Introduction. The control of diabetes mellitus (DM) has been improved since the insulin pens were introduced into the diabetes treatment. In pen insulin injection site the new cutaneous complication — lipohypertrophy (LHT) was observed.

Objectives. The assessment of the occurrences and risk factors of LHT in insulin receive patients. Patients and methods. 130 patients of the Regional Outpatient Diabetes Clinic in Zabrze were included to the study. The demographic, clinical characteristic, insulin therapy technique and knowledge about LHT were noticed in. The inclusion criteria: type 1 and 2 DM, > 2 years insulin therapy, insulin pen usage. LHT was defined as subcutaneous lump in ≥ 1 place in physical examination. Patients were divided into 2 groups according to diameter and thickness of LHT.

Results. LHT was observed in 78 (60%) of patients, but 48 (61.5%) patients developed LHT in 1 site, 30 (38.5%) patients developed LHT in > 1 site. 78 (60%) patients could defined LHT, but only 47 (60%) in LHT group. Patients with LHT longer suffer from DM, longer receive insulin and longer use the same needle. They had higher fasting and postprandial glycaemia, higher insulin requirement and more often complain about hypoglycemia. In the multivariate analysis the independent factors for presence of LHT were: needle reuse > 1 day, not changing sites of injection and human insulin usage.

Conclusions. LHT is a common cutaneous complication of insulin pen usage. Risk factors obtained in this study are modifiable and they should be taken into account in daily clinical practice.