Obesity Flashcards
Principle characteristic of obesity is what?
excess adipose tissue
BMI Classification?
BMI 25 -29.9 =overweight BMI 30-34.9 obesity class 1 BMI 35-39.9 obesity class 2 BMI >40 class 3 or Morbid Obesity
BMI calculation
BMI= weight (kg)/height(m)2
At what percentile are US Children and Adolescent at risk for overweight?
Obese?
85th - 95th percentile at risk overweight
> 95th percentile for age Obesity
LIMITATIONS of BMI
3
Fat mass versus lean mass
Distribution of fat
Ethnic differences
The most accurate way to assess body composition is what? 2
Less accurate but lower cost? 2
Dexa scan , CT(high cost)
bioimpedance , water displacement
What is the worst fat?
visceral, abdominal fat
There are genes responsible but what is often the case at a molecular level?
leptin resistance (never full)
Autosomal Dominant diseases that contribute to obesity?
2
- PCOS
2. Prader-Willi syndrome(most common)
Autosomal Recessive diseases that contribute to obesity?
2
- Bradet-Biedl syndrome (polydactyly)
2. Cushing syndrome
X-linked diseases that contribute to obesity?
1
Wilson-Turner
MEDICAL COMPLICATIONS of OBESITY
Pulmonary disease-OSA, Restrictive lung disease. Nonalcoholic fatty liver OG/GYN –infertility. Osteoarthritis. Idiopathic intracranial HTN CVA Coronary artery disease. CHF , dyslipidemia, HTN. Diabetes Cancer- breast ,colon, pancreas ,uterus ,cervix esophagus, kidney, prostate DVT , phlebitis, venous stasis
DISEASES MADE WORSE WITH WEIGHT LOSS
3
Paradoxical effect on CHF if you already had it
Body mass loss leading to sarcopenia.
5 fold increase successful suicide rate following gastric bypass surgery.
RESISTIN –increased level in what pts? 2
Resistin increases what substances in the body? 3
obesity , DM.
pro inflammatory cytokines : 1. interleukin,
- TNF ,
- intracellular adhesion molecule-1.
Weight gain is directly related to these CV risk factors:
5
- dyslipidemia 2. HTN 3. elevated insulin 4. elevated fibrinogen 5. OSA
DIRECT EFFECT of INSULIN RESISTANCE on MYOCARDIUM
4
- Epicardial fat deposition.
- Increased intra-myocardial triglyceride deposition.
- Lipotoxicity.
- Cardiomyocyte apoptosis producing cardiac dysfunction.
OBESITY CAUSES HTN.
How?
5
- Enhanced sodium retention.
- Vascular smooth muscle hypertrophy
- Stimulation of renin-angiotensin-aldosterone pathway.
- Increased activation of sympathetic NS increased vasoconstriction
- Decreased NO mediated vasodilatation.
OBESITY CAUSES LVH.
How?
4
- Due to the need for high cardiac output.
- Increases risk for SCD
- Increases risk for CHF
- Dx on ECG when sum of S inV1 and R in V5 >35mm
OBESITY and CHF:
Possible causes?
Each increase in BMI of 1 unit increases risk of CHF in men and women? (percent)
Explain the paradox of CHF and weight.
Frequent complication of severe obesity.
Severe hypoxemia of OSA is one of several possible causes.
Each increase in BMI of 1 unit increases risk of CHF 5% man, 7% woman.
Paradox of established CHF Once the HF established , higher BMI has improved outcome.
OBESITY and STROKE.
For each increase of 1 unit BMI.
hemorrhagic stroke increases ?
ischemic stroke increases ?
6%.
4%.
OBESITY and PULMONARY DYSFUNCTION.
Pathology?
Causes an increase in?
Decrease in? 2
Arterial blood gases affected how?
Common side effect?
Increased risk for?
A restrictive ventilatory defect.
Increased RR and
decreased tidal volume and TLC.
Hypoxic arterial blood gases in moderate/severe obesity.
Dyspnea is common (with and without exercise ).
Increased risk for asthma.
ALZHEIMER’S DISEASE and BMI.
In what population?
Obesity at high ages increases risk for AD in women.
For every 1 unit increase BMI at age 70 AD risk increases by 36%.
These associations were not found in men.
OBESITY and OSA.
Occurs in what % of sevrely obese?
Occurs in in ~50% of severely obese.
OSA presents in up to 90% of obese patients seeking bariatric surgery.
Potentially life-threatening.
RISK FACTORS for OSA.
4
- Upper body obesity.
- More common in males.
- Associated with snorring (tiredness in the morning is more specific than snoring)
- Large neck girth in those who snore is highly predictive of OSA (neck circumference >17inches in men ,16 inches in women).
CV COMPLICATIONS of OSA.
4
- Acute coronary syndrome increase risk of plaque rupture increase risk of thrombosis
- Increased risk of stroke.
- HTN
4, Increased platelets aggregation.
OBESITY and NON-ALCOHOLIC FATTY LIVER
this is a precursor to what?
Precursor to liver failure
Transient increase in transaminases with weight loss, especially rapid weight loss.
Wealth of epidemiological data connecting obesity and various malignancies. What kinds?
6
- Post menopausal breast cancer.
- Colon ,
- pancreas ,
- endometrium,
- kidney,
- esophagus.
Requirements for bariatric surgery
2
BMI 35 or more with risk factors
BMI of 40 or more no matter what