Optimizing insulin injection technique and its effect on blood glucose control.

Purpose: The purpose of the study is to assess whether proper Injection Technique (IT) is associated with improved glucose control over a three month period.

Methods: Patients ( = 346) with diabetes from 18 ambulatory centers throughout northern Italy who had been injecting insulin ≥ four years answered a questionnaire about their IT. The nurse then examined the patient's injection sites for the presence of lipohypertrophy (LH), followed by an individualized training session in which sub-optimal IT practices highlighted in the questionnaire were addressed. All patients were taught to rotate sites correctly to avoid LH and were begun on 4 mm pen needles to avoid intramuscular (IM) injections. They were instructed not to reuse needles.

Results: Nearly 49% of patients were found to have LH at study entry. After three months, patients had mean reductions in HbA1c of 0.58% (0.50%-0.66%, 95% CI), in fasting blood glucose of 14 mg/dL (10.2-17.8 mg/dL, 95% CI) and in total daily insulin dose of 2.0 IU (1.4-2.5 IU, 95% CI) all with  < 0.05. Follow-up questionnaires showed significant numbers of patients recognized the importance of IT and were performing their injections more correctly. The majority found the 4 mm needle convenient and comfortable.

Conclusions: Targeted individualized training in IT, including the switch to a 4 mm needle, is associated with improved glucose control, greater satisfaction with therapy, better and simpler injection practices and possibly lower consumption of insulin after only a three month period.