Why use it

Approximately 50 million people with diabetes worldwide observe Ramadan fasting annually. Complications during fasting — particularly hypoglycemia — are common and potentially life-threatening. The IDF-DAR risk stratification helps clinicians initiate pre-Ramadan medical assessment (ideally 6–8 weeks before Ramadan), individualize medication adjustments, provide structured diabetes education, and determine whether fasting is medically safe or strongly discouraged. It facilitates the clinician–patient shared decision-making conversation that respects religious practice while minimizing medical risk.

About

The International Diabetes Federation and Diabetes and Ramadan (IDF-DAR) International Alliance Risk Stratification Tool is a validated clinical framework developed to assess the individual risk associated with fasting during the holy month of Ramadan in patients with diabetes. Published and updated in the IDF-DAR Practical Guidelines (2016, updated 2021), the tool categorizes patients into three risk levels — Very High/High Risk, Moderate Risk, and Low Risk — based on a comprehensive evaluation of diabetes type, treatment regimen, glycemic control, comorbidities, and social factors. Ramadan fasting involves abstaining from all food and drink (including medications) from dawn to sunset for approximately 29–30 days, which profoundly affects glucose metabolism and medication pharmacokinetics, creating risks of hypoglycemia, hyperglycemia, dehydration, and diabetic ketoacidosis (DKA) — particularly in type 1 diabetes and poorly controlled type 2 diabetes. The IDF-DAR guidelines are endorsed by the International Diabetes Federation and widely used across Muslim-majority countries and among Muslim diabetic patients worldwide.

When to use

Pre-Ramadan medical assessment ideally 6–8 weeks before Ramadan begins — all patients with diabetes intending to fast
When a patient with diabetes expresses intention to fast during Ramadan
Annual review in patients known to fast, to reassess risk as clinical status changes
After major changes in diabetes management (insulin initiation, new complications, recent hospitalization)
Adjustment of medications and education prior to fasting commencement

Formula

IDF-DAR Risk Categories: VERY HIGH RISK — Strongly advised NOT to fast: • Type 1 diabetes (any) • Uncontrolled type 2 diabetes (HbA1c >10% / 86 mmol/mol) • History of recurrent hypoglycemia or hypoglycemia unawareness • Acute illness at time of Ramadan • DKA or hyperosmolar hyperglycemic state (HHS) within 3 months • Pregnancy with pre-existing or gestational diabetes • Renal failure (eGFR <30), dialysis, or kidney transplant • Stroke or major cardiac event within 3 months • Advanced macrovascular complications • Old age with ill health HIGH RISK — Advised NOT to fast (or to fast with extreme caution and specialist supervision): • Severe hypoglycemia within 3 months • On multiple daily insulin injections or mixed insulin regimens • HbA1c >9% / 75 mmol/mol • Type 2 on insulin with poor glycemic control • Significant renal disease (eGFR 30–60) or macroalbuminuria • Occupational risk (heavy labor, driving) • Significant cognitive or psychiatric disorders affecting self-management MODERATE RISK — May fast with pre-Ramadan education, monitoring, and medication adjustment: • Well-controlled T2DM on short-acting insulin • Well-controlled T2DM on sulfonylurea • Stable macrovascular disease • Sustained moderate kidney disease LOW RISK — Fasting generally safe with basic education and minor medication adjustments: • Well-controlled T2DM on lifestyle measures alone • T2DM on metformin, DPP-4 inhibitors, GLP-1 RAs, or SGLT-2 inhibitors (with caution) • Well-controlled T2DM on low-risk oral agents, HbA1c <8%

Pearls & pitfalls

Type 1 diabetes is inherently very high risk for Ramadan fasting — it should NEVER be undertaken without specialist supervision and intensive glucose monitoring.
Hypoglycemia is the most common acute complication during Ramadan — the risk increases particularly in the last 2–3 hours before iftar (sunset meal).
All patients must be counseled that they SHOULD break their fast if blood glucose falls <70 mg/dL (3.9 mmol/L) or rises >300 mg/dL (16.7 mmol/L), or if they feel significantly unwell.
Sulfonylureas carry the highest hypoglycemia risk among oral agents and should typically be reduced or switched (e.g., to a DPP-4 inhibitor or SGLT-2 inhibitor for low-risk patients).
GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT-2 inhibitors have favorable risk profiles during Ramadan — SGLT-2 inhibitors require caution due to dehydration and DKA risk.
Basal insulin generally should be reduced by 20–30% if taken at suhoor (pre-dawn meal) — pre-mixed insulins require more complex adjustment.
The pre-Ramadan consultation is ideally ≥6–8 weeks before Ramadan starts to allow time for medication switches, education, and glycemic optimization.
Patients with eGFR <30 mL/min/1.73m² should not fast (very high risk) due to fluid-electrolyte risks and altered drug clearance.
Pregnant women with diabetes should NEVER fast during Ramadan — this is an absolute contraindication.
Self-monitoring of blood glucose (SMBG) frequency should be increased during Ramadan, especially in higher-risk patients — at suhoor, midday, 1–2 hours before iftar, 2 hours after iftar, and before sleep.

Next steps

Very High/High Risk: Advise strongly against fasting. Engage in shared decision-making. If patient insists on fasting, provide intensive monitoring plan, frequent glucose checks, and clear DKA/hypoglycemia action plans. Modify medications under specialist supervision. Moderate Risk: Fasting may be possible with appropriate preparation. Pre-Ramadan structured education. Medication adjustment. Frequent SMBG. Emergency action plans. Regular monitoring throughout Ramadan. Low Risk: Fasting is generally safe with basic education and minor medication adjustments. Provide structured diabetes and Ramadan education. Advise on dose timing adjustments. Remind about signs of hypoglycemia and hydration.

Evidence

IDF-DAR International Alliance. Diabetes and Ramadan: Practical Guidelines 2021. Brussels, Belgium: International Diabetes Federation; 2021. Ellulu MS et al. — International Diabetes Federation (IDF). Ramadan and diabetes: a narrative review and practice update. Diabetes Metab Syndr. 2022. The EPIDIAR study (Salti I et al., Diabetes Care 2004) showed that Ramadan fasting increased the risk of severe hypoglycemia 4.7-fold in type 2 diabetes and 7.5-fold in type 1 diabetes.

References

International Diabetes Federation and Diabetes and Ramadan International Alliance. IDF-DAR Practical Guidelines 2021. — link
Salti I et al. A population-based study of diabetes and its characteristics during the fasting month of Ramadan in 13 countries (EPIDIAR). Diabetes Care. 2004;27(10):2306-2311. — link
Hassanein M et al. Diabetes and Ramadan: practical guidelines 2021. Diabetes Res Clin Pract. 2022;185:109185. — link

International Diabetes Federation-Ramadan Alliance (IDF-DAR)

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