Validation of earlobe site as an alternative blood glucose testing approach

BACKGROUND: Drawing blood from the fingertips for glucose testing is painful and likely to cause tissue damage over time. Earlobes are an alternative site for glucose measurement. OBJECTIVE: This work aims to validate the earlobe as an alternate test site for blood glucose testing by demonstrating valid and reliable statistically significant differences between the earlobes and standard reference sites. METHODS: Blood glucose concentrations from 50 volunteers were measured and statistically analysed from the reference sites (forearm and fingertip) and earlobe. The analysis included: 1) one-way analysis of variance (ANOVA), 2) regression analysis, 3) Bland Altman analysis, and 4) Clarke Error Grid analysis. RESULTS: The results indicated that there is no statistically significant difference between the three blood glucose-testing methods. For the forearm-earlobe and fingertip-earlobe, all measurements were grouped around the mean of 3.7 ± 1.96 SD and 2.96± 1.96 SD, respectively. Error grid analysis showed > 97% of all earlobe and references measurements fell in Zones A and B and were in the clinically acceptable level. CONCLUSIONS: The results have shown that the earlobe is a valid substitute for blood glucose measurements.