The Appropriateness of the Length of Insulin Needles Based on Determination of Skin and Subcutaneous Fat Thickness in the Abdomen and Upper Arm in Patients with Type 2 Diabetes

Abstract

BackgroundLonger needle and complicated insulin injection technique such as injecting at a 45-degree angle and making skinfolds may decrease patient compliance to insulin injection therapy. In this light, shorter insulin needles have been recently developed. However, it is necessary to ascertain that such shorter needles are appropriate for Korean patients with diabetes as well.MethodsFirst, the diverse demographic and diabetic features of 156 Korean adults with diabetes were collected by a questionnaire and a device unit of body fat measurement. The skin and subcutaneous fat thicknesses of each subject were measured by Ultrasound device with a 7- to 12-MHz probe. Data were analyzed using analysis of variance and multiple linear regression.ResultsThe mean skin thickness was 2.29±0.37 mm in the abdomen and 2.00±0.34 mm in the upper arms, and the mean subcutaneous fat thickness was to 10.15±6.54 mm in the abdomen and 5.50±2.68 mm in the upper arms. Our analysis showed that the factors affecting the skin thickness of the abdomen and upper arms were gender and body mass index (BMI), whereas the factors influencing the subcutaneous fat thickness in the abdomen were gender and BMI, and the factors influencing the subcutaneous fat thickness in the upper arms were gender, BMI, and age. Insulin fluids may not appear to be intradermally injected into the abdomen and upper arms at any needle lengths. The risk of intramuscular injection is likely to increase with longer insulin needles and lower BMI.ConclusionIt is recommended to fully inform the patients about the lengths of needles for insulin injections. As for the recommended needle length, the findings of this study indicate that needles as short as 4 mm are sufficient to deliver insulin for Korean patients with diabetes.

Lipohypertrophy among Insulin - Treated Patients

“…Approximately 90% of our patients were obese and had thicker SC fat. We found a significant association between SC thickness of the arm and thigh and BMI, which is consistent with recent studies 24,25 . Therefore, the results could not be extrapolated to patients with normal BMI where the risk for IM injection could be higher.…”

“…It was found that when patients received injection training from a diabetes nurse, they had a significant decrease in A1C, unexpected hypoglycemia and glucose variability 23 . US of our patients revealed higher mean skin thickness compared to recent studies 24,25 . The mean skin thickness found was less than 2.5 mm compared to 3.1 mm in our study.…”

Subcutaneous Injection Depth Does Not Affect the Pharmacokinetics or Glucodynamics of Insulin Lispro in Normal Weight or Healthy Obese Subjects

“…Needles of 5-mm and even 4-mm length are estimated to provide reliable subcutaneous drug delivery, with substantially reduced risk of IM injection. 6,15 This is the first study comparing the PK and GD of insulin after administration of single doses at either a 5-mm or an 8-mm injection depth in both normal weight and obese healthy subjects using the euglycemic clamp procedure. The randomized crossover design was selected to allow comparison between injection depths on an intrasubject basis, allowing each subject to serve as his/her own control.…”

Optimal Insulin Delivery

“…The skin averages approximately 2-2.5-mm thick and varies in its 95% confidence interval (CI) between 1.25 and 3.25 mm. These studies included patients with type 2 diabetes (T2DM) from the Philippines [9], Korea [10], China [11], and India [12]; both type 1 diabetes (T1DM) and T2DM adults from the USA (including four different ethnic groups) [7]; and children from South Africa [13] and Italy [14].…”