Glucose monitoring is the cornerstone of diabetes management during Ramadan, especially for people who are at high risk of hypo- or hypoglycaemia. Food abstinence during fasting in people who are treated with sulfonylureas or insulin predisposes the to the risk of hypoglycaemia, while medication dose adjustments made during Ramadan may increase the risk of hyperglycaemia. Hyperglycaemia in turns increases the risk of dehydration in people who are not drinking due to fasting.
The decision to adjust medication doses during Ramadan, especially insulin, and when to terminate fasting depends on blood glucose readings. Glucose monitoring is recommended at important times of the day including before sahur, morning, mid-day, mid-afternoon, before iftar (breaking fast), after iftar, and at any time a person feels unwell or experiences symptoms of hypo- or hyperglycaemia. However, the frequency of blood glucose testing depends on a person's risk of hypoglycaemia, hyperglycaemia, and diabetes treatment especially insulin.
Timings for blood glucose monitoring during Ramadan fasting. Image from IDF-DAR (click on image to zoom).