Assessment of risk of fasting during Ramadan under optimal diabetes care, in high-risk patients with diabetes and coronary heart disease through the use of FreeStyle Libre flash continuous glucose monitor (FSL-CGMS)

Aim: Most of Muslims patients with diabetes and Coronary Heart Disease (CHD) elect to fast in Ramadan, but the actual risk in this subset of patients with diabetes is largely unknown. We aimed to understand the safety of fasting in CHD patients with diabetes insisting on fasting Ramadan under optimal care. We also monitored the change in biophysical and biochemical parameters of these patients before and after Ramadan. We conducted this prospective study in a tertiary care hospital in Dubai during Ramadan 2016, (June 6th till July 5th). Patients and methods: 21 Patients with T2DM with stable known CHD during the three months prior to study and insisted on fasting despite advice against it were recruited for the study. All patients received continuous glucose monitoring with free style libre monitoring device (FSL-CGM) during and outside Ramadan period. We recorded DM or CVD-related emergency visit or hospitalisation, change in BMI, systolic and diastolic BP, lipids profile, e-GFR, HBA1c, and frequency of hypoglycemia during Ramadan fasting and not-fasting period. Results: This is first study using CGM in CHD patients with diabetes who observe fast in Ramadan. Patients had a significantly higher incidence (3.2 +/- 2.8 vs 1.1 +/- 1.6 episodes, p = 0.033) and prolonged duration of hypoglycemia (117.8 +/- 87.2, 49.1 +/- 59.1 min p 0.022) during fasting compared to non-fasting respectively. No significant alteration was seen in BMI, SBP and DBP, lipid profile and renal function. There is a significant improvement in HBA1c during Ramadan. Conclusion: We could not associate any adverse cardiovascular effects with fasting Ramadan in patients with stable CHD under optimal diabetes care. FSL-CGMS data showed higher frequency of hypoglycemia during Ramadan fasting. Studies with larger sample size are needed for further validation of these findings. (C) 2019 Elsevier B.V. All rights reserved.