Background and aims:

• In the Netherlands most patients with diabetes mellitus that are treated with insulin, use an insulin pen for insulin administration. The injection technique can influence the absorption rate of insulin.
• The aim of this study is to compare the effect of insulin injections using a 5 mm insulin needle with insulin injections using a longer needle, on HbA1c, bloodglucose levels, hypoglycaemic events, bleeding, bruising, insulin leakage and pain perception.
• Study Hypothesis: 'Insulin injected with needles of 5 mm can be given without a skinfold. The length of the needle will not influence HbA1c levels and bloodglucose levels'.

• In this randomised, clinical trial with cross-over design, 52 patients with Diabetes type 1 and 2 using a 8 or 12 mm needle, are randomised into two groups.
• Group I starts using 5 mm needles for insulin administration, after 13 weeks group I returns to their previously used 8 or 12 mm needle
• Group II continues using their own 8 or 12 mm needle, after 13 weeks group II starts using 5 mm needles for insulin administration.
• During each visit the HbA1c level is measured and a copy is made of the logbook of the patient with the blood glucose measurements.
• Insulin doses and number of experienced hypoglycaemic events are registered at each visit.
• The opinion and experiences of the patients regarding the different needles are obtained by using a questionnaire.
• Within-group analyses are computed, using the Wilcoxon signed Ranks Test. Between-group analyses are computed using the Mann-Whitney U test.

Inclusion Criteria:

• males and females diagnosed with diabetes Type 1 or 2
• using insulin for at least one year
• using an insulin pen and a needle of 8-mm or longer
• 18 years or older
• capable of reading the written information
• prepared to, and capable of signing an informed consent

Exclusion Criteria:

patients that

• change their own insulin dosage and don't keep an administration of these changes
• had an HbA1c that varied more than 15 % in the past year
• use a needle of 5 or 6-mm
• have hypoglycaemia unawareness
• are pregnant or wanted to become pregnant
• have a BMI < 18
• have a skinfold thickness of 10 mm or less at the injection sites (abdomen and thigh)
• had hemoglobinopathies which could limit the ability of haemoglobin to be glycated
• had skin problems like lipodystrofie