Prevalence, Pathophysiology, and Factors Influencing Renal Outcomes in Patients with Type 1 Diabetes: A Systematic Review

Background: Diabetic kidney disease, which affects up to 40% of those with type 1 diabetes mellitus, significantly increases morbidity and mortality in individuals with type 1 diabetes mellitus. Even with improvements in diabetes treatment, diabetic kidney disease remains a major consequence of chronic hyperglycemia, which damages the kidneys irreversibly. Recent studies emphasize non-albuminuric eGFR decline and acute kidney injury, particularly in children with diabetic ketoacidosis. Ethnic differences significantly complicate the progression of diabetic kidney disease. Objective: The aim is to review recent studies on renal outcomes in type 1 diabetes, with a focus on the incidence of eGFR trajectories, albuminuria evolution, prevalence of CKD, risk factors associated with CKD progression, and the impact of early therapies. Methods: A systematic review that complied with PRISMA 2020 was conducted. Eligible studies were observational studies published in English during the preceding five years that included type 1 diabetes mellitus patients with a diagnosis based on WHO criteria. After screening, ten high-quality studies were selected from the examined databases, including Google Scholar, PMC, and PubMed. The risk of bias was assessed using the NHLBI instrument. Results: Of the 91,296 patients with type 1 diabetes included in the review, 52.64% were male and 47.36% were female. The incidence of albuminuria ranged from 9.8% to 78.9%, and up to 14% of patients had a sharp drop in eGFR. Although it exists, the incidence of end-stage renal disease was comparatively low. Both modifiable risk variables (poor glycemic management, hypertension, dyslipidemia) and non-modifiable ones (diabetic duration, age at onset, and ethnicity) were consistently associated with the advancement of diabetic kidney disease. Conclusion: Diabetic kidney disease is still a serious side effect of type 1 diabetes that calls for better screening and individualised treatment plans. Future studies should improve early intervention strategies, validate predictive biomarkers, and investigate non-albuminuric chronic kidney disease causes.