Pathophysiology Of Diabetes Flashcards

Question

How does insulin stimulate glycogen synthesis?

Answer 1

Promotes activation of glycogen synthase

Answer 2

Promotes protein synthesis + inhibits protein breakdown Promotes lipogenesis + inhibits lipolysis (via hormone sensitive lipase) Promotes mitogenesis (induces cell division) via insulin-like GH homology Suppress ketogenesis

Answer 3

Major counter-regulatory hormone produced by pancreatic islet α cells Secretion regulated primarily by blood glucose levels (released in hypoglycaemia) & suppressed by insulin

Answer 4

Stimulates gluconeogenesis & glycogenolysis Stimulate proteolysis Increase hepatic FA oxidation & ketone formation Stimulates lipolysis in adipose cells, increases circulating FFA & reduce adipocyte glucose uptake

Answer 5

14-16 hours fast where glucose levels are relatively stable because balance of glucose entrance & utilisation is equal

Answer 6

80% from liver: 50% glycogenolysis + 50% gluconeogenesis -> proportion shift to 90% gluconeogenesis by 48hrs as fast progresses + glycogen stores deplete Kidneys contribute primarily via gluconeogenesis (contain little glycogen) with output of this process comparing to the liver

Answer 7

Favours glucagon because its a primarily catabolic state Loss of insulin action to supress lipolysis + proteolysis so there is production of precursors of gluconeogenesis + production of other fuels e.g. ketones

Answer 8

Insulin responds to rising glucose levels & acute exposure to FFA so insulin:glucagon ratio favours insulin as this is a primarily anabolic state

Answer 9

L-cells of SI produce GI insulinotropic polypeptides such as Glucagon-Like Peptide (GLP) + Gastric Inhibitory Peptide (GLP) which augment insulin secretion in response to oral glucose load Enzymes rapidly degraded by Dipeptidyl Peptidase 4 (DPP4)

Answer 10

ANS directly innervates the pancreatic islets: Sympathetic response releases A/NA which inhibit insulin + promotes glucagon secretion Parasympathetic response has opposite action

Answer 11

Take several hours to have effect but promote gluconeogenesis + inhibit glucose transport into cells Cortisol also directly inhibits insulin secretion (important when considering prescribed steroids, syndromes of cortisol or GH excess)

Answer 12

1. Normal 2. Impaired fasting glycaemia 3. Impaired glucose tolerance 4. Diabetes

Answer 13

MAINLY into type 1 + type 2 by underlying pathogenesis Other types + causes: monogenic, gestational, genetic, pancreas, endocrine or drugs

Answer 14

Autoimmune disease with selective destruction of β cells resulting in complete insulin deficiency - associated with other autoimmune conditions e.g. thyroid disorders, coeliac disease Accounts for 5-10% of DM

Answer 15

Typically rapid but can be a honeymoon period Only treated with insulin Typically seen in younger, lean patients

Answer 16

``` Hyperglycaemia Polyuria Polydipsia Weight loss Fatigue Ketoacidosis ```

Answer 17

< 7.8 mmol/L

Answer 18

There is loss of insulin secretion so an inability to uptake glucose into cells or store it as glycogen Also, unopposed glucagon action (as in a fasted state) causes glycogenolysis + gluconeogenesis

Answer 19

Hyperglycaemia results in glycosuria which exceeds the renal capacity to reabsorb glucose so patients urinate more often to rid the body of glucose Glucose in urine also inhibits concentrating ability of kidney

Answer 20

Physiological response to dehydration to maintain fluid balance High blood [glucose] directly stimulates thirst response too

Answer 21

Unopposed lipolysis + proteolysis for gluconeogenesis precursors

Answer 22

Product of FA metabolism produced as an alternative energy source 1. Acetone 2. Acetoacetate 3. β-hydroxybutyrate)

Answer 23

When ketone production leads to acidaemia -> medical emergency seen almost exclusively in T1DM patients (can be 1st presentation in undiagnosed T1DM often preceded by other acute illness due to stress hormone release or insulin omission)

Answer 24

Signs of shock from severe dehydration High RR (to blow off acid) Abdominal pain (can be severe)

Answer 25

Heterogenous condition characterized by insulin resistance + initially hyperinsulinaemia Loss of 1st phase insulin response + β cell exhaustion occurs over time

Answer 26

Indolent; often asymptomatic at presentation

Answer 27

``` Overweight/obesity (BMI > 25kg/m^2) Central/visceral obesity Lack of physical activity Smoking Poor diet (high saturated fat, low fibre, dyslipidaemia) Low socioeconomic status ```

Answer 28

``` Age > 40yrs (>25 if South Asian origin) FH Ethnicity (Black African, South Asian) History of gestational diabetes/baby > 4.5kg at birth Impaired glucose regulation (prediabetes or non-diabetic hyperglycaemia) Mental health/antipsychotic use history HTN, CVD or stroke history Low birth weight POS ```

Answer 29

Men: >94cm South Asian men: >90cm Women: >80cm

Answer 30

Diet, exercise + lifestyle measures Oral hypoglycaemic agents Injectable agents

Answer 31

Biguanides (e.g. metformin): decrease hepatic gluconeogenesis Sulfonyureas: increase insulin secretion Thiazolidinediones: reduce insulin resistance α-glucosidase inhibitor: decrease carb absorption DPP-4 inhibitors: prevent breakdown of GLP SGLT2 inhibitors: promote glycosuria

Answer 32

GLP-1 analogues Insulin

Answer 33

Hypoglycaemia of treatment Microvascular: nephropathy, retinopathy or neuropathy Macrovascular: IHD, cerebrovascular disease or PVD

Answer 34

``` Sweats Illness Agitation Aggression Irrationality Memory loss ```

Pathophysiology Of Diabetes Flashcards

(58 cards)