Diabetes Mellitus Type 1

Question 1

Define Diabetes mellitus type 1

Answer 1

Chronic metabolic hyperglycaemic condition caused by absolute insufficiency of pancreatic insulin production, causing impaired carbohydrate, protein and fat metabolism.

Question 2

What is the aetiology of T1DM

Answer 2

Destruction of the pancreatic insulin-producing β-cells, → absolute insulin deficiency
Often due to an autoimmune process (90%) against the β cells (GAD, insulin, IP2, ZnTB)
90% β cell destruction → hyperglycaemia

Question 3

What is the epidemiology of T1DM

Answer 3

One of the most common chronic disease in childhood (<20)
Accounts for 5-10% of all diabetic patients and >85% of diabetes under 20
Can present at any age, but highest incidence is children 10-14

Question 4

What are the symptoms of T1DM

Answer 4

Polyuria
Polydipsia
Weight loss
Nocturia
Fatigue, excessive tiredness
Blurred vision
± symptoms of complications
± other autoimmune diseases e.g. vitiligo, Addison’s, thyroid disease

Question 5

What investigations should be done for T1DM

Answer 5

Bedside: BM, urine dip, urinary ketones (+ve = T1DM, -ve = T2), ECG, fundoscopy
Bloods
- Random plasma glucose: >11
- Fasting plasma glucose: >6.9
- HbA1c: >48 (glucose for 2-3 months)
- OGTT >11.1 (impaired = 7.9-11.1) - for borderline/GDM
- Plasma ketones: present (T1)
- Fasting C peptide: low or undetectable in T1DM
- Auto-immune markers (+ve)
- Fasting lipid: often normal (Differentiate from T2DM)
- Renal function

Question 6

What is the management for T1DM

Answer 6

MDT - paediatric diabetes team

Conservative: personalised care plan
- Nutritional advice (DAFNE - dose adjustment for normal eating): carbs (low glycaemic index), weight, CVD risk - NO RESTRICTION (still growing)
- Physical activity
- Self-monitoring
- Hypoglycaemia awareness education + avoidance
- CVD risk monitoring
- Complication monitoring
- Monitor HbA1c every 3-6 months

Pharmacological: Insulin therapy

Question 7

What is the strategy for self monitoring in children with T1DM

Answer 7

Offer real-time continuous glucose monitoring (rtCGM) to all children with T1DM
Or intermittently scanned continuous glucose monitoring (isCGM)/ “flash”
Or capillary glucose monitoring (CGM) 5x a day at least

Hyperglycaemia:
- Offer blood ketone testing strips and a meter
- Test for ketonaemia if they are ill or have hyperglycaemia

Question 8

Describe insulin therapy for T1DM

Answer 8

1. Basal bolus insulin regimen (long acting + short acting before meals)
   - Long acting = determir (2x daily) OR glargine
   - Rapid (before meals) = lispro, aspart, glulisine
2. Continuous SC insulin infusion
3. Mixed insulin regimen (unable to manage 3-4 injections daily)
4. Sliding scale (hospital use) → metabolic stress → fluctuating glucose levels (adjustment of short acting insulin according to glucose levels every 4 hours)

Diabetes sick day rules: when unwell, If a patient is on insulin, they must not stop it due to the risk of diabetic ketoacidosis. They should continue their normal insulin regime but ensure that they are checking their blood sugars frequently

Question 9

What should children be monitored for in T1DM

Answer 9

Thyroid disease, at diagnosis then annually until transfer to adult services
Diabetic kidney disease via albumin:creatinine ratio (ACR) measurement, annually from 12 years
Hypertension, annually from 12 years
Retinopathy screening, from 12 years - refer to diabetic eye screening programme
Dental health reviews
Coeliac disease
Foot problems

Question 10

What are the complications of insulin treatment

Answer 10

Weight gain (can predispose to diabulimia where diabetics do not take insulin due to fear of weight gain)
Fat hypertrophy at injection sites
Hypoglycaemia (missing meals, overdose)

Question 11

What are the complications of T1DM

Answer 11

Long term hyperglycaemia → Vascular complications
- Microvascular complication: retinopathy, neuropathy, nephropathy
- Macrovascular complications: cardiovascular, cerebrovascular, peripheral vascular disease
- Hyperglycaemia → oxidative stress → endothelial dysfunction → allows LDL entry → atherosclerosis
Periodontitis
Juvenile cataracts
Necrobiosis lipoidica
Addison’s disease
DKA
Increased risk of other autoimmune diseases

Question 12

What is the management for the following complications of T1DM:
Retinopathy
Nephropathy
Neuropathy
Gastroparesis
Erectile dysfunction
Foot care
Cardiovascular risk

Answer 12

Retinopathy: routine eye screening
Nephropathy: monitor albumin:creatinine ratio, ACEi/ABR
Neuropathy: autonomic neuropathy → duloxetine
Gastroparesis: mashed/purred food for symptomatic relief
Erectile dysfunction: phosphodiesterase-5 inhibitor
Foot care: X-ray/MRI feet
Cardiovascular risk: albuminuria, glucose control, BP, cholesterol

Question 13

What is the prognosis for T1DM

Answer 13

Untreated - fatal due to DKA
Poor controlled T1DM is a risk factor for many chronic complications, including blindness, renal failure, foot amputation and heart attack
Intensive glycaemic control has been shown to decrease the incidence of microvascular and macrovascular disease in T1DM
Even a few years of intensive glucose control translate to reduced rates of microvascular and macrovascular complications 10 years later
Overall, cardiovascular disease is the major cause of death and a major cause of morbidity for patients with diabetes