Why Do So Many People with Type 2 Diabetes Who Take Insulin Have Lipohypertrophy? Fate or Educational Deficiencies?

Abstract

Introduction: Cutaneous lipohypertrophy (LH) is a thickened, "rubbery" lesion in the subcutaneous tissue following multiple injections performed at the same site, i.e., an incorrect injection technique. It is widespread, averaging 47% of insulin patients worldwide, and has severe direct and indirect consequences. Direct consequences consist mainly of poor metabolic control and frequent hypoglycemic events (HYPOs), and indirect ones of markedly increased healthcare costs related to hospital access due to acute events and long-term disease complications. This observation also holds for Italy, despite the National Health System organization expecting every patient with diabetes to undergo a series of visits by different care team members, each performing a specific treatment/education task. Indeed, the recent literature points to poor awareness of LH relevance and metabolic consequences among doctors from general and diabetic hospital wards, with educational deficiencies on correct injection practice in nurses too. The aim was to establish if, to what extent, and by whom they had received training on correct insulin injection techniques, and how many initially received notions had persisted over time.

Methods: We investigated the possible causes of such a failure from the point of view of 1160 insulin-requiring subjects with type 2 diabetes (T2DM), reporting for the first time to specialized diabetic structures through a validated questionnaire and, in the same patients, we searched for LH by inspection/palpation according to international guidelines, further confirmed by ultrasound scans. We then analyzed differences in education and injecting behavior between subjects classified as LH+ or LH- depending on the presence or absence of LH lesions.

Results: We documented significant educational gaps, with 50% of patients failing to refer to healthcare professionals and relying on their peers with diabetes, thought to be more experienced in 15% of the cases. Seventy-five percent of LH- patients received education from healthcare providers, while 90% of LH+ learned from another patient or could not remember how they knew, and 68% of LH+ versus 52% of LH- (p < 0.01) patients had failed to receive training on injection techniques by healthcare providers. All of this enabled the most disabling features of diabetes from the very beginning of the disease history.

Conclusions: This study documents, from the patients' point of view, that educational gaps are significant and that, even in initially trained subjects, education on correct injection techniques has a fleeting effect if not regularly recalled. Therefore, to rehabilitate LH+ patients as soon as possible and prevent LH- patients from inadvertently slipping into the other group, there is an urgent need to educate doctors and nurses repeatedly on the importance of correctly injecting insulin to improve patients' knowledge and skills.

Keywords: Education; Education durability; Injection technique; Lipohypertrophy; Rehabilitation; Type 2 diabetes.

Fig. 1

Frequency of LH in relation to the number of daily insulin injections (**p < 0.005; *p < 0.001)

Fig. 2

Mean HbA1c (%) values ± SD in subjects with (LH +) and without (LH−) lipohypertrophy, and significance of differences (**p < 0.01)

Fig. 3

Frequency of needle reuse (%)

Fig. 4

Frequency of severe (371) and symptomatic (135) total hypoglycemic episodes in LH+ (red columns) and LH− (blue columns) subjects. Nocturnal episodes were all severe

Fig. 5

Answers to the question “who taught you how to correctly inject insulin?”

Fig. 6

“Who taught you where within the body to inject insulin by rotating the injection sites?”