Potential Consequences of Obesity & Obesity Surgery

1. Metabolic Sequelae of
Bariatric Surgery
Dr Sumeet Shah
Laparoscopic & Bariatric Surgeon
Sir Ganga Ram Hospital

2. WEIGHT LOSS SURGERY
Gastric Bypass

3. Potential Consequences
of Obesity
• Obesity is associated with a rise in many comorbid
conditions, including:
• Type 2 Diabetes
• Hyperlipidemia
• Hypertension
• Obstructive Sleep Apnea
• Heart Disease
• Stroke
• Asthma
• Back and lower extremity weight-
bearing degenerative problems
• Cancer
• Depression
• AND MORE!

4. Visceral
Obesity
Heart Disease,
Stroke Risk
Insulin Resistance &
Hyperinsulinemia
Dense LDL HDL Cholesterol
Triglycerides
Source: NAASO, 2005
The emergence of metabolic disease: a direct
clinical pathway from obesity

5. Types of Bariatric Surgery
• Purely Restrictive
• Gastric Balloons
• Sleeve Gastrectomy
• Gastric adjustable banding
• Restrictive > Malabsorptive
• Short-limb/Roux-en-Y gastric bypass
• Malabsorptive > Restrictive
• Biliopancreatic diversion (BPD)
• BPD with duodenal switch
• Long limb Roux-en-Y gastric bypass

6. Weight Loss Benefits vs.
Nutritional Risk
0
10
20
30
40
50
60
70
Band Gastroplasty GBP DS
EWL
Mortality
B12 def

7. N Engl J Med. May 24 2007;356(21):2176-2183.

8. Long Term Complications:
Nutritional Deficiencies
• Nutritional deficiencies are uncommon
with purely restrictive procedures
unless
• Eating habits are excessively restricted or
complications occur (emesis)
• Folate is the most common deficiency after
restrictive procedures

10. • Hormonal Sequelae - Human body
regulates nutrient intake over time
by secreting hormones. Over 40
hormones play a role in regulation
of feeding.
• Nutritional Sequelae
Metabolic Sequelae

11. Metabolic Sequelae
• Two types:
• Satiety hormones
• Short-term
• Help regulate meal size; daily intake
• Secretion decreases meal size; reduces
time to stop
• Includes (among others) cholecystokinin,
amylin, glucagon-like-peptide 1 (GLP-1),
enterostatin, and bombesin
• Adiposity hormones
• Long-term
• Related to energy stores
• Secretion delays onset of beginning of meal
• Includes insulin, leptin

12. PROTEINS: GHRELIN
• A peptide secreted by Gastric mucosa on an
empty stomach (Fasting   Ghrelin Levels)
• Also releases growth hormone
• Ghrelin  during fasting
•   Appetite   Food intake
•   Fat utilization
• In Obesity, GHRELIN LEVELS ARE 

13. GHRELIN..
• Activates appetite stimulating neurons in
Hypothalamus
• Short term appetite control
• Overproduction  OBESITY
• PRADER-WILLI SYNDROME
• Highest level of ghrelin ever measured in humans

14. GHRELIN
• Ghrelin levels  when weight is lost while
dieting
• Opposes the effect of dieting
• In Gastric Bypass and Sleeve Gastrectomy,
GHRELIN LEVEL  at least in the short term
due to exclusion/ removal of the fundus

15. Metabolic Sequelae
• Further investigation is needed, but
the reason why certain types (i.e.,
RYGB/ Sleeve) of bariatric surgery
are successful at reducing food
intake and causing weight loss may
be related to enhanced secretion of
satiety signals (ghrelin or others).

