Shift work and diabetes

Shift work is associated with (1):

• increased risk of becoming overweight and obese (both general and abdominal)
• increased risk of type 2 diabetes
  
  
• Management of Type 2 diabetes and shift work:
  
  
  • metformin does not have a high risk of hypoglycaemia and is unlikely to be affected by changing of shift pattern - doses would not be altered but timing of dose would be changed to reflect change in meal pattern
    
    
  • glitazones do not have a high risk of hypoglycaemia and is unlikely to be affected by changing of shift pattern - dose would not be altered
    
    
  • sulphonylureas - there is a relatively high risk of hypoglycaemia associated with sulphonylurea use (compared with agents such as metformin, glitazones, SGLT inhibitors and gliptins) - therefore if changes in work shift patterns also are accompanied by changing meal patterns then these needs to be borne in mind with timing of sulphonylurea dosing. If meals are "missed" during particular shifts then changes to the dosing/use of sulphonylureas might be required
    
    
  • sodium glucose co-transporter 2 (SGLT2) inhibitors - have a much lesser risk of hypoglycaemia than sulphonylureas. There is however an increased hypoglycaemia risk if used in combination with a sulphonylurea or insulin
    
    
  • gliptins
    • in previous NICE guidance it was stated that (2):
      • "..a DPP-4 inhibitor (sitagliptin, vildagliptin) should considered as an alternative to a sulfonylurea as second-line therapy to first-line metformin when control of blood glucose remains or becomes inadequate (HbA1c >=6.5%, or other higher level agreed with the individual) if:
        • the person is at significant risk of hypoglycaemia or its consequences
          • people who are risk in this category include older people and people in certain jobs [e.g. those working at heights or with heavy machinery] or people in certain social circumstances [e.g. if a person lives alone])..."
      • this NICE guidance would suggest that gliptins might be an appropriate treatment option for shift workers where meal times are often chaotic. In these circumstances hypoglycaemic effects of sulphonylureas (which are not glucose dependent in terms of stimulation of insulin release) might be better replaced by a gliptin (glucose dependent insulin release) where the risks of hypoglycaemia are significantly less than those of sulphonylureas
        
        
  • meglitinides e.g repaglinide, nateglinide - lower blood glucose by stimulation of insulin release from the pancreas - they are short-acting and therefore might be a useful treatment option where meal taking is not regular as might occur if a worker is changing shift pattern. However these agents still have the risk of hypoglycaemia if taken and a meal is "missed"
    
    
  • incretin mimetics (e.g. exanatide) also have a low risk of hypoglycaemia relative to agents such as sulphonylureas
    
    
• Insulin and shift work (3)
  
  • if a diabetic is working shift patterns then some modification in drug treatment and meal pattern may be necessary, as may a dietetic review
    • meal planning is important - with meals evenly spaced at around 4-5 hour intervals and snacks if required, with consistent types and amounts of food
  • if on the afternoon shift
    • only change to the meal plan that may be required is to include a larger evening snack to match increased physical activity, particularly if the person is on insulin
  • if on an overnight shift
    • this working pattern requires a significant adjustment in meal planning, allowing for the greater amount of food to be eaten during the shift, with an adequate amount of food for the periods of sleep during the day
  • insulin adjustments are usually necessary when working shifts, although insulin can be delayed 1-2 hours without significantly affecting diabetic control
    • delaying insulin treatment by 1-2 hours may be all that is required to manage the afternoon shift. If extra food is consumed later in the day, a slight increase in the late-evening insulin dose may be required
• other considerations when working shift patterns include:
  • ensuring availability of food
  • having meal breaks are at set times
  • having available a rapid-acting carbohydrate is available for treatment of hypoglycaemia
  • note that increased physical activity can result in fluctuations in blood glucose control. If the work is physically demanding, particularly at unexpected times, there is a risk of hypoglycemia

Notes:

• patients with diabetes who work shifts should discuss their work patterns with a specialist in the management of diabetes
• frequent self-monitoring, and recording of blood glucose concentration, is of great importance to help determine patterns of blood glucose control, identify problem areas and plan ahead

Reference:

1. Kecklund G, Axelsson J. Health consequences of shift work and insufficient sleep. BMJ. 2016;355:i5210.
2. NICE (May 2009). Type 2 diabetes: newer agents Type 2 diabetes: newer agents for blood glucose control in type 2 diabetes
3. Drug and Therapeutics Bulletin 2005; 43(10):73-77.