Ramadan fasting risk calculator for adults with diabetes

A long fast changes the times of meals and treatment, so blood glucose can fall or rise more than during the rest of the year [2]. Patients with diabetes who fast have a higher risk of hypoglycemia, dehydration, hyperglycemia and ketoacidosis [2]. During Ramadan, the fast lasts a month, and there is no food or water every day from dawn to sunset [2].

The risk differs greatly from one patient to another, depending on the type of diabetes, the treatment and the complications [1] [2]. Hypoglycemia occurs more often in patients treated with insulin or a sulfonylurea than in those treated with other diabetes medicines [2]. About half of hypoglycemic episodes occur in the last hours of the fast, so it is best to avoid intense physical effort during this time [2]. The meal that breaks the fast often contains a lot of carbohydrates, sugar and fat, and blood glucose can rise sharply after it [2].

The score adds up the points given for 14 items related to diabetes, treatment, complications and the way the fast is kept [1]. Six situations each receive 6.5 points and lead on their own to high risk [1]. They are pregnancy, hypoglycemia unawareness, unstable cardiovascular disease, advanced chronic kidney disease, impaired memory and thinking, and advanced frailty [1]. Using a glucose sensor lowers the score by half a point, while a lack of fasting education raises it by one point [1].

A total of up to 3 points means low risk, and fasting is probably safe if the treatment is reviewed beforehand and blood glucose is tested carefully [1]. A total between 3.5 and 6 points means moderate risk, so the safety of fasting is uncertain, and the treatment must be adjusted and blood glucose tested often [1]. A total above 6 points means high risk, and fasting is not safe [1]. Religious rules allow exemption from fasting for patients at high risk [1]. The calculator places a total of 3.25 points in the moderate risk category, because this value is not covered by the published categories.

It is best to discuss fasting with your doctor 6–8 weeks before Ramadan, because some items of the score can improve [2] [3]. That is when the doses of insulin or other medicines, the blood glucose testing times and the meals are set [2] [3]. For long fasting days, medicines with a low risk of hypoglycemia are preferred [2].

The fast must be broken immediately if blood glucose falls below 70 mg/dL (3.9 mmol/L) [3]. The fast is also broken if blood glucose rises above 300 mg/dL (16.7 mmol/L) or if symptoms of hypoglycemia or an acute illness appear [3]. If blood glucose is between 70 and 90 mg/dL (3.9–5.0 mmol/L), it should be tested again within an hour [3]. Blood glucose testing and insulin injections do not break the fast, so blood glucose should be tested as often as needed [3].

The score was built for patients with any type of diabetes, and its earlier version was validated in adults in several countries [1] [4]. Patients classified as high risk had hypoglycemia and hyperglycemia more often during the fast [4]. There is no validated risk score yet for children and adolescents with diabetes, so the calculator is used only from 18 years of age [5]. Preparing a child or adolescent with diabetes for fasting is done by the pediatric diabetes team, through counseling and education [5].

The score can also give guidance for other fasts without food and water during the day, although their risks may differ [2]. The score does not apply to food fasts, such as the Christian fast, in which certain foods are given up, for example animal products. The result only gives you guidance, and the decision to fast and the treatment plan are made together with your doctor.