The Diabetes Control and Complications Trial (DCCT) and its long-term follow-up, the Epidemiology of Diabetes Interventions and Complications (EDIC) study, radically influenced the management of type 1 diabetes by showing the fundamental importance of strict glycaemic control in preventing diabetic complications. 1 Epidemiology of Diabetes Interventions and Complications (EDIC) Study Group
Epidemiology of Diabetes Interventions and Complications (EDIC). Design, implementation, and preliminary results of a long-term follow-up of the Diabetes Control and Complications Trial cohort.

Diabetes Care. 1999; 22: 99-111

Cognitive function, which was assessed at baseline, has been followed up longitudinally, with no significant abnormalities being observed at 2 and 5 years and only minor abnormalities after 18 years. 2 Jacobson AM Musen G Ryan CM et al. Long-term effect of diabetes and its treatment on cognitive function.

N Engl J Med. 2007; 356: 1842-1852

, 3 Jacobson AM Ryan CM Cleary PA et al. Biomedical risk factors for decreased cognitive functioning in type 1 diabetes: an 18 year follow-up of the Diabetes Control and Complications Trial (DCCT) cohort.

Diabetologia. 2011; 54: 245-255

Alan Jacobson and colleagues now present the 32 year follow-up of cognitive function in 1051 people from the original DCCT cohort. 4 Jacobson AM Ryan CM Braffett BH et al. Cognitive performance declines in older adults with type 1 diabetes: results from 32 years of follow-up in the DCCT/EDIC Study. Lancet Diabetes Endocrinol. 2021; (published online May 27.) In this paper, published in The Lancet Diabetes and Endocrinology, the potential roles of various biomedical characteristics on cognitive function have been re-examined, including glycaemic control (assessed by HbA1c), blood pressure, and frequency of severe hypoglycaemia. 4 Jacobson AM Ryan CM Braffett BH et al. Cognitive performance declines in older adults with type 1 diabetes: results from 32 years of follow-up in the DCCT/EDIC Study. Lancet Diabetes Endocrinol. 2021; (published online May 27.) The DCCT has delivered a plethora of valuable information on the natural history of type 1 diabetes with much information of intrinsic value to clinical care, and this report provides important long-term observations.