T1DM Flashcards
what is the definition of T1DM
usually leads to absolute insulin deficiency, for most part caused by auto-immune process of varying severity occurring within pancreatic beta-cell
what are the risk factors for developing T1DM
age, sex, race, genotype, possibly geographic location & seasonality
describe the relation between age and T1DM
85% T1DM in under 20s, peak between 1014 y/o, but 25% are diagnosed as adults
(so not disease specific to young)
describe the relation between sex and T1DM
M=F in young, but in Europe M>F after puberty
describe the relation between genotype and T1DM
increased influence of environmental factors
HLA genes represent ~50% familial risk of T1DM
highest risk is DR3-DQ2/DR4-DQ8, confers 19 fold increased risk
(95% diagnosed under 30y/o have one of these genes)
what are some possible environmental/accelerating factors for T1DM
viral infection, maternal factors, weight gain, vitamin D, puberty, stress
what % of people in Scotland with diabetes have T1DM
10.7%
what is the pathophysiology behind T1DM
auto-immune disease, lymphocytes attack islets of Langerhans and subsequently beta-cells causing insulin secretory defects
what auto-antibodies are tested for in diagnoses of T1DM
GAD 65ab, IA-2AB, ZnT8AB
if all 3 +ve chance of T1DM >95%
what are some of the clinical features of T1DM
raised glucose, ketones, decreased insulin, decreased beta-cell mass and decreased C-peptide
what tests are sued to initially diagnose diabetes(not what type)
fasting glucose >/= 7mmol/L
random >/= 11mmol/L
and symptoms
what tests are used to identify if someone has type 1 diabetes
often diagnosed on history and presentation(eg DKA) alone
if any doubt GAD/IA2 antibodies and C peptide may help
what is a typical clinical presentation for someone with type 1 diabetes
pre-school/peri-puberty, small peak in early 30s, usually lean, acute onset, severe symptoms, severe weight loss, ketonuria +/- metabolic acidosis, no evidence of microvascular disease diagnosis, immediate and permanent requirement for insulin
what is LADA
latent autoimmune diabetes of adults
late onset T1DM, probably quite common in ‘typical’ T2DM patients
ketosis = T1DM
what HbA1c range can be sued to diagnose T1DM
can’t use HbA1c to diagnose T1DM
what are some of the symptoms people with diabetes can present with
thirst, polyuria, thrush, weakness/fatigue, blurred vision, infections, weight loss, keto-acidosis
when should hospitalisation be considered in diabetes presentation
DKA, significant ketonaemia, vomiting
what are the aims of T1DM therapy
prevent hyperglycaemia, avoid hypoglycaemia and reduce chronic complications
what is involved in the management of newly diagnosed T1DM patients
BG and ketone monitoring, insulin usually basal bolus regime, carb estimate, regular dietician contact, education about self-management(ie DAFNE)
what is involved in the annual review assessment of T1DM patients
weight, BP, bloods(HbA1c, renal function, lipids), retinal screening, foot risk assessment
describe the action of prandial insulin analogues, and give an example
onset action 10-15 mins, peak action 60-90mins, duration 4-5hrs
example = NovoRapid
what is the benefit of an analogue basal insulin over an isophane basal insulin, and give an example of each
analogue = longer duration of action, less peak activity(flatter profile), can be given once or twice a day example = Lantus(analogue), Insulatard(isophane)
describe how most T1DM patients should be treated with insulin
multiple daily injections(3/4 daily) or CSII(insulin pump), educated how to match prandial insulin dose to carb intake, most should use insulin analogues(reduce hypoglycaemia risk)
what situations decrease the likelihood of someone having T1DM, ie is it wrong diagnosis
diabetes diagnosed <6months old, detectable insulin production >/= 3years after diagnosis, undetectable pancreatic antibodies at diagnosis
what are some associated auto-immune conditions with T1DM
thyroid disease, coeliac disease, pernicious anaemia, Addison’s disease, IgA deficiency
