Diabetes Mellitus Flashcards

2.4

1
Q

what is diabetes mellitus

A

Group of metabolic disorders sharing the common Hyperglycemia.(defects in insulin secretion, insulin action or both.)
* Metabolic derangement associated with secondary damage in multiple organs -
kidneys, eyes, nerves & blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what have contributed to the
increases in diabetes and obesity, also know as Diabesity epidemic

A

Increasingly sedentary lifestyles and poor eating habits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define prediabetes

A

elevated blood sugar that does not reach the criterion accepted for an outright diagnosis of
diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Diagnostic criteria for:
Diabetes Mellitus

A

➢Random blood glucose concentration >200 mg/dL
➢Fasting blood glucose concentration greater than 126 mg/dL
➢Oral glucose tolerance test (OGTT)
➢Glycated hemoglobin(HbA1c)>6.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. A fasting plasma glucose between 100 and 125 mg/dL and/or
  2. A 2-hour plasma glucose between 140 and 199 mg/dL during an OGTT test, and/or
  3. HbA1C level between 5.7% and 6.4%

is termed as:

A

Impaired glucose tolerance (prediabetes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pathogenesis of Type I DM

A
  • Autoimmune disease islet destruction is caused primarily by T cells reacting against endogenous β-cell antigens.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

“insulin-dependent diabetes mellitus” is what type of DM

A
  • Absolute lack of insulin *
    TYPE 1 DM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

TYPE 1 DM accounts for _________-% of cases

A

5-10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

TYPE ____DM Develops in childhood and peaks at puberty

A

type 1 DM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

_____ and ______ – late in course of illness ( >90% β cell loss) for type 1 DM

A

Ketoacidosis and coma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

genetic susceptibility of type 1 DM: HLA

A

✓HLA: Strongest association class II MHC coded on Chr 6p21 (HLA-DR3 and DR4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

genetic susceptibility of type 1 DM: NON-HLA

A

Insulin gene- reduced expression in thymus & reduced elimination of self reactive T cells

CTLA4 + PTPN22 ==> inhibit T cell response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

genetic susceptibility of type 1 DM: NON-HLA

A

Insulin gene- reduced expression in thymus & reduced elimination of self reactive T cells

CTLA4 + PTPN22 ==> inhibit T cell response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

loss of self tolerance lead to __________- against a variety of beta cell antigens, including insulin and the beta cell enzyme glutamic acid decarboxylase detected in
70-80% patients

A

autoantibodies,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

loss of self tolerance lead to __________- against a variety of beta cell antigens, including insulin and the beta cell enzyme glutamic acid decarboxylase detected in
70-80% patients

A

autoantibodies,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are Initiating triggers for Type 1 DM

A

Mumps, Rubella & Coxsackie B viruses - Molecular mimicry to β cell antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are Intestinal dysbiosis for type 1 DM

A

Change in GUT flora ? Cause or effect of hyperglycemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

determine if APS1 or APS2

  • Mutations in the autoimmune regulator (AIRE) gene - chromosome 21q22.
  • In the absence of AIRE function, central T-cell tolerance to peripheral tissue antigens is
    compromised, promoting autoimmunity.
A

APS1 or APECED (Autoimmune polyendocrinopathy, candidiasis, & ectodermal dystrophy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe APS2

A
  • starts in early adulthood
  • combination of adrenal insufficiency and autoimmune thyroiditis or type 1 diabetes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe APS2

A
  • starts in early adulthood
  • combination of adrenal insufficiency and autoimmune thyroiditis or type 1 diabetes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

determine if type 1 or type 2 DM:
Accounts for 90% to 95% of diabetic cases
multifactorial complex disease.
interactions of genetics, environmental risk factors, and inflammation

Primary defect
❖ Insulin resistance:
- derrangement of B cell secretion

A

type 2 DM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe what insulin resistance

A

decreased response of peripheral tissues to insulin

-Insulin resistance predates hyperglycemia and is accompanied by compensatory beta cell
hyperfunction and hyperinsulinemia in the early stages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

environmental factors of type 2 DM

A

sedentary Life style, dietary habits, obesity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

insulin resistance :
Failure to inhibit endogenous glucose production (____________) in the liver, which
contributes to _____________ blood glucose levels

A

gluconeogenesis , high fasting blood glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

insulin resistance :
Abnormally low _____________ and ________- synthesis in skeletal muscle following a meal, which contribute to a high ____________-blood glucose level

A

low glucose uptake, and glycogen

postprandial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

insulin resistance :
Failure to inhibit hormone-sensitive______ in adipose tissue, leading to excess circulating __________ - insulin resistance

A

lipase ,free fatty acids (FFAs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

insulin resistance :
Failure to inhibit hormone-sensitive______ in adipose tissue, leading to excess circulating __________ - insulin resistance

A

lipase ,free fatty acids (FFAs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the Direct role of FFA :
Excess FFA are taken up in muscle and liver leading to increased intracellular triglyceride ____________ (acquired insulin resistance state)

A

potent inhibitors of insulin signaling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the Indirect ( Inflammatory Cytokines) role of FFA :
Excess FFAs within macrophages and beta cells activate the inflammasome (multiprotein cytoplasmic complex) that leads to secretion of the cytokine ________ that promotes insulin resistance

A

interleukin IL-1β

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

list the mechanisms of B cell dysfunction

A
  • Excess FFA
  • Chronic hyperglycemia
  • Amyloid replacement in >90% islets (?cause / effect)
    End result: by inadequate insulin secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Adiponectin levels _____ in obesity – insulin resistance

A

decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

____________ release of hormones from adipocytes in relation to metabolic state

A

Adipokine Cytokines:

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Thiazolidinediones (TZD) are synthetic ligands of _______ decreases insulin resistance.

A

PPAR gamma (Peroxisome proliferator-activated
receptor gamma (PPARγ

33
Q

Effect of prolonged Insulin resistance in type 2 DM
* initial stages compensatory B cell hyperactivity leads to

A

hyperinsulinemia – euglycemic

34
Q

Effect of prolonged Insulin resistance in type 2 DM* Inability for long term adaptation leads to

A
  • insulin deficiency
35
Q

describe the morphology of Type 1 Diabetes

A

insulitis: Leukocytic infiltrates (T lymphocytes)

36
Q

describe the morphology of Type 2 Diabetes

A

Amyloid deposition within islets

37
Q

describe the morphology of Type 2 Diabetes

A

Amyloid deposition within islets

38
Q

what happens in Nondiabetic new borns of diabetic mothers:

A

increase in the number and size of islets as a response to maternal hyperglycemia

39
Q

what are the 4 C/F of type 1 DM

A

polyruia, polydipsia, polyphagia and ketoacidosis

40
Q

list how type 1 DM leads to polyuria and polydipsia

A

hyperglycemia → glycosuria → osmotic diuresis → polyuria → loss of water and electrolytes → along with hyperosmolarity due to hyperglycemia → deplete intracellular water → polydipsia

41
Q

list how type 1 DM leads to polyphagia

A

def of insulin → catabolic metabolism → negative energy balance → polyphagia

42
Q

list how type 1 DM leads to ketoacidosis

A

Severe insulin def with hyperglucagonemia → break down of adipose stores → increased FFAs → oxidized in the liver (glucagon) → ketone bodies → acetoacetic acid and B-hydroxybutyric acid → dehydration → ketoacidosis

43
Q

what are the electrolyte disturbances in type 1 DM

A
  • Lack of insulin shifts intracellular potassium to extracellular fluid
  • Acidosis also shifts I.C K+ to E.C K+
  • Osmotic diuresis also causes K+ and Na+ loss in urine
44
Q

symptoms for DKA

A

: Shock, Abdominal pain / nausea / vomiting, Fruity odour ( exhaled ketones)

