2. The story of lipids
Chylomicrons transport fats from the intestinal
mucosa to the liver
In the liver, the chylomicrons release triglycerides
and some cholesterol and become low-density
lipoproteins (LDL).
LDL then carries fat and cholesterol to the body’s
cells.
High-density lipoproteins (HDL) carry fat and
cholesterol back to the liver for excretion.
3. The story of lipids (cont.)
When oxidized LDL cholesterol gets high,
atheroma formation in the walls of arteries
occurs, which causes atherosclerosis.
HDL cholesterol is able to go and remove
cholesterol from the atheroma.
Atherogenic cholesterol → LDL, VLDL, IDL
6. Dietary sources of Cholesterol
Type of Fat Main Source Effect on
Cholesterol levels
Monounsaturated Olives, olive oil, canola oil, peanut oil, Lowers LDL, Raises
cashews, almonds, peanuts and most HDL
other nuts; avocados
Polyunsaturated Corn, soybean, safflower and cottonseed Lowers LDL, Raises
oil; fish HDL
Saturated Whole milk, butter, cheese, and ice cream; Raises both LDL and
red meat; chocolate; coconuts, coconut HDL
milk, coconut oil , egg yolks, chicken skin
Trans Most margarines; vegetable shortening; Raises LDL
partially hydrogenated vegetable oil; deep-
fried chips; many fast foods; most
commercial baked goods
7. Hereditary Causes of Hyperlipidemia
Familial Hypercholesterolemia
Codominant genetic disorder, coccurs in heterozygous form
Occurs in 1 in 500 individuals
Mutation in LDL receptor, resulting in elevated levels of LDL at birth and
throughout life
High risk for atherosclerosis, tendon xanthomas (75% of patients), tuberous
xanthomas and xanthelasmas of eyes.
Familial Combined Hyperlipidemia
Autosomal dominant
Increased secretions of VLDLs
Dysbetalipoproteinemia
Affects 1 in 10,000
Results in apo E2, a binding-defective form of apoE (which usually plays
important role in catabolism of chylomicron and VLDL)
Increased risk for atherosclerosis, peripheral vascular disease
Tuberous xanthomas, striae palmaris
9. Checking lipids
Nonfasting lipid panel
measures HDL and total cholesterol
Fasting lipid panel
Measures HDL, total cholesterol and triglycerides
LDL cholesterol is calculated:
LDL cholesterol = total cholesterol – (HDL + triglycerides/5)
10. When to check lipid panel
Two different Recommendations
Adult Treatment Panel (ATP III) of the National Cholesterol
Education Program (NCEP)
Beginning at age 20: obtain a fasting (9 to 12 hour) serum lipid profile
consisting of total cholesterol, LDL, HDL and triglycerides
Repeat testing every 5 years for acceptable values
United States Preventative Services Task Force
Women aged 45 years and older, and men ages 35 years and older
undergo screening with a total and HDL cholesterol every 5 years.
If total cholesterol > 200 or HDL <40, then a fasting panel should be
obtained
Cholesterol screening should begin at 20 years in patients with a
history of multiple cardiovascular risk factors, diabetes, or family
history of either elevated cholesteral levels or premature
cardiovascular disease.
11. Goals for Lipids
LDL HDL
< 100 →Optimal < 40 → Low
100-129 → Near optimal ≥ 60 → High
130-159 → Borderline Serum Triglycerides
160-189→ High < 150 → normal
≥ 190 → Very High 150-199 → Borderline
Total Cholesterol 200-499 → High
< 200 → Desirable ≥ 500 → Very High
200-239 → Borderline
≥240 → High
12. Determining Cholesterol Goal
(LDL!)
Look at JNC 7 Risk Factors
Cigarette smoking
Hypertension (BP ≥140/90 or on anti-
hypertensives)
Low HDL cholesterol (< 40 mg/dL)
Family History of premature coronary heart
disease (CHD) (CHD in first-degree male relative
<55 or CHD in first-degree female relative < 65)
Age (men ≥ 45, women ≥ 55)
18. Definition
A BMI of 25.0 to 29.9 kg per m2 is
defined as overweight; a BMI of 30.0
kg per m2 or more is defined as
obesity.
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19. Classification of Overweight
and Obesity
BMI Classification
<18.5 Underweight
18.5-24.9 Normal weight
25-29.9 Overweight
30-34.9 Obesity Class I
35-39.9 Obesity Class II
40-49.9 Obesity Class III
50 and above Super Obesity
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20. Why is it so hard to lose
weight? Brain
External factors
Emotions
Food characteristics
Central Signals Lifestyle behaviors
Stimulate Inibit Environmental cues
NPY Orexin-A α-MSH CART
AGRP dynorphin CRH/UCN NE
galanin GLP-I 5-HT
Peripheral signals Peripheral organs
Glucose
Gastrointestinal
CCK, GLP-1, tract
− Apo-A-IV
Vagal afferents
Food
Insulin
Intake
+ Ghrelin
Adipose
− Leptin tissue
+ Cortisol Adrenal glands
21. Medical Complications of Obesity
Pulmonary disease
abnormal function
obstructive sleep apnea Stroke
hypoventilation syndrome
Cataracts
CHD
Nonalcoholic fatty liver disease Diabetes
steatosis Dyslipidemia
steatohepatitis Hypertension
cirrhosis
Severe pancreatitis
Gall bladder disease
Cancer
Gynecologic abnormalities breast, uterus, cervix
abnormal menses colon, esophagus, pancreas
kidney, prostate
infertility
Osteoarthritis
PCOS Phlebitis
venous stasis
Gout
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22. Weight Loss Strategies
Diet therapy
Increased Physical Activity
Pharmacotherapy
Behavioral Therapy
Surgery
Any combination of the above
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23. Principles Of Dieting
Women should consume atleast 1200 kcal/day, men
1500 kcal/day.
Select a diet that has:
>75g/day proteins (15% of total calories)
> 55% total calories from carbs
▪ Fat should contribute 30% or less of total calories
Atleast 3 meals/day.
High fiber (20-30g/day), fruits and vegetables.
Supplement the diet with multivitamis and minerals.
Avoid sugar containing beverages and fat spreads.
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24. Surgery
Roux-en-Y gastric bypass.
Lap band procedure
Criteria: a) BMI > 40 or >35 with 2 comorbidities.
b) Failure of non surgical methods
c) Presence of 2 or more medical
conditions that would benefit with weight loss.
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28. Hypertension:
IDF:
BP >130/85 or on Rx for previously Dxed
hypertension
WHO:
BP >140/90
NCEP ATP III:
BP >130/80
29. Obesity:
IDF:
Central obesity - waist circumference >94 cm for
Europid men, >80 Europid women with ethnicity
specific values for other groups
WHO:
Waist-hip ratio >0.9 - men or >0.85 - women
ATP III:
Waist circumference >40 in. - men, 35 in. -
women
30. Glucose Abnormalities:
IDF:
FPG >100 mg/dL (5.6 mmol.L) or previously
diagnosed type 2 diabetes
WHO:
Presence of diabetes, IGT, IFG, insulin
resistance
ATP III:
FBS >110 mg%, <126 mg% (ADA: FBS >100)
32. Necessary Criteria to Make
Diagnosis:
IDF:
Require central obesity plus two of the other
abnormalities
WHO:
Also requires microalbuminuria - Albumen/
creatinine ratio >30 mg/gm creatinine
ATP III:
Require three or more of the five criteria
In 1997, the International Obesity Task Force,10 convened by the World Health Organization (WHO), recommended a standard classification of adult overweight and obesity
Presently, there is no precise clinical definition of obesity based on the degree of excess body fat that places an individual at increased health risk. General consensus exists for an indirect measure of body fatness, called the weight-for-height index or body mass index (BMI). The BMI is an easily obtained and reliable measurement for overweight and obesity and is defined as a person's weight (in kilograms) divided by the square of the person's height (in meters) Other Measurements Waist Circumference >35 inches in women or 40 inches in men indicates hazardous fat distribution Waist/Hip Ratios >0.8 indicates hazardous fat distribution
Leptin signals the brain about the quantity of stored fat. Modulates food intake.
Waist circumference measurements greater than 40 inches (102 cm) in men and 35 inches (89 cm) in women also indicate an increased risk of obesity-related comorbidities.
Waist-hip measurement not likely to be done by busy clinicians. 40 in. = 101.6 cm 35 cm = 88.9 cm