Type 1 diabetes describes a condition in which the pancreas is no longer able to produce sufficient insulin due to the destruction of the pancreatic beta cells by an autoimmune process. It is a condition which occurs predominantly in younger people, from childhood to young adults, and is increasing in the population, particularly in the under-5 age group. See the separate Diabetes Mellitus article.
Type 1 diabetes accounts for over 90% of diabetes in young people aged under 25 years. 12-15% of young people aged under 15 years with diabetes have an affected first-degree relative. Children are three times more likely to develop diabetes if their father has diabetes than if their mother has diabetes.
The successful management of the person with diabetes depends on working in partnership with the person affected and all members of the team responsible for the various elements of their care. Before a management plan can be agreed, an initial assessment of the health and lifestyle of the patient must be undertaken with particular reference to:
- Diabetic history, both recent and historical.
- Symptoms of potential complications - eg, deterioration in eyesight.
- Other medical conditions.
- Drug history, current medications.
- Family history.
- Occupation and social history - eg, level of exercise, type of diet, smoking history, use of alcohol and recreational drugs.
- Prior knowledge of, attitudes to and concerns about the condition.
- General examination.
- Examination of feet (eg, ulcers, loss of sensation).
- Examination of eyes (eg, cataracts, diabetic retinopathy).
- Blood pressure measurement.
- Examination of peripheral pulses.
Consideration should be given to performing the following investigations, depending on age and previous history of the condition:
- Urine albumin excretion: albumin:creatinine ratio (ACR).
- Glycated haemoglobin (HbA1c).
- U&Es, estimated glomerular filtration rate (eGFR).
- Full lipid profile (including HDL and LDL cholesterol and triglycerides).
- Consider measurement of C-peptide and/or diabetes-specific autoantibody titres if there is a doubt whether a person has type 1 or type 2 diabetes.
- Serological testing for coeliac disease at diagnosis.
Initial management plan
When type 1 diabetes has been diagnosed, initial referral to hospital is often required. Urgent referral is essential if the person is unwell or for pregnant women. See the separate Diabetes in Pregnancy article.
However, if the person is well and sufficient expertise, care and support are available then the initial care and management can be provided at home. The Scottish Intercollegiate Guidelines Network (SIGN) has recommended that a home-based programme for initial management and education of children with diabetes and their families is an appropriate alternative to a hospital-based programme.
Consider referring adults with type 1 diabetes, who have recurrent severe hypoglycaemia that has not responded to other treatments, to a centre that assesses people for islet and/or pancreas transplantation. Consider islet or pancreas transplantation for adults with type 1 diabetes with suboptimal diabetes control who have had a renal transplant and are currently on immunosuppressive therapy.
See the separate Diabetes Education and Self-management Programmes article.
- Discuss diet and give dietary advice taking into account other factors - eg, obesity, hypertension, renal impairment; offer referral to dietician.
- Advise that regular physical activity can reduce arterial risk in the medium to long term and, where appropriate, discuss adjustments to insulin regime or calorie intake during exercise.
- Give advice and support on smoking cessation where appropriate.
- Ask the patient to consider wearing a medical emergency identification bracelet or similar.
- If appropriate, advise of the need to contact the DVLA to inform them of the diagnosis.
- Advise the patient to carry insulin in their hand luggage if they are travelling.
Insulin therapy and blood glucose monitoring
Patients with type 1 diabetes require insulin therapy. See the separate Insulin Regimens article.
- Discuss patient preferences for twice-daily or multiple injection regimes.
- Arrive at the regime in partnership with the patient, as patients arriving at informed shared decisions with their practitioner are more likely to be successfully controlled with the chosen regime.
- Twice-daily regimes using isophane insulin (neutral protamine Hagedorn (NPH) insulin) or long-acting insulin analogues (insulin glargine) may be more suitable for those who require assistance, or have a dislike of injecting.
- Multiple injection regimes using unmodified or 'soluble' insulin or rapid-acting insulin analogues, are suitable for well-motivated individuals with a good understanding of disease control, or those with active or erratic lifestyles.
- Patients should be given instruction in injection technique using a device best suited to each patient's requirements.
- Advise routine self-monitoring of blood glucose levels for all people with type 1
diabetes and recommend testing at least four times a day, including before each
meal and before bed.
- Advise adults with type 1 diabetes to aim for a fasting plasma glucose level of 5-7 mmol/L on waking, and a plasma glucose level of 4-7 mmol/L before meals at other times of the day.
