Impact of Early Subcutaneous Basal Insulin With Intravenous Insulin Infusion for Diabetic Ketoacidosis and Glycaemic Outcomes: A Systematic Review and Meta‐Analysis

BACKGROUND: Diabetic ketoacidosis (DKA) is a life-threatening metabolic emergency requiring prompt insulin therapy. Although intravenous (IV) insulin infusion remains the standard treatment, early initiation of subcutaneous (SC) basal insulin during IV therapy may improve outcomes. We evaluated the efficacy and safety of early basal insulin administration in adults with DKA. METHODS: A systematic review and meta-analysis following PRISMA 2020 guidelines searched PubMed, Embase and Cochrane Library from inception to February 2026 for randomised controlled trials (RCTs) comparing early SC basal insulin plus IV insulin versus IV insulin alone in adults with DKA. Primary outcomes were time to DKA resolution and hospital length of stay. Secondary outcomes included total fluid requirement, hypoglycaemia, rebound hyperglycaemia, recurrent DKA, electrolyte disturbances and mortality. Meta-regression explored sources of heterogeneity. Total fluid requirements decreased by approximately 400 mL, although clinical significance was modest. No significant differences were observed in hospital length of stay, rebound hyperglycaemia, recurrent DKA, hypoglycaemia, hypokalaemia, or mortality. Meta-regression showed no significant effect modification by age, BMI, sample size, or male proportion. CONCLUSIONS: Early SC basal insulin combined with IV insulin significantly shortens DKA resolution time and modestly reduces fluid requirements without increasing adverse events. While no significant effects were observed on hospital stay or recurrence outcomes, these findings support the safety and potential clinical benefit of early basal insulin use in DKA management. Larger multicentre trials are warranted.