Management of Obesity

1. OBESITY
BY
OYEWUSI D.O.
POSTGRADUATE SEMINAR
DEPATMENT OF INTERNAL MEDICINE
LAUTECH TEACHING HOSPITAL

2. OUTLINE
• INTRODUCTION
• EPIDEMIOLOGY
• CLASSIFICATION
• CLINICAL ASSESSMENT TOOL
• AETIOLOGY
• PATHOLOGIC CONSEQUENCE OF OBESITY
• EVALUATION
• TREATMENTS
• CONCLUSION

3. INTRODUCTION
• The body has the ability to store energy in excess of what is required
for immediate use. This energy is stored as triglyceride in fat cells,
which are widely distributed round the body
• This physiologic system is orchestrated through endocrine and neural
pathways and permits humans to survive starvation for several
months

4. • However in the presence of nutritional abundance and physical
inactivity, influenced by genetic factors, this system increases adipose
energy stores producing adverse health consequences
• Overweight and obesity as defined by the WHO is abnormal or
excessive fat accumulation that presents a risk to an individual‘s
health

5. • Obesity is not only a chronic disease in itself but also a major risk
factor for the world’s leading causes of poor health and early death
including diabetes, cardiovascular diseases and several common
cancers.
• The epidemic of obesity is now recognized as one of the most
important public health problems facing the world today

6. EPIDEMIOLOGY
• Obesity was once a problem only in the high income countries but has now
dramatically risen even in the middle and low income countries. Such
countries are now facing a “double burden” of disease for while they
continue to deal with problems of infectious diseases and undernutrition
they are also experiencing a rapid upsurge of chronic non communicable
diseases for which overweight and obesity are important risk factors.
• According to WHO (2016), there are around 2 billion adults that are
overweight and 650 million of them considered to be affected by obesity

7. • In 40years the number of school age children and adolescents with obesity
has risen more than 10fold from 11million to 124million (2016 WHO
Estimation)
• Preventing obesity in this age group provides a unique opportunity to halt
a course to an unhealthy adult life as childhood obesity is often carried
through into adulthood.
• Prevalence of obesity is found to be higher in women than in men.

8. CLASSIFICATION
• The most commonly used method today for classifying an individual as
overweight or obese is based on the Body Mass Index (BMI) regardless of sex and
age.
• The use of BMI to assess weight related health risk has gained international
acceptance because of the associations between BMI and adipocity, BMI and
disease risk and BMI and mortality.
• Its simplicity has enabled easy comparisons of various populations world wide

10. • The major limitation of BMI is that it does not differentiate between
weight that is fat (i.e fat mass) and weight that is muscle (i.e free fat
mass) and therefore may lead to misclassification of very muscular
individuals as overweight.
• Older adults may also appear to have a healthy BMI despite having
excess fat and reduced muscle mass

11. WAIST CIRCUMFERENCE
• Waist circumference is another clinically feasible measurement that may be used
independently or in addition to BMI to assess weight related health risk.
• It provides an estimate of the abdominal fat.
• Abdominal fat is more strongly associated with health risk than fat stored in other
regions of the body due to the fact that intra abdominal adipocytes are more
lipolytically active than those from other depots.
• It requires only a tape measure.

13. • The WHO has identified sex- specific waist circumference values that
signify increased health risk
>/= 88cm in women
>/= 102cm in men

15. Other assessment technique
• Anthropometry (skinfold thickness): It is a simple, economical and
potentially reliable technique. Performed using calipers
• Accuracy is however compromised in individuals with extreme obesity
or altered hydration status
• High inter observer variability with use of different calipers

16. Other assessment technique
• Bioeletrical impedance analysis (BIA): is another method used to estimate adiposity by
measuring resistance to a low frequency electrical current. Current flows through
aqueous compartments where as, adipose tissue which is non aqueous impedes the flow
• It is portable , of modest cost, non invasive , brief assessment time required and good
validity and reliability in many populations.
• Individual variability can be high
• Accuracy is compromised in situations of altered hydration status and extreme obesity.

17. Other assessment technique
• Densitometry (underwater/hydrostatic weighing)
• Dual-energy x-ray absorptiometry (DEXA)
• Isotope dillusion
These are dependent on sophisticated equipments generally available
only in research settings

18. PHYSIOLOGIC REGULATION OF ENERGY BALANCE
• Body weight regulation/dysregulation depends on a complex interplay of humoral and neural
signals.
• Body weight is influenced by many factors that are integrated by the brain, most importantly
within the hypothalamus. Signals that impinge on the hypothalamic centres include neural
afferents, hormones and metabolites.
• Vagal inputs are particularly important bringing information from visceral such as gut distention.
• Appetite is increased and energy expenditure reduced with increasing weight loss and with
overfeeding, appetite falls and energy expenditure increases.

