Diabetes Flashcards
can we get diabetes because of eating too much sugar or too much fat?
its not so much the sugar or fat that causes diabetes, but the excess energy from eating these in excess leading to to excess weight and fat deposition
diabetes mellitus definition
a metabolic disorder characterized by elevated blood glucose concentrations and disturbances of carbohydrates, lipids, and protein due to defective insulin secretion and/or action
characteristics of type 1 DM
- insulin dependent (IDDM)
- juvenile or growth onset
- ketosis prone [lack of insulin secretion]
characteristics of type 2 DM
- non-insulin dependent mostly
- maturity onset mostly
- not prone to ketoses
characteristics of gestational diabetes
diagnosed during pregnancy, resolved at delivery
what causes type 1 diabetes
caused by an autoimmune or idiopathic destruction of pancreatic beta-cells due to islet cell auto-antibodies (ICA) causing absolute deficiency in insulin production
- predisposition, viruses, toxins can trigger development of ICA
what causes type 2 diabetes
excessive food intake, lack of exercise, genetic predisposition -> obesity -> inflammation
- > cells do not respond normally to insulin (resistance)
- cells do not take up and utilize glucose efficiently -> hyperglycemia
- pancreas may compensate or not with insulin production -> hyperinsulinemia or normal levels followed by beta-cell insufficiency [decreased production fo insulin]
how do you treat type 1 diabetes
insulin injection
how do you treat type 2 diabetics prone to ketosis
insulin injection
how do you treat type 2 diabetics resistant to ketosis
- diet treatment
- oral medication
- insulin injection when prolonged duration
what are some risk factors associated with diabetes
age and obesity
which populations are more at risk of diabetes?
- south asian, Asia, African, hispanic descent
- aboriginal, First Nations: 2-5 times more diabetes
- overweight, older, low income
what are the symptoms of type 1 diabetes
- increased thirst
- increased urination
- increased hunger
- weight loss or obesity
which clinical laboratory tests reveal T1 diabetes?
- glycosuria
- hyperglycemia
- abnormal glucose tolerance GTT
what are the various actions of insulin
- increased glucose uptake ans storage
- decreased glycogenolysis and gluconeogenesis = decreased endogenous glucose production
- increased lipogenesis
- decreased lipolysis
- increased protein synthesis
- decreased proteolysis
- growth/mitogenesis
- reproduction
- lifespan
- cognition
what are the general effects on insulin deficiency
There is a decrease in glucose uptake by cells, causing polyphagia, and an increase in hepatic glucose production both causing hyperglycemia -> glycosuria -> polyuria -> dehydration -> peripheral circulatory failure -> renal failure and low cerebral blood flow.
There is also decreased TG synthesis and increased lipolysis -> increased blood fatty acids -> ketosis -> metabolic acidosis > diabetic coma.
+ decreased amino acid uptake by cells [increased blood AA -> gluconeogenesis] and increased protein degradation -> muscle wasting -> weight loss
what happens metabolically in the fasted state in a diabetic patient
high lipolysis -> a lot of FA substrate for kept acids
+ high rates fo proteolysis releasing AA in circulation -> gluconeogenesis in liver -> glucose in the circulation + kept acids -> excess excreted in urine
what happens metabolically in the fed state in a diabetic patient
same as fasted start but worse: high lipolysis -> a lot of FA substrate for kept acids
+ high rates fo proteolysis releasing AA in circulation -> gluconeogenesis in liver -> glucose in the circulation + kept acids -> excess excreted in urine
++++ glucose and AA from food
what is insulin resistance
defines as a lesser sensitivity to insulin’s action in suppressing hepatic glucose production and stimulating glucose uptake. Mostly due to defective insulin signaling within cells
what are the steps involved in insulin-induced glucose uptake
- in response to a rise in blood glucose, the pancreas releases more insulin into the blood
- insulin bond to a membrane-bound receipt
- the binding of insulin to its receptor signals glucose transporters to move from the cytoplasm to the cell membrane
- glucose transporters enable glucose to move from the extracellular space into the cytoplasm
what are the mechanisms that can cause insulin resistance
- receptor defects: decreased number and affinity [rare cases of genetic mutations of INSR gene]
- post-receptor second messenger signaling [most cases of IR]
what are the risk factors of type 2 diabetes
- age
- family history
- high-risk population
- prediabetes: impaired fasting glucose or impaired glucose tolerance
- history of GDM/delivery of macrosomic infant
- cardiovascular risk factors
- presence of end-organ damage associated: CV ad microvascular
- Low birth weight (<2.5kg) and high birth weight (>4.0kg)
which are the cardiovascular risk factors for T2D?
dyslipidemia, abdominal obesity, HTN, smoking, sedentary lifestyle
what are the metabolic stages of type 2 diabetes?
- pre-diabetes: obesity -> insulin resistance and impaired fasting glucose and glucose tolerance + beta-cell defect -> decreased insulin secretion
- late diabetes: beta-cell failure, non-reversible