Correlation between CGMSBG and SMBG in different settings of measurement

Objective To evaluate the correlation between MiniMed continuous glucose monitoring system blood glucose(CGMSBG)and self monitoring blood glucose(SMBG)detected at different blood sugar levels and different time points to see whether there is any correlation between them.Methods 130 patients with type 2 diabetes admitted to this hospital were submitted to CGMS.The correlation and coincidence between CGMSBG and SMBG values at different blood sugar levels and different time points were assessed by Person correlation analysis.Results 1.The correlation coefficient r of 1609 CGMSBG values and paired SMBG values was 0.929(P=0.0001).When the age was below 70 years,the correlation coefficient r was 0.901(P=0.0001).When it was between70 and 80,the correlation coefficient r was 0.932(P=0.0001).When it was above 80,the correlation coefficient r was 0.875(P=0.0001).2.When SMBG value was below 4.4 mmol/L,the correlation coefficient r was 0.286(P=0.025).When it was between 4.4 and 10 mmol/L,the correlation coefficient r was 0.825(P=0.0001).When it was above 10 mmol/L,the correlation coefficient r was 0.838(P=0.0001).3.At 1～6h,7～12h,13～24h,25～48h and 49～72h after the installation of CGMS,the correlation coefficient r of CGMSBG values and SMBG values was 0.802,0.904,0.954,0.949 and 0.926 respectively.Conclusions 1.The correlation and coincidence between SMBG values and CGMSBG values are not affected by age.2.At different blood glucose levels,the correlation and coincidence between SMBG and CGMSBG values are favorable.The SMBG value and the CGMSBG value are most comparable when they are at the moderate level.3.At different time points of measurement,SMBG values and paired CGMSBG values are well correlated,especially at 25～48h.