Diabetes control during Ramadan fasting

Hypoglycemia

For patients with type 1 diabetes, fasting increases the risk of hypoglycemia 4.7 times, and the risk is 7.5 times higher for patients with type 2 diabetes.² However, this is often under-reported, as mild to moderate hypoglycemia does not usually require medical assistance.

Precipitating factors include long fasting hours, missing the Suhur meal, and failure to modify drug dosage and timing.

Hyperglycemia

The risk of severe hyperglycemia during fasting is 3.2 times higher in patients with type 1 diabetes and 5 times higher in those with type 2 diabetes.² Precipitating factors include lack of diet control during the Iftar meal and excessive reduction in the dosage of diabetes medications due to fear of hypoglycemia.

Diabetic ketoacidosis

Ketoacidosis can be precipitated by a lack of diet control during the Iftar meal, excessive reduction in the dosage of insulin due to fear of hypoglycemia, acute stress, and illness or infection.

Dehydration and thrombosis

Patients can become dehydrated during long fasting hours in especially hot weather, by sweating during physical activity, and by osmotic diuresis in poorly controlled diabetes.

Diabetes is a procoagulant condition, and dehydration increases the risk of thrombosis.

Oral diabetes drugs

Drugs such as metformin, alpha glucosidase inhibitors, thiazolidinediones, the short-acting insulin secretagogue nateglinide, dipeptidyl peptidase 4 inhibitors (eg, sitagliptin), and glucagon-like peptide 1 receptor agonists are associated with a lower risk of hypoglycemia and can be used during Ramadan fasting without significant changes in the daily dose (Table 3).⁸

Sulfonylureas carry a higher risk of hypoglycemia and should be used cautiously during fasting, with appropriate modification in dose and timing.^9,10

Sodium-glucose cotransporter 2 inhibitors, when not combined with insulin or sulfonylureas, carry a lower risk of hypoglycemia, but during Ramadan fasting there is an increased risk of dehydration, urinary tract infection, and postural hypotension since fluids cannot be taken during fasting hours.

Dipeptidyl peptidase 4 inhibitors carry a low risk of hypoglycemia and can be used during Ramadan without dosing modification. Glucagon-like peptide 1 agonists also can be used without adjusting the dosage.¹¹

Insulins

Insulin treatment is associated with a higher risk of hypoglycemia during Ramadan fasting.¹² During fasting, the risk of hypoglycemia from premixed insulin can be minimized by changing to a multiple-dose regimen involving a basal insulin and short-acting insulin before meals, with adjustment of the short-acting insulin dose based on the anticipated carbohydrate intake for each meal.¹³

Patients taking premixed insulin preparations consisting of 70% intermediate-acting or long-acting insulin and 30% short-acting insulin should change to a 50/50 preparation during Ramadan fasting to reduce hypoglycemic risk and improve glycemic control; taking more of the fast-acting component controls postprandial hyperglycemia, and taking less of the intermediate or long-acting component minimizes the risk of hypoglycemia during fasting hours.^14,15

Insulin analogues carry a lower risk of hypoglycemia than human insulin. Compared with a human insulin 70/30 preparation, an analogue premix containing 75% neutral protamine lispro and 25% insulin lispro resulted in better glycemic control during Ramadan fast ing.¹⁶ This could be related to the pharmacodynamics of low-ratio premix analogues, as well as to the mealtime flexibility of analogue insulin, as the injections of the 75/25 mix were given immediately before the morning and evening meals. Insulin analogues are also less likely to cause postprandial hypoglycemia.¹⁶

A multiple-dose insulin regimen involving a long-acting basal insulin (eg, glargine, detemir, degludec) and a short-acting insulin (eg, glulisine, aspart, lispro) before meals is preferred in view of better glycemic control and lower risk of hypoglycemia.¹⁷

Use of an insulin pump during Ramadan is associated with a reduced risk of hypoglycemia.¹⁸ In patients with an insulin pump, the rate of basal insulin must be reduced during daytime, and the postprandial bolus of insulin must be increased after breaking the fast.