Determination of Insulin Requirements: Excessive Insulin Dosages Common in Type 1 Diabetes Mellitus

Factors determining insulin requirements in women with type 1 diabetes mellitus during pregnancy: a review

Most women with type 1 diabetes mellitus (T1DM) have increased insulin requirements during pregnancy. However, a minority of women have a fall in insulin requirements. When this occurs in late gestation, it often provokes concern regarding possible compromise of the feto-placental unit. In some centres, this is considered as an indication for delivery, including premature delivery. There are, however, many other factors that affect insulin requirements in pregnancy in women with type 1 diabetes mellitus and the decline in insulin requirements may represent a variant of normal pregnancy. If there is no underlying pathological process, expedited delivery in these women is not warranted and confers increased risks to the newborn. We will explore the factors affecting insulin requirements in gestation in this review. We will also discuss some novel concepts regarding beta-cell function in pregnancy.

Management of the hospitalized patient with type 1 diabetes mellitus

Patients with type 1 diabetes mellitus (T1DM) have minimal to absent pancreatic β-cell function and rely on the exogenous delivery of insulin to obtain adequate and life-sustaining glucose homeostasis. Maintaining glycemic control is challenging in hospitalized patients with T1DM, as insulin requirements are influenced by the presence of acute medical or surgical conditions, as well as altered nutritional intake. The risks of hyperglycemia, ketoacidosis, hypoglycemia, and glycemic variability are increased in hospitalized patients with T1DM. Diabetic ketoacidosis and severe hypoglycemia are the 2 most common emergency conditions that account for the majority of hospital admissions in patients with T1DM. The association between hyperglycemia and increased risk of complications and mortality in patients with type 2 diabetes (T2DM) is well established; however, the impact of glycemic control on clinical outcomes has not been determined in patients with T1DM who present without ketoacidosis. To decrease complications associated with insulin therapy, health care professionals must be well versed in the use of insulin because it is a common source of medication error. For non-critically ill, hospitalized patients, subcutaneous insulin given to cover basal and prandial needs instead of sliding scale is the preferred method of insulin dosing. Protocols are available for initiating and titrating insulin doses, as well as for transitioning from an insulin infusion to a subcutaneous regimen. In our review, we identify and discuss special considerations related to inpatient glycemic control of non-ketotic patients with T1DM. Additionally, point differences and similarities associated with the management of patients with T2DM are discussed.

Benefits of a bolus calculator in pre- and postprandial glycaemic control and meal flexibility of paediatric patients using continuous subcutaneous insulin infusion (CSII)

AIMS

To assess the efficacy in pre- and postprandial glycaemic control and the impact on treatment satisfaction of a bolus calculator (Bolus Wizard) incorporated into the insulin pump in Type 1 diabetic (T1D) paediatric patients using continuous subcutaneous insulin infusion (CSII) treatment at various stages of pubertal development.

METHODS

Thirty-six T1D patients on CSII treatment (19 males; mean age 13.9 +/- 3.5 years; range 4.9-17.8 years), were prospectively enrolled into this two-period crossover study. Eighteen patients were randomized to begin phase A using the Bolus Wizard, followed by phase B, using their current conventional insulin dosing method to determine pre-meal boluses. The remaining subjects were randomized to begin with phase B followed by phase A. Each study period lasted 2 weeks. A questionnaire assessing treatment satisfaction with the Bolus Wizard was compiled.

RESULTS

There was a significant reduction in blood glucose levels before and 2 h after meals and in the number of correction boluses during phase A with respect to phase B of the study. The lower frequency of hypoglycaemic events during phase A did not reach statistical significance. There were no differences between the two phases: insulin requirement, daily bolus rate (%) and meal bolus quantity.

CONCLUSIONS

When paediatric patients used CSII, the bolus insulin dose calculated using the Bolus Wizard was more effective in improving pre- and postprandial glycaemic control with fewer correction boluses, without differences in the prandial insulin requirements and without restriction in the carbohydrate content of meals. The use of the Bolus Wizard was easy and was associated with a high level of satisfaction in these patients.

Beneficial effects of continuous subcutaneous insulin infusion in older patients with long-standing type 1 diabetes

OBJECTIVE

To assess the effect of continuous subcutaneous insulin infusion (CSII) on glycemic control, hypoglycemia, and daily insulin requirements in five older patients with long-standing type 1 diabetes previously treated with multiple-dose insulin injections (MDII).

METHODS

We undertook a retrospective analysis of five older patients (three women and two men) with type 1 diabetes and a mean age of 66.4 years (range, 57 to 76). The mean duration of disease was 33 years (range, 18 to 49), and all patients had suboptimal glycemic control (glycosylated hemoglobin or HbA(1c) >8.0%), presence of microvascular complications, and unacceptably frequent hypoglycemia during MDII therapy. A diabetes care team monitored their clinical course after their treatment was changed to a CSII regimen. Data pertaining to HbA(1c), severe hypoglycemia, and insulin dose before and after conversion to CSII were compared with use of paired t tests.

RESULTS

After initiation of CSII therapy, the mean HbA(1c) value decreased from 9.16% to 7.6% (P<0.0025), the rate of severe hypoglycemia decreased from 3.2 episodes to 0.4 episode per year (P<0.02), and the mean total daily insulin dose was reduced from 44.9 IU to 32.4 IU (P<0.05) during a mean duration of 12.6 months of CSII therapy.

CONCLUSION

Insulin pump therapy can prove highly beneficial in older patients with type 1 diabetes by improving glycemic control, reducing hypoglycemic episodes and insulin dosage, and possibly increasing treatment satisfaction. These changes can potentially prevent morbidity and prove to be cost-effective. For implementation of pump conversion to be safe and successful, careful patient selection, proper education, and ongoing support through a comprehensive diabetes education and management program are imperative. Future reports of experience with CSII in elderly patients should help to elucidate its promising advantages in this patient population and provide guidelines for use.