Aim: To decide most appropriate time to measure fasting blood sugar (FBS) using continuous glucose monitoring (CGM) .

Methodology: All persons who came to our clinic between 1st March to 30th August’21 were screened. Out of 60 persons with A1c <7.5, with FBS >130mg/dl who were measuring after 7.30am (using glucose meter) and having dinner before 9:30 pm, 28 persons who consented for CGM (Libre Pro) were included. Persons who were on SU/insulin or had nocturnal hypoglycaemia, T1DM, CRF, CLD, steroids or malignancy were excluded. The enrolled persons were told to measure their blood sugar between 5.30am to 6.30 am ; 6.30 am to 7.30am ; 7.30am to 8.30am on alternate days for 14 days by glucose meter along with CGM.

Results: Observed glucose values on different times were106±10mg/dl between 5.30 to 6.30am ;114±12mg/dl between 6.30 to 7.30am and 130±16mg/dl between 7.30 to 8.30am. These sugar values of all persons were correlated with CGM Libre pro data. AGP data of 2 out of the 28 persons have been shown in the graphs attached.

Discussion: It is a routine clinical practice to ask PWD to measure FBS but there is ambiguity in timings as no specification of timing is advised. It is important that patients measure fasting sugar around 6.30 am ± 1 hour as it correlates best with sunrise and has less effect of Dawn phenomenon.

Conclusion: To optimise treatment, persons with diabetes should be advised to measure their FBS before 7.30 am.


B.D.Saboo: None. T.C.Vyas: None. K.Chennamsetti: None. M.N.Parekh: None. V.Patel: None. A.M.Prajapati: None.

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