- Give advice on how to change the regime in case of illness. See the separate Diabetes and Intercurrent Illness article.
- Consider a Dose Adjustment For Normal Eating (DAFNE) programme.See the separate Diabetes Education and Self-management Programmes article.
- Give advice on how to recognise a hypoglycaemic episode and what action to take.
- Advise patients to carry a source of glucose in case of hypoglycaemic episodes.
- Consider training a partner/parent in the administration of glucagon.
- Patients should be made aware of contact numbers for advice and it may be helpful to provide written information and/or details of how to access further information if required.
All people with diabetes should be reviewed at least annually and more frequently if there are any factors which may cause concern to the patient or their doctor. The aim of regular review should be to assess and decrease the risk of known complications of diabetes, such as peripheral arterial disease, nephropathy and retinopathy. A review appointment may involve many healthcare workers, such as the dietician, optometrist, podiatrist or other appropriately trained members of staff. Use of a review protocol will ensure that all areas are covered. A review appointment should include:
- Glycaemic control:
- Reinforce the need for lifestyle measures. See the separate Diabetes Diet and Exercise article.
- HbA1c: agree an individualised HbA1c target with each adult with type 1 diabetes, taking into account factors such as the person's daily activities, aspirations, likelihood of complications, comorbidities, occupation and history of hypoglycaemia.
- Full lipid profile.
- Urinary albumin excretion: ACR.
- Renal function: eGFR.
- Measure blood thyroid-stimulating hormone (TSH) levels in adults with type 1 diabetes at annual review.
- Blood pressure measurement: intervention levels for recommending blood pressure management should be 135/85 mm Hg unless the adult with type 1 diabetes has albuminuria or two or more features of metabolic syndrome, in which case it should be 130/80 mm Hg - maintain below 130/80 mm Hg.
- Examination of eyes for signs of retinopathy and cataracts.
- Examination of feet for ulceration/sensation/peripheral pulses.
- Examination of injection sites.
- If the patient is male, ask about impotence.
- Females will need pre-conception advice when appropriate.
Children and young adults
Offer children and young people with type 1 diabetes monitoring for:
- Thyroid disease at diagnosis and then annually until transfer to adult services.
- Diabetic retinopathy annually from age 12 years.
- Microalbuminuria (ACR 3-30 mg/mmol) to detect diabetic kidney disease, annually from age 12 years.
- Hypertension annually from age 12 years.
- See Diabetic Ketoacidosis and Hyperosmolar Hyperglycaemic State.
- See Emergency Management of Hypoglycaemia.
- Cardiovascular disease: see Stable Angina, Acute Coronary Syndrome, Cerebrovascular Events and Peripheral Arterial Disease.
- See Diabetic Nephropathy.
- See Diabetic Retinopathy and Diabetic Eye Problems.
- See Diabetic Neuropathy, Autonomic Neuropathy, Neuropathic Pain and its Management.
- See Diabetic Foot, Leg Ulcers, Painful Foot.
- Frequent, recurrent and persistent infections.
- Without insulin replacement, people with type 1 diabetes are likely to die within days or weeks.
- With insulin replacement, people with type 1 diabetes can participate normally in the usual activities of daily life but are at risk of complications.
- The risk of disability associated with complications is greatly reduced by adherence to a healthy lifestyle, good glucose, lipid and blood pressure control and early detection and management of any complications.
Further reading and references
Continuous subcutaneous insulin infusion for the treatment of diabetes mellitus; NICE Technology Appraisal Guidance, July 2008
Integrated sensor-augmented pump therapy systems for managing blood glucose levels in type 1 diabetes (the MiniMed Paradigm Veo system and the Vibe and G4 PLATINUM CGM system); NICE Diagnostics Guidance, February 2016
Management of diabetes; Scottish Intercollegiate Guidelines Network - SIGN (March 2010 - updated Sept 2013)
Type 1 diabetes in adults: diagnosis and management; NICE Guidelines (August 2015, updated July 2016)
Coeliac disease: recognition, assessment and management; NICE Guidance (September 2015)
Assessing fitness to drive: guide for medical professionals; Driver and Vehicle Licensing Agency
Diabetes (type 1 and type 2) in children and young people: diagnosis and management; NICE Guidelines (Aug 2015, updated Nov 2016)
Diabetes - type 1; NICE CKS, December 2014 (UK access only)