Randomized trial on the influence of the length of two insulin pen needles on glycemic control and patient preference in obese patients with diabetes.

This study determined the influence of needle length for insulin administration on metabolic control and patient preference in obese patients with diabetes mellitus. In this multicenter, open-label crossover study, insulin pen needles of two different lengths (5 mm and 8 mm) were compared. A total of 130 insulin-treated type 1 and type 2 diabetes patients with a body mass index ≥30 kg/m(2) were randomized, and 126 patients completed the study. Patients started using the 5-mm needle for 3 months, after which they switched to injecting insulin with the 8-mm needle for another 3 months, or vice versa. Hemoglobin A1c (A1C), fructosamine, and 1,5-anhydroglucitol were measured, and self-reported side effects and patient preference were recorded. No within-group changes were observed with respect to A1C, serum fructosamine, 1,5-anhydroglucitol, hypoglycemic events, bruising, and pain. When data of all 126 subjects were pooled, there was a small, but significant, difference between needle lengths (5-mm, A1C 7.47 ± 0.9%; 8-mm, 7.59 ± 1.0%; P = 0.02). Patients reported less bleeding with the 5-mm needle (P = 0.04) and less insulin leakage from the skin with the 8-mm needle (P = 0.01). There were no significant differences in patient preference, with 46% of the patients preferring the 5-mm needle, 41% the 8-mm needle, and 13% not preferring a particular needle length. A 5-mm needle is similar to an 8-mm needle in obese patients with diabetes with respect to metabolic control, injection-related complaints, or patient preference and can be used safely.