T1D Onset Before Age 10 Tied to Higher Dementia Risk

TOPLINEIndividuals diagnosed with type 1 diabetes (T1D) before the age of 10 years had a 37% higher risk of developing all-cause dementia later in life than those diagnosed between ages of 18 and 30 years.METHODOLOGYResearchers conducted a prospective cohort study using a linked Swedish national register to examine whether a younger age at T1D onset was associated with a higher risk for dementia.T1D was defined as treatment with insulin and an age at diagnosis of 30 years or below.They analysed data of 43,440 individuals with T1D (mean age at cohort entry, 33 years; 44% women) and no history of dementia, grouped by age at T1D onset: below 10 years (n = 11,776), 10-17 years (n = 15,846), and 18-30 years (n = 15,818).The primary outcome was all-cause dementia, including Alzheimer's disease, vascular dementia, and other dementia.The overall median follow-up duration was 29.3 years.TAKEAWAYOverall, all-cause dementia occurred in 100 (0.9%), 158 (1.0%), and 272 (1.7%) individuals in the age-at-onset groups of below 10 years, 10-17 years, and 18-30 years, respectively.After adjustment for sex, region of birth, education, and marital status, individuals with T1D onset before the age of 10 years had a 37% higher risk for all-cause dementia than those with T1D onset at ages of 18-30 years (hazard ratio [HR], 1.37; 95% CI, 1.08-1.73).T1D onset before the age of 10 years was also linked to a higher risk for vascular dementia than the onset at ages of 18-30 years (HR, 1.65; 95% CI, 1.10-2.47), with no significant difference in the risk for Alzheimer's disease.Individuals diagnosed with T1D between ages of 10 and 17 years showed no significant difference in the risk for dementia compared with those diagnosed between ages of 18 and 30 years.IN PRACTICE"[The study] findings highlight the need for a life-course approach to brain health in type 1 diabetes. As survival improves and more individuals live into older ages with long-standing disease, dementia prevention and early cognitive monitoring may become increasingly important components of care," the authors of the study wrote.SOURCEThe study was led by Milena Jancev, University Medical Center Utrecht, Utrecht, Netherlands. It was published online on July 19, 2026, in Diabetes, Obesity and Metabolism.LIMITATIONSDetailed data on lifestyle factors and glycaemic variability were unavailable. Dementia was identified from hospital and specialist outpatient records, and diagnostic codes might have limited ability to distinguish dementia subtypes. Finally, the study population consisted predominantly of individuals born in Sweden, potentially limiting generalisability to other geographic regions or ethnic groups.DISCLOSURESOne author received support from the Dutch Diabetes Research Foundation and the European Foundation for the Study of Diabetes. Several authors reported receiving honoraria for speaking, consulting fees, or research grants or having other relationships with multiple companies.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.