what are we doing before they walk out the door? Diabetes Manag 2012; 2: 379-384.
- 14. Clements MA, Foster NC, Maahs DM, et al. Hemoglobin A1c (HbA1c) changes over time among adolescent and young adult participants in the T1D exchange clinic registry. Pediatr Diabetes 2016; 17: 327-336.
- 15. Cooper MN, de Klerk NH, Jones TW, et al. Clinical and demographic risk factors associated with mortality during early adulthood in a population-based cohort of childhood-onset type 1 diabetes. Diabet Med 2014; 31: 1550-1558.
- 16. Carlsen S, Skrivarhaug T, Thue G, et al. Glycemic control and complications in patients with type 1 diabetes: a registry-based longitudinal study of adolescents and young adults. Pediatr Diabetes 2016; doi: 10.1111/pedi.12372 [Epub ahead of print].
Publication of your online response is subject to the Medical Journal of Australia's editorial discretion. You will be notified by email within five working days should your response be accepted.