Unexplained Hypoglycaemia and Large Glycaemic Variability: Skin Lipohypertrophy as a Predictive Sign

Abstract

Rationale and Aims of the Study: Strong efforts to keep DM under control cause frequent hypoglycaemic events (Hypos) with relevant clinical, social and economic consequences. Moreover, long-lasting rebound hyperglycaemia and patients’ poor compliance or exaggerated corrective behaviors cause high glucose variability (GV). Several Hypos are unexplained and might be due to inappropriate insulin administration. In fact, the reported association between lipohypertrophy (LH) and Hypos might depend on poor education. The purpose of this study was to assess whether LH rate might predict Hypos and GV in insulin treated patients. Methods: This was an observational, retrospective, multicentre study involving 387 DM patients referred to specialized settings for Hypos and/or GV carefully performing self monitoring blood glucose (SMBG) and filling in a structured Hypo questionnaire. Results: Twenty-eight percentages had at least one severe and 72% one non-severe episode (average: 3.3 Hypos/week). T1DM, long standing disease and high insulin doses were significantly associated with LH and impressive odds ratio (ORs) were reached by unexplained Hypos/GV (UHGV; p<0.001). The presence of LH predicted about 77.1% of UHGV, which displayed a 4.38 times higher risk when LH was combined with low socio-economic level, loneliness, poor metabolic control, disease complications and inappropriate injection technique (longer/larger and/or reused needles, missed injection site rotation). In multivariate analysis, the latter was still strongly associated with UHGV. Conclusions: In the presence of UHGV, injection sites should be systematically explored in search of LH areas. Furthermore, appropriate educational activities should be implemented to improve patients’ behavior, including periodical verification of their injection habits.