Ten years trajectories of estimated glomerular filtration rate (eGFR) in a multiethnic cohort of people with type 1 diabetes and preserved renal function.

Objectives: We aim to evaluate estimated glomerular filtration rate (eGFR) patterns of progression in a multiethnic cohort of people with type I diabetes mellitus and with baseline eGFR ≥45 mL/min/1.73 m.

Design: Observational cohort.

Setting: People with a clinical diagnosis of type 1 diabetes, attending two university hospital-based outpatient diabetes clinics, in South London between 2004 and 2018.

Participants: We studied 1495 participants (52% females, 81% white, 12% African-Caribbean and 7% others).

Primary And Secondary Outcome Measures: Clinical measures including weight and height, systolic blood pressure, diastolic blood pressure and laboratory results (such as serum creatinine, urine albumin to creatinine ratio (ACR), HbA1c were collected from electronic health records (EHRs) and eGFR was estimated by the Chronic Kidney Disease-Epidemiology Collaboration. Ethnicity was self-reported.

Results: Five predominantly linear patterns/groups of eGFR trajectories were identified. Group I (8.5%) had a fast eGFR decline (>3 mL/min/1.73 m year). Group II (23%) stable eGFR, group III (29.8%), groups IV (26.3%) and V (12.4%) have preserved eGFR with no significant fall. Group I had the highest proportion (27.6%) of African-Caribbeans. Significant differences between group I and the other groups were observed in age, gender, HbA1C, systolic and diastolic blood pressure, body mass index, cholesterol and urine ACR, p<0.05 for all. At 10 years of follow-up, 33% of group I had eGFR <30 and 16.5%<15 (mL/min/1.73 m).

Conclusions: Distinct trajectories of eGFR were observed in people with type 1 diabetes. The group with the highest risk of eGFR decline had a greater proportion of African-Caribbeans compared with others and has higher prevalence of traditional modifiable risk factors for kidney disease.