Patient Information MANAGING DIET ON AN INSULIN PUMP. Dietetic Department Therapy Services Shrewsbury and Telford NHS Trust 1
Food Bolusing on a pump (ADJUSTING YOUR INSULIN WITH YOUR DIET) Hopefully you have already learnt a lot about adjusting your insulin bolus according to the amount of carbohydrate you eat and have maybe already started to consider how you might need to make further adjustments according to the types of foods you eat. On a normal basal bolus regimen you can consider the timings of boluses or splitting them but with a pump a whole new set of options open up to you. The overall aim of adjusting insulin boluses is to minimize the highs and lows in blood glucose levels after eating and for the insulin action to match the absorption of glucose into the bloodstream. You are aiming for the blood glucose levels 2 hours after eating to be no more 2 2.5mmol/l than the before eating. As you can imagine this takes some thought and knowledge and a lot of practice and patience. Food types and your bolus When you calculate how much carbohydrate is in your meal or snack it is important to think how about the amount AND how quickly the carbohydrate will be digested. Different foods will affect your blood glucose levels in different ways. This is dependent on what the foods are made of and the mix of foods in a meal which affects how they are digested and absorbed It is the TOTAL amount of Carbohydrate that will have the main effect on insulin requirements, but having some knowledge about how fast the glucose will be released will help you decide how to give your bolus. What affects the rate of absorption? Some of this was covered in CHO counting book 2. FIBRE FAT PROTEIN GLYCAEMIC INDEX (GI) MEAL SIZE For example you may find that slowly digested carbohydrate may give a slow rise in blood glucose levels and a standard insulin bolus may work to reduce glucose levels before the food has taken affect. This could cause a hypo. On the other hand this may also result in a high blood glucose level as the food is released into the blood later when the insulin bolus is no longer active. On a standard basal bolus regimen you could decide to delay your bolus or split it and take some insulin with your meal and the rest after. On a pump there are more options. 2
TYPES OF BOLUS Standard (normal) - this is given immediately. You may choose this if foods are mostly CHO / high GI. And going to give less than 5 units of insulin. Split half the bolus can be given just before the meal and the rest after. You may choose this if fatty meal or eating out and meal is extended. This can be an option if you are not sure how much you are going to eat bolus for the amount you are sure you will eat and then give the rest after. Beware though the second bolus is often forgotten. If you are going to need more than 5 units of insulin you have the choice of a split, extended or dual / mulitwave bolus. Extended (Square wave) - This dose is given over a set amount of time. From 30 minutes plus. Useful for fatty meals / Low GI or eating out/ prolonged meals. Multiwave (Dual wave) Most closely matches normal physiology as some insulin is given before or at the start of the meal and then the rest is given over a longer time. The split is usually 30:70 or 50:50 but you can vary this to suit you. This means that 30% of calculated bolus is given immediately then rest (70%) is given extended over 30 minutes to several hours. This will probably the bolus of choice if giving over 5 units as most meal will have a mixture of carbohydrate, protein fat and fibre. 3
The table below will help you with starting advanced bolus options but regular monitoring will help you to fine tune it. Beware of over extending boluses start conservatively then build up. A mixed meal contains protein, carbohydrate and vegetables. High fat meals considered to be >20g. *This assumes blood glucose levels before you eat are within range - you may to adjust if they are not. If your pre meal blood glucose is high you may wish to bolus earlier to stop it increasing further before dropping. If blood glucose is is below target then you may need to bolus as the meal starts or 10 15 minutes after the start. MEAL / SNACK Insulin Dose When to deliver * Extend bolus Mostly high GI (>70) Less than 5 Standard bolus 20 carbohydrate snack or units minutes before X small meal. E.g. bread, eating will start to potatoes white rice, most increase blood breakfast cereals glucose within 30 45 mins Moderate GI (56-69) e.g. basmati rice, new potatoes, bran cereals, banana. High fat mixed meal with high GI carbohydrate eg burger and fries OR Low fat meal with low GI (<55) carbohydrates eg pulses, oats, muesli, milk and yoghurt, apples More than 5 units Before eating or consider split before and after eating. Any Just before eating may start to increase blood glucose within 30 45 mins. If bolus too early blood glucose may drop. 30-60 minutes 30 to 60 may need 1-3 hours Dual or Multiwave? X 30 minutes( no rmal meal) up to 60mins (rice, pasta) 1 3 hours. Start at 1 hr and extend in 15 30 min intervals. Large or extended meals or high fat mixed meal with low GI (<55) carbohydrate e.g. pasta with a creamy sauce Any Consider small percentage at start of meal or delay until after meal has started. As should show a small steady rise in blood glucose levels. May need to consider temporary basal rate too. up to 6 hours up to 6 hours Remember low GI foods may not always be the healthiest choices and it is often the amount of Carbohydrate eaten that you need to consider. You may find calculating the Glycaemic Load is also helpful. 4
