energy balance Flashcards
what is the primary control of insulin secretion
negative feedback between beta cells and glucose concentration in the blood
what does diabetes refer to
large volume of urine produced by diabetics
mellitus meaning
sweet urine- assocaited with hyperglycemia and glucose output in the urine
insipiddus meaning
tasteless urine- diabetes that is not associated with hyperglucemia but with ADH deficiency
IDDM
autoimmune destruction of B cells
in children or before 40 yrs
regular insulin injections required
what happens in IDDM when insulin absence is occuring
glucagon release from a cells is triggered- glucose sensing fails in the a cells leading to additional glucose in the blood thorugh glucagon action
what is possible therapy for IDDM
insulin and GHIH (somatostatin) to inhibit glucagon secretion
what is A1C a measure
glycosylation state of hemoglobin
how often is the turnover of Hb in RBC
every 3 months therefore testing is done every 3 months
what is %glycosylation a function of
average glucose levels over time (1-3 months prior)
what is the A1C value for non diabetics
5%
what is the A1C value for diabetics
greater than 6.5-7%
what is an important indicator of diabetes control
A1C monitoring
why is uncontrolled glucose a problem
advanced glycation end products- AGEs- interfere with physiological systems such as arterial stiffness in diabetes mellitus
gestational diabetes
gestational diabetes mellitus refers to glucose intolerance with onset or first recognition during pregnancy
what is a risk during GDM- gestational diabetes mellitus
fetal malformations at early gestational time points
risk of macrosomia and metabolic complications with late gestation GDM
what are the risk factors of GDM
> 35 yrs
on cortisol therapy
race
obesity
pre diabetic condition
T2DM in the family
PCOS
how many pathways lead to type D diabetes
multiple
what is a precursor state of diabetes type 2
prediabetes
what can happen in type 2 diabetes
progress to type 1
what is the normal fastsing range
less than 6mmol/L
what does chronic over eating lead to
inc in blood glucose
inc in insulin secretion
dec sensitivity of target cells to insulin- insulin resistance
what is type 2 diabetes assocaited with
hypertension and hyperlipidemia
what is hyperlipidemia and hypertension
metabolic disease
what percentage of people who develop type 2 diabetes are overweight
90%
what is the smoking gun
B cells deteriorate during diabetes
why do b cells deteriorate during diabetes
they are more vulnerable to the by products of their own metabolism bc they are the sensors for insulin release
what are the by products of beta cells
ROS, endoplasmic reticulum stress, AGE
what does chronic insulin secretion lead to
beta cell exhaustion leading type 2 to progress to type 1
what are the insulin sensitizing drug class for type 2 DM
thiazolidinediones TZDS
what improves A1C and glucose control
TZDS for type 2 DM
what is TZDS mechanism of action
increased fat storage in the adipocyte, effectively reducing circulating FA, blood glucose and hyperinsulinemia
what are the side effects of TZDS
bone density, cancer, CVD
what are some estimates of adiposity
BMI and waist circumference
waist circumference
used to determine regional adiposity
helps estabolish if body fat is peripheral or central obseity
gender specific
higher risk of obesity associated illness
high risk waist circumference sizes
more than 35 in women and 40 in men
what provides accurate esitimate of body fat and health risk
BMI and waist circumference
what does diabetes do to your lifespan
decreaeses it by 15 yrs
you have the same health risk as someone 15 yrs younger than you
Type 2 diabetes treatments
moderate energy intake
exercise routine
balanced physique: adipose to muscle ratio
body energy
energy intake - energy output
energy input
foods we eat, digest and absorb
energy output
work and heat/ waste
what is BMR dictated by
gender, lean muscle mass, level of activity, food ingestion, thyroid hormones and catecholamines, metabolic efficiency/ genetics
what does food ingestion do to BMR
spike it
appetite or hunger
desire for food
satiety
sense of fullness or satisfaction
what are the two control centres for the hypothalamus with regards to food
feeding centre
satiety center
what are the 4 types of input to the hypothalamus
neural input from the cerebral cortex
neural input from the limbic system (amugdala, hypocampus, cinguate gyrus)
peptide hormmones from the GI tract
Adipokines from adipose tissue
glucostatic theory
theory proposes that blood glucose levels ultimately control feeding and satiety centers
lipostatic theory
theory that proposes that level of body fat regulates feeding and satiety centres
discovery of several peptides from adipose tissue seems to support this theory
Ghrelin resposne to body fat
inc to decreased body fat
ghrelin and muscle mass
increase to increased muscle mass
what is ghrelin impacted by
macronutrient content of meals and can be regulated by diet
when is the highest ghrelin post prandial suppresion
carb then protein and finally fat
fat is last bc it is used as a mechanism for weight gain associated with high fat diets
leptin and obesity
does not work exogenously with majority of obese individuals and therefore it is not as significant as animal models
leptin reistance occurs when there is high expose to high cituclating concentration
contributions to net energy excess and adipose storage
adipokine imbalance
lack of physical exertion
variation in the efficiency of energy extraction from foods
endocrine disorders such as hypothyroidism
energy dense food availability; modern expecations
genetics, mental health, eating behaviour
what do calorie restricted diets do
significantly lengthen the life span of many species including humans
metabolic syndrome
high blood glucose
high blood pressure
high triglycerides
low HDL
abdominal obesity
