The month-long fast that takes place in the 9th month of the Islamic lunar calendar each year is one of the five pillars of Islam. The fast is obligatory for all healthy Muslims who have reached puberty and takes place during daylight hours. The amount of time spend fasting will vary according to the time of year in which Ramadan falls and depends on the season and geographical location. Followers must refrain from eating, drinking, using oral medications, smoking and sexual activity from the sunrise to sunset.
Fasting is not reserved for Muslims only, for example: The Catholic Church historically observes the disciplines of fasting and abstinence at various times each year, the Orthodox Christians abstain from certain foods for 40-48 days before Easter and Hinduism is characterised by many festivals with periods of feasting or fasting from 1-9 days.
Although certain groups of people, such as those with chronic conditions like diabetes, are exempt from fasting during Ramadan, many people still choose to fast for religious, social and cultural reasons, thereby creating a medical challenge for themselves and their health care providers. One study by Hassanein (2017) showed that around 40% of people with type 1 diabetes fast during Ramadan. In those with type 2 diabetes almost 80% will fast during the Holy Month; this equates to over 115 million people worldwide.
Physiology of fasting
When we eat, insulin secretion is stimulated to promote the storage of glucose, in the form of glycogen, into the liver and muscles. Glucose levels drop during fasting, which leads to a decrease in insulin secretion and increase in the release of glucagon, and this in turn stimulates gluconeogenesis in an effort to maintain glucose concentrations in the physiological range. As fasting exceeds several hours during Ramadan glycogen stores become depleted and the low levels of insulin will allow for increased fatty acid release from adipocytes, which leads to the formation of ketones that can be used as fuel for various organs, thereby sparing any remaining glucose for use by the brain.
In people with diabetes the glucosehomeostasis is affected, amongst other things by the medications, which are designed to enhance or supplement insulin secretion. Hypoglycaemia and hyperglycaemia are common risk factors for people with diabetes who are fasting.
Complications during fasting
Glucagon secretion may fail to increase appropriately in response to hypoglycaemia in those with type 1 diabetes (T1D). The EPIDIAR study showed that fasting during Ramadan increased the risk of severe hypoglycaemia about 4.7 fold in T1D and 7.5 fold in those with type 2 diabetes (T2D).
Hyperglycaemia and DKA
A prolonged fast in the absence of adequate insulin can lead to excessive glycogen breakdown and increased gluconeogenesis and could lead to hyperglycaemia and ketoacidosis. Ketoacidosis is uncommon in those with type 2 diabetes, except in some cases where the patient is treated with a SGLT-2 inhibitor. The severity of hyperglycaemia in those with T2D depends on the extent of insulin resistance and/or insulin deficiency. The EPIDIAR study showed a 5-fold increase in severe hyperglycaemia (requiring hospitalisation) in those with T2D and around 3-fold increase in T1D (with or without ketoacidosis). It is believed that hyperglycaemia during Ramadan may be caused by excessive reduction in medication dosages to prevent hypoglycaemia.
Dehydration and thrombosis
Prolonged limitation of fluid intake during the fast can cause dehydration, which may become severe as a result of excessive perspiration in those who perform hard, physical labour and in hot and humid climates, such as in Australian Summers. Hyperglycaemia can further contribute to dehydration and the resulting increased blood viscositymay increase the risk of thrombosis and stroke.
There is currently no data available on the effect of fasting on mortality in patients with diabetes.
To Fast or Not to Fast?
Most often the medical recommendation is not to fast. However, many Muslims with diabetes are passionate about fasting; they enjoy the spiritual atmosphere during Ramadan, don’t perceive themselves as being sick and don’t want to miss out. It is therefore important to talk to your patients about the risk of fasting.
Healthcare providers need to provide appropriate and culturally sensitive advice regarding fasting during Ramadan, on an individual basis and patients should be made aware that they may need to break their fast if their blood glucose levels drop below 3.9 mmol/L or rise above 16 mmol/L, to prevent symptoms of hypoglycaemia, hyperglycaemia, dehydration or acute illness.
Other than discussing the risks associate with fasting and when to stop the fast, we need to discuss the importance of blood glucose monitoring, assist the patient in meal planning and review of physical activity and provide guidance regarding the timing and dosing of diabetes medications.
Patients should be encouraged to:
Never skip suhur (the dawn meal)
Include fruit and vegetables at both suhur and iftar (breaking of the fast)
Focus on high fibre carbohydrates
Limit fried or fatty foods
Limit their intake of high sugary foods (such as dates or juice, often used to break the fast)
Limit the intake of salty foods to reduce the risk of dehydration
Take in sufficient fluids, to replenish fluid loss during the day
Supper after Tarawih can be taken as a replacement of a pre-bed snack.
Although most medications, such as DPP-4 inhibitors, Meglitinides, Thiazolodinediones, Alpha-glucosidase inhibitors, require no adjustments, for some medications, such as SGLT-2 inhibitors, it may be worthwhile switching the dosing to the sunset meal. Immediate release Sulphonylureas, such as Gliclazide (not MR) and Glibenclamide may need to be omitted or changed to modified release preparations to reduce the risk of hypoglycaemia. Metformin 3x daily is best split to two-third of the dosage at iftar (the sunset meal) and one-third of the dosage at suhur (the pre-dawn meal), though a BD dosing of Metformin or Metformin XR would not require any change.
Basal (long or intermediate-acting) insulin doses generally will need to be reduced by around 15-30% and are best taken after iftar.
Bolus (rapid or short-acting) insulin doses would need to be omitted at lunchtime and the suhur dosage will need to be reduced by around 25-50%. Usually the regular bolus dosage can be maintained at iftar.
For those on premixed insulin once daily the dosage can be taken at iftar. If taking twice daily premixed insulin the suhur dosage will need to be reduced by around 25-50%. If the patient is usually on 3 lots of premixed insulin at main meals the lunchtime will need to be omitted and the iftar and suhur doses should be adjusted.
Patients on an insulin pump should generally decrease their basal rates by 20-40% in the last 3-4 hours of fasting and they should increase their basal rates by up to 30% after iftar. Normal carbohydrate counting and insulin sensitivity principles apply in regards to bolus doses.
Of course the above medication and insulin dose adjustment recommendations are a guideline only.
Article written by Carolien Koreneff, CDE-RN, FADEA
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