Correlation between capillary and venous blood glucose levels in diabetic patients

Abstract

Abstract Background Rapid blood glucose estimation is required to prescribe treatments and to make dose adjustments in diabetic patients. However, measuring plasma glucose levels is time consuming. Therefore, the use of glucometers has greatly increased. Objectives To measure the correlation between capillary and venous blood glucose levels. Methods Seventy patients with type 2 diabetes mellitus (T2DM) were enrolled in the present study and informed written consent was obtained from all participants. Demographic characteristics and clinical information was noted. Capillary and venous glucose levels were determined. Statistical Package for Social Sciences version 21 was used for data analysis. Results Mean age of patients was 52 ± 12 years. It included 29% men; 71% women; 9% smokers; and 90% poor. Mean venous glucose was 11.73 ± 4.64 mmol/L and mean capillary glucose 12.57 ± 5.21 mmol/L. These findings demonstrated a significant intermethod mean difference of 0.84 mmol/L (P < 0.001). Inter-glucose difference was not significant at glucose levels near normal. However, it increased gradually with rise in glucose measurements and was significant at elevated glucose levels. Both concordance correlation coefficient and intraclass correlation coefficient demonstrated positive correlation and more consistency between glucose estimations. A Bland and Altman plot presented excellent agreement between glucometrically and photometrically determined glucose levels. Conclusion A positive correlation coefficient showed strong association between capillary and venous glucose measurements.