Since our last publication about diabetes and fasting during Ramadan (1), we have received many inquires and comments concerning important issues that were not discussed in the previous document, including the voluntary 1- to 2-day fasts per week that many Muslims practice throughout the year, as well as the effect of prolonged fasting (more than 18 h a day) in regions far from the equator during Ramadan when it occurs in summer—a phenomenon expected to affect millions worldwide for the next 10–15 years. Since 2005, there have been substantial additions to the literature, including two studies examining the effect of structured education and support for safe fasting, both of which had promising results (2,3). In addition, new medications, such as the incretin-based therapies, have been introduced with less risk for hypoglycemia. According to a 2009 demographic study, Islam has 1.57 billion adherents, making up 23% of the world population of 6.8 billion, and is growing by ∼3% per year (4). Fasting during Ramadan, a holy month of Islam, is a duty for all healthy adult Muslims. The high global prevalence of type 2 diabetes—6.6% among adults age 20–79 years (5)—coupled with the results of the population-based Epidemiology of Diabetes and Ramadan 1422/2001 (EPIDIAR) study, which demonstrated among 12,243 people with diabetes from 13 Islamic countries that ∼43% of patients with type 1 diabetes and ∼79% of patients with type 2 diabetes fast during Ramadan (6), lead to the estimate that worldwide more than 50 million people with diabetes fast during Ramadan. Ramadan is a lunar-based month, and its duration varies between 29 and 30 days. Muslims who fast during Ramadan must abstain from eating, drinking, use of oral medications, and smoking from predawn to after sunset; however, there are no restrictions on food or fluid intake between sunset …

Since the first ADA working group report on the recommendations for management of diabetes during Ramadan in 2005 and our update in 2010, we received many inquiries asking for regular updates on information regarding education, nutritional habits and new oral and injectable agents that may be useful for the management of patients with diabetes during Ramadan. Patients can be stratified into their risk of hypoglycemia and/or complications prior to the start of the fasting period of Ramadan. Those at high risk of hypoglycemia and with multiple diabetic complications should be advised against prolonged fasting. Even in the lower hypoglycemia risk group, adverse effects may still occur. In order to minimize adverse side effects during fasting in patients with diabetes and improve or maintain glucose control, education and discussion of glucose monitoring and treatment regimens should occur several weeks prior to Ramadan. Agents such as metformin, thiazolidinediones and dipeptidyl peptidase-4 inhibitors appear to be safe and do not need dose adjustment. Most sulfonylureas may not be used safely during Ramadan except with extreme caution; besides, older agents, such as chlorpropamide or glyburide, should not be used. Reduction of the dosage of sulfonylurea is needed depending on the degree of control prior to fasting. Misconceptions and local habits should be addressed and dealt with in any educational intervention and therapeutic planning with patients with diabetes. In this regard, efforts are still needed for controlled prospective studies in the field of efficacy and safety of the different interventions during the Ramadan Fast.

Fasting the Holy month of Ramadan constitutes one of the five pillars of the Muslim faith. Although there is some evidence that intermittent fasting during Ramadan may be of benefit in losing weight and cardiometabolic risk factors, there is no strong evidence these benefits apply to people with diabetes. The American Diabetes Association/European Association for the Study of Diabetes consensus recommendations emphasize the importance of patient factors and comorbidities when choosing diabetes medications including the presence of comorbidities, atherosclerotic cardiovascular disease, heart failure, chronic kidney disease, hypoglycemia risk, weight issues and costs. Structured education and pre-Ramadan counseing are key components to successful management of patients with diabetes. These should cover important aspects like glycemic targets, self-monitoring of blood glucose, diet, physical activity including Taraweeh prayers, medication and dose adjustment, side effects and when to break the fast. The decision cycle adapted for the specific situation of Ramadan provides an aid for such an assessment. Children with type 1 diabetes should strongly be advised not to fast due to the high risk of acute complications such as hypoglycemia and probably diabetic ketoacidosis (DKA), although there is very little evidence that DKA is increased in Ramadan. Pregnant women with diabetes or gestational diabetes should be advised to avoid fasting because of possible negative maternal and fetal outcomes. Hypoglycemia is a common concern during Ramadan fasting. To prevent hypoglycemic and hyperglycemic events, we recommend the adoption of diabetes self-management education and support principles. The use of the emerging technology and continuous glucose monitoring during Ramadan could help to recognize hypoglycemic and hyperglycemic complications related to omission and/or medication adjustment during fasting; however, the cost represents a significant barrier.

Hajj is one of the five pillars of Islam and is a must-do for all adult Muslims once in their life provided they are able to do it. Considering the 8.8% global prevalence of diabetes, coupled with the number of Muslims performing Hajj (~2.5 million adult Muslims), it could be estimated that Muslims with diabetes performing Hajj may exceed 220 000 per year. According to Islamic rules, Hajj should not cause severe difficulties for Muslims. The Holy Qur’an specifically exempts from this duty Muslims who are unable physically or financially if it might lead to harmful consequences for the individual. This should be applicable to subjects with diabetes considering its severe and chronic complications. During the Hajj, diet, amount of fluid intake and physical activity may be altered significantly. This exemption from the duty is usually not considered a simple permission; Muhammad the Prophet of Islam mentioned, ‘God likes his permission to be fulfilled, as he likes his will to be executed’. However, most Muslims with diabetes prefer to do the Hajj duty, and this may cause major medical challenges for Muslims with diabetes and their healthcare providers. So it is very important that healthcare providers are aware of the possible risks that could happen during the Hajj. People with diabetes may face many health hazards during the Hajj, including but not limited to the ‘killer triad’: hypoglycemia, foot injury and infections. Many precautions are necessary in the prevention and treatment of possible serious complications. Risk stratification, medication adjustments, proper clinical assessment, and education before doing the Hajj are crucial.