Ultrasound-guided measurement of skin and subcutaneous tissue thickness in children with diabetes and recommendations for giving insulin injections.

Aim: To measure skin thickness (ST) and skin + subcutaneous layer thickness (SCT) by ultrasound and estimate the risk of intramuscular injection (IM) with different needle lengths across injection sites according to age group.

Method: Children recruited between 1 and 18 years with type 1 and 2 diabetes on insulin injections and divided into three age groups: 1-6 years, 7-12 years and 13-18 years. A portable ultrasound was used to measure ST and SCT at four injection sites on the abdomen, arm, thigh and buttock.

Results: Total 153 children enrolled for the study. The mean (SD) measurement of ST & SCT at four sites on abdomen, arm, thigh & buttocks were as follows; 4.33 mm (±2.22), 5.55 mm (±2.26), 5.83 mm (±3.12), 6.48 mm (±3.47) in 1-6 years old; 7.11 mm (±3.68), 7.79 mm (±4.54), 7.17 mm (±3.62), 8.51 mm (±3.65) in 7-12 years old; 8.94 mm (±4.50), 8.42 mm (±5.00), 8.61 mm (±4.76), 9.76 mm (±4.38) in 13-18 years old. Young children, 1-6 years have the highest risk of IM injection with all needle lengths, i.e. 4, 5, 6, 8 & 12.7 mm, while older children 7-12 & 13-18 years have a lower risk with shorter needles (4, 5 and 6 mm) as compared to longer needles (8 and 12.7 mm).

Conclusions: Children with diabetes on insulin therapy should be advised on the appropriate needle length accordingly to their age and BMI.