TOPLINE

In a cohort of patients with childhood-onset type 1 diabetes (T1D) followed up for more than 30 years, more than 80% developed diabetic retinopathy and nearly half developed albuminuria, with the two complications following distinct temporal patterns. The duration of diabetes was the dominant predictor of retinopathy, and chronological age was more strongly associated with albuminuria.

METHODOLOGY

• Researchers in Sweden conducted a retrospective cohort study using linked national registers to assess the impact of perinatal factors, age at diabetes onset, and glycaemic control on the development of microvascular complications in patients with childhood‑onset T1D.
• They included 94 patients (47 boys) with T1D who were diagnosed between ages of 0 and 14 years from 1981 to 1992; registry follow‑up data were available for 90 patients.
• Exposures included early glycaemic control (mean A1c levels during years 0-5 and 5-10 after diagnosis), perinatal measures (birth weight and gestational age), age at onset (< 11 years [prepubertal] vs ≥ 11 years [pubertal]), and diabetes duration. A decline in kidney function was measured as the annual change in the estimated glomerular filtration rate.
• Outcomes were diabetic retinopathy (any retinopathy and proliferative diabetic retinopathy) and diabetic nephropathy — defined as the presence of albuminuria, ie, microalbuminuria (urinary albumin‑to‑creatinine ratio, 3-30 mg/mmol) or macroalbuminuria (urinary albumin‑to‑creatinine ratio > 30 mg/mmol).
• The median follow‑up duration was 33 years.

TAKEAWAY

• Over follow‑up, 85% of patients (n = 80) developed diabetic retinopathy, of whom 19% (n = 18) progressed to proliferative diabetic retinopathy. Albuminuria occurred in 45% (n = 42), and 12% (n = 11) developed macroalbuminuria.
• The duration of diabetes was a significant predictor of diabetic retinopathy and proliferative diabetic retinopathy (P < .001 and P = .007, respectively), and chronological age predicted albuminuria (P < .001).
• Higher mean A1c levels were associated with a greater risk for microvascular complications: A1c was linked to a higher risk of developing albuminuria (hazard ratio [HR], 1.02) and diabetic retinopathy (HR, 1.02) and progression to proliferative diabetic retinopathy (HR, 1.05; P < .05 for all).
• Female sex was independently associated with about a threefold higher risk for proliferative diabetic retinopathy (HR, 3.28; P = .029); no sex-based differences were observed for albuminuria or a decline in kidney function. Prior retinopathy doubled the risk for subsequent albuminuria (HR, 2.07), and prior albuminuria increased the risk for later diabetic retinopathy (HR, 1.74; P < .05 for both).

IN PRACTICE

"Despite contemporary care, substantial long-term microvascular risk persists, underscoring the need for lifelong intensive management of glycemia and other known modifiable risk factors. Our results indicate that treatment strategies potentially could be tailored to individual patient characteristics, particularly sex and age at diabetes onset, to optimize long-term microvascular outcomes," the authors of the study wrote.

SOURCE

The study was led by Edvin Hornbrinck, Uppsala University, Uppsala, Sweden. It was published online on August 03, 2026, in the Journal of Diabetes and Its Complications.

LIMITATIONS

The study had a relatively small sample size. Because the study was observational, it could not prove cause and effect between exposures and outcomes. Data on important risk factors were incomplete. Residual confounding could not be excluded, and the results may not have applied to broader or more ethnically diverse populations.

DISCLOSURES

This study was supported by multiple sources, including Uppsala University Hospital ALF grants, the CUWX Foundation, the Swedish Kidney Foundation, and the Swedish National Strategic Research Initiative (Excellence of Diabetes Research in Sweden). The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.