Comparison of acute daytime and nocturnal insulinization on diurnal glucose homeostasis in NIDDM

Overnight CSII as supplement to oral antidiabetic drugs in type 2 diabetes

AIM

To evaluate the potential advantages of a constant overnight subcutaneous delivery of insulin in type 2 diabetic patients who fail to achieve glycaemic control on oral antidiabetics.

METHODS

Ten type 2 diabetic patients treated with oral antidiabetic drugs without gaining sufficient glycaemic control were included in this three-period study. All patients received continuous subcutaneous insulin infusion (CSII) with a short-acting insulin analogue, 2 IU/h, for 8 h during three consecutive nights (period A). Based upon the results from period A, two additional dose regimens of three nights (period B and C) were studied in random order. Serum insulin aspart, human insulin and plasma glucose (PG) profiles were recorded.

RESULTS

In period A, fasting plasma glucose (FPG) was reduced from a mean +/- s.d. (mmol/l) value of 11.6 +/- 2.9 to 5.5 +/- 1.6 (p < 0.0001) during the first night. No additional lowering of FPG was seen the two succeeding nights. FPG narrowed as the range before the infusion was 7.3-15.2 mmol/l compared with 3.6-6.1 mmol/l on the last morning after infusion. The variability in PG profile during the first and the last night of CSII was small and not significantly different. The rising insulin aspart was mirrored by a decrease in human insulin. In period B and C, similar tendencies as for period A were seen. In period A, two patients each experienced one mild hypoglycaemic episode.

CONCLUSIONS

CSII with an insulin analogue overnight effectively reduced FPG without occurrence of major hypoglycaemia in type 2 diabetic patients who fail to achieve glycaemic control on oral antidiabetic treatment.

Overnight versus 24 hours of continuous subcutaneous insulin infusion as supplement to oral antidiabetic drugs in type 2 diabetes

BACKGROUND

Basal continuous subcutaneous insulin infusion (CSII) therapy at a fixed rate may effectively improve glycemic control in patients with type 2 diabetes when oral antidiabetic treatment fails. Regimens of simple constant subcutaneous delivery of insulin may provide theoretical advantages in type 2 diabetes.

METHODS

Ten subjects with type 2 diabetes who obtained insufficient glycemic control on oral antidiabetic drugs were included. Following an initial control day, two periods of 3 days with CSII of a rapid-acting insulin analogue, 1.5 IU/h (dose obtained from a preceding study), for 8 hours overnight and for 24 hours, respectively, were carried out in random order. Profiles of serum insulin aspart, serum endogenous insulin, and plasma glucose were recorded.

RESULTS

Compared to the control day, an 8-hour overnight insulin infusion during a 3-day period improved fasting plasma glucose (FPG) (mean differences +/- SEM; Delta59.0 +/- 10.1 mg/dl; p < 0.01) and 2-hour postprandial plasma glucose (PPPG) (Delta57.8 +/- 10.6 mg/dl; p < 0.01) after breakfast. Compared to an 8-hour overnight infusion, a 24-hour infusion further improved all three PPPG values after breakfast, lunch, and dinner (Delta28.8 +/- 8.1 mg/dl, Delta30.6 +/- 8.1 mg/dl, and Delta35.1 +/- 7.9 mg/dl; p < 0.01). During insulin infusion, only one hypoglycemic episode with PG <55.8 mg/dl and mild symptoms was recorded.

CONCLUSION

Continuous subcutaneous insulin infusion with a rapid-acting insulin analogue at a fixed rate of 1.5 IU/h, either overnight or for 24 hours, improved glycemic control without safety concerns in patients with type 2 diabetes who had secondary failure to oral antidiabetic drugs. The effect on FPG was similar for both treatments, whereas the effect on PPPG was superior when insulin was infused during the entire 24 hours.