(a) How to estimate the initial dosage: When starting insulin therapy, all diabetic patients should use short-acting insulin. Moreover, the initial dosage must be estimated according to the following methods on the basis of relatively stable diet and exercise, and then adjusted according to the results of disease monitoring. 1. Estimation according to fasting blood sugar: Daily insulin dosage (μ) = [fasting blood sugar (mg/dl) – 100] x 10 x body weight (kg) x 0.6 ÷ 1000 ÷ 2 100 is the normal value of blood sugar; x 10 is the amount of higher than normal blood sugar per liter of body fluid; x 0.6 is the amount of body fluid of the whole body is 60%; ÷ 1000 is the conversion of blood sugar mg to grams; ÷ 2 is 2 grams of blood sugar using 1 μ insulin. To avoid hypoglycemia, the actual use of its 1/2 – 1/3 amount. 2.Estimated by 24-hour urine glucose: Those with mild disease, no diabetic nephropathy and normal renal glucose threshold are given 1μ insulin for every 2 grams of urine glucose. 3.According to body weight: 0.5–0.8μ/kg for high blood glucose and severe disease; 0.4–0.5μ/kg for mild disease; no more than 1.0μ/kg for severe disease and stress. 4.Estimated by 4 times urine sugar: Without diabetic nephropathy and with a normal renal sugar threshold, estimate the amount of urine sugar qualitatively “+” before each meal. Generally a “+” requires 4μ insulin. 5. Comprehensive estimation: There are many factors affecting insulin action in the body and individual differences, so the above calculation may not meet the actual situation. (B) How to allocate insulin dosage According to the above estimation, the dosage of insulin should be allocated as the dosage before breakfast > before dinner > before lunch, which should be injected 15 – 30 minutes before three meals daily. Since the body secretes more hormones antagonizing insulin before breakfast, the insulin dosage should be larger; while the peak time of short-acting insulin is generally 2–4 hours, so the dosage before lunch is the smallest; most patients do not use insulin before bedtime, and use it again until the next morning, so the dosage before dinner is larger than before lunch. If it is still used once before bedtime, the dosage should be reduced before dinner and even less before bedtime to prevent hypoglycemia at night. (C) How to adjust insulin dosage After the initial estimated dosage is observed for 2 – 3 days, the dosage will be further adjusted according to the condition, blood sugar and urine sugar. 1. Qualitative adjustment according to 4 times of urine glucose: Only for patients who have no condition to measure blood glucose and have normal renal glucose threshold. Adjustment according to 4 times urine sugar qualitative in the first 3-4 days: insulin dosage before breakfast is based on urine sugar before lunch, insulin dosage before lunch is based on urine sugar before dinner, insulin dosage before dinner is based on urine before bedtime or the next morning (including morning urine of the same day). 2. Adjustment according to blood glucose: diabetic patients, especially type I diabetes and patients with abnormal renal glucose threshold, should adjust insulin dosage according to the blood glucose value before three meals and bedtime, as detailed in the following table: Blood glucose value (mmol/l) mg/dl Pre-meal insulin increment Other treatment <2.8 <50 Reduction 2--3μ Immediate meal 2.8--3.9 50--70 Reduction 1--2μ 3.9-- -7.2 70--130 -7.2 70--130 Original dose 7.2--8.3 130--150 Add 1 μ 8.3--11.1 150--200 Add 2 μ 11.1--13.9 200--250 Add 3 μ 13.9--16.6 250--300 Add 4--6 μ 16.6--19.4 300--350 Add 8--10 μ Increase in pre-meal activity Minus 1--2 μ or extra meal Decrease in activity before meal Plus 1--2 μ