Endocrine Abstracts

Introduction: The length of the insulin needle in last three decades has reduced from 16 mm to 4 mm. The BMI of 10 kg/m² difference accounts for a 4 mm difference in subcutaneous tissue thickness. We compared the glycemic control in patients switched from 4 mm needle to 6 mm needle in the Normal Weight (NW) patients (BMI < 25 kg/m²) with the Obese and Overweight (OOW) patients (BMI ≥ 25 kg/m²)

Methods: We observed 93 T2DM patients (51 females) for the change in HbA1c over a period of four years from Bliss Total Diabetes Care (BTDC) registry from 2016 to 2019. Comparisons were made using ANOVA, Fisher’s exact and unpaired t test.

Results: The mean HbA1c in the total population at baseline was 9.1% (s.d. ± 1.9, minimum 5.3, maximum 14, range 8.3, 95% CI 8.7 to 9.5) which significantly reduced to 8.5% (s.d. ± 2.1, minimum 5, maximum 14, range 8.7, 95% CI 8.1 to 8.9), (P = 0.039). The mean reduction in HbA1c in the NW (n = 33) and OOW (n = 60) was 0.4% (s.d. ± 1.6, minimum –3, maximum 4.6, range 7.6, 95% CI –0.17 to 0.98) and 0.7% (s.d. ± 1.8, minimum –3.7, maximum 6, range 9.7, 95% CI 0.27 to 1.2), (P = 0.39 NS), respectively. We compared the proportions for patients achieving the good glycemic control (HbA1c < 7%) in NW (n = 7) and OOW (19) with inadequate glycemic control in NW (n = 26) and OOW (41). The association between the glycemic control (target HbA1c < 7%), and BMI was not statistically significant (P = 0.33 NS)

Discussion: The overweight and obese patients achieved a favourable, numerically superior glycemic reduction with 6 mm needle, which would be accounted by the better penetration of the thicker subcutaneous tissue and effectiveness to inject insulin. However, the difference was statistically insignificant which may be attributed due to the chronic progressive nature of diabetes with multiple, unadjusted confounding variables.

Conclusion: We found that longer insulin pen needles may be a better option for their appropriateness and effectiveness in patients with higher BMIs. In order to contribute immensely to the evidence-based decisions of appropriate needle length, the results of our study need corroboration with larger multi-centric studies.