Post on 05-Apr-2018
8/2/2019 Obesity Arun
1/18
Click to edit Master subtitle style
4/28/12
OBESITY (cont.)
Arun ThulasiMD (Y&R)2ND Semester
8/2/2019 Obesity Arun
2/18
4/28/12
General Introduction
Environmental forces Vs. Individualgene substrate = OBESITY
Remember Overweight BMI above 27 kg/m2.
Obesity BMI above 30 kg/m2.
Fat topography has a profoundinfluence on the health risk.
White adipose tissue (WAT) is the
physiological site of energy storage
8/2/2019 Obesity Arun
3/18
4/28/12
PREVALENCE
As of 2008, The World HealthOrganization claimed that 1.5 billionindividuals over the age of 20 are
considered obese .
The rate of obesity also increaseswith age at least up to 50 or
60 years old .
By 2015, WHO estimates thatapproximately 2.3 billion adults will
be overweight and more than 700
8/2/2019 Obesity Arun
4/18
4/28/12
PATHOGENESIS
1) Gene susceptibility
1) Fat cell & obesity
1) Environmental factors
1) Pro-inflammatory factors
8/2/2019 Obesity Arun
5/18
4/28/12
1. Gene susceptibility
Extensive studies have indicated that30-50 % of the fat variability is believed
to be genetically determined.
Mainly 4 genes have been identified thatis believed to be causing obesity:
i. Leptin gene (mainly)
ii. 3 adregenic receptor gene
iii. TNF gene overall contribution is
small
8/2/2019 Obesity Arun
6/18
4/28/12
Leptin gene
Leptin is one moleculethat provides for thiscoupling between
energy intake andenergy expenditure.
Leptin protein is
normally secreted fromfat cells itscirculating levels are
high in obesity.
8/2/2019 Obesity Arun
7/18
4/28/12
8/2/2019 Obesity Arun
8/18
4/28/12
8/2/2019 Obesity Arun
9/18
4/28/12
2. Fat cell & obesity
Most forms of obesity are associated
with enlarged fat cells. Fat cells fat storage + secretory
organ
Fat cell generates lots of lactate glucose metabolism glycerol-3-phosphate TG synthesis
8/2/2019 Obesity Arun
10/18
4/28/12
3. Environmental factors:
Environmental factors interact with
genetic susceptibility.
E.g.: hypothalamic injury (trauma)
lesion in ventromedial nucleus
hyperphagia OBESITY
8/2/2019 Obesity Arun
11/18
4/28/12
4. Pro-inflammatory factors:
What is adiponectin?
o It is an insulin-sensitising effector, whichhelps to counteract the effects of obesity.
o circulating adiponectin levels aredecreased in obesity-related insulinresistance, type 2 diabetes and coronaryheart disease.
o
It inhibits liver neoglucogenesis andpromotes fatty acid oxidation in skeletalmuscle.
o
It counteracts the pro-inflammatory effectsof TNF- on the arterial wall
8/2/2019 Obesity Arun
12/18
4/28/12
WAT infiltrated by macrophages
Pro-inflammatory cytokines produced(leptin,TNF- ,IL-6,resistin)
Insulin resistance adiponectin
8/2/2019 Obesity Arun
13/18
4/28/12
Other factors that affectobesity
Hypothyroidism Medications such as birth control
pills, antidepressants, and
antipsychotics. Menopause (oestrogen affects
obesity).
Pregnancy ( glucose homeostasis &fat oxidation are all disrupted bymaternal obesity)
uittin smokin nicotine
8/2/2019 Obesity Arun
14/18
4/28/12
Some researches
Risk for Alcoholism Linked toRisk for Obesity
(reward centre)
-Science Daily (Dec. 31, 2010) How Fatty Diets Cause Diabetes
(damage of glycosyltransferase)
-ScienceDaily (Aug. 15, 2011)
Link Between Brain Molecule and
Obesity and Diabetes Discovered
8/2/2019 Obesity Arun
15/18
4/28/12
Related with yoga.
Yoga Reduces Cytokine LevelsKnown to Promote Inflammation
ScienceDaily (Jan. 14, 2010)
o Many of the metabolic disturbancesassociated with obesity and themetabolic syndrome may be due to
cytokine production by adipocytes.o Particularly IL-6, associated with stress,
reduced with yoga practice.
8/2/2019 Obesity Arun
16/18
4/28/12
Regular Yoga Practice IsAssociated With Mindful Eating
ScienceDaily (Aug. 16, 2009)
o Mindful Eating- those were aware of whythey ate and stopped eating when full.
o A strong association between yogapractice and mindful eating
o no association between other types ofphysical activity, such as walking or
running, and mindful eating
8/2/2019 Obesity Arun
17/18
4/28/12
Yoga's Ability to Improve Moodand Lessen Anxiety Is Linked toIncreased Levels of a CriticalBrain Chemical, Research Finds
- [ ScienceDaily (Nov. 12, 2010) ]
o GABA is the chief inhibitoryneurotransmitter which regulates
neuronal excitability; associated withanxiety.
o Brain GABA increases with fat feeding;
balances between energy dense diet &su ression of food.
8/2/2019 Obesity Arun
18/18
4/28/12
Thankyou