Fasting blood glucose is 16mmol/L. Whether it can be lowered without insulin depends on the type of diabetes of the patient. 1. Playing insulin: For patients with type 1 diabetes, the pancreatic islet cells in their bodies are severely damaged and cannot produce insulin, so they need to supplement insulin to lower their blood sugar. Fasting blood glucose 16mmol / L represents the blood sugar continues to rise for a long time and the patient’s absolute lack of insulin, without the use of insulin will not be able to improve the root cause of the disease. 2. No insulin: For patients with type 2 diabetes mellitus, the pancreatic islet cells in the body can produce some insulin, which belongs to the relative lack of insulin, and glucose-lowering drugs such as metformin, gliclazide, etc. can be used to reduce blood glucose. However, subcutaneous insulin injection is also needed when oral medications are not well controlled. It should be noted that fasting blood glucose 16mmol / L without timely glucose lowering treatment, easy to induce diabetic ketoacidosis. It is recommended that patients go to regular hospitals in time, under the guidance of endocrinologists to standardize the treatment, so as not to delay the condition.