Adult Obesity and Metabolic Syndrome

Question 1

Define obesity using BMI and waist circumference

Answer 1

BMI= weight in kilograms divided by height in meters squared (BMI = kg/m2)

Overweight= BMI of 25.0 to 29.9
Obesity= BMI of 30 or greater
Severe obesity is >40

Waist circumference definitions currently are the same for all ethnic groups (greater than or equal to 35 inches for women, greater than or equal to 40 inches for men

BMI and WC both have value independently in predicting risk

Question 2

Causes of obesity

Answer 2

Genetics play an important role in susceptibility to weight gain and obesity, but the predominant factor in the rise of obesity in the U.S. is changes in the environment for food and physical activity.

These changes include larger portion sizes, more energy dense foods, easy availability of food, and technology that reduces physical activity during activities of daily living.

Question 3

Health problems that are associated with obesity

Answer 3

obstructive sleep apnea 
type 2 diabetes 
hypertension 
hyperlipidemia 
cardiovascular disease (heart attack, stroke, and heart failure) 
non-alcoholic fatty liver disease 
erectile dysfunction 
polycystic ovarian disease 
infertility 
certain forms of cancer (e.g., breast, colon) 
depression 
low back pain 
osteoarthritis

Question 4

What is the definition of metabolic syndrome?

Answer 4

Three or more of the following:

1. Waist circumference > 40 inches in men and >35 inches in women
2. Triglycerides >150 mg/dL (or on drugs to lower lipids)
3. HDL cholesterol less than 40 mg/dL in men and less than 50 in women
4. BP greater than 130/85 or on HTN meds
5. Fasting glucose over 100 mg/dL or hypoglycemic drug

Question 5

What are the steps in the clinical evaluation of an obese patient?

Answer 5

1) Measure degree of adiposity
2) Assess other existing risk factors for cardiovascular disease
3) Screen for complications of obesity
4) Rule out medical causes of obesity
5) Assess readiness for treatment

Question 6

How does weight loss benefit obese patients and lower their risk for other health problems?

Answer 6

Weight loss for these individuals will have the potential for an immediate benefit by helping treat their existing co-morbidity.

This benefit can often occur with only moderate amounts of weight loss (5% to 10% of starting weight). This amount of weight loss has been shown to improve glycemia, blood pressure, lipids, fatty liver disease, symptoms of
osteoarthritis, and severity of obstructive sleep apnea.

Most experts believe individuals with preexisting co-morbidities should be treated more aggressively given that their weight is already having a detrimental impact on their health and the prescribed weight loss will help treat the existing complication or disease.

Question 7

Why do we care about metabolic syndrome?

Answer 7

The presence of metabolic syndrome carries an increased risk of heart attack and stroke, even if the patient does not yet have hypertension or type 2 diabetes.

Need for treatment!

Question 8

Where should waist circumference be measured?

Answer 8

Over the superior margin of the iliac crests

Question 9

According to measured values (NHANES data), the prevalence of obesity and overweight among adults ages 20 and over in the United States are:

Answer 9

Obesity 35%, Overweight 33.5%

Question 10

What labs are normal to order in the evaluation of an obese patient?

Answer 10

Thyroid stimulating hormone (TSH)
Diabetes screening: fasting blood glucose and/or hemoglobin A1c
Lipid panel
Liver associated enzymes
Remainder of tests determined by individual assessment and clinical suspicion (e.g., sleep study)