GUIDELINE FOR THE MANAGEMENT OF PATIENTS WITH
DIABETES HAVING WEIGHT LOSS SURGERY
Version
1
Name of responsible (ratifying) committee
Surgical and Cancer Governance committee
Date ratified
3rd April 2014
Document Manager (job title)
Bariatric Practitioner
Date issued
16th May 2014
Review date
15th May 2015
Electronic location
Clinical Guideline
Related Procedural Documents
Diabetes guideline
Key Words (to aid with searching)
Bariatric, Diabetes, Weight loss surgery
Version Tracking
Version
Date Ratified
Brief Summary of Changes
Management of Diabetic Patients Having Weight Loss Surgery
Issue date
16/05/2014
(Review date May 2015
Author
Version 1
Page 1 of 6
CONTENTS
1.
INTRODUCTION.......................................................................................................................... 3
2.
PURPOSE ................................................................................................................................... 3
3.
SCOPE ........................................................................................................................................ 3
4.
DEFINITIONS .............................................................................................................................. 3
5.
PROCESS ................................................................................................................................... 4
6.
TRAINING REQUIREMENTS ...................................................................................................... 4
7.
REFERENCES AND ASSOCIATED DOCUMENTATION ............................................................ 5
8.
MONITORING COMPLIANCE ..................................................................................................... 5
9.
EQUALITY IMPACT ASSESSMENT ............................................................................................ 8
Management of Diabetic Patients Having Weight Loss Surgery
Issue date
16/05/201 (Review date May 2015
Page 2 of 11
Version 1
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1. INTRODUCTION
This guideline has been developed to provide a framework for the postoperative management
of diabetic patients who have had weight loss surgery.
Patients who are having weight loss surgery are more likely to have hypoglycaemic episodes as
they lose weight rapidly and in gastric bypass surgery have altered absorption and reduced
calorie intake, therefore affecting the amount of medication they need, if any.
2. PURPOSE
The purpose of this guideline is to ensure that all patients who have diabetes and have had
weight loss surgery are managed appropriately using the attached algorithm to avoid
hypoglycaemic events during their weight loss journey.
3. SCOPE
This guideline will apply to adult inpatients that have Type 1 or Type 2 diabetes requiring
management decisions on treatment for their diabetes post operatively and on discharge. To be
used in conjunction with the trust guideline for Hypoglycaemia.
4. DEFINITIONS
Weight Loss Surgery
Any surgical procedure that produce weight loss by restricting food intake and/or interfering
with nutrition through malabsorption.
Diabetes
There are two major types of diabetes:
Type 1: an autoimmune disease characterised by hyperglycaemia resulting from absolute
deficiency of insulin affecting a heterogeneous group of people. (1)
Type 2: a metabolic disease characterised by hyperglycaemia resulting from relative insulin
deficiency and insulin resistance affecting a heterogeneous group of people. (1)

