IMPACT OF INJECTION SITES FOR SOLUBLE INSULIN ON GLYCEMIC CONTROL IN TYPE-1 (INSULIN-DEPENDENT) DIABETIC-PATIENTS TREATED WITH A MULTIPLE INSULIN INJECTION REGIMEN

The absorption rate of rapid acting (soluble) insulin is slow from the subcutaneous tissue of the thigh compared to intramuscular injection into the thigh and s. c. injection into the abdominal wall. The aim of the study was to evaluate the impact of soluble insulin injected either intramuscularly into the thigh (IMT), s. c. into the abdominal wall (SCA) or s.c. into the thigh (SCT) on glycaemic control in Type 1 (insulin-dependent) diabetic outpatients treated with the basal bolus insulin delivery regimen. Fifty-five, C-peptide negative Type 1 diabetic outpatients were included in a randomised 3-month intervention study. The insulin doses were adjusted frequently by blinded observers based on the patients' self-monitored blood glucose values and reported hypoglycaemic episodes. The serum fructosamine value was within normal limits in three patients in the IMT group, in six patients in the SCA group and in none of the patients in the SCT group following the intervention period (p < 0.01). However, the difference in mean serum fructosamine values did not reach statistical significance (IMT: 1.24 mmol/l (95 % confidence interval; 1.17 to 1.31), SCA: 1.25 mmol/l (1.18 to 1.32), SCT. 1.34 mmol/l (1.26 to 1.41), (p = 0.09)). Blood glucose excursions were larger in the SCT group than in the SCA and IMT group from post-lunch to pre-dinner measurements and from pre- to post-dinner measurements. A higher number of measured low nocturnal blood glucose values (less than 4 mmol/l) was observed in the SCT group (34 of 85) than in the IMT (14 of 64) and SCA (21 of 81) group (p < 0.05). Three patients in the IMT group, two in the SCA group, and seven in the SCT group experienced severe hypoglycaemic episodes (p = 0. 14). In conclusion s. c. injection of soluble insulin into the abdominal wall is preferable compared to s. c. injection into the thigh in the basal bolus insulin delivery regimen. Furthermore, soluble insulin injection s. c. into the thigh during daytime has important clinical implications for the development of nocturnal hypoglycaemia independently of the NPH insulin injection at bedtime.