Comparison Between Shorter Straight and Thinner Microtapered Insulin Injection Needles

BACKGROUND: Many diabetes patients who require insulin perform multiple subcutaneous injections every day that often cause pain, discomfort, and anxiety. We compared efficacy (glycemic control) and patient preference for two types of needle: a shorter straight needle (32 gauge×4 mm, straight wall; Nippon Becton Dickinson Co., Ltd., Tokyo, Japan; hereafter referred to as BD32S4) and a thinner microtapered needle (33-gauge tip and 28-gauge base×5 mm, double-tapered wall; Terumo Corp., Tokyo, Japan; hereafter referred to as TR33T5) in a single-center study. PATIENTS AND METHODS: Eighty-four patients with diabetes were enrolled in a randomized, open-label crossover trial. The patients injected their usual insulin dosage with one type of needle for 4 weeks and then switched to the other type for the next 4 weeks. The serum glycated albumin level was measured before and after each 4-week period. Each patient assessed pain during injection on a 150-mm visual analog scale (VAS). Needle preference, perceptions of handling, and acceptance were assessed by the patients, who completed a questionnaire after using each type of needle for 4 weeks. RESULTS: In total, 79 patients completed the study. There was no difference of glycemic control between the two needles. The mean VAS score was -14.5 mm (95% confidence interval, -20.9, -8.0 mm), indicating that the patients perceived less pain with the BD32S4 needle. In the overall evaluation, a significantly higher percentage of patients selected the BD32S4 as the better needle compared with the TR33T5 (60.3% vs. 19.2%; P<0.0001). CONCLUSIONS: The BD32S4 needle was more highly evaluated and was preferred by the patients with respect to pain during injection, usability, and visual impression, without having a negative impact on glycemic control. The overall preference of patients for the shorter needle in this study suggests that needle length may be one of the major contributing factors for patients' comfort in insulin injection, although the other relevant factors of needles still need to be considered.