21. LEPTIN
• Leptin is a 16 KD hormone
• Synthesized by fat cells, it is the product of the ob gene
• Responsible for long term regulation of energy balance
• Deficient leptin or its receptors fail to sense the adequacy of fat stores
leading to over eating, weight gain and reduced energy expenditure.

22. • The single gene mutations affecting this pathway in humans e.g leptin,
leptin receptor, POMC, McR4, PC1 and SIM 1 are rare and recessive, with
the exception of the McR4 which is common and dominant
• McR4 mutation accounts for 2-6% of human obesity
• These mutation are of little significance as obesity is predominantly
polygenic in origin

23. GHRELIN
• A 28 amino-acetylated peptide produced by the oxyntic cells of the
stomach
• It is the first known gastrointestinal peptide that stimulates appetite
• The circulatory content is high before meal and reduced rapidly by
ingestion of a meal or glucose

24. Aetiology
• Obesity is the result of genetic, behavioural environmental, physiological, social and
cultural factors that results in energy imbalance and promote excessive fat deposition.
Although genes play an important role in the regulation of body weight , the WHO
consultation on obesity concluded that behavioural and environmental factors are
primarily responsible for the dramatic increase in obesity during the past two decades.
• The genetic contribution to obesity has been elucidated by studies involving twin in
which concordance rates for varying degree of overweight were twice as high among
monozygotic twins than dizygotic twins

25. • Another classic study involving adult adoptees revealed a strong
correlation between the adoptees weight and there biological parents’ BMI
whereas no such relationship was observed with the adoptees’ parent BMI.
Identical twins have similar BMIs whether reared together or apart.
• However whatever the role of genes, its clear that the environment plays a
key role in obesity as evidenced by the fact that famine limits obesity in
even the most obesity prone individual. The rapid rise in prevalent of
obesity is far to high to be due to changes in the gene pool.

27. Conditions associated with obesity
• Hypothyroidism : it is an uncommon cause of obesity and can easily be ruled out by measuring thyroid
stimulating hormone. Much of the weight gain is due to myxedema
• Insulinoma :patients with insulinoma often gain weight as a result of overeating to avoid hypoglycemia
symptoms. The increased substrate with high insulin levels promote energy storage in fat
• Craniopharyngioma:tumor arising from the rathekes pouch results into hypothalamic disturbance of systems
controlling satiety, hunger and energy expenditure causing varying degree of obesity.
• Cushing’s syndrome :High level of cortisol with deposition of adipose tissue in peculiar areas to form moon
fascie, buffalo hump and truncal obesity
• Prader wili’s syndrome

28. Drugs associated with obesity
• Antidiabetic drugs: Sulphonyureas, thiazolidinediones ,Insulin
• Steroid hormones
• Antipsychotic agents:clozapine, olanzapine, risperidone
• Mood stabilizers: lithium
• Antidepressants: tricyclics, MAO inhibitors , paroxetine, mirtazapine
• Anti epileptic drugs: valproate, gabapentin, carbamazepin

29. PATHOLOGIC COMPLICATIONS OF OBESITY
INSULIN RESISTANCE AND T2DM
Insulin resistance is more strongly linked to intraabdominal fat than to fat in
other depots. Molecular links between obesity and insulin resistance in fat,
muscle and liver can be partly explained by
• Insulin inducing receptor downregulation
• Increased level of free fatty acids that are capable of impairing insulin
action

30. • Obesity linked inflammation including macrophages infiltration into
tissues and induction of endoplasmic reticulum stress response which
can bring about resistance to insulin action in cells
• Release of several cytokines including TNF alpha, IL-6, and
adiponectin which have altered expression on adipocytes and can
modify insulin action

31. CARDIOVASCULAR DISEASE
• Excess insulin play a role in the retention of sodium, expansion of blood
volume, production of excess norepinephrine and smooth muscle
proliferation that are the hallmarks of hypertension
• Abdominal obesity is also associated with atherogenic lipid profile with
increased LDL ,cholesterol and triglyceride as well as decreased HDL and
decreased level of vascular protective adipokine adiponectin.
• An independent risk factor for CAD and CHF

