Type 2 Diabetes Mellitus Flashcards
Definition of diabetes (in particular T2)
Diabetes mellitus can be defined as a state of chronic hyperglycaemia sufficient to cause long-term damage to specific tissues, notably the retina, kidney, nerves, and arteries
T2DM is not ketosis prone (much less likely to have ketones than in T1)
T2DM is not mild
T2DM often involves weight, lipids and blood pressur
What are the biochemical markers of diabetes?
Fasting Glucose above 7 (6-7 is impaired fasting glucose)
2h Glucose above 11 (7.8-11 is impaired glucose tolerance)
Random Glucose above 11
Which type of diabetes is more common?
T2DM (More genetic than T1. It is not a disease of lifestyle, it is a genetic condition It is accelerated by lifestyle)
Prevalence of diabetes
10% at 60yrs
- > prevalence is increasing and is now also seen more in children and young individuals
- > prevalence varies enormously
- > Greatest in ethnic groups that move from rural to urban lifestyle
MODY
- Several hereditary forms (1-8)
- Autosomal dominant
- Ineffective pancreatic B cell insulin production
- Mutations of transcription factor genes, glucokinase gene
- Positive FH, no obesity
- Specific treatment for type
- monogenic diabetes
Pathophysiology of T2DM?
- MODY relatively uncommon but gives useful metabolic insights
- Genes and intrauterine environment and adult environment. (IU environment: predicts adult environment and it can accelerate given a particular diet/exercise.)
- Insulin resistance and insulin secretion defects
- Fatty acids important in pathogenesis and complications (some FAs seem particularity important for insulin resistance)
What do twin studies in diabetes show?
there is a higher genetic link in T2DM than in T1DM
i.e. identical twins 35% both T1, 70% both T2; nonidentical twins 10% both T1, 40% both T2
Diabetes Type 2 summarised
- Genetics: can make you prone to obesity and FAs as well as Insulin resistance with adipocytokines -> inflammation
- there is interplay between genetics and intrauterine growth restriction (e.g. not enough food)
- obesity and fatty acids process the development of Insulin resistance
- Insulin resistance has metabolic effects: mitogenic and metabolic dyslipidemia which causes microvascular complications such as stroke or MI
- eventually the insulin resistance wears down the beta cells and causes beta-cell failure
- beta cell failure causes hyperglycaemia which has microvascular complications
- beta cell failure also makes dyslipidamiea and metabolic defects worse
- at a certain point the beta-cell-failure may become absolute and the person has insulin requirement
What is the connection between baby weight and diabetes?
Babies with lower weight at 1yr of age had a higher (22%) chance of having blood sugar problems later than babies that had a higher weight (6%)
Relationship between Insulin resistance and insulin production
- at some point everyone becomes insulin resistant, for some people it is at the age of 50 and for others at a potential age of 110
- insulin resistance increases with age
- T2DM is a balance between the 2
- insulin resistance increases and insulin production decreases over time in T2DM
Metabolism and presentation of T2DM
- Heterogeneous
- Obesity
- Insulin resistance and insulin secretion deficit
- Hyperglycaemia and dyslipidaemia
- Acute and chronic complications
- more cholesterol carried in a harmful way
- there are preventable and dilatable complications but some people now show up when it has already progressed so far that e.g. their eyesight is harmed
Can NEFAs be used to make glucose?
No
How is insulin release impaired in someone with diabetes or prediabetes?
- there is a big loss in first phase insulin production in both cases, it is the first thing that goes.
- there is also a generally reduced. insulin release.
What are some chemical released by adipocytes?
Adipose tissue = endocrine organ
- TNF-alpha, IL-6
- Leptin (elevated in obesity)
- Resistin (elevated in obesity and T2DM)
- Apelin
- Visfastin
- Adiponectin
- Endocannabinoids
- Glucocorticoids (increase 11beta-hsd1 in fat)
- Fatty acids
Obesity and T2DM
- More than a precipitant
- Fatty acids and adipocytokines important
- Central or omental obesity (Central adipocytes (in omentum) are more active (more turnover also more active from endocrine perspective), drain directly into the liver)
- 80% T2DM are obese (at diagnosis, more than gen pop and T1)
- Weight reduction useful treatment
Preturbations in gut microbiota
- Obesity, insulin resistance T2DM (more ass. with obesity than diabetes but not necessarily causation)
- Host signaling
- Bacterial lipopolysaccharides fermentation to short chain FA, bacterial modulation bile acids
- Inflammation, signaling metabolic pathways (altering them)
- Most studies correlative