title: Safety and efficacy of insulin therapy delivered via a 4mm pen needle in obese patients with diabetes.
abstract: OBJECTIVE
  To determine whether insulin delivered via a 4-mm × 32-gauge pen needle (PN) provides equivalent glycemic control as 8-mm × 31-gauge and 12.7-mm × 29-gauge PNs in obese (body mass index ≥30) patients with diabetes.
  
  
  METHODS
  This prospective, multicenter, randomized, open-label, 2-period, crossover, equivalence, home-based study was conducted from October 26, 2010, through May 31, 2012. After a 3-week wash-in period, eligible patients aged 18 to 80 years with a hemoglobin A1c (HbA1c) level of 5.5% to 9.5% (37-80 mmol/mol) were randomized to compare either 4- vs 8-mm PNs or 4- vs 12.7-mm PNs, using each of the 2 assigned PNs for 12 weeks in random order. The primary outcome was change in HbA1c level, with equivalence limits of ±0.4%.
  
  
  RESULTS
  The 274 patients randomized (mean ± SD age, 56.7±11.0 years) had a mean ± SD body mass index of 37.0±6.1 (range, 29.1-59.9) and took up to 350 U of insulin daily; 226 patients were included in the modified intention-to-treat analysis. Mean (95% CI) changes in HbA1c levels with the 4-mm PN were -0.08% (-0.21 to 0.06) and -0.10% (-0.19 to 0.00) vs the 8- and 12.7-mm PNs, respectively, within equivalence margins. The 4-mm PN was less painful than the larger PNs (P<.05), with similar leakage rates reported (4.1%-4.3%). Patients preferred the 4-mm PN over the 12.7-mm PN (P<.05) but not significantly vs the 8-mm PN. There were no differences between PNs in insulin doses and hypoglycemic or hyperglycemic adverse event rates.
  
  
  CONCLUSIONS
  The 4-mm × 32-gauge PN provides equivalent glycemic control as 8- and 12.7-mm PNs in obese patients with diabetes, with less pain and no increase in leakage. Shorter PNs should be considered in all insulin-requiring patients with diabetes, including those who are obese.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT01231984.
authors: International Diabetes Center at Park Nicollet Clinic, Minneapolis, MN. Electronic address: Richard.Bergenstal@ParkNicollet.com.
authors: Richard M
authors: RM
authors: Bergenstal
authors: International Diabetes Center at Park Nicollet Clinic, Minneapolis, MN.
authors: Ellie S
authors: ES
authors: Strock
authors: International Diabetes Center at Park Nicollet Clinic, Minneapolis, MN.
authors: Diana
authors: D
authors: Peremislov
authors: BD Diabetes Care, Franklin Lakes, NJ.
authors: Michael A
authors: MA
authors: Gibney
authors: BD Diabetes Care, Franklin Lakes, NJ.
authors: Valentin
authors: V
authors: Parvu
authors: BD Diabetes Care, Franklin Lakes, NJ.
authors: Laurence J
authors: LJ
authors: Hirsch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018592:Cross-Over Studies; D003920:Diabetes Mellitus / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009339:Needles; D009765:Obesity / Q000150:complications*; D061214:Patient Safety; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin