Transcript Slide 1

 Obesity is a multifactorial disease that develops from the
interaction between genotype and the environment. Our
under-standing of how and why obesity occurs is incomplete;
however, it involves the integration of social, behavioral,
cultural, physiological, metabolic, and genetic factors.
 Obesity is a significant public health crisis in the
developed world. The prevalence is also increasing rapidly in
numerous developing nations worldwide. This growing
incidence represents a pandemic that needs urgent attention
if the potential morbidity, mortality, and economic tolls that
will be left in its wake are to be avoided.
 Increase in body weight beyond skeletal and physical
standards as the result of an excessive accumulation of fat
in the body. More than two times the ideal weight is
considered obesity.
Obesity: excess adipose tissue
 Overweight: excess weight for height
The etiology of obesity is multifactorial either: Metabolic factors, genetic factors, level of activity, behavior,
endocrine factors, race, sex, and age factors, ethnic and cultural
factors, socioeconomic status, dietary habits, smoking cessation,
pregnancy and menopause, psychological factors, history of
gestational diabetes, & lactational history in mothers.
 Secondary causes of obesity may include diseases as
hypothyroidism, insulinoma & growth hormone deficiency; or
drugs as oral contraceptive use, medication-related (e.g.,
phenothiazines, sodium valproate, carbamazepine, tricyclic
antidepressants, lithium, glucocorticoids, thiazolidinediones,
sulphonylureas, insulin, adrenergic antagonists, serotonin
antagonists), eating disorders (especially binge-eating disorder, &
bulimia nervosa.
 The pathogenesis of obesity is far more complex than the
simple paradigm of an imbalance between energy intake and
energy output .
Two major groups of factors with a balance that variably
intertwines in the development of obesity are genetics, which is
presumed to explain 40-70% of the variability in obesity
variance, and environmental factors.
 The critical enzymes involved in adipocyte metabolism are
endothelial lipoprotein lipase (involved in lipid storage),
hormone-sensitive lipase (involved in lipid elaboration and
release from adipocyte depots), acylcoenzyme A (acyl-CoA)
synthetases (involved in fatty acid synthesis), and a cascade of
enzymes (involved in beta oxidation and fatty acid metabolism).
Ghrelin:
 Ghrelin is a new endogenous peptide, discovered in 1999. This
peptide is composed of 28 amino acids with a unique octanoyl
modification of hydroxy group on serine at the third position
that is essential for its function. Ghrelin is usually produced
by cells called Gr cells that are part of the endocrine system of
the digestive tract.
 This peptide also plays an important role in signaling
hypothalamic centers which regulate feeding and caloric state.
 Some research demonstrated that the intracereberal and
peripheral administration of ghrelin leads to an increase of
food intake and a decrease of energy expenditure. In addition,
ghrelin is a potent stimulator of gastric motility and gastric
acid secretion.
 Cigarette smoking
 Hypertension
 High-risk low-density lipoprotein (LDL)
 Low high-density lipoprotein (HDL)
 Family history of premature CHD
 Age more than or equal to 45 years for men or age more
than or equal to 55 years for women (or postmenopausal)

Atherosclerosis
 Hypertension
 Diabetes mellitus
 Renal Failure
 Heart Failure
 Stroke
 Gallbladder Disease
 Full lipid panel (fasting cholesterol, triglycerides, low-
density lipoprotein,
and high-density lipoprotein)
 Hepatic panel
 Thyroid function tests
 Twenty four hours urinary free cortisol
 Fasting glucose and insulin
 Assessment of a patient should include:
1. The evaluation of body mass index (BMI)
2. Waist circumference
3. Overall medical risk
Goals for weight loss & management: Reduce body weight
 Maintain a lower body weight at long term
 Prevent further weight gain
Weight Management Techniques:-
Dietary Therapy, Physical Activity, Behavior Therapy,
Pharmacotherapy, & Weight Loss Surgery
 Physical activity should be an integral part of weight loss
therapy and weight maintenance. Initially, moderate levels of
physical activity for 30 to 45 minutes, 3 to 5 days per week, should
be encouraged. An increase in physical activity is an important
component of weight loss therapy, although it will not lead to a
substantially greater weight loss than diet alone over 6 months.
 Self-monitoring refers to observing and recording some
aspect of behavior, & eating behaviors such as caloric
intake, exercise sessions, medication usage to recognize
the relation between these habits & increase in the body
weight
 To break the relationship between these habits &
ingestion of meal.
 Positive feedback
 Drug therapy may also be useful for patients with a BMI
more than or equal to 27 who also have concomitant
obesity related risk factors or diseases. The drugs used to
promote weight loss have been anorexiants or appetite
suppressants. Three classes of anorexiant drugs have been
developed, all of which affect neurotransmitters in the
brain
 They may be designated as follows: those that affect
catecholamines, such as dopamine and norepinephrine;
those that affect serotonin; and those that affect more
than one neurotransmitter. These drugs work by increasing
the secretion of dopamine, norepinephrine, or serotonin
into the synaptic neural cleft, by inhibiting the reuptake of
these neurotransmitters into the neuron,
or by a combination of both mechanisms.
 Sibutramine inhibits the reuptake of norepinephrine and
serotonin. Orlistat is not an appetite suppressant and has a different
mechanism of action; it blocks about one-third of fat
absorption.
 These drugs are modestly effective in their ability to produce
weight loss. Net weight loss attributable to drugs has generally been
reported to range from 2 to 10 kilograms (4.4 to 22 lbs).
 Weight loss surgery is an option for weight reduction
in patients with clinically severe obesity, i.e., a BMI more than or
equal two 40, or a BMI more than or equal two 35 with comorbid
conditions. Weight loss surgery should be reserved for patients in
whom other methods of treatment have failed and who have
clinically severe obesity (once commonly referred to as “morbid
obesity”). Weight loss surgery provides medically significant
sustained weight loss for more than 5 years in most patients.
 Two types of operations have proven to be effective: those that
restrict gastric volume (banded gastroplasty) and those that, in
addition to limiting food intake, also alter digestion (Roux-en-Y
gastric bypass).
 Late complications are uncommon, but some patients may
develop incisional hernias, gallstones, and, less commonly &
weight loss failure. Patients who do not follow the instructions to
maintain an adequate intake of vitamins and minerals may
develop deficiencies of vitamin B12 and iron with anemia.
Neurologic symptoms may occur in unusual cases. Thus,
surveillance should include monitoring indices of inadequate
nutrition. Documentation of improvement in preoperative
comorbidities is beneficial and advised