GP Endocrinology and Haematology Flashcards
List some causes of hypothyroidism?
Hashimotos
post partum
iodine deficiency
drug induced e.g. amiodarone
surgery
secondary - any disease of hypothalamus or pituitary
Describe hashimotos thyroiditis?
most common cause of hypothyroidism, it is an autoimmune conditions where antibodies attack the thyroid
Describe postpartum thyroiditis?
condition after birth where the woman becomes transiently hyperthyroid followed by hypothyroidism 3-4 months post-partum, most women recover spontaneously and don’t need treatment but it should be noted that the hypothyroid phase is associated with postnatal depression
What is the most common cause of hypothyroidism in the developing world?
iodine deficiency
What is the most common cause of hypothyroidism?
Hashimotos
List some clinical features of hypothyroidism?
• Cold skin and cold intolerance
• Bradycardia
• Dry skin, coarse and sparse hair
• Decreased appetite but weight gain
• Constipation
• Macroglossia and a deep voice
• Slow reflexes
• Menorrhagia
• Fluid retention and oedema
• Loss of libido
Investigations for hypothyroidism?
• In primary hypothyroidism there is an increased TSH and a decreased fT4/T3
• In secondary hypothyroidism there is a decreased TSH and a decreased fT4/T3
• Thyroid peroxidase antibodies (TPO) will be present in Hashimoto’s thyroiditis
Management of hypothyroidism?
• If there is a fixable underlying cause e.g. iodine deficiency or drug that can be stopped or secondary cause with pituitary or hypothalamus that can be fixed – do so
• Those with Hashimotos etc are given replacement therapy with levothyroxine (T4) for life
• Starting dose depends on severity, age and fitness of the patient, 100ug daily for young and fit patients is given and for older patients they are started on 50ug and increased gradually to 100ug
• The aim of therapy is to restore T4 and TSH to normal range
• Those with Hashimoto’s thyroiditis are at higher risk of developing other auto-immune diseases
• Should also be noted that women require higher thyroid hormone replacement during pregnancy
What is a myxoedema coma?
severe hypothyroidism deterioration that typically affects elderly women
Presentation of myxoedema coma?
• Presents with hypothermia, severe cardiac failure (bradycardia, heart block, T wave inversion, prolonged QT), hypoventilation, hypoglycaemia and hyponaetremia
Type 1 vs Type 2 diabetes causes?
type 1
• Absolute insulin deficiency
• Auto-immune attack of beta cells which produce insulin in the pancreas
type 2
• Relative insulin deficiency
• Predominantly insulin resistance
Which groups tend to get type 1 diabetes?
• Tends to present in first 5 decades
• Big peak at school age
• There is genetic susceptibility and HLA types
• Associated with other organ specific auto-immune diseases such as thyroid, coeliacs, Addison’s and pernicious anaemia
Presentation of type 1 diabetes?
• Usually acute onset of symptoms and can present as DKA
• Weight loss
• Severe polyuria and polydipsia
• Polyphagia
• Fatigue
• Weakness
• Doesn’t usually present with diabetic complications as presentation is so acute
Investigations for type 1 diabetes?
• Can be diagnosed on clinical grounds if random plasma glucose is more than 11mmol/L
• Type 1 antibodies test – have 95% sensitivity when combined – GAD, IA-2, ZnT8
• Measure C peptide, not useful for diagnosis as it takes time to decrease but can be useful to confirm type 1 diagnosis later on (C peptide is a byproduct of insulin and will be reduced in type 1 as you produce no insulin)
Management of type 1 diabetes?
if type 1 is suspected you need to refer the adult or child to same day diabetes care team in hospital to confirm diagnosis and provide immediate care
insulin treatment
Insulin treatment in type 1 options?
There are 3 main groups:
1) Rapid acting/ short acting
2) Intermediate/ long acting
3) Mixtures
• A multiple injection regimen with a short acting insulin and a longer acting insulin is suitable for most adults and allows flexibility
• With a twice daily regimen you need a fixed diet
• Insulin pumps are another option, where continuous short acting insulin is delivered by a wearable pump, mealtimes can be programmed and can choose different settings
• Most insulin is given by subcutaneous injection and sites need to be rotated to reduce risk of lipohypertrophy (abdomen, arm, thigh)
Why do insulin sites need to be rotated?
to avoid lipohypertrophy
List 4 complications of insulin therapy?
lipohypertrophy
scarring
weight gain
hypos
What are some techniques to evaluate metabolic control of diabetes?
• Finger prick – glucose capillary – only provides a snapshot so doesn’t always give full picture
• Glycated haemoglobin – HbA1c – measures blood glucose control over a long time
• Flash glucose monitoring and continuous glucose monitoring – device worn that measures interstitial glucose
Risk factors for type 2 diabetes?
• Obesity
• Genetic susceptibility (more so than in type 1)
• South-east Asia have higher rates in slimmer adults
• Family history
• Associated with hypertension, hyperlipidaemia, hyperglycaemia and PCOS (so must check for these)
Presentation of type 2 diabetes?
• May present asymptomatic from screening or incidental finding in hospital
• Usually doesn’t present acutely and there are often signs of microvascular complications already
• Symptoms include polydipsia, polyuria, thrush, weakness, fatigue, blurred vision, infections, complications e.g. neuropathy and retinopathy
What can persistent hyperglycaemia be defined as?
• HbA1c of 48 mm/mol or above
• Fasting plasma glucose of 7.0mm/L or above
• Random plasma glucose of 11.1mmol/L or above
• OGTT of 11.1mmol/L or above
Management of type 2 diabetes?
Lifestyle changes – diet, increase physical activity, stop smoking
Drug Treatments
• Metformin is first line (however it is contraindicated in renal impairment)
• Sulfonylureas (e.g. gliclazide, glipizide) are first line in those who are intolerant to metformin or have contraindications, can also be considered as an add on treatment
• In those with cardiovascular disease offer an SGLT-2 inhibitors (e.g. canagliflozin, dapagliflozin and empagliflozin) as these are proven to have cardiovascular benefit in addition to metformin
• If metformin is ineffective consider dual therapies with DPP-4 inhibitors (e.g. sitagliptin, saxagliptin) or sulfonylureas (e.g. gliclazide)
• GLP agonists for those with a BMI > 30 in combination as 3rd or 4th line therapy, these can facilitate weight loss (injectable drug) e.g. liraglitide, semaglutide
• Insulin is last line in type 2 diabetes when control cannot be achieved any other way
HbA1c targets in type 2 diabetes?
• 48mmol/mol is target for those on no drug therapy or those on drug therapy that doesn’t cause hypos
• 53mmol/mol is target for those on drug therapies that cause hypoglycaemia (e.g. sulfonylureas)
List some complications of diabetes?
• Macrovascular complications – stroke, MI, peripheral vascular disease, atherosclerosis risk all increased
Microvascular complications
- diabetic eye disease
-nephropathy
-neuropathy
What are the main types of neuropathy that you can get in diabetes?
peripheral - glove and stocking distribution
autonomic - gastroparesis
Testing for diabetic nephropathy?
• Earliest evidence is microalbuminuria, need special dipsticks or radio-immunoassay to detect
• Progression to intermittent albuminuria then persistent proteinuria
• All patients with diabetes should have urinary albumin concentration and serum creatinine measured at diagnosis and at regular intervals, usually annually
First line drug for diabetic nephropathy?
ACEi (or ARB if intolerant)
