Abstract

Objective: To compare and evaluate the impact of inhaled versus injected insulin on potential mediators of patient acceptance of insulin therapy while maintaining comparable HbA_1c levels.

Research Design and Methods: During a non-inferiority efficacy trial conducted in 40 centers in the United States, we surveyed treatment satisfaction, quality of life and adherence barriers at weeks -4, -1, 6, 12, 20 and 24 in adolescents aged 12-17 yrs and adults with type 1 diabetes who received premeal regular plus twice daily NPH insulin during a 4-week run-in, and then were randomized to premeal inhaled human insulin plus twice daily NPH (adults, N=102; adolescents, N=60) (INH) or remaining on run-in therapy (N=105 and 60) (SC).

Results: Overall treatment satisfaction (0--100) increased by 13.2±1.1 units for INH (baseline = 63.3±1.2) compared to 1.7±0.8 for SC (baseline = 64.1±1.2), P<0.0001. All 12 satisfaction subscales favored INH (all P<0.01) and effects did not vary by age or sex. Despite similar baseline-adjusted endpoint HbA_1c for INH (7.7±0.1%) and SC (7.9±0.1%), quality-of-life scales of mental health, symptoms, health status, cognitive functioning and adherence barriers during treatment were more favorable for INH (all P<0.05). Greater satisfaction was associated with fewer barriers to insulin adherence (rho = -0.78, P<0.0001) and a greater reduction in HbA_1c (rho = -0.18, P<0.001).

Conclusions: Treatment satisfaction was substantially more favorable, adherence barriers moderately lower, and quality of life moderately higher for INH as compared to SC. It remains to be demonstrated whether these patient-reported outcomes will translate into improved adherence and glycemic control.

Conclusions: Clinical Trial Registry #: NCT00424333 clinicaltrials.gov