Those with very poor glucose control should be discouraged from fasting

• A total fast is not recommended for anyone with diabetes. Adequate hydration is important even during the period of fasting.
• For those on insulin, a partial fast is preferred to absolute or normal forms of fasting.
• Self-blood glucose monitoring (SBGM) is mandatory for people with diabetes who elect to fast.
• Once-a-day monitoring is adequate for patients on diet only or diet with metformim.
• In patients on insulin secretagogues, SBGM should be done at least three times a day.
• Doctor and patients should agree on how to handle abnormal results of SBGM and as to when to terminate the fast, e.g. frequent hypoglycaemia, intercurrent infection.
• If hyperglycaemia is marked, retesting should be more frequent and the urine tested for ketones. Clear guidelines should be set as to when to terminate the fast, e.g. frequent hypoglycaemia, intercurrent infection.
• Vigorous activity should be avoided during period of fast.
• People who fast should have ready access to their health-care providers during the period of fast.

Management of normal fasting for people treated with oral hypoglycaemic agents

• Fasting is possible in this situation.
• Usual dietary advice should be followed at this time.
• Patients on metformin, alpha-glucosidase inhibitors and thiazolidinediones (glitazones) can continue taking the usual doses at the usual times.
• If on chlorpropamide, this should be stopped and substituted with a shorteracting agent.
• If on a second or third generation sulphonylurea (glibenclamide, gliclazide, glipizide, glimepiride), this should be taken at the time of breaking the fast and not before dawn.

Management of normal fasting for T2DM patients on insulin

• If on once daily insulin before bed, this can be given as usual
• If on twice daily short- and intermediate-acting insulin:

o Before the dawn meal, give the usual evening dose of short-acting insulin without any intermediate-acting insulin.
o Before the evening meal give the usual morning dose of short-acting and intermediate-acting insulin.

• If on basal bolus regimen:Usual doses of the short-acting insulin can be given before the dawn and evening meals, and usual doses of the intermediate-acting insulin can still be given at 10pm.
• Regular SBGM is essential to ensure prevention of hypoglycaemia, and titration of doses should occur according to SBGM results.
• Neither the insulin injection nor the breaking of the skin for SBGM will break the fast. Management of other fasting types