Type 1 diabetes mellitus Flashcards
Describe the pathophysiology of T1DM
- Autoimmune destruction of pancreatic beta-cells resulting in insulin insufficiency
- Presence of antibodies ICA and GAD65
- Associated with HLA D3 and D4
What is the DVLA guidance for diabetes mellitus
All patients must be able to produce a blood glucose >5 mmol/L at least 45 minutes prior to driving
Outline the role of insulin
- Decreased glycogenolysis
- Increased hepatic glucose uptake
- Increased uptake in muscles and adipose
- Increased FFA clearance
- Active transport of amino acids into cells
- Decreased protein catabolism
- Decreased gluconeogensis
- Suppresses ketone production
Outline patient education for diabetes mellitus
Offer structured education at time of diagnosis with annual reinforcement and review. Ownership is crucial to preventing/delaying onset of complications.
Daily glucose monitoring using BM machines, and 3-monthly HbA1c.
T1DM: DAFNE course provides education on glycaemic index of food, and insulin doses. Patients have greater freedom with food and activities.
T2DM: DESMOND course
When should statins be offered to people with T1DM?
- Over 40 years old
- T1DM for over 10 years
- Established nephropathy
- Other CVD risk factors
State 3 side-effects of insulin
- Weight gain: inappropriate dose, emphasise lifestyle
- Hypoglycaemia
- Hyperglycaemia
- Lipoatrophy/lipohypertrophy
- Painful injections: shallow injection
- Insulin allergic reaction (exceptionally rare)
What advice should be given regarding insulin injections?
Insulin is administered as subcutaneous injections in the abdomen, thighs, or upper arm.
Needle inserted to its full length - too shallow is painful
Rotate injection site to prevent lipohypertrophy
What are the sick-day rules that T1DM should adhere to during illness?
- Increase frequency of blood glucose monitoring to four hourly or more frequently
- Encourage fluid intake: at least 3L/d
- If struggling to eat, sugary drinks
- Have a box of ‘sick day supplies’
- Access to mobile phone
What are the classic features of T1DM?
- Hyperglycaemia, polydipsia, polyuria
- Lethargy, recurrent/prolonged infections
- Ketosis
- Rapid weight loss
- Age of onset below 50 years
- BMI below 25 kg/m2
- Personal or FHx of autoimmune disease
What investigations can be used to confirm T1DM when it presents with atypical features, or clinical suspicion of monogenic form of diabetes?
C-peptide and/or diabetes specific antibody titres
How often is HbA1c monitored in T1DM?
Every 3-6 months
Why might HbA1c monitoring be invalid? How should blood glucose control be assessed in these cases?
- Disturbed erythrocyte turnover
- Abnormal haemoglobin type
Use fructosamine estimation
What is the initial target HbA1c level for T1DM?
48 mmol/mol or lower
To minimise risk of long-term vascular complications
Advise a patient with T1DM about self-monitoring of blood glucose
- Routing self-monitoring at least 4 times a day
- Including before each meal and before bed
- Up to 10 times a day
- Target HbA1c not met
- Hypoglycaemic episodes more frequent
- DVLA requirement
- Periods of illness
- Before, during, after sport
- Diabetes in pregnancy
- More than 10 times a day
- Specific lifestyle
- Impaired hypoglycaemic awareness
State the advised blood glucose targets for T1DM
- Fasting plasma glucose of 5-7 mmol/L on waking
- Plasma glucose of 4-7 mmol/L before meals
- If testing after meals: 5-9 mmol/L at least 90 minutes after eating
- Individualised bedtime targets
