Psychological Insulin Resistance in Type 2 Diabetes Patients Regarding Oral Antidiabetes Treatment, Subcutaneous Insulin Injections, or Inhaled Insulin

Background: "Psychological insulin resistance'' (PIR) is an obstacle to insulin treatment in type 2 diabetes, and patients' expectations regarding alternative ways of insulin delivery are poorly understood. Subjects and Methods: PIR and beliefs regarding treatment alternatives were analyzed in patients with type 2 diabetes (n = 532; mean glycated hemoglobin, 68 +/- 12 mmol/mol [8.34 +/- 1.5%]) comparing oral antidiabetes treatment, subcutaneous insulin injections, or inhaled insulin. Questionnaires were used to assess barriers to insulin treatment (BIT), generic and diabetes-specific quality of life (Short Form 36 and Problem Areas in Diabetes, German version), diabetes knowledge, locus of control (Questionnaire for the Assessment of Diabetes-Specific Locus of Control, in German), coping styles (Freiburg Questionnaire of Illness Coping, 15-Items Short Form), self-esteem (Rosenberg Self-Esteem Scale, German version), and mental disorders (Patient Health Questionnaire, German version). Patients discussed treatment optimization options with a physician and were asked to make a choice about future diabetes therapy options in a two-step treatment choice scenario. Step 1 included oral antidiabetes drugs or subcutaneous insulin injection (SCI). Step 2 included an additional treatment alternative of inhaled insulin (INH). Subgroups were analyzed according to their treatment choice. Results: Most patients perceived their own diabetes-related behavior as active, problem-focused, internally controlled, and oriented toward their doctors' recommendations, although their diabetes knowledge was limited. In Step 1, rejection of the recommended insulin was 82%, and in Step 2, it was 57%. Fear of hypoglycemia was the most important barrier to insulin treatment. Patients choosing INH (versus SCI) scored higher regarding fear of injection, expected hardship from insulin therapy, and BIT-Sumscore. Conclusions: The acceptance of insulin is very low in type 2 diabetes patients. The option to inhale insulin increases the acceptability for some but not the majority of patients.