Diabetes Mellitus type 2 Flashcards
Define
DEFINITION: characterised by increased peripheral resistance to insulin action, impaired insulin secretion and increased hepatic glucose output
Causes
Genetic and environmental
There are a few monogenic causes of diabetes (e.g. MODY, mitochondrial diabetes)
Obesity increases the risk of T2DM (due to the action of adipocytokines)
Diabetes can happen secondary to:
- Pancreatic disease (e.g. chronic pancreatitis)
- Endocrine disease (e.g. Cushing’s syndrome, acromegaly, phaeochromocytoma, glucagonoma)
- Drugs (e.g. corticosteroids, atypical antipsychotics, protease inhibitors)
Epidemiology
UK Prevalence: 5-10%
Asian, African and Hispanic people are at greater risk
Incidence has increased over the past 20 yrs
This is linked to an increasing prevalence of obesity
Symptoms
May be an incidental finding
Polyuria
Polydipsia
Tiredness
Patients may present with hyperosmolar hyperglycaemic state (HHS)
Infections (e.g. infected foot ulcers, candidiasis, balanitis)
Assess cardiovascular risk factors: hypertension, hyperlipidaemia and smoking
Signs
Calculate BMI
Waist circumference
Blood pressure
Diabetic foot (ischaemic and neuropathic signs)
- Dry skin
- Reduced subcutaneous tissue
- Ulceration
- Gangrene
- Charcot’s arthropathy
- Weak foot pulses
Skin changes (RARE):
Necrobiosis lipoidica diabeticorum (well-demarcated plaques on shins or arms with shiny atrophic surface and red-brown edges)
Granuloma annulare (flesh-coloured papules coalescing in rings on the back of hands and fingers)
Diabetic dermopathy (depressed pigmented scars on shins)
Investigation
T2DM is diagnosed if one or more of the following are present:
- Symptoms of diabetes and a random plasma glucose > 11.1 mmol/L
- Fasting plasma glucose > 7 mmol/L
- Two-hour plasma glucose > 11.1 mmol/L after 75 g oral glucose tolerance test
Monitor:
- HbA1c
- U&Es
- Lipid profile
- eGFR
- Urine albumin: creatinine ration (look out for microalbuminuria)
Management
Glycaemic control - there is a step-wise approach to the management of T2DM:
- At diagnosis: lifestyle + metformin
- If HbA1c > 7% after 3 months: lifestyle + metformin + sulphonylurea
- If HbA1c > 7% after 3 months: lifestyle + metformin + basal insulin
- If HbA1c > 7% after 3 months and fasting blood glucose > 7 mmol/L: add premeal rapid-acting insulin
- NOTE: sulphonylurea may be given as a monotherapy if patients cannot tolerate metformin
- NOTE: pioglitazone (thiazolidinedione) may also be given alongside metformin and a sulphonylurea
Screening for complications
- Retinopathy
- Nephropathy
- Vascular disease
- Diabetic foot
- Cardiovascular risk factors (e.g. blood pressure, cholesterol)
Pregnancy - requires strict glycaemic control and planning of conception
Hyperosmolar Hyperglycaemic State - management is similar DKA
Except use 0.45% saline if serum Na+ > 170 mmol/L
Complication
Hyperosmolar hyperglycaemic state
- Due to insulin deficiency
- Marked dehydration
- High Na+
- High glucose
- High osmolality
- No acidosis
Neuropathy:
- Distal symmetrical sensory neuropathy
- Painful neuropathy
- Carpel tunnel syndrome
- Diabetic amyotrophy
- Mononeuritis
- Autonomic neuropathy
- Gastroparesis (abdominal pain, nausea, vomiting)
- Impotence
- Urinary retention
Nephropathy:
- Microabuminuria
- Proteinuria
- Renal failure
- Prone to UTI
- Renal papillary necrosis
Retinopathy:
- Background
- Pre-proliferative
- Proliferative
- Maculopathy
- Prone to glaucoma, cataracts and transient visual loss
Macrovascular complications:
- Ischaemic heart disease
- Stroke
- Peripheral vascular disease
Prognosis
Good prognosis with good control
Pre-diabetes can be diagnosed based on fasting blood glucose and oral glucose tolerance test:
- Impaired Fasting Glucose (IFG) = fasting blood glucose 5.6-6.9 mmol/L
- Impaired Glucose Tolerance (IGT) = plasma glucose level of 7.8-11.0 mmol/L measured 2 hrs after a 75 g oral glucose tolerance test
People with IFG or IGT are at high risk of developing type 2 diabetes
