Barriers to effective insulin treatment: the persistence of poor glycemic control in type 2 diabetes

Background: Contrary to longstanding recommendations on type 2 diabetes (T2D) management, the de facto standard of care in Canada includes lag times of many years prior to introducing effective glycemic control. Even patients transitioned to insulin may continue to experience poor glycemic control, with attendant diabetic complications, suggesting poor adherence or inadequate dose titration. Objective: To identify barriers to timely and effective use of insulin in T2D. Methods: PubMed searches were conducted to find research articles on insulin initiation, adherence and intensification. Also, because recent data on the consequences of intensive glycemic control may be taken as justification for relaxing glycemic targets, a secondary search on this literature was conducted, including the UKPDS and ACCORD trials, plus post hoc and meta-analyses of these data. No formal evaluation of level of evidence was conducted while researching this narrative literature review. Findings: Timely, effective glycemic control remains an important clinical goal but is complicated by patient, physician and treatment factors. Patient barriers to accepting insulin initiation include fear of hypoglycemia, injections and weight gain, and reluctance to accommodate the inflexible timing of scheduled insulin doses. Adherence issues, including dose omission, are common and are associated with some of the same factors. Fear of hypoglycemia also underlies many physicians' reluctance to prescribe insulin. Caregivers' failure to provide training or answer questions about insulin's risks and benefits was also associated with low patient adherence. Poor communication may also be at fault when patients on insulin fail to titrate or intensify their treatment adequately. Conversely, glycemic control can be significantly improved by facilitating ongoing communication between patients and caregivers. Discussion: Although innovations in injectable therapy for T2D may help address the current pattern of poor glycemic control, improved communication between patients and caregivers is also a powerful approach and can be implemented with existing therapies.