Pre-Ramadan planning in type 2 diabetes with stage 3b CKD and previous hypoglycaemia
A 56-year-old man with type 2 diabetes for 12 years (HbA1c 9.1%, BMI 31 kg/m2) attends for pre-Ramadan counselling. He works as a taxi driver. His eGFR is 38 mL/min/1.73 m2 and urine albumin-to-creatinine ratio is 180 mg/g. Current medication: metformin 1 g twice daily, gliclazide MR 60 mg each morning, insulin glargine 26 units at bedtime, ramipril 10 mg daily and atorvastatin 20 mg daily. During the previous Ramadan he had two symptomatic hypoglycaemic episodes (capillary glucose 3.1 and 2.8 mmol/L), both in the late afternoon while driving, and he broke two fasts. He is determined to fast this year; the fast will run from about 04:00 to 19:30 (15.5 hours). He has no history of ketoacidosis, no foot ulcer and no recent hospital admission. He checks his glucose irregularly, about twice a week.
1. Stratify his risk using a validated Ramadan fasting risk framework and explain which elements make him high risk. What advice do you give him about fasting?
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Using the IDF-DAR risk stratification, he is high risk on several independent counts:
- Prior hypoglycaemia during Ramadan, with glucose 2.8-3.1 mmol/L and two broken fasts - the single strongest predictor of recurrence.
- Insulin plus a sulfonylurea, both hypoglycaemia-prone.
- CKD stage 3b (eGFR 38), which reduces insulin clearance and impairs counter-regulation.
- Occupation as a taxi driver - hypoglycaemia while driving endangers him and the public.
- Long fast (15.5 hours) and poor self-monitoring (twice weekly).
IDF-DAR recommends that high-risk people should not fast, and this advice must be unambiguous and documented after a clear discussion of the risks. The decision is ultimately his, but "you may try" is not adequate counselling.
If he insists on fasting:
- He must agree to monitor glucose at least four times daily and to break the fast when criteria are met.
- He must not drive during the fast, or must check glucose before driving and carry fast-acting glucose in the car.
- Provide a written plan, involve a family member in the discussion, and arrange a follow-up call in the first week.
- Explain sick-day rules in advance.
2. Redesign his glucose-lowering regimen for the fasting month, giving doses and timing, and explain the rationale for each change.
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Stop gliclazide MR 60 mg. Sulfonylureas cause the highest rate of Ramadan hypoglycaemia, especially with CKD, and this is the most likely cause of his late-afternoon episodes. Reducing the dose is insufficient - stop it and replace it.
Insulin glargine: reduce by about 20% to 20 units and give at iftar rather than at bedtime. Giving basal insulin at iftar covers the post-iftar and overnight period when eating occurs, and reduces late-afternoon hypoglycaemia during the fast.
Metformin: 500 mg twice daily, taken with iftar and suhoor (maximum 1 g/day at eGFR 38). Metformin does not itself cause hypoglycaemia, but 2 g/day is excessive at this eGFR; stop it temporarily during acute illness or dehydration.
Add sitagliptin 50 mg once daily at iftar (dose reduced for eGFR 30-45). It is weight-neutral with a low hypoglycaemia risk. Avoid adding a sulfonylurea; an SGLT2 inhibitor would have limited glucose-lowering effect at eGFR 38 and adds dehydration risk during a long fast.
Continue ramipril and atorvastatin, both taken at iftar.
Targets: fasting/pre-iftar glucose 4.5-7.0 mmol/L if achievable without hypoglycaemia, 2-hour post-iftar below 10 mmol/L, and an HbA1c individualised to about 8% during Ramadan rather than the usual 7%.
3. List the situations in which he must break the fast immediately, and set out the monitoring and driving counselling plan.
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Break the fast immediately if:
- Capillary glucose below 3.9 mmol/L (70 mg/dL) at any time, or symptoms of hypoglycaemia even if the meter reads higher.
- Glucose above 16.7 mmol/L (300 mg/dL) with symptoms or ketones, because of the risk of DKA or hyperosmolar decompensation.
- Acute illness, vomiting, diarrhoea, dehydration, or any new foot wound.
Monitoring:
- Glucose before suhoor, at mid-day, mid-afternoon (the time of his previous episodes), before iftar, and 2 hours after iftar; more often if unwell.
- Check blood or urine ketones if glucose is above 16.7 mmol/L.
Driving counselling:
- Do not fast on days with long shifts; test before driving and every 2 hours while driving; keep glucose tablets within reach and stop the car before treating hypoglycaemia.
- Break the fast rather than drive with a glucose below 3.9 mmol/L.
General:
- Hydrate between iftar and suhoor, avoid sugary drinks, and keep the evening meal balanced with slow-release carbohydrate and protein.
- Inspect feet daily and stop fasting during any foot problem.
- Bring the glucose diary to a 2-week review; measure HbA1c after Ramadan and re-titrate the regimen then.