32. PULMONARY SYSTEM
• Reduced chest wall compliance
• Increased work of breathing
• Increased minute ventilation due to increased metabolic rate
• Decreased functional residual capacity and expiratory reserve volume
• Obstructive sleep apnea
• Obesity hypoventilation syndrome

33. SKELETAL SYSTEM
• Obesity is associated with an increased risk of osteoarthritis partly
due to trauma of added weight and partly due to activation of
inflammatory pathways than can promote synovial pathology

34. SKIN
• Acanthosis nigricans
• Risk of fungal infections
• Increased friability of skin
• Striae distensae
• Intertrigo, carbuncles
• Increased venous statis and stasis pigmentation of legs

35. PSYCHOLOGICAL
• Depression/ low self esteem
• Body image disturbance
• Social stigmatization

38. Metabolic syndrome

39. EVALUATION
• All adult patients should be screened for obesity and offer intensive counselling and behavioral interventions to promote sustained
weight loss. The following steps are used in the evaluation of a patients with obesity
• 1)focused obesity related history :
what factors contributes to patients obesity
how is the obesity affecting the patients health
what is the patient’s level of risk from obesity
what does the patient find difficult about managing obesity
what are the patient’s goal and expectation
is patient motivated to begin a wait management program
what kind of help does the patient need

40. EVALUATION
• Physical examination : to determine the degree and type of obesity.
• Weight, height and waist circumference or waist to hip ratio.
• Measurement of the waist circumference is a surrogate for visceral
adipose tissue and abdominal fat, which is independently associated
with a higher risk for diabetes and cardiovascular disease.

41. • Assessment of obesity associated comorbid conditions:
This can be assessed from patients symptoms and having high index of
suspicion in identifying high risk individuals through the use of risk
assessment tools.

43. • Assessing patients readiness to change.
An attempt to initiate lifestyle changes when the patient is not ready
usually leads to frustration on the part of the individual and clinician.
Patients motivation , support, time availability and costraints should be
assessed. Appropriateness of goals and expectations should as well be
assessed

44. TREATMENT
• The primary aim of treatment is to reduce the risk of developing and
improve obesity related comorbidities. The decision of how
aggressively to treat the patient and which modality to use is
dependent on patient’s risk status, expectation and available
resources.

45. Treatment modalities
• Lifestyle management
• Pharmacological therapy
• Surgery

46. LIFESTYLE MANAGEMENT
• Dietary habit: focus is to reduce overall calorie consumption . The obesity association
recommend initiating treatment with a calorie deficit of 500-750 kcal/day compared with
the patients habitual diet or alternatively 1200-1500kcal for women and 1500-1800kcal
for men. This can be achieved by
• Smaller food portion
• Consumption of fruits and vegetables
• Consumption of more whole grain cereals
• Skimmed dairy products
• Reduce consumption of fried foods or feeds with added fats and oils

47. Life style management
• Physical activity therapy: the combination of dietary modification and
exercise is the most effective behavioral approach for the treatment of
obesity. The most important role of exercise appears to be in the
maintenance of weight loss.
• The 2008 physical activity guidelines for Americans recommend 150min of
moderate intensity or 75min of vigorous intensity aerobic physical activity
per week performed in episodes of 10min, Preferably spread through out
the week.

48. • Brisk walking, use of stairs ,doing house work or yard work and engaging in
sports
• Use of a pedometer or accelerometer to monitor total accumulation of
steps or kcal expended as part of the activities of daily living is a useful
strategy
Behavioral therapy: self monitoring technique, stimulus or appetite control,
stress management and social support

49. PHARMACOLOGICAL THERAPY
Should be considered for patients with
BMI >30kg/m
BMI >27kg/m( who have concomitant obesity related disease
and for whom dietary and physical activity therapy has not been
successful.)

50. • Appetite suppressants (anorexiants)
• Gastrointestinal fat blockers

51. Centrally acting anorexiant medications :
• This medications affects satiety and hunger. By increasing satiety and decreasing hunger , these
agents help patients reduce calorie intake without a sense of deprivation
• Target site of the actions of anorexiants is the ventromedial and lateral hypothalamic regions in
the central nervous system
• The biologic effect of these agents on appetite regulation is produced by augmentation of the
neurotransmission of three monoamines , norepinephrine and to a lesser extent , dopamine.
• Examples are sibutramine and tesofensine

