4.5.2.0 Basal Insulin
Basal insulin alone is the most convenient initial insulin regimen and can be added to metformin and other oral agents. Starting doses can be estimated based on body weight (e.g., 10 units a day or 0.1–0.2 units/kg/day) and the degree of hyperglycemia, with individualized titration over days to weeks as needed. The principal action of basal insulin is to restrain hepatic glucose production, with a goal of maintaining euglycemia overnight and between meals (59,60). Control of fasting glucose can be achieved with human NPH insulin or with the use of a long-acting insulin analog. In clinical trials, long-acting basal analogs (U-100 glargine or detemir) have been demonstrated to reduce the risk of symptomatic and nocturnal hypoglycemia compared with NPH insulin (61-66), although these advantages are generally modest and may not persist (67). Longer-acting basal analogs (U-300 glargine or degludec) may convey a lower hypoglycemia risk compared with U-100 glargine when used in combination with oral agents (68-74). Despite evidence for reduced hypoglycemia with newer, longer-acting basal insulin analogs in clinical trial settings, in practice they may not affect the development of hypoglycemia compared with NPH insulin (75).
The cost of insulin has been rising steadily, and at a pace several fold that of other medical expenditures, over the past decade (76). This expense contributes significant burden to the patient as insulin has become a growing “out-of-pocket” cost for people with diabetes, and direct patient costs contribute to treatment nonadherence (76). Therefore, consideration of cost is an important component of effective management. For many patients with type 2 diabetes (e.g., individuals with relaxed A1C goals, low rates of hypoglycemia, and prominent insulin resistance, as well as those with cost concerns), human insulin (NPH and Regular) may be the appropriate choice of therapy, and clinicians should be familiar with its use (77). Table 9.3 provides AWP (52) and NADAC (53) information (cost per 1,000 units) for currently available insulin and insulin combination products in the U.S. As stated for Table 9.2, AWP and NADAC prices listed do not account for discounts, rebates, or other price adjustments that may affect the actual cost to the patient. For example, human regular insulin, NPH, and 70/30 NPH/Regular products can be purchased for considerably less than the AWP and NADAC prices listed in Table 9.3 at select pharmacies.