Background: This 12-month study assesses the effects of basal insulin analog (glargine) treatment duration on glycemic parameters and lipid profiles in patients with poorly controlled type 2 diabetes. Methods: Patients with type 2 diabetes mellitus (T2DM) aged 30-70 years who had an HbA1c ≥ 6.5% despite taking oral hypoglycemic agents were included in this observational study. Insulin glargine was started, and baseline and interval lipid profiles, as well as glycemic parameters such as fasting blood glucose (FBG), postprandial blood sugar (PPBS), and HbA1c, were measured. For the first three months, follow-ups were done monthly; after that, they were done every three months.