All studies were included if they met the following eligibility criteria, which can be described as PICOS: 1) P (Patients): Diabetes Ketoacidosis patients (DKA); 2) I (Intervention): Intravenous insulin; 3) C (Control): none; 4) O (Outcome): effect of Intravenous Insulin in DKA patients; 5) S (Studies): Cohorts and Randomized Controlled Trials published in English. The gene discussed is INS; the disease is diabetic ketoacidosis.