Comparative glycemic control, safety and patient ratings for a new 4mm x 32G insulin pen needle in adults with diabetes

Objective: Pen needles (PN) for subcutaneous insulin therapy have become smaller; 5 mm PNs are now the shortest in use. We evaluated the safety, efficacy and patient ratings of a new 4 mm x 32 gauge (G) PN. Research design and methods: Subjects with type 1 and type 2 diabetes and HbA1c 5.5% to 9.5% participated in a randomized non-inferiority cross-over trial, at four U. S. centers. Subjects used 4 mm x 32G PNs and either 5mm x 31G PNs (4/5 mm) or 8 mm x 31G PNs (4/8 mm) in two, 3-week treatment periods; order of needle use was controlled. Subjects were either 'low dose' or 'regular dose' users (highest single insulin dose <= 20 units and 21-40 units, respectively). Percent absolute change in serum fructosamine (% vertical bar Delta Fru vertical bar) was the primary endpoint; unexplained, severe hypo-or hyperglycemia was a secondary measure. Leakage at injection sites and pain measured by visual analog scale were tertiary measures. Equivalent glycemic control was defined a priori as % vertical bar Delta Fru vertical bar (including 95% CI) within 20%; 40 subjects per subgroup provides 90% power at a = 0.05. Clinical trial registration: The study was registered on clinicaltrials. gov (identifier: NCT00928057). Results: Of 173 subjects randomized, 168 completed the study, and 163 were included in the fructosamine analyses -83 and 80 in the 4/5 mm and 4/8 mm groups, respectively. Subjects were 56% male, mean 52.6 yrs, 63% type 2. Baseline HbA1c = 7.5 +/- 1.0% and fructosamine 301 +/- 55.1 mu mol/L. Mean % vertical bar Delta Fru vertical bar was 4.9% (95% CI 3.8, 6.0) and 5.5% (4.5, 6.4), respectively, for the 4/5 mm and 4/8 mm groups, meeting glycemic equivalence criteria; results were similar in both dose groups. The median vertical bar Delta Fru vertical bar was 11.0 mu mol/L (8.0, 13.0) and 13.5 mu mol/L (9.8, 18.0) for the 4/5 mm and 4/8 mm groups, respectively. Unexplained, severe hypo-and hyperglycemic episodes were infrequent and not different between PNs. The 4 mm PN was rated significantly less painful and preferred by approximately 2/3 of subjects (p < 0.01). All three PNs had similar reported injection site leakage. Limitations: The study was of relatively short duration, in adults in the U. S. Further trials in other patients (e. g., GLP-1 users, pediatrics, obese) should be performed. Conclusions: The 4 mm x 32G PN provided equivalent glycemic control compared to 31G, 5 mm and 8 mm PNs with reduced pain, no difference in insulin leakage and was preferred by patients.