Basal Bolus Insulin

Synthetic insulin preparations designed to achieve either a prolonged steady effect or an acute action, mimicking physiologic insulin secretion, have allowed patients to develop personal and flexible injection schedules. This is known as the basal bolus regimen and is indicated in the treatment of type 1 diabetes. It provides rapidly acting or bolus insulin to cover carbohydrate ingestion in meals and snacks, and basal insulins are usually given at bedtime to achieve a steady state at breakfast, with an ideal FSG target of 120 mg/dL or less. To a large extent, control of the important fasting blood (serum) glucose will depend on attaining an ideal bedtime value of 120 to 140 mg/dL, which is based on rapidly active insulin given at dinner. The authors' experience indicates that basal insulin is most predictable in patients who demonstrate overnight glucose production and have controlled glucose values at bedtime. However, an occasional patient will experience hypoglycemia at 4 am, and therefore nighttime monitoring is necessary when increasing dosage. Hypoglycemia can also be seen before lunch with overnight basal insulinization.

The starting dosage of insulin as previously discussed is often a conservative approximation. In general, a type 1 diabetic patient requires approximately 0.5 U/kg, half of which is given as basal insulin and the other half in divided boluses before a meal. Experience and clinical judgment may suggest a lower starting dosage if the diabetes is mild, especially with children and elderly patients, who may receive a starting dose of 0.1 or 0.2 U/kg/day. However, hyperglycemia may have resulted in secondary insulin resistance caused by cellular dysfunction, and higher dosages may quickly become necessary. If the patient is not at risk of ketoacidosis, cautiously increasing the dosage from 0.5 U/kg/day is prudent (usually by 10% per day).

The effectiveness of a specific dose of most insulin preparations depends on local factors at the injection site related to capillary perfusion. Insulin uptake is enhanced when hydration is adequate and a patient is vasodilated after exercise or a warm shower (or has a fever). The effectiveness of short-acting preparation is also related to the carbohydrate load about to be consumed. Preprandial hyperglycemia may adversely affect the action of insulin and should be considered as well in deciding proper insulin dosage.

Patients using basal bolus regimens may be taught how to adjust dosage based on the preprandial glucose value, carbohydrate content of anticipated meal, and physical activ ity. If glucose monitoring indicates prebreakfast dosage is achieving postprandial glucose of 160 mg/dL or less, and subsequent premeal values are 120 mg/dL or less, the short-acting insulin dosage and the long-acting steady-state dosages are in perfect harmony with the patient's diet and lifestyle.

A long-acting insulin analog (e.g., glargine, detemir) can be used to provide the basal insulin, but in a dynamic situation, intermediate-duration insulin preparations such as N (formerly known as NPH) provides more short-term flexibility and "kick" in the first 12 to 24 hours (see Table 34-4). The short-acting insulin preparations available include R (formerly known as Regular), lispro, aspart, and glulisine. The latter three are synthetic insulins and are ideal for limiting postprandial glucose elevations. R insulin does not have a sharply defined absorption and may remain active for 4 to 6 hours. A patient with slow GI absorption may find the slower onset of action of insulin R more efficacious. However, R can have a delayed effect, putting a tightly controlled patient at hypoglycemic risk, especially if N insulins are also used, with their potential for peak action.

As with 70/30 human N/R insulin, lispro and aspart have been formulated as mixtures of 75/25 and 70/30, respectively, with acute and intermediate duration of action. These might be used to introduce insulin in a subacute presentation of type 1 diabetes to avoid deterioration to ketoacidosis, but these are not as safe and lack the fine-tuning potential of basal bolus regimens. Insulin combinations may promote hypoglycemia if insulin needs to be administered at intervals of less than 12 hours. The treatment of type 1 patients during illness or daily living requires insulins that minimize the risk of hypoglycemia and are therefore safe enough for multiple daily injections.

When glucose values of less than 200 mg/dL are achieved at bedtime, the patient is ready to begin long-acting basal insulin analogs to preclude early-morning hypoglycemia, more often seen with intermediate insulin. Basal insulin analogs are given either at a dosage of 80% of the total daily N requirement or at the calculated basal dosage of 0.25 U/ kg/day. Clinical judgment and instinct may modify this recommendation because this dosage should be further titrated based on the agreed fasting glucose target level. Usually, daily bedtime insulin increments of 10% or 2 to 4 U are safe.

Estimating the correct insulin schedule provides goals for the patient. Unless the family physician is proficient and available, nutritionists who are certified diabetic educators should instruct patients on carbohydrate content of meals and insulin dosing. Motivated patients given proper diabetic education will eventually determine their ideal, safe insulin/ carbohydrate ratios and corrections for other factors such as activity. Only patients capable of this self-management can successfully use the insulin pump (discussed later).

Supplements For Diabetics

Supplements For Diabetics

All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.

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