Hypoglycaemia
Hypoglycaemia results from an imbalance between glucose supply, glucose utilization, and
insulin levels resulting in more insulin than is needed at that time (3)
Hypoglycaemia is defined as a blood glucose level being equal or less than 4mmols/l, with
or without symptoms (1). Hypoglycaemia can occur not only with people who are requiring
insulin treatment, but also those who are taking oral anti-diabetic tablets such as gliclazide or
Pioglitazone (1). Insulin and Sulphonylureas (such as gliclazide) tablets give most risk of
hypoglycaemic events. Hypoglycaemic events are common but should not be a daily
normality. Hypoglycaemia is a side effect of treatment for diabetes and therefore is unlikely
to occur in people treated with diet and exercise alone.
Risk of Hypoglycaemic events after bariatric surgery
Gastric restrictive procedures such as Laparoscopic adjustable gastric banding,
Sleeve gastrectomy and Vertical gastroplasty limit gastric volume and therefore restrict the
intake of calories by inducing satiety (4)
Malabsorptive procedures such as Roux en Y bypass and Gastric switch surgery promote
weight loss by interrupting the digestive process causing food to be poorly digested and
absorbed. Hence diabetes remits within days, even before the patient has lost much
weight.(4) Therefore requiring reduced or no diabetes medication.
Management of Diabetic Patients Having Weight Loss Surgery
Issue date
16/05/201 (Review date May 2015
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PROCESS
Post Operative Therapy for Diabetes Following Bariatric Surgery
Type 2 Diabetes Therapy
Type 1
Diabetes
Therapy
It is sometimes difficult to decide if a patient has type 1 or type 2 diabetes, as either type can be on Insulin. However, if a patient is thought
to be type 2 and is in fact type 1, and their insulin is stopped inappropriately, serious events such as DKA can be caused. So if unsure,
treat as type 1 by withdrawing insulin slowly as the blood sugars will allow. Using the algorithm below.
Dietary and
Lifestyle
Monitor
glucose
levels
GP
follow up
Oral Therapy
GLP - 1
Planned procedure:
Gastric Bypass or
Sleeve gastrectomy,
discontinue
Insulin < 20units total / day
and Oral Therapy
Discontinue
Planned procedure:
adjustable gastric band,
continue with GLP – 1
once eating,
discontinue insulin
or oral therapy
Insulin > 20units total / day
Discontinue unless
(a) Type 1 or
(b) Type 2
administering
more than 20 units
total daily dose pre
procedure and then
follow type 1
diabetes therapy
(See right)
Post procedure: patient to monitor glucose levels pre and 2 hrs post meals (min two tests per day).
See GP at two weeks to review glucose levels
If taking metformin pre procedure recommence at two weeks in all cases,
regardless of glucose level, start at 500mg with evening meal
If 50% of results are > 10 mmols/l after 4 weeks then recommence pre procedure medication, in the
following order starting at minimal doses and titrate upwards according to response:
a)
Oral Therapy in addition to Metformin
b)
GLP – 1
c)
Insulin therapy (to contact diabetes centre and discuss with DSNs Anita Thynne and Joanne Buchanan)
Insulin
Do Not Discontinue
Confirm diagnosis:
Type 1 = started on
Insulin at diagnosis
Type 2 =
diet/lifestyle changes
and/or tablets
at diagnosis
Re-commence
insulin at 25%
of original dose
administered
pre commencing
the milk diet
Monitor capillary
blood glucose
pre-meal and 2 hrs
post meals.
If 50% of results
are >10mmols/l
to titrate insulin up
in the usual manner
Diabetes centre
follow up
.
5. TRAINING REQUIREMENTS
All staff involved in clinical care of inpatients who have diabetes and are having weight loss
surgery should read this guideline and use the algorithm as a guide to managing their diabetes.
Management of Diabetic Patients Having Weight Loss Surgery
Issue date
16/05/201 (Review date May 2015
Page 4 of 11
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6. REFERENCES AND ASSOCIATED DOCUMENTATION
1) Diabetes UK (2011) [online] Monitoring Your Health / Glucose Levels. www.diabetes.org.uk
TEL: 020 73231531
2) British National Formulary 60.Section 6.1, Drugs Used In Diabetes.
London
BMJ Group.
3) Turner H and Wass JA (2007). Oxford Handbook of Diabetes. Oxford University Press.
Oxford
4) Kashyap, S., Gastmaitan, P., Brethauer, S. (2010). ‘Bariatric surgery for type 2
diabetes: Weighing the impact for obese patients’. Cleveland Clinic Journal of Medicine.
vol 77,.No 7, Pg 468-476.
7. MONITORING COMPLIANCE
This policy will be monitored as follows:

Management of patients with diabetes who are having weight loss surgery and who are
suffering from hypoglycaemia episodes despite the use of the algorithm will be referred
to the diabetes specialist nurse.

Specialist diabetes team will discuss unfavourable hypoglycaemia management issues
and the suitability of the algorithm.

Annual audits will capture hypoglycaemia management. Results of the audit will be
considered by the specialist diabetes and Endocrinologist team and any educational
needs will be identified and addressed by the Bariatric nurse practitioner/team.
8. EQUALITY IMPACT ASSESSMENT
Portsmouth Hospitals NHS Trust is committed to ensuring that, as far as is reasonably
practicable, the way we provide services to the public and the way we treat our staff reflects
their individual needs and does not discriminate against individuals or groups on any grounds.
This guideline has been assessed accordingly
Management of Diabetic Patients Having Weight Loss Surgery
Issue date
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Management of Diabetic Patients Having Weight Loss Surgery
Issue date
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