Prevalence and risk factors of lipohypertrophy in insulin-injecting patients with diabetes.

ABSTRACT

INTRODUCTION: Our objective was to assess the frequency of lipohypertrophy (LH) and its relationship to site rotation, needle reuse, glucose variability, hypoglycaemia and use of insulin. METHODS: The study included 430 outpatients injecting insulin who filled out a wide-ranging questionnaire regarding their injection technique. Then, a diabetes nurse examined their injection sites for the presence of LH. RESULTS: Nearly two-thirds (64.4%) of patients had LH. There was a strong relationship between the presence of LH and non-rotation of sites, with correct rotation technique having the strongest protective value against LH. Of the patients who correctly rotated sites, only 5% had LH while, of the patients with LH, 98% either did not rotate sites or rotated incorrectly. Also, 39.1% of patients with LH had unexplained hypoglycaemia and 49.1% had glycaemic variability compared with only 5.9% and 6.5%, respectively, in those without LH. LH was also related to needle reuse, with risk increasing significantly when needles were used > 5 times. Total daily insulin doses for patients with and without LH averaged 56 and 41 IU/day, respectively. This 15 IU difference equates to a total annual cost to the Spanish healthcare system of > €122 million. This was also the first study in which the use of ultrasound allowed the description of an "echo signature" for LH. CONCLUSION: Correct injection site rotation appears to be the critical factor in preventing LH, which is associated with reduced glucose variability, hypoglycaemia, insulin consumption and costs.