45
Q

phyisical exam findings in DKA

A

altered mental status ( delirium / psychosis)
signs of dehydration (skin turgor, dry mucous membranes)

46
Q

Lab findings in DKA

A
  • Hyperglycemia, inc.H+ & dec. HCO3 – (Anion gap metabolic acidosis),
  • inc. urine and blood ketone levels,
  • leukocytosis.
  • Normal/ inc. serum K+ , but depleted intracellular K+ due to transcellular shift from dec .insulin and acidosis.
  • Osmotic diuresis K+ loss in urine total body inc. K+ depletion
    inc .Na+ loss in urine total body Na+ depletion
47
Q

lab findings in total body potassium depletion

A
  • Normal/ inc. serum K+ , but depleted intracellular K+ due to transcellular shift from dec .insulin and acidosis.
  • Osmotic diuresis K+ loss in urine total body inc. K+ depletion
    inc .Na+ loss in urine total body Na+ depletion
48
Q

determine Dx:

Marked insulin deficiency leads to ketonemia and ketonuria (acetoacetic acid & β-hydroxybutyric acid)

Seen most commonly in older patients with concurrent cardiac and renal pathology with stress / infection and increased insulin requirement

A

DKA

49
Q

determine Dx:

Marked insulin deficiency leads to ketonemia and ketonuria (acetoacetic acid & β-hydroxybutyric acid)

Seen most commonly in older patients with concurrent cardiac and renal pathology with stress / infection and increased insulin requirement

A

DKA

50
Q

Clinical features- Type II DM

A
  • Patient >40 years
  • Obese
  • Polyuria, polydipsia, may present with weight loss
51
Q

what is more common in type 2 DM than ketoacidosis

A

Hyperosmolar hyperosmotic syndrome (HHS) without ketosis is a more common

52
Q

In contrast to type 1 diabetes, the frequency of ketoacidosis is______- in type II diabetes because
of higher ________- levels in these patients prevents unrestricted hepatic fatty acid oxidation and keeps the formation of ketone bodies in check.

A

lower , portal vein insulin

53
Q

what are some symptoms in Type 2 DM

A

Thirst, polyuria, lethargy, focal neurologic deficits, seizures

54
Q

[Type 2 DM]:

Sustained osmotic diuresis → Decompensated state (dehydration and increased S osmolality)
→ _______________ especially debilitated patient with inadequate water intake

A

Hyperosmolar nonketotic coma

55
Q

Lab findings in HHS

A

Hyperglycemia (often > 600 mg/dL)
Increased serum osmolality (> 320 mOsm/kg)
Normal pH (no acidosis)
No ketones
Normal / inc. serum K+ , but depleted intracellular K+

56
Q

Macrovascular disease:

A
  • long-standing diabetes leads to accelerated atherosclerosis involving Aorta, large & medium sized muscular arteries
    increased risk of myocardial infarction, stroke, and lower extremity gangrene.
57
Q

Smaller vessels
more in HTN with DM
amorphous, hyaline thickening of the wall of the arterioles, which causes narrowing of the lumen

A

Hyaline arteriolosclerosis

58
Q

describe morphology of Diabetic microangiopathy

A

diffuse thickening of the BM (capillaries of skin, skeletal muscle, retina, renal glomeruli,
and renal medulla)\
* nonvascular structures - renal tubules, bowman cap, peripheral nerves, placenta- thickened
by deposition of type IV collagen
* despite thickening , the capillaries are more leaky to plasma proteins

59
Q

what are some Diabetic Ocular Complications in diabetic microangiopathy

A

retinopathy : hemorrhages, retinal exudates, microaneurysms, venous dilations, edema, and
thickening of the retinal capillaries (microangiopathy)
* cataract formation, glaucoma