52. • Newer drugs are lorcaserin, phentamine/topiramate extended release,
naltrexone SR/bupropion SR and liraglutide.
• Phentamine is the most commonly prescribed of the sympathomimetic
adrenergic agents.
• 0.6-6kg was lost after 2-24weeks of treatment
• Common side effects are restlessness, insomnia, dry mouth , constipation
and increased blood pressure and heart rate

53. Phentamine/topiramate
• The mechanism responsible for weight loss is uncertain but is thought to be
mediated through the drugs modulation of gamma amino butyric acid receptors,
inhibition of carbonic anhydrase and antagonism of glutamate.
• The common side effects are paraesthesia, dry mouth, constipation and insomnia
• Topiramate has increased risk of congenital foetal oral cleft. Women of child
bearing age should have a negative pregnancy test before treatment and monthly
thereafter

54. • Locarserine is a selective 5-HTc receptor agonist with a functional
selectivity to prevent the drug induced valvulopathy documented
with two other serotonergic agents (fenfluramine and
dexfenfluramine)
• Locarserine is thought to decrease food intake through the pro-
opiomelanocortin system of neurons

55. NaltrexoneSR/BupriopionSR
• Bupriopion stimulates secretion of alpha MSH from POMC where as
naltrexone blocks the feedback inhibitory effects of opiod receptors
activated by the beta-endorphins released in the hypothalamus , thus
allowing the inhibitory effect of MSH to reduce food intake

56. Liraglutide
• This is a glucagon like peptide-1 (GLP-1)
• In addition to its effect as an incretin hormone (glucose induced
insulin secretion), liraglutide inhibits both gastric emptying and
glucagone secrtion. It also stimulates GLP-1 receptors in the aquate
nucleus of hypothalamus to reduce feeding.

57. Peripherally acting medications
Orlistat: an inhibitor of pancreatic and gastric lipases. It reduces dietary
fat absoption and aids weight loss.
Orlistat blocks the digestion and absorption of approximately 30% of
dietary fat. Therapeutic dose of 120mg trice daily
Diarrhea and increased fecal fat content is a common side effect.

58. BARIATRIC SURGERY
• Bariatric surgery can be considered in individuals who have severe
obesity or for those with moderate obesity associated with a serious
medical condition. It is classified into:
• Restrictive
• Malabsorptive.

59. • Restrictive surgery limit the amount of food the stomach can hold and slow
the rate of gastric emptying .
• Laparoscopic adjustable gastric band is the prototype.
• A band is placed around the upper stomach to produce a small proximal
pouch and a distal remnant. The mean percentage of total body weight lost
at 5years is estimated as 20-25%. Long term follow up has been
disappointing leading to near abandonment of the procedure.

60. • Laparoscopic sleeve gastrectomy : the stomach is restricted by
stapling and dividing it vertically, removing up to 80% of the greater
curvature and leaving a slim banana shaped remnant stomach along
the lesser curvature.
• Weight loss after this procedure is superior to that of laparoscopic
adjustable gastric banding.

61. pic

63. Roux-en-Y gastric bypass (gastrojejunostomy)
• incorporates both restrictive and malabsorbtive component.
• Most commonly undertaken and accepted bypass procedure.
Routinely performed by laparoscopy
• May result in nutrient deficiencies.

65. others
• Biliopancreatic diversion
• Biliopancreatic diversion with duodenal switch.
These procedure generally produce a 30-35% average total body weight
loss that is maintained in up to 60% of patients at 5years with
significant improvement in multiple obesity related comorbid
conditions.

66. • The common surgical complications of these procedures include stomal
stenosis and marginal ulcers. These present as prolonged nausea and post
prandial vomiting or inability to tolerate solid food
• Endoscopic balloon dilation and acid suppression therapy are used
respectively in the treatment of these complications.
• Micronutrient deficiency is common in the restrictive malabsorptive
procedures and so may require lifelong supplementation.

67. • Liposuction : the removal of large amount of fat by suction. This does
not correct the problem and weight gain frequently occurs

69. CONCLUSION
• Obesity is viewed as disturbance in complex homeostatic mechanism
controlling energy balance in the body.
• It is a major health problem in developed nations with an increasing
incidence in developing countries
• Obesity is known to contribute significantly to morbidity and mortality
rates in various countries around the world
• Lifestyle modifications play a great role in its control

70. REFERENCES
• World Health Organization. Obesity and overweight Geneva ,
switzerland 2016 technical report seriesp.845 1-1-9950
• Obesity prevention and managing the global epidermic, report of
WHO consultation
• Harrison text book of internal medicine 20th edition

71. THANK YOU