GLYCAEMIC LOAD Glycaeimc Load considers the amount AND quality of the carbohydrate. Spaghetti has a low GI value but we tend to eat large quantities. A portion of 250g has a glycaemic load of 23, which is considered to be high. Watermelon is a high GI food ( 80) an average serving of 120g has a glycaemic load of 5. To calculate Glycaemic Load: GI x net carbs ( total carbs fibre) 100 Any value over 20 is considered high. ALCOHOL Because of the potential of alcohol to reduce blood glucose levels in general it is best not to bolus for alcoholic drinks. However some beers and Alco pops do have significant amounts of Carbohydrate in them. It is suggested that to combat the initla rise in blood glucose that you bolus 0.5 units per pint for the first 2 pints and then not for the rest as the risk of a delayed hypo is increased. You can help overcome this by having a snack or supper and considering reducing the basal rate at night. In general if 5 units use Multiwave or split Bolus for snacks 5g CHO Be conservative start low and extend time with practice. Don t bolus with alcohol. Regular monitoring will help you spot trends, but speak with your team if you need more guidance. 5
NOW your turn Now think about foods you enjoy - will they be digested slow, medium or fast? If you are not sure speak with your dietitian. Slow Medium Fast What adjustments would you make to the amount of timing of the bolus for these foods? SNACKS Your treatment plan gives you more flexibility over diet and snacks. You do not need to include them if you don t want to, but if you do then you may need additional insulin. If your snack contains more than g of CHO then should consider an extra bolus. EATING OUT AND PARTIES If you are excited or active then you may want to adjust your basal rate and you may need a supper. Remember that foods eaten out may have more carbohydrate than you might normally eat so adjust your bolus and consider an extended bolus option. If it is high use a correction dose at the next meal. You will probably need to wait until the food arrives before you know what to bolus and it is often easier to bolus with each course. You may even want to delay the bolus until after you have eaten if you are not sure how much you are going to eat. If you are away from home or on holiday then your usual routine may need to change. Consider what you might do in the following situations. When would you take your bolus and what else might you need to think about? Are there any things you would like to change and do differently? Write them down here and discuss them with your diabetes team. 6
Reference Diabetes UK www.glycaemicindex.com Think like a pancreas Gary Scheiner Other Sources of Information Patient Advise and Liaison Services (PALS) PALS will act on your behalf when handling patient and family concerns; they can also help you get support from other local or national agencies. PALS are a confidential service. Royal Shrewsbury Hospital Tel: 0800 783 0057 or 01743 261691 Princess Royal Hospital Tel: 01952 282888 Robert Jones & Agnes Hunt Hospital Tel: 01691 404606 NHS Direct A nurse-led advice service run by the NHS for patients with questions about diagnosis and treatment of common conditions. Telephone: 0845 4647 Website: www.nhsdirect.nhs.uk Equip A West Midlands NHS website which signpost patients to quality health information and provides local information about support groups and contacts. Website: www.equip.nhs.uk Patient UK Provides leaflets on health and disease translated into 11 languages as well as links to national support/self help groups and a directory of UK health websites. Website: www.patient.co.uk Disclaimer This leaflet is provided for your information only. It must not be used as a substitute for professional medical care by a qualified doctor or other health care professional. Always check with your doctor if you have any concerns about your condition or treatment. This leaflet aims to direct you to quality websites: these are correct and active at the time of production. The Shrewsbury & Telford Hospital NHS Trust is not responsible or liable, directly or indirectly, for ANY form of damages whatsoever resulting from the use (or misuse) of information contained in this leaflet or found on web pages linked to by this leaflet. Not to be copied without permission Information produced by: Dietetics Department Date of Publication: September 2012 Due for Review: September 2014 SaTH NHS Trust Author: Lynn Mander Website: www.sath.nhs.uk 7
Your Dietitian is:.. If you have any questions or problems concerning this advice, please contact your dietitian: Department of Nutrition & Dietetics Royal Shrewsbury Hospital Mytton Oak Rd, Shrewsbury Tel 01743 261139 or tel/fax 01743 261462 E-mail: dietitians@rsh.nhs.uk Department of Nutrition & Dietetics Princess Royal Hospital Apley Castle, Telford Tel 01952 641222 ext 4419 E-mail: dietitians@prh.nhs.uk Dietitian, Robert Jones & Agnes Hunt Hospital Gobowen Oswestry Tel 01691 404536 E-mail: dietitian@rjah.nhs.uk Publication Date September 2012 Review Date September 2014 Website www.sath.nhs.uk Not to be copied without permission. 8