60
Q

what are some Diabetic neuropathy sx in diabetic microangiopathy

A
  • peripheral, symmetric neuropathy of the lower extremities affecting both motor and sensory function
  • Autonomic neuropathy: Disturbances in bowel and bladder function
    neurologic changes - result of microangiopathy and *increased permeability *of the capillaries that supply the nerves, as well as direct axonal damage
61
Q
  1. Formation of Advanced Glycation End Products: in DM
A
  • nonenzymatic reactions between intracellular glucose-derived precursors (glyoxal, methylglyoxal, and 3-deoxyglucosone) and the amino groups of proteins.
62
Q

AGEs bind to a specific receptor (______), which is expressed on inflammatory cells (macrophages & T cells, ______ and vascular smooth muscle.

A

RAGE, endothelium

63
Q

5 Effects of AGE- RAGE signaling in vascular compartment:

A
  1. release of pro-inflammatory cytokines and growth factors from intimal macrophages
    TGF β – deposition of basement membrane like material
    VGEF – neovascularization – diabetic retinopathy
  2. generation of reactive oxygen species in endothelial cells
  3. increased procoagulant activity on endothelial cells and macrophages
  4. enhanced proliferation of vascular smooth muscle cells and synthesis of extracellular matrix.
  5. AGEs can directly cross-link extracellular matrix proteins.
64
Q

how do AGEs directly cross-link extracellular matrix proteins.

A
  • Cross-linking traps plasma / interstitial proteins
  • LDL trapped – accelerates atherosclerosis
  • Albumin trapped – basement membrane thickening (microangiopathy)
65
Q

Increased ______ from glycolytic intermediates causes PKC activation

A

DAG

66
Q

what are 3 effects of Protein Kinase C activation

A

Proangiogenic
profibrogenic
vasoconstriction

67
Q

Effects of Protein Kinase C activation : vasoconstriction

A
  • Increase in vasoconstrictor endothelin and decreased vasodilator endothelial
    nitric oxide synthase
68
Q

Effects of Protein Kinase C activation :
profibrogenic

A

TGF β leads to deposition of extracellular matrix and BM

69
Q

Effects of Protein Kinase C activation :
proangiogenic

A

VEGF implicated in the neovascularization characterizing diabetic retinopathy

70
Q

Intracellular Hyperglycemia and Disturbances in Polyol Pathways.:

This excess glucose is metabolized by _________-to _______(Polyol) and then to ______ (Reaction that uses NADPH)

A

aldose reductase , sorbitol , fructose

71
Q

NADPH is also required by the enzyme ________- for reducing [GSH]

A

glutathione reductase

72
Q

unavailability of GSH - Increases cellular susceptibility to_______– ________

A

oxidative stress

73
Q

insulin for glucose transport not required in what 4 areas

A

nerves, lenses, kidneys, blood vessels.

74
Q

what is also known as (“glucose neurotoxicity by oxidative stress)”

A

diabetic neuropathy

75
Q

determine DX:
is a slow-progressing form of autoimmune diabetes
* features of both Type 1 DM and Type 2 DM. Misdiagnosed as type II DM
* usually over age 30
Criteria
1. Age greater than 35 years
2. Positive autoantibodies to islet beta cells
3. Insulin independence for at least the initial 6 months after initial diagnosis

A

Latent autoimmune diabetes in adults (LADA) (DM 1.5)

76
Q

what are the 8 important lab values in DM

A

-blood sugar estimation
- HbA1C
- serum insulin
-c-peptide
* Complete lipid profile -
* Blood urea and serum creatinine
* Microalbuminuria (albumin 50-300 mg/day)
* Urine albumin-to-creatinine ratio (UACR) >30 mg/g

77
Q

describe HbA1C:

A

formed by nonenzymatic addition of glucose moieties to hemoglobin in red cells.

78
Q

Unlike blood glucose levels, HbA1C is a measure of glycemic control over____ periods of time

A

long -periods of time = 2-3 months

79
Q

HbA1C is relatively ______ by day-to-day variations.

A

unaffected