16. Role of Incretins
GIP
• Released from K cells
in duodenum
• Modest effect on
gastric emptying
• No significant
inhibition of glucagon
secretion
• No significant effects
on satiety or body
weight
GLP-1
• Released from L cells
in ileum
• Potent inhibition of
gastric emptying
• Potent inhibition of
glucagon secretion
• Reduction of food
intake and body weight

17. Role of Incretins
GIP
• Potential effects
on beta cell growth
& survival
• Stimulate insulin
secretion via beta
cell
• Inactivation by
DPP-4
GLP-1
• Significant effects
on beta cell growth
and survival

18. Regulation of Food Intake
Brain
NPY
AGRP
galanin
Orexin-A
Dynorphin
ECS/CB1
Stimulate
α-MSH
CRH/UCN
GLP-I
CART
NE
5-HT
Inibit
Central Signals
Glucose
CCK, GLP-1,
Apo-A-IV
Vagal afferents
Insulin
Ghrelin
Leptin
Cortisol
Peripheral signals Peripheral organs
+


+
Gastrointestinal
tract
Adipose
tissue
Food
Intake
Adrenal glands
External factors
Emotions, Drugs
Food characteristics
Lifestyle behaviors
Environmental cues

19. Modified from Marx, Science 2003 February 7; 299: 846-849. (in News)
Gastrointestinal Peptides
Hormones
food intake regulation
digestion and metabolism
Anti-obesity potential
Anti-diabetes potential
Vagus
nerve
Ghrelin
Insulin
Amylin
Glucagon
Leptin
PYY
GLP-1
CCK

20. Effect on Comorbid
Conditions
• Diabetes
• 76.8% - Completely resolved
• 86.0% - Resolved or improved
• Hyperlipidemia
• 70% - Improved
• HTN
• 61.7% - Resolved
• 85.7% - Resolved or improved
• Obstructive Sleep Apnea
• 83.6% - Resolved
• 85.7% - Resolved or improved
Buchwald H, et al. Bariatric Surgery:
A Systematic Review and Meta-
analysis. JAMA, 14:1724-37, 2004

21. Metabolic Changes and
Diabetes
• Many metabolic changes contribute to
improvement and/or resolution of DM
• Recovery of acute insulin response
• Decreases of inflammatory indicators (C-
reactive protein and interleukin 6)
• Improvement in insulin sensitivity correlated
w/increases in plasma adiponectin
• Changes in the enteroglucagon response to
glucose
• Reduction in ghrelin levels
• Improvement in beta cell function

22. Risk of Vitamin and Mineral
Deficiencies Post-op
• Calcium and Vitamin D
• Reduced absorption d/t bypassed duodenum,
proximal jejunum (R-en-Y)
• Life-long supplements mandatory
• Iron
• Absorption decreased d/t decreased contact of food
with gastric acid; reduced conversion of iron from
ferrous to ferric form (MVI)
• Vitamin B12
• Absorption decreased d/t decreased contact with
intrinsic factor
• 60% of patients require long term supplementation
of B12
• Thiamine
• Connection to Wernicke’s syndrome
• Cases not well documented

23. Review: what gets absorbed
where?

24. Recommended
management
Dietary modification
• Reduce food volume consumed, chew food
very well, slow pace of eating
• Do not consume fluids with food
• 30 minutes before or after meal
• Protein rich-food should be major component
of each meal
• Cheese, fish, poultry, eggs & meat
• 40-60g/day after RYGB
• 60-90g/day after BPD-DS
• Avoid empty calories

25. Recommended
management
Dietary supplements
• All patients should receive
• Multivitamin with iron
• Vitamin B12, B complex with thiamine
• Vitamin C
• Calcium
• Additional supplements may be needed for
menstruating or pregnant women
• Depending on procedure, patient may need fat
soluble vitamin supplements (BPD)

26. Recommended management
Am J Med Sci. Apr 2006;331(4):219-225.

27. In Summary……
• Role of Gut and G I hormones
• Fat as Endocrine organ
• Nutritional Sequlae
• Resolution of diabetes mellitus
and improvement in lipid profile
central in providing metabolic
role to bariatric surgery